Green Cars Part 2 - Biofuels
Posted 02-03-2009 at 02:13 PM by mattW
Tags biofuels
Last week we established that the so called green car is a myth; cars are inherently harmful to the environment. Despite this, most of us would like to carry on using our cars because; let’s face it, they are really convenient. Those of us lacking the environmental zeal to give up the mixed blessing of the automobile are left to seek an alternative to the current expensive black stuff that has us hooked. What are the options for a recovering oilaholic? Well this week I’m going take a rather critical look at the five most talked about options to see, blind optimism aside, whether our love of cars has any hope to continue. The main factors we will look at are efficiency, impact, viability and availability. In this post we’ll look at the two big Biofuels before covering hydrogen, compressed air and battery power later in the week.
Biodiesel
At least initially, Biodiesel seems like a pretty good option to replace traditional oil. Biodiesel uses fats or vegetable oils and other ingredients to create a replacement for conventional oil derived diesel (petrodiesel). According to Wikipedia, this replacement functions in much the same way as petrodiesel but can substantially reduce green house emissions (other than nitrogen oxide), especially when a mix of the two fuels is used. The fuel is biodegradable, non-toxic to humans and can be used in conventional diesel engines. The fuel can even be recycled from used vegetable oil that would otherwise be discarded from restaurants, though if adopted widely demand would far exceed supply.
Biodiesel is not without its critics however, even within environmental spheres. The ease at which Biodiesel can be produced at home has been greatly exaggerated, with significant safety and cost issues to be done well. The production of palm oil crops for the fuel has already resulted in widespread deforestation in the Philippians and Indonesia, threatening natural wildlife and resulting in more CO2 from the burning of the rainforests. As it is based on crops, Biodiesel production can have a significant impact on food prices which is a significant humanitarian issue. Several University studies have concluded that the energy and pollution payback from crop-produced is poor and the process is not sustainable. While the end product of Biodiesel is quite environmentally friendly, the actual process of producing large scale quantities may actually be more damaging than the fuel they are trying to replace. Unless there is a major breakthrough in production (possibly with algae?), I’m afraid that sustainable Biodiesel will be limited to small scale production dependant on the availability of waste vegetable oil, and won’t be a major player in the green movement.
Ethanol
Ethanol, like Biodiesel, is a plant derived alternative to oil derived fuel. Ethanol burns with 20% less CO2 than unleaded gasoline (petrol) and is particulate-free. The CO2 that it does emit was only recently in the atmosphere anyway so it can’t do much more harm. The fuel is renewable and offsets nasty oil usage. Most modern cars can run on a mix of up to 10% ethanol without any modification and vehicles can be produced to run on pure ethanol.
But like its cousin Biodiesel, Ethanol is not the green messiah it’s cracked up to be. According to the Economist article, Ethanol, schmethanol;“the amount of heat you get from burning a litre of ethanol is a third less than that from a litre of petrol. What is more, it absorbs water from the atmosphere. Unless it is mixed with some other fuel, such as petrol, the result is corrosion that can wreck an engine's seals in a couple of years.” Ethanol generally reduces the fuel economy of cars compared to normal gasoline. Ethanol production uses a lot of potential food, water and land as well as having distribution issues. It too is causing deforestation, this time in the Amazon. The clearing of forests has been said to build up a carbon debt which may take up to 420 years to make up with the CO2 reduction of ethanol usage.. Some have suggested the energy payback is too small for it to be sustainable (at least with corn). Some scientists have predicted an increase in respiratory health problems due to ethanol usage. As with Biodiesel, the wider cost of ethanol, especially in the light of other alternatives seems to limit its potential as the widespread replacement of oil based fuel.
I’m not sure how successful Biofuels will be in the future, they are certainly controversial. Large scale, I personally don’t think the ends justify the means when the humanitarian and wider environmental costs are taken into account. Future production breakthroughs may yield higher energy and emission paybacks but an energy source that competes with food production for land, water and fertiliser is only going to stretch an already overpopulated planet where there are plenty of people going hungry. This is not to say that Biofuels do not serve any benefit. I see a limited but nevertheless important role in the reuse of excess or waste matter to produce electricity with oil, food or even manure (via methane) that would otherwise go to waste. This is commonly referred to as biomass but the principle is the same as with Biofuels. Later in the week I will cover three options for turning electricity into motion for the cars of the future (and today).
Biodiesel
At least initially, Biodiesel seems like a pretty good option to replace traditional oil. Biodiesel uses fats or vegetable oils and other ingredients to create a replacement for conventional oil derived diesel (petrodiesel). According to Wikipedia, this replacement functions in much the same way as petrodiesel but can substantially reduce green house emissions (other than nitrogen oxide), especially when a mix of the two fuels is used. The fuel is biodegradable, non-toxic to humans and can be used in conventional diesel engines. The fuel can even be recycled from used vegetable oil that would otherwise be discarded from restaurants, though if adopted widely demand would far exceed supply.
Biodiesel is not without its critics however, even within environmental spheres. The ease at which Biodiesel can be produced at home has been greatly exaggerated, with significant safety and cost issues to be done well. The production of palm oil crops for the fuel has already resulted in widespread deforestation in the Philippians and Indonesia, threatening natural wildlife and resulting in more CO2 from the burning of the rainforests. As it is based on crops, Biodiesel production can have a significant impact on food prices which is a significant humanitarian issue. Several University studies have concluded that the energy and pollution payback from crop-produced is poor and the process is not sustainable. While the end product of Biodiesel is quite environmentally friendly, the actual process of producing large scale quantities may actually be more damaging than the fuel they are trying to replace. Unless there is a major breakthrough in production (possibly with algae?), I’m afraid that sustainable Biodiesel will be limited to small scale production dependant on the availability of waste vegetable oil, and won’t be a major player in the green movement.
Ethanol
Ethanol, like Biodiesel, is a plant derived alternative to oil derived fuel. Ethanol burns with 20% less CO2 than unleaded gasoline (petrol) and is particulate-free. The CO2 that it does emit was only recently in the atmosphere anyway so it can’t do much more harm. The fuel is renewable and offsets nasty oil usage. Most modern cars can run on a mix of up to 10% ethanol without any modification and vehicles can be produced to run on pure ethanol.
But like its cousin Biodiesel, Ethanol is not the green messiah it’s cracked up to be. According to the Economist article, Ethanol, schmethanol;“the amount of heat you get from burning a litre of ethanol is a third less than that from a litre of petrol. What is more, it absorbs water from the atmosphere. Unless it is mixed with some other fuel, such as petrol, the result is corrosion that can wreck an engine's seals in a couple of years.” Ethanol generally reduces the fuel economy of cars compared to normal gasoline. Ethanol production uses a lot of potential food, water and land as well as having distribution issues. It too is causing deforestation, this time in the Amazon. The clearing of forests has been said to build up a carbon debt which may take up to 420 years to make up with the CO2 reduction of ethanol usage.. Some have suggested the energy payback is too small for it to be sustainable (at least with corn). Some scientists have predicted an increase in respiratory health problems due to ethanol usage. As with Biodiesel, the wider cost of ethanol, especially in the light of other alternatives seems to limit its potential as the widespread replacement of oil based fuel.
I’m not sure how successful Biofuels will be in the future, they are certainly controversial. Large scale, I personally don’t think the ends justify the means when the humanitarian and wider environmental costs are taken into account. Future production breakthroughs may yield higher energy and emission paybacks but an energy source that competes with food production for land, water and fertiliser is only going to stretch an already overpopulated planet where there are plenty of people going hungry. This is not to say that Biofuels do not serve any benefit. I see a limited but nevertheless important role in the reuse of excess or waste matter to produce electricity with oil, food or even manure (via methane) that would otherwise go to waste. This is commonly referred to as biomass but the principle is the same as with Biofuels. Later in the week I will cover three options for turning electricity into motion for the cars of the future (and today).
Delicious
Digg
StumbleUpon
Reddit
Newsvine
Facebook
Google
Yahoo
Total Comments 8
Comments
-
Short article - standard high level summary of the biofuels but lacking any details. While biofuels will never be 'THE' solution, they can have a significant contribution to reducing our footprints and should not be cast aside.
I agree, biodiesel will always be smart for a small segment using waste oil to fuel vehicles, but it will not become mainstream. Growing crops only for the purpose of creating biodiesel is very questionable.
As for ethanol, there is no mention in the article of cellulose based ethanol. As you state, crop based ethanol is not a wise sustainable solution. For those not familiar, waste biomass such as the straw left from wheat crops, oat husks, and other organic materials that are crop waste and not food crops can be broken down through mechanical methods, chemical methods, or enzymes and fermented to produce ethanol – alcohol (yes with you could drink it but…). These materials are typically discarded or left to rot in the fields. By transporting them to a plant, they can be converted to fuel with the addition of very little energy. The residue left after fermentation can be used as a heat source. The end result is creating fuel from waste with very little energy input yielding a far higher net energy gain than from corn or wheat based ethanol.
The current leaders in cellulose ethanol would have to be:
http://iogen.ca/
there are others in this space, but Iogen looks to emerge as the leader in this area.
As for the reduced energy content in ethanol – this is indisputable, however, small amounts of ethanol added to boost the octane levels of gasoline have been proven to increase the fuel efficiency of a gasoline powered vehicle. In cases where engines are designed to run on ethanol, they can have improved efficiency due to the increased octane levels. E-85 (85% ethanol, 15% gasoline) has an octane rating of around 104. With this level of octane rating, small turbocharged engines can be designed with high levels of boost that increase efficiency in the Otto cycle delivering similar hp with a much smaller engine.
Please keep going with the articles, I am enjoying them. Can you please address the concern that hydrogen is nothing more that a battery and a comparison of the storage efficiency of a battery system to a hydrogen fuel cell is essential. I believe this nuance is lost on most people. Somehow most people thing hydrogen is some magical fuel source that has no ill effects…
cheers!Posted 03-14-2008 at 12:05 AM by GeEkBoY 
-
You state that bio-fuels can not replace fossil fuels. This is indisputable. however, I would like to see someone do an article on the viability of using bio-fuels in range-extended electric vehicles or PHEV's. The article would need to first evaluate how much biofules might actually be available vs how much biofuels might be needed if all privately-owned vehicles were designed to travel at least 35 miles on electric only.
Posted 03-14-2008 at 02:43 AM by xrotaryguy
-
@Geekboy- I'm glad you've found the articles interesting. How did you come across them (i'm curious because i'm wondering how to expand my audience)? I tried to make it more of a summary with plenty of links to more detailed reports, otherwise this would be about a 30 part series :P The next post will be on "energy storage alternatives" meaning hydrogen, air and (in the last post) battery electric all of which get their power primarily from electricity at varying efficiencies.
@xrotary I am still deciding what I think about the solution for efficient interstate travel. I'm pretty convinced that battery electric is the best option for all personal transport <120 miles (200km). But i'm not sure what the best option is for long distance/ large vehicles (prime movers etc). It may be an area where hydrogen gets an edge, or perhaps the demand is not so high as to exclude efficient biofuel production. Either way its going to take a pretty big infrastructure change and if we are going to do that then fast charge EV stations would be a pretty good option too. Anyways i'll discuss it a bit more in the next 2 posts.Posted 03-15-2008 at 02:11 AM by mattW
-
The problem with the method you describe is that those remains left in the field to rot are helpful in keeping the soil viable. Remove them and you'll have to reintroduce those nutrients artificially, not very efficient.Quote:Originally Posted by GeEkBoY
As for ethanol, there is no mention in the article of cellulose based ethanol. As you state, crop based ethanol is not a wise sustainable solution. For those not familiar, waste biomass such as the straw left from wheat crops, oat husks, and other organic materials that are crop waste and not food crops can be broken down through mechanical methods, chemical methods, or enzymes and fermented to produce ethanol – alcohol (yes with you could drink it but…). These materials are typically discarded or left to rot in the fields. By transporting them to a plant, they can be converted to fuel with the addition of very little energy. The residue left after fermentation can be used as a heat source. The end result is creating fuel from waste with very little energy input yielding a far higher net energy gain than from corn or wheat based ethanol.Posted 03-15-2008 at 05:22 PM by JRP3
-
Matt:
I came across the forums a month or two ago when I was reinvestigating the viability of an electric car with only a small battery pack and an onboard diesel generator for longer trips (due to my personal driving habits of short commuting but long weekend trips). The articles were found as a result of viewing the forums. I have always had an interest in autos but have known for sometime we must reduce our impact on the earth, I enjoy researching enabling technologies from time to time.
If you are trying to expand your audience, you need to have more in-depth articles. If you can produce the 30-article version, that would be great! The shorter versions (EV for dummies or the pop-sci version) would be great in drawing in an audience, but you need more meat once you get the people interested. If you have ever read 'The Weathermakers' by Tim Flannery (a very good book on global warming) the author compiles and distills an enormous amount of research and presents it in an easy to understand style. If you could present a similar series of articles on human transportation, I am sure that it would draw in a great amount of interest. All to often, articles are written to infuelnce a special interest group that takes an unscientific slant to attempt to reinforce a point.
JRP3:
Two things to consider:
What you mention is a common problem in corn-based ethanol as corn strips many of the nutrients out of the soil. I grew up in a farming community and crop rotation was essential for certain crops but not for others (corn being one of the worst offenders). Many of the nutrients would go to the food portion of the crops, there would be little nutrients left in the stalks of the plants. If you were to grow hemp, one of the if not the most efficient plant at converting sunlight into biomass energy, you do not need to rotate your crops.
Second and most important, the residue left after fermentation contains the nutrients and can be returned to the fields. The process of fermentation does not consume these nutrients. Cellulose based ethanol production is very ‘opportunistic’ hence my comments on it being part of the solution but not ‘the’ solution to our energy problems.Posted 03-15-2008 at 10:00 PM by GeEkBoY
-
Is it more efficient to use hemp for ethanol production or biodiesel? Has cellulosic ethanol actually been produced at a positive EROEI on an industrial scale?Quote:Originally Posted by GeEkBoY
What you mention is a common problem in corn-based ethanol as corn strips many of the nutrients out of the soil. I grew up in a farming community and crop rotation was essential for certain crops but not for others (corn being one of the worst offenders). Many of the nutrients would go to the food portion of the crops, there would be little nutrients left in the stalks of the plants. If you were to grow hemp, one of the if not the most efficient plant at converting sunlight into biomass energy, you do not need to rotate your crops.
Cellulose based ethanol production is very ‘opportunistic’ hence my comments on it being part of the solution but not ‘the’ solution to our energy problems.
But then you have additional energy consumed in spreading those nutrients back onto the fields. How does that affect the equation?Quote:Second and most important, the residue left after fermentation contains the nutrients and can be returned to the fields. The process of fermentation does not consume these nutrients.Posted 03-16-2008 at 07:25 AM by JRP3
-
Currently cellulose plants operating are at the Pilot stage or proof of concept. They are being used to demonstrate the conversion technology and prove the economic viability. That said there are fully commercial plants under planning or early construction phases.
A good article discussing biofuels can be found here:
http://grist.org/news/maindish/2006/12/04/montenegro/
I am unsure of the conversion efficiency for hemp. I am unaware of any large scale tests mainly due to availability due to governments preventing farmers from growing this crop (special permits aside). A quote about the conversion efficiency from that article:
“According to the U.S. Department of Energy, corn-based ethanol provides 26 percent more energy than is required for its production, while cellulosic provides 80 percent more energy. And while conventional ethanol reduces greenhouse-gas emissions 10 to 20 percent below gasoline levels, the reductions with cellulosic range from 80 percent below gasoline to completely CO2 neutral.”
I mentioned hemp as it is one of the most efficient crops for converting solar energy into biomass energy needing no fertilizers nor pesticides to grow. It would probably make more sense to grow hemp for cellulose ethanol than switch grass, but the drug agencies don’t like hemp as it looks the same as marijuana. That said, it would still displace food growth and crop waste is still a better way to go.
Wikipedia contains a wealth of info and links to other articles and studies:
http://en.wikipedia.org/wiki/Cellulosic_ethanol
On returning the nutrients to the fields – the trucks that take the crops from the fields to the plant need to go back to pick up the next load… so you are only left with the energy spent by the farmer spreading it on the fields.Posted 03-16-2008 at 12:36 PM by GeEkBoY
-
I think that algae-based biofuel production is the way to go. Why take up acres and acres of viable land for fuel production, when a ten story factory taking up an acre of land would work just as well? Build up, use less land. Even if algae is not as efficient per unit of land area consumed, if you build upwards that efficiency starts to rise. Two story is twice as much fuel from the same acreage.
That's assuming it can be made to work.
As for range extended BEVs (series hybrid, ect), the first problem is of course getting a powerful-enough genset that is small enough to fit into a car. A diesel would be best, out of the commercial models available, as it's not very hard to get it running on alternative fuels. Though personally I'm going to look into stirling engines, as they are much more flexible when it comes to fuel type.
One thing about waste veg oil is that even after filtering, you can still use the left over lard for other things. There is a guy here in Perth that runs his diesel ute on waste veg oil from a fish and chips shop. He filters it once, and stores it in a tank. The left over lard is used to run another diesel engine, which is turns a generator to charge batteries in his home (he has a 12v system wired around his home for low power things like phone chargers and radios, ect). Not only that, the waste heat from the engine (exhaust and radiator, iirc) is used (or will be, when it's finished) to heat the water in his hot water system. Very little goes to waste.
I suppose such a set up is not restricted to WVO, but it struck me as an excellent use of something that would otherwise be turfed.Posted 03-17-2008 at 05:01 AM by Thalass
