A little more than a year ago I read Plastic: A Toxic Love Story by Susan Freinkel. My desire to read the book stemmed from three disturbing things that are symptoms of our dependency on plastics: the Pacific Ocean Gyre, dependence on hydrocarbons for plastics, and disturbing data about endocrine disruptors.
Freinkel’s journalistic coverage of the endocrine disruptors is perfectly adequate to inform the general public about this quietly ignored issue. Bisphenol A (or BPA) and phthalates are slowly becoming bad words, but they should become taboo much faster. BPA is a known endocrine disruptor and is primarily found in polycarbonates. Think sports water bottles, eyeglasses, baby bottles, and plastic water pitchers that are wonderfully clear and seem to resist water spots. BPA binds to receptor sites in the human body and blocks the reception of natural hormones, particularly those related to sexual development. Worse yet, because BPA disrupts the function of the endocrine system, it is altering our genetic history because pregnant women exposed to BPA can disrupt the sexual development and genetic makeup of their unborn children. Therefore, BPA isn’t just an acute danger – it can cause problems for extended generations.
This issue of generational alteration due to modifications to our environment illuminates a particularly insidious kind of societal dysfunction. The other problems that we’ve identified and fixed were certainly more acute. The ozone layer problem was addressed by getting rid of CFC’s, with noticeable results. Acid rain was addressed by putting scrubbers on flue stacks and it helped. Waste water dumping was stopped in areas where it was hurting communities, and the water table repaired itself. But now we’re talking about genetic mutations that are altering the future makeup of humans. In this case, science fiction meets reality as we witness the accidental modification of our biology as a consequence of our desire for convenience.
Getting away from plastic will certainly be a challenge. Few materials can be so easily molded into complex shapes for such low cost. The creation of plastics is an easy byproduct of hydrocarbon refining, and it has spawned megalithic industrial growth. It was only in the late 1950s that we still relied on primarily metals, wood, and fibers for consumer products. Today, we make everything from plastics.
In perhaps a bit of subtle protest, I tend to fill my recycling bin with even the plastics that I know the recycling facility cannot process. Plastics with dyes are almost a guaranteed contaminant for recycling facilities. Several years ago I visited the local recycling facility and took a tour, and I was frankly a bit disappointed to learn that their business function is very limited. They simply collect, sort, and redistribute recycling materials. That’s it. Therefore, anything that doesn’t fit their customer base is redirected to the landfill. This means that even well-intentioned people who are trying to recycle cannot guarantee that the materials they put in the bin will survive in a second life. Nevertheless, my philosophy is that if the recycling facility reaches a critical threshold where they are spending a lot of man hours diverting unused materials to the landfill, they will seek opportunities to put those junk materials to use and therefore turn their waste into profit. Therefore, I encourage people to clutter up the recycling facilities with materials that are not conventionally recycled… but could be. If it becomes a hassle for the recycling facility, they will adapt and find ways to make money from those materials.
This is particularly true for polyethylene bags. Those plastic bags at the grocery store are flighty little suckers that can sail from the recycling truck with the slightest breeze, and then find their way to storm drains, and eventually the river, and eventually the sea, where they may take months or years to finally collect in a calm portion of the sea that is called a gyre, or a dead zone with very little wind or current. Thousands of square miles of plastic debris clog the Pacific Ocean Gyre, and there isn’t much that people can do about it. It certainly isn’t cost effective to troll the gyre and scoop up these materials for reuse, so nobody is doing it. Most recycling facilities or Materials Recovery Facilities (MRFs) use a trommel system to sort lightweight materials from heavier materials. Polyethylene grocery bags tend to flutter and clog up the trommel, and therefore MRFs try to reject them before they enter the trommel. The bag collection spots at the grocery stores consolidate the bags and bypass this sorting nightmare, and can therefore divert PE bags to an appropriate recycling process. However, the batch-like processes of recycling bags at grocery stores isn’t as seamless as it would be if we could just throw our junk into the trash and have confidence that it will be appropriately sorted for reuse elsewhere.
In the meantime, finding products that eliminate contact of plastic with food and ingested liquids is a challenge on its own, but there are products out there. For example, we threw out our plastic coffee maker and replaced it with a stainless steel percolator. We replaced our plastic Rubbermaid lunch containers with glass containers. When we buy juice, we look for glass bottles.
But many plastics are simply unavoidable. Even the organic, free range chicken breasts you buy at the grocery store are wrapped in vacuum sealed plastic. Soup cans are lined with a plastic coating to prevent corrosion of the metal, and those coatings are unregulated and many contain BPA as a plasticizing agent. Those little plastic tripods they put in the pizza to prevent contact with the pizza box are made from who-knows-what. Even the thermal paper used to print receipts uses a plasticizer that gets on your hands after you touch it, and then you use your hands to eat. BPA is most common in the #7 plastic category that isn’t really a category at all, but a catch-all label for “everything else”. Ingredients in those plastics vary wildly. According to this article and others, plastics 2, 4, and 5 appear to be the safest with the lowest occurrence of BPA and phthalates.
Wednesday, January 18, 2012
Friday, December 30, 2011
What is the tipping point price for solar?
I was wandering through Lowes the other day gathering supplies for a closet remodel I'm working on, when I rediscovered their renewable energy and efficiency aisle. About a year ago they opened this aisle and stocked it with solar panels, home automation kits, LED lighting, and other things. I considered this to be a win for the industry; when a Lowes in Ohio sees a need for it, it must be mainstream. At the time, they had 175 watt photovoltaic panels for about $750 each, which corresponds to $4.28/W. A year prior to that I was writing a research paper on mechanisms of efficiency degradation in solar panels, and I had priced them around $5/W. Yesterday, Lowes had the panels on clearance for $550 each, or $3.14/W.
I looked on a few solar websites this morning and found prices far better than this. Sharp 240W panels for $430, or about $1.80/W. Thin film panels have already proven to be produced for $1/W. There were a lot of predictions that this kind of pricing would lead to widespread adoption. So where is it?
I try looking at it another way. Consider appliances that come with a house when it is purchased. These items include a furnace, water heater, refrigerators, microwaves, ovens, and dishwashers. The cost of these items ranges from $300 for a microwave to several thousand dollars for a furnace or refrigerator. If $3,000 is the average tolerable cost of a home appliance, then perhaps one might consider this the upper end of what a homeowner would be willing to pay for a solar installation that stays with the house.
Today, $3,000 would buy about 1.6 kW if the online prices I found are reliable, not including any labor for installation if the home owner isn't a DIY type. This isn't enough to completely replace the electricity demand of the average US house. The EIA indicates that electricity consumption is about 39 kWh per capita (including all sectors). Residential usage is about 1/3 of that, so we can use 13 kWh per person as a metric. A family of four would then require 52 kWh per day per house. If we assume 6 hours of full sunlight, this means we need a capacity of 8.6 kW at a cost of approximately $15,500. Obviously this is far above the $3,000 price tag of a home appliance.
So how do we get to $3,000 from $15,500? It indicates that we would have to cut the cost by 5, which means solar should get to $0.30-$0.40/W.
Now, recall what I mentioned in the first paragraph. Two years ago solar PV appeared to be selling for $5/W. Today it is selling for $1.80/W (these are off the shelf prices not including subsidy). That means we have a slope of about $1.50/W per year. If you would believe we could drop it to $0.30/W next year, the price slope would prove true. But costs don't drop linearly... they drop exponentially. The question is where we are on the curve. Have we already started to bottom out, or can we go further?
At any rate, we can also approach this problem from the efficiency side. Consider, for example, a newly built, well insulated home that would cut the energy demand of each person by 1/3. The same family of four in the new house would then only require 34 kWh per day, and therefore only require 5.7 kW to be self sufficient. For 5.7 kW to cost $3,000, the price of solar need only drop to $0.52/W.
Therefore the power of efficiency is revealed, and hence the large investment in efficiency programs in the US DOE. We can reduce our demand, and therefore reduce the burden on technology and economy to support energy innovation. The tipping price of solar - based on the assumptions outlined here - appears to be $0.30-$0.50 per watt.
I looked on a few solar websites this morning and found prices far better than this. Sharp 240W panels for $430, or about $1.80/W. Thin film panels have already proven to be produced for $1/W. There were a lot of predictions that this kind of pricing would lead to widespread adoption. So where is it?
I try looking at it another way. Consider appliances that come with a house when it is purchased. These items include a furnace, water heater, refrigerators, microwaves, ovens, and dishwashers. The cost of these items ranges from $300 for a microwave to several thousand dollars for a furnace or refrigerator. If $3,000 is the average tolerable cost of a home appliance, then perhaps one might consider this the upper end of what a homeowner would be willing to pay for a solar installation that stays with the house.
Today, $3,000 would buy about 1.6 kW if the online prices I found are reliable, not including any labor for installation if the home owner isn't a DIY type. This isn't enough to completely replace the electricity demand of the average US house. The EIA indicates that electricity consumption is about 39 kWh per capita (including all sectors). Residential usage is about 1/3 of that, so we can use 13 kWh per person as a metric. A family of four would then require 52 kWh per day per house. If we assume 6 hours of full sunlight, this means we need a capacity of 8.6 kW at a cost of approximately $15,500. Obviously this is far above the $3,000 price tag of a home appliance.
So how do we get to $3,000 from $15,500? It indicates that we would have to cut the cost by 5, which means solar should get to $0.30-$0.40/W.
Now, recall what I mentioned in the first paragraph. Two years ago solar PV appeared to be selling for $5/W. Today it is selling for $1.80/W (these are off the shelf prices not including subsidy). That means we have a slope of about $1.50/W per year. If you would believe we could drop it to $0.30/W next year, the price slope would prove true. But costs don't drop linearly... they drop exponentially. The question is where we are on the curve. Have we already started to bottom out, or can we go further?
At any rate, we can also approach this problem from the efficiency side. Consider, for example, a newly built, well insulated home that would cut the energy demand of each person by 1/3. The same family of four in the new house would then only require 34 kWh per day, and therefore only require 5.7 kW to be self sufficient. For 5.7 kW to cost $3,000, the price of solar need only drop to $0.52/W.
Therefore the power of efficiency is revealed, and hence the large investment in efficiency programs in the US DOE. We can reduce our demand, and therefore reduce the burden on technology and economy to support energy innovation. The tipping price of solar - based on the assumptions outlined here - appears to be $0.30-$0.50 per watt.
Thursday, December 15, 2011
High Octane Fuel Alternatives
Just a short post on this topic:
I was intrigued to read Robert Zubrin's testatment to high fuel economy for methanol. He found that he achieved 24 mpg with methanol (M100) compared to 36 mpg with gasoline (E10 blended, 10% ethanol as it is in most pumps). While that doesn't sound very good, consider that methanol has an energy density of ~19 MJ/kg vs. ~47 MJ/kg in gasoline, which means that a gallon of methanol contains 40% as much energy as a gallon of gasoline. Therefore, if you were to estimate fuel economy by energy content alone, you would expect the 36 mpg gas Cobalt to achieve about 14 mpg on methanol. Instead Zubrin reports 24 mpg and attributes the improved fuel economy to higher octane and therefore cleaner combustion, i.e., the Cobalt's little engine eeks out higher fractions of energy from methanol than gasoline.
Ethanol has shown similar octane benefits - enough that some drag racers with boosted engines prefer it. Higher octane fuels resist detonation and reduce the probability of the engine grenading under boost. Detonation is more commonly referred to as "engine knock" and it occurs when fuel combusts before the spark plug sparks, which is usually before the piston reaches top dead center (TDC). My parents used to have a mid 1980s Plymouth Voyager with a 2.6L Mitsubishi four cyclinder engine that knocked terribly. Usually when the engine was cold, we would pull out of the driveway and start moving up the hill and we'd hear the clatter-clatter-clatter of detonation until the engine warmed up. I can still pick out that engine by ear based on its clatter, as it was put in most of the Chrysler K-cars pre-1986 (thumbs up to Iacocca). Like a Honda starter, that engine has a distinctive whine to it that is distinct from any other engine. The Voyager lasted a long time without issues, but boosted engines have a higher compression ratio and engine knock at high RPMs can spell disaster for engine parts. This is why ethanol and methanol are great fuels for boosted engines.
Tiny turbo motors like GM's 1.4L Ecotec in the Cruze are optimized for high octane fuels. A smaller engine that generates similar power for less fuel is the solution to many of our fuel demand issues. Supplementation of gasoline (and perhaps its eventual replacement) with sustainably derived methanol or ethanol can provide substantial energy independence benefits given the octane advantage.
Of course, all of this depends on where we get the methanol. I'm not as jazzed as Zubrin about sourcing methanol from other fossil hydrocarbons, but there are other ways to make it.
I was intrigued to read Robert Zubrin's testatment to high fuel economy for methanol. He found that he achieved 24 mpg with methanol (M100) compared to 36 mpg with gasoline (E10 blended, 10% ethanol as it is in most pumps). While that doesn't sound very good, consider that methanol has an energy density of ~19 MJ/kg vs. ~47 MJ/kg in gasoline, which means that a gallon of methanol contains 40% as much energy as a gallon of gasoline. Therefore, if you were to estimate fuel economy by energy content alone, you would expect the 36 mpg gas Cobalt to achieve about 14 mpg on methanol. Instead Zubrin reports 24 mpg and attributes the improved fuel economy to higher octane and therefore cleaner combustion, i.e., the Cobalt's little engine eeks out higher fractions of energy from methanol than gasoline.
Ethanol has shown similar octane benefits - enough that some drag racers with boosted engines prefer it. Higher octane fuels resist detonation and reduce the probability of the engine grenading under boost. Detonation is more commonly referred to as "engine knock" and it occurs when fuel combusts before the spark plug sparks, which is usually before the piston reaches top dead center (TDC). My parents used to have a mid 1980s Plymouth Voyager with a 2.6L Mitsubishi four cyclinder engine that knocked terribly. Usually when the engine was cold, we would pull out of the driveway and start moving up the hill and we'd hear the clatter-clatter-clatter of detonation until the engine warmed up. I can still pick out that engine by ear based on its clatter, as it was put in most of the Chrysler K-cars pre-1986 (thumbs up to Iacocca). Like a Honda starter, that engine has a distinctive whine to it that is distinct from any other engine. The Voyager lasted a long time without issues, but boosted engines have a higher compression ratio and engine knock at high RPMs can spell disaster for engine parts. This is why ethanol and methanol are great fuels for boosted engines.
Tiny turbo motors like GM's 1.4L Ecotec in the Cruze are optimized for high octane fuels. A smaller engine that generates similar power for less fuel is the solution to many of our fuel demand issues. Supplementation of gasoline (and perhaps its eventual replacement) with sustainably derived methanol or ethanol can provide substantial energy independence benefits given the octane advantage.
Of course, all of this depends on where we get the methanol. I'm not as jazzed as Zubrin about sourcing methanol from other fossil hydrocarbons, but there are other ways to make it.
Saturday, December 10, 2011
How to determine where the water came from in the foot well of your Volkswagen
I am often a detective in a mystery where there perpetrator of the crime is myself. More on that in a moment...
I’ve had water dripping into the passenger footwell of my mk3 Volkswagen Jetta for a little more than a year, but only in the last few months has it become severe enough that I can see the water with my eyes after it rains.
Last time I touched it, I spent significant effort removing the windshield to remove rust, repaint, and reseal it. It stopped a leak there but shortly afterward my wife and I were going for a drive when it started to rain, and she informed me that it was raining on her feet.
After searching numerous VW forums I found that this problem is common across multiple models including the Phaeton. How disappointing it must have been for Phaeton owners to discover such a stupid problem in such an expensive car. Phaeton buyers thought they were buying a car to compete with the big boys, only to find that VW uses the same arcane drainage systems from Seat and Skoda in its upscale flagship. How embarrassing.
The leak in the passenger footwell is often attributed to the following culprits:
- blocked drainage in the cowl at the bottom of the windshield (sometimes called the “rain tray” or “windshield cowl”, located at the top of the firewall, bridging the space between the struts where the windshield meets the fenders). Drainage holes are located at either side of the rain tray near the strut towers, and can become blocked with leaves, dirt, and pine needles, thus making the rain tray a bathtub. Water fills and then spills via numerous pathways to the passenger footwell
- An improper seal around the cabin air filter, also located in the rain tray. Once the blocked or slowed drainage of the rain tray occurs, water leaks through the cabin intake… into the passenger footwell.
- Improper sunroof drainage from multiple flexible plastic tube channels meant to direct water from the sunroof area to various drainage points in the A and B pillars. If these tubes are blocked (or somehow disconnected), they often end up leaking water… into the passenger footwell
- Blocked drainage holes inside the passenger door which cause water to collect in the bottom of the door and promptly spill over the interior seals… into the passenger footwell
- The condenser for the air conditioner evidently disposes of water via a drip channel in the firewall (also near the passenger footwell). This drip channel can become blocked and then the water – with nowhere else to go – spills into the cabin and the passenger footwell
- The coolant system can develop a leak. Since the heater core is located behind the dash and relies on coolant from the engine to build heat (which is why many VWs have a “sweet” smell when the heat is on, attributed to the radiator fluid), the core can go bad which will then spill coolant into the interior of the car. Again, it tends to collect in the passenger footwell
I was astounded that so many different sources of water or fluid could end up in the passenger footwell. This seems like a major oversight since it occurs in generation after generation of VWs, up to and including the poor Phaeton - a car that is perhaps undeserving of its dismal sales.
I was also astounded that since the causes are so varied, the solutions to the problem are also wildly varied. Forum members who have experienced the heater core problem will instantly advise someone that the heater core is the problem, which it could very well be the sunroof drains or any of the other problems. Prescription after improper diagnosis runs as rampant in the car domain as it does in the medical professions.
I’ve been trying to track the source of the leak down for the past few days. It doesn’t smell like coolant so it isn’t the heater core. It only gets wet when it rains so it likely isn’t the AC condenser issue either.
It is therefore either the sunroof drain tubes or the cabin air filter.
Buried in the A pillar is a tube which runs from the sunroof to the pillar and connects to a drainage port near the passenger door hinge. The purpose is to direct captured water from the sunroof to the low points of the car where it can safely be spilled outside the vehicle and away from the passengers. However, it has been said that this tube can disconnect from the final fitting in the pillar at the door jamb, and therefore it can spill inside the car at will. This evidently occurs often. Since I just put in a new headliner, I’m in no mood to take it out again and investigate the sunroof. I recall no blockage and I’ll check the hose connection in the A-pillar first. Exploring this potential cause would be my last resort and since the rain tray is more accessible, I decided to start there.
I removed parts of the rain tray which requires removal of the windshield wipers and several plastic grommets that inevitably broke during the process. Underneath I revealed the cabin air intake which is often the source of the leak. However the seal around the bottom of the intake did not appear to be damaged or worn out. The possible water entry points are shown in the figure below with green arrows. Any water that enters the rain tray will drain at the drainage points near the strut towers (white arrows).
The first order to source the leak is to clear away any debris that might be blocking any possible water exits in the rain tray or the sunroof drains. I did not have any blockage but I cleaned a few leaves out of the rain tray. It appeared that the plastic cowl which covers my rain tray is doing a poor job of deflecting water from the windshield, and perhaps I am getting a direct drip into my cabin intake, which would certainly cause a leak. However, I can’t tell if that is the main cause, so I need to do some trial and error.
This is the procedure I eventually ended up following:
Logic:
- Pour water on the windshield. If leak, proceed to step 2. If no leak, proceed to END (Result = leak detected, so I proceeded to step 2)
- Pour water to right of cabin intake (closer to ECU). If leak, reseal around rain tray. If no leak, proceed to step 3. (Result = no leak)
- Pour water to left of cabin intake. If leak, check for unseen blockage in drainage. If no leak, proceed to step 4. (Result = no leak)
- Trickle water into the air cabin intake. If leak, address rain tray cover. If this cannot fix problem, address sunroof drainage.
I found something funny after going back to the raintray. While it had cracks in some spots, they were not near the cabin air intake. So I started to reinsert the raintray to reassemble it and look for any defects. Installing the passenger side of the rain tray is cumbersome as it has a tight fit and requires some jiggling to find its proper position. As I wrestled with it I noticed it was hung up on something that I couldn’t see, located near the passenger fender. When I craned my neck to look…Lo and behold, I discovered that my previous installation of the rain tray had an error. There is a vertical barrier that isolates the cabin air intake port from the weather, yet allows air into the rain tray compartment for air intake. This vertical section is part of the driver’s side rain tray cover, and I had bent it upon installing it previously. As a result, it was bent and directed to the top of my cabin intake, acting as a perfect capillary pathway for dripping water. I had found my problem.
I reinstalled the rain tray correctly, bending the baffle back so that it hung alongside my cabin air intake instead of being bent over the top of it. I also purchased new plastic fasteners off eBay (which were a poor fit) and replaced my broken connectors. I then sat in the car while pouring a tall glass of water on the windshield. No leak!
So, the typical forum responses would have been unhelpful to me here, because no one could possibly know that I installed the rain tray cover incorrectly and that was the cause of my water problem. For now, the leak issue is solved.
One of my next car posts will be a story about how I solved a vibration problem in my Silverado. Until next time…
I’ve had water dripping into the passenger footwell of my mk3 Volkswagen Jetta for a little more than a year, but only in the last few months has it become severe enough that I can see the water with my eyes after it rains.
Last time I touched it, I spent significant effort removing the windshield to remove rust, repaint, and reseal it. It stopped a leak there but shortly afterward my wife and I were going for a drive when it started to rain, and she informed me that it was raining on her feet.
After searching numerous VW forums I found that this problem is common across multiple models including the Phaeton. How disappointing it must have been for Phaeton owners to discover such a stupid problem in such an expensive car. Phaeton buyers thought they were buying a car to compete with the big boys, only to find that VW uses the same arcane drainage systems from Seat and Skoda in its upscale flagship. How embarrassing.
The leak in the passenger footwell is often attributed to the following culprits:
- blocked drainage in the cowl at the bottom of the windshield (sometimes called the “rain tray” or “windshield cowl”, located at the top of the firewall, bridging the space between the struts where the windshield meets the fenders). Drainage holes are located at either side of the rain tray near the strut towers, and can become blocked with leaves, dirt, and pine needles, thus making the rain tray a bathtub. Water fills and then spills via numerous pathways to the passenger footwell
- An improper seal around the cabin air filter, also located in the rain tray. Once the blocked or slowed drainage of the rain tray occurs, water leaks through the cabin intake… into the passenger footwell.
- Improper sunroof drainage from multiple flexible plastic tube channels meant to direct water from the sunroof area to various drainage points in the A and B pillars. If these tubes are blocked (or somehow disconnected), they often end up leaking water… into the passenger footwell
- Blocked drainage holes inside the passenger door which cause water to collect in the bottom of the door and promptly spill over the interior seals… into the passenger footwell
- The condenser for the air conditioner evidently disposes of water via a drip channel in the firewall (also near the passenger footwell). This drip channel can become blocked and then the water – with nowhere else to go – spills into the cabin and the passenger footwell
- The coolant system can develop a leak. Since the heater core is located behind the dash and relies on coolant from the engine to build heat (which is why many VWs have a “sweet” smell when the heat is on, attributed to the radiator fluid), the core can go bad which will then spill coolant into the interior of the car. Again, it tends to collect in the passenger footwell
I was astounded that so many different sources of water or fluid could end up in the passenger footwell. This seems like a major oversight since it occurs in generation after generation of VWs, up to and including the poor Phaeton - a car that is perhaps undeserving of its dismal sales.
I was also astounded that since the causes are so varied, the solutions to the problem are also wildly varied. Forum members who have experienced the heater core problem will instantly advise someone that the heater core is the problem, which it could very well be the sunroof drains or any of the other problems. Prescription after improper diagnosis runs as rampant in the car domain as it does in the medical professions.
I’ve been trying to track the source of the leak down for the past few days. It doesn’t smell like coolant so it isn’t the heater core. It only gets wet when it rains so it likely isn’t the AC condenser issue either.
It is therefore either the sunroof drain tubes or the cabin air filter.
Buried in the A pillar is a tube which runs from the sunroof to the pillar and connects to a drainage port near the passenger door hinge. The purpose is to direct captured water from the sunroof to the low points of the car where it can safely be spilled outside the vehicle and away from the passengers. However, it has been said that this tube can disconnect from the final fitting in the pillar at the door jamb, and therefore it can spill inside the car at will. This evidently occurs often. Since I just put in a new headliner, I’m in no mood to take it out again and investigate the sunroof. I recall no blockage and I’ll check the hose connection in the A-pillar first. Exploring this potential cause would be my last resort and since the rain tray is more accessible, I decided to start there.
I removed parts of the rain tray which requires removal of the windshield wipers and several plastic grommets that inevitably broke during the process. Underneath I revealed the cabin air intake which is often the source of the leak. However the seal around the bottom of the intake did not appear to be damaged or worn out. The possible water entry points are shown in the figure below with green arrows. Any water that enters the rain tray will drain at the drainage points near the strut towers (white arrows).
The first order to source the leak is to clear away any debris that might be blocking any possible water exits in the rain tray or the sunroof drains. I did not have any blockage but I cleaned a few leaves out of the rain tray. It appeared that the plastic cowl which covers my rain tray is doing a poor job of deflecting water from the windshield, and perhaps I am getting a direct drip into my cabin intake, which would certainly cause a leak. However, I can’t tell if that is the main cause, so I need to do some trial and error.
This is the procedure I eventually ended up following:
Logic:
- Pour water on the windshield. If leak, proceed to step 2. If no leak, proceed to END (Result = leak detected, so I proceeded to step 2)
- Pour water to right of cabin intake (closer to ECU). If leak, reseal around rain tray. If no leak, proceed to step 3. (Result = no leak)
- Pour water to left of cabin intake. If leak, check for unseen blockage in drainage. If no leak, proceed to step 4. (Result = no leak)
- Trickle water into the air cabin intake. If leak, address rain tray cover. If this cannot fix problem, address sunroof drainage.
I found something funny after going back to the raintray. While it had cracks in some spots, they were not near the cabin air intake. So I started to reinsert the raintray to reassemble it and look for any defects. Installing the passenger side of the rain tray is cumbersome as it has a tight fit and requires some jiggling to find its proper position. As I wrestled with it I noticed it was hung up on something that I couldn’t see, located near the passenger fender. When I craned my neck to look…Lo and behold, I discovered that my previous installation of the rain tray had an error. There is a vertical barrier that isolates the cabin air intake port from the weather, yet allows air into the rain tray compartment for air intake. This vertical section is part of the driver’s side rain tray cover, and I had bent it upon installing it previously. As a result, it was bent and directed to the top of my cabin intake, acting as a perfect capillary pathway for dripping water. I had found my problem.
I reinstalled the rain tray correctly, bending the baffle back so that it hung alongside my cabin air intake instead of being bent over the top of it. I also purchased new plastic fasteners off eBay (which were a poor fit) and replaced my broken connectors. I then sat in the car while pouring a tall glass of water on the windshield. No leak!
So, the typical forum responses would have been unhelpful to me here, because no one could possibly know that I installed the rain tray cover incorrectly and that was the cause of my water problem. For now, the leak issue is solved.
One of my next car posts will be a story about how I solved a vibration problem in my Silverado. Until next time…
Tuesday, November 15, 2011
What you need to know about Air Compressors
I've owned an Ingersoll Rand SS3L3 air compressor for the last 7 years or so and I've been through a lot with it. It has taught me a lot to know about air compressors. The main lessons are that there is a significant price leap from 3 HP to 5 HP, from high RPM cheaper systems to low RPM more expensive systems.
What most people want to know about air compressors is air flow (in cubic feet per minute or CFM) and pressure (pounds per square inch or psi). Those are certainly good metrics, but really it comes down to what you want to use it for.
I've essentially learned that a small pancake-style compressor is great for nail guns and impact wrenches, and that's about it. Maybe air brushing. An air compressor like my SS3L3 here is okay for die grinding and orbital sanding, but I'd limit my usage of sand blasting. To get sand blasting capability, you're likely looking at $1,000+ with a 5 hp or more motor. Even in that category, you will see a price gap between high RPM compressors and low RPM compressors, the latter being the more expensive (and more robust) product.
Your biggest limitation is the compressor itself - how much air it flows, how long it can run without getting too hot, and its durability. Pancake compressors are designed to be low cost with short duty cycles. They run at high RPM on 110V. Medium duty compressors like this SS3L3 also run at high RPM but are 230V systems for higher power and more CFM. Heavy duty compressors Use greater power at lower RPM and can sustain almost continuous duty, i.e., if you are sandblasting.
I purchased my Ingersoll Rand SS3L3 compressor from Northern Tool in the early summer of 2005. It was priced lower than present day prices. This is the first air compressor that I have ever owned, so it was a learning experience from the start. It's been a good tool for me and I've probably gotten my money's worth, and I'll likely recoup significant cost if I ever sell it.
It is recommended that you purchase the IR SS3L3 startup kit as the compressor is delivered to you without any oil in it. In some cases the warranty is not valid unless you have purchased the startup kit. I didn't do that - more on that later.
One thing I immediately noticed was that the pressure switch was flimsy. When I plugged in the compressor to test it out, I found that the motor continued to run even as the gauge on the tank passed 130 psi. As it creeped closer to 135 psi (the limit printed on the tank), I pulled the plug. I ordered a new switch from Ingersoll Rand for ~ $35 and this fixed the problem. Perhaps I could have made a warranty claim, but it was easier to order the switch as there is an authorized IR dealer nearby and I had the switch within 2 days.
In the remaining time I've owned the compressor, I've replaced this switch 2 additional times. Total cost of switches: ~$105
I ran the compressor off and on for several months without any major issues. I used it for several things, but it's heaviest use has been blowing sawdust out of my garage and using a right angle die grinder for doing some body work on my car around the windshield. It has held up OK, but here are some things I have learned about the compressor since its purchase:
1. This unit uses a 3 HP "split phase" motor, which can be run on a standard 30A 230V household outlet - it draws about 15A during continuous duty. This is pretty normal for motors in this power and RPM range - typically 3-4 HP motors run somewhere around 3400 RPM, which is screamin'. The motor does not output a true 3 HP at all times. At startup the motor may approach its 3 peak horsepower, but during normal operation it may only be outputting half that power, so in truth it is essentially a 1.5 HP motor. This borderline false advertising is similar to peak and RMS power ratings in audio amplifiers, though it is fairly standard operating procedure to rate motors in this fashion. It is not a question of efficiency - it is an intended feature built into the windings of the motor.
2. The motor runs at 3450 RPM. Though it is quieter than a direct drive unit like the 30 gallon compressors sold at most hardware stores, 3450 RPM is still quite fast. With the pulley ratios, the compressor crank spins at 1200 RPM. Heavier duty systems might have the AC motor running at 1200-1750 RPM with the compressor running at ~700 RPM or less, resulting in a much quieter setup. Onomatopoeia description: The difference between them is "waaaaaaaahhhhhhhh!" (3450/1200) and "glug glug glug" (1750/700). If I could do it over, I would consider a slower, beefier unit with a true power rating that runs at a slower, more quiet speed.
3. There is apparently no available rebuild kit for the compressor itself, according to the local IR dealer, though they do sell gaskets and the oiling kit. This may also be common, but this model is really the bottom of IR's product line, as they have units that are massive 3 phase monsters for industrial use. So the SS3L3 is an acceptable compromise for the DIY homeowner like you or I. It is a very simple design, consisting of essentially three parts; a cylinder head, cylinder block, and crankcase. It is a two cylinder, single stage compressor. The "valves" in the head are "reed valves", which are simply spring loaded "fingers" that cover holes in the cylinder head, and they move with the blowing/sucking of air as the pistons move in the cylinders (no mechanical actuation of the valves). The pistons are aluminum, and though I measured, I don't remember the diameter... something on the order of 60 mm. The rods are also aluminum, and there are no rod bearings. The crankshaft is cast iron machined at the journals, and the aluminum rods rotate on the crank without any rod bearings. The crankcase does not have a removeable oil pan, and the cylinder block bolts to the crankcase. I was somewhat disappointed to discover the absence of rod bearings and the use of aluminum rods.*
*(How do I know this? Recall that I didn't get the oiling kit. I ran it the first time without oil in it like a dummy, and upon discovering my accident I promptly turned it off. Then I disassembled it to assess the damage. Luckily, nothing was seriously damaged, but I learned a lot about the inner workings of my compressor)
4. The compressor can run fairly hot, especially when pressurizing the tank from zero pressure. I build a copper coil from the compressor outlet to the tank which nearly brings the air to room temperature by the time it enters the tank. It was also my hope that the sideways-mounted coil would capture condenstation and oil residue. It seems to have lessened the oil in the tank bottom - more on that in a minute. Total Cost: ~$50 Intercoolers on larger compressors are more common, as are oil-removal and air drying systems. My poor-man's intercooler functions adequately. I haven't added an oil-removal or dryer yet, as I haven't painted any cars (yet).
5. There is a flimsy petcock drain valve in the bottom of the tank that is difficult to access. It is irritatingly small and difficult to reach. I added a Swagelok right angle 1/4" male NPT to 1/4" tube adaptor to this drain orifice, then plumbed 1/4" tubing out from under the tank and connected this to a ball valve. The valve is now accessible from the front of the tank. I also made some feet for the tank out of 2x4 lumber and some carriage bolts so that it sits higher and I have better access underneath. I angled the tubing downward so that condensation is sprayed in pretty patterns on the floor. On any given day I release about 1/4 cup of oily, rusty, watery residue. Since I added the cooling coil, it is a bit less. I found the Swagelok parts on eBay by buying assorted lots of parts. Total Cost: ~$30
6. I have made several trips to the hardware store to find the correct fittings to get the unit running properly, though most fittings were readily available. It seems to me that a lot of the fittings on the system are kind of cheap, though I am used to the Swagelok fittings that I use at work, which are expensive and well worth the price. Again, this is how they can keep this compressor under $1000 for you or I.
7. The oil reservoir drain plug is on the bottom of the crank case, however this is no practical way to drain the oil without spilling it all over the top of the tank. One could remove the compressor to change the oil, but a better soultion would be to insert a ball valve in the oil drain plug for easy draining. I suspect that the threading on the oil plug is standard NPT like all of the other fittings on the tank - possible 1/4" or 3/8" but I have continued to use the existing plug. I have since adapted a plastic tray from one of my toolboxes to sit under the oil drain to catch the oil. Oil changes: ~$30
8. Beware of a failing head gasket. One of the wierdest things I experienced was inexplicable long run times for the compressor. I was in the garage one day blowing sawdust off the benches and cleaning up a bit, when the compressor kicked on as it normally would. It proceeded to run for several minutes which was a bit longer than usual. Suddenly it became much louder and it startled me, and I ran over to it to discover that the air filter (inlet) had fallen off. I shut off the compressor and felt the top - it was hot! Hot enough to melt the plastic air filter housing. It took me awhile to figure out that the head gasket was bad and it wasn't building pressure. So it overheated itself. This is an indication of the design limits - obviously it couldn't sustain continual running due to inadequate cooling. It is designed to refill the tank and then cool. I purchased a new gasket and air filter from the IR dealer and the air compressor is now back in action. Head Gasket Kit (and another oil change while I'm at it): ~$70
And that's the weakness of compressors with less than 5 HP. They run hot and too fast for any kind of sustained operation. An overbuilt compressor could supply plenty of CFM for sandblasting or painting without any overheating problems. However, I could only afford this SS3L3 at the time so that's what I got.
I've probably put another $285 worth of parts into this thing over the years. But I've used it to fix a lot of things. I've rotated countless tires, done a few brake and suspension jobs, did some body work, and I've used it quite a bit for woodworking, sanding, and blowing dust around. It's saved me at least what I've put into it, no doubt. Maybe I would have been better off getting something a bit more heavy duty. I've had my eye on Eaton Compressor for some time, such as this little beauty:
IR sells the SS5L5, which uses the same 60 gallon tank, but a 5 HP split phase 3450 RPM motor running a different two piston single stage compressor. For someone considering more power, this unit is still quite affordable, but it will still have some of the drawbacks of this system. It turns out that 5 HP is about the most one can get out of a 30A single phase 230V household circuit without flipping breakers.
My biggest complaints for the SS3L3 are the use of the split phase motor, the relatively cheap design of the compressor (aluminum rods and lack of rod bearings), the flimsy pressure switch, and the cheap fittings used all over the machine. Really the other complaints aren't relevant - most of the money I've spent has been in pressure switches, air filter housings, and gaskets. But this compressor has taken most of what I've thrown at it which is all I can expect.
I will continue to use this unit for some time, but I am already considering either building my own low RPM, true 4-5 HP air compressor from various parts suppliers, or just purchasing a new one from a company like Eaton Compressor. Ingersoll Rand makes the Type 30 series which is a step above the SS series, and I have considered these units as well, but I would almost feel safer building the unit on my own so that I know exactly what is going into it.
The bottom line is that if you want a low RPM compressor that won't overheat, you'll be lucky to get it for less than $1,000. If you want to sand blast and die grind every day, spend the extra cash for a low RPM, 5 hp compressor.
What most people want to know about air compressors is air flow (in cubic feet per minute or CFM) and pressure (pounds per square inch or psi). Those are certainly good metrics, but really it comes down to what you want to use it for.
I've essentially learned that a small pancake-style compressor is great for nail guns and impact wrenches, and that's about it. Maybe air brushing. An air compressor like my SS3L3 here is okay for die grinding and orbital sanding, but I'd limit my usage of sand blasting. To get sand blasting capability, you're likely looking at $1,000+ with a 5 hp or more motor. Even in that category, you will see a price gap between high RPM compressors and low RPM compressors, the latter being the more expensive (and more robust) product.
Your biggest limitation is the compressor itself - how much air it flows, how long it can run without getting too hot, and its durability. Pancake compressors are designed to be low cost with short duty cycles. They run at high RPM on 110V. Medium duty compressors like this SS3L3 also run at high RPM but are 230V systems for higher power and more CFM. Heavy duty compressors Use greater power at lower RPM and can sustain almost continuous duty, i.e., if you are sandblasting.
I purchased my Ingersoll Rand SS3L3 compressor from Northern Tool in the early summer of 2005. It was priced lower than present day prices. This is the first air compressor that I have ever owned, so it was a learning experience from the start. It's been a good tool for me and I've probably gotten my money's worth, and I'll likely recoup significant cost if I ever sell it.
It is recommended that you purchase the IR SS3L3 startup kit as the compressor is delivered to you without any oil in it. In some cases the warranty is not valid unless you have purchased the startup kit. I didn't do that - more on that later.
One thing I immediately noticed was that the pressure switch was flimsy. When I plugged in the compressor to test it out, I found that the motor continued to run even as the gauge on the tank passed 130 psi. As it creeped closer to 135 psi (the limit printed on the tank), I pulled the plug. I ordered a new switch from Ingersoll Rand for ~ $35 and this fixed the problem. Perhaps I could have made a warranty claim, but it was easier to order the switch as there is an authorized IR dealer nearby and I had the switch within 2 days.
In the remaining time I've owned the compressor, I've replaced this switch 2 additional times. Total cost of switches: ~$105
I ran the compressor off and on for several months without any major issues. I used it for several things, but it's heaviest use has been blowing sawdust out of my garage and using a right angle die grinder for doing some body work on my car around the windshield. It has held up OK, but here are some things I have learned about the compressor since its purchase:
1. This unit uses a 3 HP "split phase" motor, which can be run on a standard 30A 230V household outlet - it draws about 15A during continuous duty. This is pretty normal for motors in this power and RPM range - typically 3-4 HP motors run somewhere around 3400 RPM, which is screamin'. The motor does not output a true 3 HP at all times. At startup the motor may approach its 3 peak horsepower, but during normal operation it may only be outputting half that power, so in truth it is essentially a 1.5 HP motor. This borderline false advertising is similar to peak and RMS power ratings in audio amplifiers, though it is fairly standard operating procedure to rate motors in this fashion. It is not a question of efficiency - it is an intended feature built into the windings of the motor.
2. The motor runs at 3450 RPM. Though it is quieter than a direct drive unit like the 30 gallon compressors sold at most hardware stores, 3450 RPM is still quite fast. With the pulley ratios, the compressor crank spins at 1200 RPM. Heavier duty systems might have the AC motor running at 1200-1750 RPM with the compressor running at ~700 RPM or less, resulting in a much quieter setup. Onomatopoeia description: The difference between them is "waaaaaaaahhhhhhhh!" (3450/1200) and "glug glug glug" (1750/700). If I could do it over, I would consider a slower, beefier unit with a true power rating that runs at a slower, more quiet speed.
3. There is apparently no available rebuild kit for the compressor itself, according to the local IR dealer, though they do sell gaskets and the oiling kit. This may also be common, but this model is really the bottom of IR's product line, as they have units that are massive 3 phase monsters for industrial use. So the SS3L3 is an acceptable compromise for the DIY homeowner like you or I. It is a very simple design, consisting of essentially three parts; a cylinder head, cylinder block, and crankcase. It is a two cylinder, single stage compressor. The "valves" in the head are "reed valves", which are simply spring loaded "fingers" that cover holes in the cylinder head, and they move with the blowing/sucking of air as the pistons move in the cylinders (no mechanical actuation of the valves). The pistons are aluminum, and though I measured, I don't remember the diameter... something on the order of 60 mm. The rods are also aluminum, and there are no rod bearings. The crankshaft is cast iron machined at the journals, and the aluminum rods rotate on the crank without any rod bearings. The crankcase does not have a removeable oil pan, and the cylinder block bolts to the crankcase. I was somewhat disappointed to discover the absence of rod bearings and the use of aluminum rods.*
*(How do I know this? Recall that I didn't get the oiling kit. I ran it the first time without oil in it like a dummy, and upon discovering my accident I promptly turned it off. Then I disassembled it to assess the damage. Luckily, nothing was seriously damaged, but I learned a lot about the inner workings of my compressor)
4. The compressor can run fairly hot, especially when pressurizing the tank from zero pressure. I build a copper coil from the compressor outlet to the tank which nearly brings the air to room temperature by the time it enters the tank. It was also my hope that the sideways-mounted coil would capture condenstation and oil residue. It seems to have lessened the oil in the tank bottom - more on that in a minute. Total Cost: ~$50 Intercoolers on larger compressors are more common, as are oil-removal and air drying systems. My poor-man's intercooler functions adequately. I haven't added an oil-removal or dryer yet, as I haven't painted any cars (yet).
5. There is a flimsy petcock drain valve in the bottom of the tank that is difficult to access. It is irritatingly small and difficult to reach. I added a Swagelok right angle 1/4" male NPT to 1/4" tube adaptor to this drain orifice, then plumbed 1/4" tubing out from under the tank and connected this to a ball valve. The valve is now accessible from the front of the tank. I also made some feet for the tank out of 2x4 lumber and some carriage bolts so that it sits higher and I have better access underneath. I angled the tubing downward so that condensation is sprayed in pretty patterns on the floor. On any given day I release about 1/4 cup of oily, rusty, watery residue. Since I added the cooling coil, it is a bit less. I found the Swagelok parts on eBay by buying assorted lots of parts. Total Cost: ~$30
6. I have made several trips to the hardware store to find the correct fittings to get the unit running properly, though most fittings were readily available. It seems to me that a lot of the fittings on the system are kind of cheap, though I am used to the Swagelok fittings that I use at work, which are expensive and well worth the price. Again, this is how they can keep this compressor under $1000 for you or I.
7. The oil reservoir drain plug is on the bottom of the crank case, however this is no practical way to drain the oil without spilling it all over the top of the tank. One could remove the compressor to change the oil, but a better soultion would be to insert a ball valve in the oil drain plug for easy draining. I suspect that the threading on the oil plug is standard NPT like all of the other fittings on the tank - possible 1/4" or 3/8" but I have continued to use the existing plug. I have since adapted a plastic tray from one of my toolboxes to sit under the oil drain to catch the oil. Oil changes: ~$30
8. Beware of a failing head gasket. One of the wierdest things I experienced was inexplicable long run times for the compressor. I was in the garage one day blowing sawdust off the benches and cleaning up a bit, when the compressor kicked on as it normally would. It proceeded to run for several minutes which was a bit longer than usual. Suddenly it became much louder and it startled me, and I ran over to it to discover that the air filter (inlet) had fallen off. I shut off the compressor and felt the top - it was hot! Hot enough to melt the plastic air filter housing. It took me awhile to figure out that the head gasket was bad and it wasn't building pressure. So it overheated itself. This is an indication of the design limits - obviously it couldn't sustain continual running due to inadequate cooling. It is designed to refill the tank and then cool. I purchased a new gasket and air filter from the IR dealer and the air compressor is now back in action. Head Gasket Kit (and another oil change while I'm at it): ~$70
And that's the weakness of compressors with less than 5 HP. They run hot and too fast for any kind of sustained operation. An overbuilt compressor could supply plenty of CFM for sandblasting or painting without any overheating problems. However, I could only afford this SS3L3 at the time so that's what I got.
I've probably put another $285 worth of parts into this thing over the years. But I've used it to fix a lot of things. I've rotated countless tires, done a few brake and suspension jobs, did some body work, and I've used it quite a bit for woodworking, sanding, and blowing dust around. It's saved me at least what I've put into it, no doubt. Maybe I would have been better off getting something a bit more heavy duty. I've had my eye on Eaton Compressor for some time, such as this little beauty:
IR sells the SS5L5, which uses the same 60 gallon tank, but a 5 HP split phase 3450 RPM motor running a different two piston single stage compressor. For someone considering more power, this unit is still quite affordable, but it will still have some of the drawbacks of this system. It turns out that 5 HP is about the most one can get out of a 30A single phase 230V household circuit without flipping breakers.
My biggest complaints for the SS3L3 are the use of the split phase motor, the relatively cheap design of the compressor (aluminum rods and lack of rod bearings), the flimsy pressure switch, and the cheap fittings used all over the machine. Really the other complaints aren't relevant - most of the money I've spent has been in pressure switches, air filter housings, and gaskets. But this compressor has taken most of what I've thrown at it which is all I can expect.
I will continue to use this unit for some time, but I am already considering either building my own low RPM, true 4-5 HP air compressor from various parts suppliers, or just purchasing a new one from a company like Eaton Compressor. Ingersoll Rand makes the Type 30 series which is a step above the SS series, and I have considered these units as well, but I would almost feel safer building the unit on my own so that I know exactly what is going into it.
The bottom line is that if you want a low RPM compressor that won't overheat, you'll be lucky to get it for less than $1,000. If you want to sand blast and die grind every day, spend the extra cash for a low RPM, 5 hp compressor.
Wednesday, November 9, 2011
Liquid Fuels for Sight Seeing
I was looking into the hydrolysis of methyl formate for various reasons when I stumbled upon a number of articles detailing the composition of interstellar gas clouds. My search query “methyl formate kJ/mol” landed me in the middle of this paper detailing the kinetics of formation of methyl formate in interstellar space gas clouds during the early formation of stars and/or planets.
So I was up for the distraction and tried to muddle through the context and chemistry to see what these folks were getting at. No practical information came up from the read, but it did make me wonder if there was any possibility that an interstellar spaceship could harvest some of this methyl formate to make fuel (such as methanol) or perhaps even water.
To make the methanol, water and heat would be required to sustain hydrolysis of methyl formate to methanol and formic acid. But in doing so, the inhabitants of said spaceship would be using valuable drinking water to make a fuel and an acid. And what would they do with a bunch of formic acid? Along those same lines… the methanol would really have no purpose inside the spaceship, either. Its combustion would make CO2 and water and might strain the O2 regeneration systems. Presumably, if we’re talking about an interstellar spaceship, it likely has a significant power source for either motivation and power or just power. So it might have a little fission reactor (like our aircraft carriers) or perhaps even a Mr. Fusion in the back.
So as long as it has fusion, who cares about methanol? But then I started wondering what would happen once the ship arrived at the planet. Assuming it doesn’t hover up in space or it has a fusion-powered dropship that goes with the colonists, the lander would be the powerplant they need. Once on the ground, they could roll out trucks and tractors and start building homes and laboratories. The fusion-powered dropship would be the generator and could recharge electric systems on their working vehicles.
But what about further exploration of the planet? If an orbiter remains above, it could scan the planet below and map the surface, and identify interesting places to visit. Perhaps the dropship could take explorers out on sight seeing trips, but if that were the case they would be without their valuable power plant. So instead they should have exploration vehicles. And those vehicles would need long range, and to obtain long range, they should run on liquid fuels.
(This of course assumes batteries and ultracapacitors still have not yet matched the energy density of fuels. I suppose if we’ve invented fusion and interstellar travel, we should have that stuff figured out too, right? But let’s assume we haven’t.)
So perhaps they could use the methyl formate they picked up in gas clouds along the way to make methanol on the planet surface, and use it to power their transcontinental jet planes for exploration purposes.
That seems overly complicated. My guess would be that if we could sustain a number of colonists on an interstellar ship with fusion, recycled water, and self-sustaining food, we could certainly figure out a way to make fuels on the planet surface with whatever water, CO2 , or biosources are available. After all, it's been done.
Anyway, back to my search on the energy required for hydrolysis of methyl formate…
So I was up for the distraction and tried to muddle through the context and chemistry to see what these folks were getting at. No practical information came up from the read, but it did make me wonder if there was any possibility that an interstellar spaceship could harvest some of this methyl formate to make fuel (such as methanol) or perhaps even water.
To make the methanol, water and heat would be required to sustain hydrolysis of methyl formate to methanol and formic acid. But in doing so, the inhabitants of said spaceship would be using valuable drinking water to make a fuel and an acid. And what would they do with a bunch of formic acid? Along those same lines… the methanol would really have no purpose inside the spaceship, either. Its combustion would make CO2 and water and might strain the O2 regeneration systems. Presumably, if we’re talking about an interstellar spaceship, it likely has a significant power source for either motivation and power or just power. So it might have a little fission reactor (like our aircraft carriers) or perhaps even a Mr. Fusion in the back.
So as long as it has fusion, who cares about methanol? But then I started wondering what would happen once the ship arrived at the planet. Assuming it doesn’t hover up in space or it has a fusion-powered dropship that goes with the colonists, the lander would be the powerplant they need. Once on the ground, they could roll out trucks and tractors and start building homes and laboratories. The fusion-powered dropship would be the generator and could recharge electric systems on their working vehicles.
But what about further exploration of the planet? If an orbiter remains above, it could scan the planet below and map the surface, and identify interesting places to visit. Perhaps the dropship could take explorers out on sight seeing trips, but if that were the case they would be without their valuable power plant. So instead they should have exploration vehicles. And those vehicles would need long range, and to obtain long range, they should run on liquid fuels.
(This of course assumes batteries and ultracapacitors still have not yet matched the energy density of fuels. I suppose if we’ve invented fusion and interstellar travel, we should have that stuff figured out too, right? But let’s assume we haven’t.)
So perhaps they could use the methyl formate they picked up in gas clouds along the way to make methanol on the planet surface, and use it to power their transcontinental jet planes for exploration purposes.
That seems overly complicated. My guess would be that if we could sustain a number of colonists on an interstellar ship with fusion, recycled water, and self-sustaining food, we could certainly figure out a way to make fuels on the planet surface with whatever water, CO2 , or biosources are available. After all, it's been done.
Anyway, back to my search on the energy required for hydrolysis of methyl formate…
Tuesday, September 13, 2011
The New C1 Chemistry
Unless you are a chemical engineer or have an in depth familiarity with organic chemistry, you are likely unfamiliar with the term “C1 Chemistry” and its relevance to our modern petrochemical infrastructure. I wasn’t either, until recently.
As a rule of thumb, all you need to know about organic chemistry is that plastic, rubber, vinyl, or other “plastics” were made possible by only three elements in the periodic table: carbon, hydrogen, and oxygen. Refineries obtain these ingredients from sources that are easy to break up, such as natural gas. Most non-fuel related petrochemical processes use natural gas as a feedstock because of its readiness to give up hydrogen and contribute its carbon atom to the next product. Most processes start with natural gas to create “synthesis gas” (syngas) which is a building block ingredient. This is called steam methane reforming (SMR). Syngas is formed in the following way:
CH4 + H2O --> CO + 3H2
Energy is input to this reaction to sustain temperatures of 850 degrees Celsius and about 40 atmospheres of pressure (~580 psi). You can see in this reaction that a single carbon feedstock produces syngas; hence “C1 Chemistry”. This reaction requires a metal catalyst (such as nickel) which is partially consumed in the process.
From syngas any number of products can be created with water and more energy input. Methanol, for example, is formed from syngas by the following reaction:
CO + 2H2 --> CH3OH
That reaction only consumes part of the hydrogen from the initial syngas reaction, but if the first reaction and the second reaction are performed in series, the energy density of methane is neatly packaged into a transportable room temperature liquid. Room temperature liquids are much easier to contain and transport than gases, hence the importance of methanol in petrochemicals production processes. Methanol is so consistently linked with the remaining family of petrochemicals that is has been proposed as a solution to our hydrocarbon problem (see The Methanol Economy).
Surprisingly, the concept of C1 Chemistry is relatively new, as a paper from 1986 implies (Keim. “C1 Chemisty: Potential and Developments.” Pure and Applied Chemistry, Vol. 58, No. 6, 825-832, 1986). The motivation for C1 chemistry at that time was the price of crude oil, which has been an acceptable feedstock for other petrochemicals in the past. Refining of petrochemicals requires an energy input for each reaction step, and this energy is often obtained via combustion of natural gas because of its high energy content. Combustion of natural gas produces water, carbon dioxide, and about 1 million BTU for every 1000 cubic feet of natural gas burned.
These stable molecules - water and carbon dioxide - contain the three magic elements as well: carbon, hydrogen, and oxygen. Unfortunately, H2O and CO2 are quite stable, and their separation into constituents requires more energy than less stable molecules such as methane or the hydrocarbon chains in crude oil. But a vision for sustainable petrochemicals would include H2O and CO2 as the feedstock.
There are pathways to obtain the hydrogen, oxygen, and carbon needed for petrochemicals from the stable feedstock of water and carbon dioxide. Water can be split into hydrogen and oxygen with electrolysis as well as photocatalytic pathways. Carbon dioxide can also be converted into useful chemicals (I must disclose that this has been some of my work in the past few years). An energy intensive, purely electrochemical pathway would be to produce hydrogen from water via electrolysis, and CO from CO2 via a nickel catalyst, thus creating syngas. However, more cost effective pathways bypass syngas altogether in order to produce useful intermediates such as methanol. The methanol pathway would open up the possibility for building many chemicals and fuels. In my own work with my colleagues, however, I have found that these pathways are not only energy intensive, but they are also intensive in consumables. The petrochemical industry is closely tied with the chlor-akali industry, as sodium hydroxide, sodium chloride, and chlorine gas are needed in the production of many chemicals and solvents. In addition to our three magic elements H, C, and O, we may also add Cl which we derive from salts. Electrolysis of water with dissolved NaCl will evolve hydroxide ions (OH-) and chlorine ions (Cl-) which combine to make chlorine gas (Cl2). Sodium hydroxide (NaOH) and sodium chloride (NaCl) provide needed conductivity in electrochemical processes, and their constituent ions OH- and Cl- can participate in reactions as well. Consider the family of polyvinylchlorides (PVCs) that make up much of our modern plumbing in houses and buildings. These materials require chlorine as part of their composition.
Therefore the modern industrial complex runs on hydrogen, oxygen, and carbon, as well as salt, lye, and lots of water. Any alternative to the hydrocarbon route must consider the consumption of these elements and materials.
Electrochemical reduction of CO2 into other products requires a hydrogen source. This source can be water itself, but it can also be sodium hydroxide. Other substitutes for acids and bases are potassium hydroxide (KOH) or potassium chloride (KCl), and sulfuric acid (H2SO4). However, to produce fuels on the scale that we produce them now would require inordinate amounts of consumable if this pathway were chosen. The only consumable with enough abundance to support that demand is water itself, which unfortunately means that more energy is required for the electrochemical process.
Due to the affordability of methanol and the energy required to produce it electrochemically from CO2, it is very difficult to make methanol from CO2 in a cost effective manner. It is easier to produce higher value chemicals such as CO and formic acid (HCO2H). I am not saying it is impossible to make methanol from CO2 affordably – I am saying it is challenging. A lot of the research in this area fails to quantify the needed cost metrics or to propose solutions to overcome cost. The main cost stems from the energy consumed. A second major cost is consumables. And a third cost (often overlooked) is the catalyst for these processes. One possible electrochemical catalyst for the conversion of CO2 to methanol is Ruthenium. Anodes are often platinum, palladium, or titanium metal oxides. If these costs are properly accounted for, the problem is then reduced to a manageable problem: financing the construction of the plant on the projected revenues.
I have published papers in my own work exposing the energy requirements and I’ve shown how the overlap of the petrochemical and electrical infrastructures can provide cost effective avenues to produce chemicals from CO2 (“Energy Storage via Electrochemical Conversion of CO2 into Specialty Chemicals” Hill, et al. ESFuelCell2011-54048. Aug 7, 2011 Washington, DC). However, this requires us to examine our entire chemical and electrical supply chain differently. Instead of requiring that energy and chemical production be performed in a consolidated, high capacity factor, 24 hour operation, we should instead consider opportunistic and distributed production. We should produce fuels from electrical energy when electrical energy is temporarily cheap, and use electrical energy fluctuations as opportunities to store energy in chemicals and fuels. Besides off peak energy, there are minute-by-minute low prices of electrical energy which instantly reflect the need to balance grid voltage. This can be done not only on an hourly basis but on a minute to minute basis, as the ancillary services market in the electric transmission sector has already shown. Marrying electrochemical processes with ancillary services would enable the adoption of renewable energy into our complete grid, ensure the production of low-carbon fuels, and maximize the utilization rate of renewable energy. The energy density of most chemicals and fuels would be greater than our best batteries of today, as we have shown previously.
These are much more dynamic business models but they are not much different than what the financial sector has already discovered. Whenever there is a dynamic and changing value, there is an opportunity to seize growth from that value. Our fuel infrastructure has been slow to realize this, though even the dinosaur-like electrical grid is beginning to see it. Like money, energy is a commodity that is in high demand and trades on a rapid basis. Restructuring of our treatment of energy is the ultimate solution to producing sustainable fuels and chemicals from CO2 and H2O.
*These views are my personal views only.
As a rule of thumb, all you need to know about organic chemistry is that plastic, rubber, vinyl, or other “plastics” were made possible by only three elements in the periodic table: carbon, hydrogen, and oxygen. Refineries obtain these ingredients from sources that are easy to break up, such as natural gas. Most non-fuel related petrochemical processes use natural gas as a feedstock because of its readiness to give up hydrogen and contribute its carbon atom to the next product. Most processes start with natural gas to create “synthesis gas” (syngas) which is a building block ingredient. This is called steam methane reforming (SMR). Syngas is formed in the following way:
CH4 + H2O --> CO + 3H2
Energy is input to this reaction to sustain temperatures of 850 degrees Celsius and about 40 atmospheres of pressure (~580 psi). You can see in this reaction that a single carbon feedstock produces syngas; hence “C1 Chemistry”. This reaction requires a metal catalyst (such as nickel) which is partially consumed in the process.
From syngas any number of products can be created with water and more energy input. Methanol, for example, is formed from syngas by the following reaction:
CO + 2H2 --> CH3OH
That reaction only consumes part of the hydrogen from the initial syngas reaction, but if the first reaction and the second reaction are performed in series, the energy density of methane is neatly packaged into a transportable room temperature liquid. Room temperature liquids are much easier to contain and transport than gases, hence the importance of methanol in petrochemicals production processes. Methanol is so consistently linked with the remaining family of petrochemicals that is has been proposed as a solution to our hydrocarbon problem (see The Methanol Economy).
Surprisingly, the concept of C1 Chemistry is relatively new, as a paper from 1986 implies (Keim. “C1 Chemisty: Potential and Developments.” Pure and Applied Chemistry, Vol. 58, No. 6, 825-832, 1986). The motivation for C1 chemistry at that time was the price of crude oil, which has been an acceptable feedstock for other petrochemicals in the past. Refining of petrochemicals requires an energy input for each reaction step, and this energy is often obtained via combustion of natural gas because of its high energy content. Combustion of natural gas produces water, carbon dioxide, and about 1 million BTU for every 1000 cubic feet of natural gas burned.
These stable molecules - water and carbon dioxide - contain the three magic elements as well: carbon, hydrogen, and oxygen. Unfortunately, H2O and CO2 are quite stable, and their separation into constituents requires more energy than less stable molecules such as methane or the hydrocarbon chains in crude oil. But a vision for sustainable petrochemicals would include H2O and CO2 as the feedstock.
There are pathways to obtain the hydrogen, oxygen, and carbon needed for petrochemicals from the stable feedstock of water and carbon dioxide. Water can be split into hydrogen and oxygen with electrolysis as well as photocatalytic pathways. Carbon dioxide can also be converted into useful chemicals (I must disclose that this has been some of my work in the past few years). An energy intensive, purely electrochemical pathway would be to produce hydrogen from water via electrolysis, and CO from CO2 via a nickel catalyst, thus creating syngas. However, more cost effective pathways bypass syngas altogether in order to produce useful intermediates such as methanol. The methanol pathway would open up the possibility for building many chemicals and fuels. In my own work with my colleagues, however, I have found that these pathways are not only energy intensive, but they are also intensive in consumables. The petrochemical industry is closely tied with the chlor-akali industry, as sodium hydroxide, sodium chloride, and chlorine gas are needed in the production of many chemicals and solvents. In addition to our three magic elements H, C, and O, we may also add Cl which we derive from salts. Electrolysis of water with dissolved NaCl will evolve hydroxide ions (OH-) and chlorine ions (Cl-) which combine to make chlorine gas (Cl2). Sodium hydroxide (NaOH) and sodium chloride (NaCl) provide needed conductivity in electrochemical processes, and their constituent ions OH- and Cl- can participate in reactions as well. Consider the family of polyvinylchlorides (PVCs) that make up much of our modern plumbing in houses and buildings. These materials require chlorine as part of their composition.
Therefore the modern industrial complex runs on hydrogen, oxygen, and carbon, as well as salt, lye, and lots of water. Any alternative to the hydrocarbon route must consider the consumption of these elements and materials.
Electrochemical reduction of CO2 into other products requires a hydrogen source. This source can be water itself, but it can also be sodium hydroxide. Other substitutes for acids and bases are potassium hydroxide (KOH) or potassium chloride (KCl), and sulfuric acid (H2SO4). However, to produce fuels on the scale that we produce them now would require inordinate amounts of consumable if this pathway were chosen. The only consumable with enough abundance to support that demand is water itself, which unfortunately means that more energy is required for the electrochemical process.
Due to the affordability of methanol and the energy required to produce it electrochemically from CO2, it is very difficult to make methanol from CO2 in a cost effective manner. It is easier to produce higher value chemicals such as CO and formic acid (HCO2H). I am not saying it is impossible to make methanol from CO2 affordably – I am saying it is challenging. A lot of the research in this area fails to quantify the needed cost metrics or to propose solutions to overcome cost. The main cost stems from the energy consumed. A second major cost is consumables. And a third cost (often overlooked) is the catalyst for these processes. One possible electrochemical catalyst for the conversion of CO2 to methanol is Ruthenium. Anodes are often platinum, palladium, or titanium metal oxides. If these costs are properly accounted for, the problem is then reduced to a manageable problem: financing the construction of the plant on the projected revenues.
I have published papers in my own work exposing the energy requirements and I’ve shown how the overlap of the petrochemical and electrical infrastructures can provide cost effective avenues to produce chemicals from CO2 (“Energy Storage via Electrochemical Conversion of CO2 into Specialty Chemicals” Hill, et al. ESFuelCell2011-54048. Aug 7, 2011 Washington, DC). However, this requires us to examine our entire chemical and electrical supply chain differently. Instead of requiring that energy and chemical production be performed in a consolidated, high capacity factor, 24 hour operation, we should instead consider opportunistic and distributed production. We should produce fuels from electrical energy when electrical energy is temporarily cheap, and use electrical energy fluctuations as opportunities to store energy in chemicals and fuels. Besides off peak energy, there are minute-by-minute low prices of electrical energy which instantly reflect the need to balance grid voltage. This can be done not only on an hourly basis but on a minute to minute basis, as the ancillary services market in the electric transmission sector has already shown. Marrying electrochemical processes with ancillary services would enable the adoption of renewable energy into our complete grid, ensure the production of low-carbon fuels, and maximize the utilization rate of renewable energy. The energy density of most chemicals and fuels would be greater than our best batteries of today, as we have shown previously.
These are much more dynamic business models but they are not much different than what the financial sector has already discovered. Whenever there is a dynamic and changing value, there is an opportunity to seize growth from that value. Our fuel infrastructure has been slow to realize this, though even the dinosaur-like electrical grid is beginning to see it. Like money, energy is a commodity that is in high demand and trades on a rapid basis. Restructuring of our treatment of energy is the ultimate solution to producing sustainable fuels and chemicals from CO2 and H2O.
*These views are my personal views only.
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