Back to cellulose ethanol discussion 9

[0707]

Back to cellulose ethanol discussion:

Conventional ethanol is derived from grains such as corn and wheat or soybeans

As more and more corn grain is diverted to make ethanol, there have been public concerns about food shortages. However, ethanol made from cellulose materials instead of corn grain, renders the food vs. fuel debate moot.

On the other way unexploited categories of cellulose material that will be removed from forests will also reduce the risk of forest fires during the warm season as it happened recently in California.

Cellulose ethanol can be produced from a wide variety of cellulose biomass feedstock including agricultural plant wastes (corn stover, cereal straws, and sugarcane bagasse), plant wastes from industrial processes (sawdust, paper pulp) and energy crops grown specifically for fuel production, such as switch grass.

The "woodchips and stalks" represent resources that are currently available from forestry and agriculture, though very underutilized. One of the largest unexploited categories is wood that needs to be removed from forests to reduce the risk of forest fires. Well over 8 billion dry tons of biomass has been identified by the U.S. Forest Service as needing fuel treatment removal. The amount of this biomass potentially available for bio energy uses is estimated to be about 60 million dry tons annually

In times of fuel shortages, fermentation ethanol has been commercially manufactured in the US from cellulose biomass feedstock using acid hydrolysis techniques. Currently, some countries in locations with higher ethanol and fuel prices are producing ethanol from cellulose feedstock. However, it is only recently that cost-effective technologies for producing ethanol-from-cellulose (EFC) in the US have started to emerge.
There are three basic types of EFC processes—acid hydrolysis, enzymatic hydrolysis, and thermo chemical—with variations for each. The most common is acid hydrolysis. Virtually any acid can be used; however, sulphuric acid is most commonly used since it is usually the least expensive.

There are no commercial plants producing ethanol from cellulose biomass in the world, although cellulose ethanol has been produced during war time by processes featuring acid hydrolysis. Several commercial ventures have been proposed involving selling ethanol produced from cellulose biomass into existing chemical or fuels markets, suggesting that cost-competitive production of ethanol from cellulose biomass in these markets, although not bulk fuel markets, is within reach today. Funding for such ventures has however not been secured to date.


With the actual oil barrel prices it is time to clean “our gardens” and start to produce cellulose ethanol.

Luis marques

 

[KENAT]

Which is better, burning the biomas in electrical power plants etc or turning it into a liquid fuel that more or less fits into the existing system?





KENAT, probably the least qualified checker you'll ever meet...

 

[0707]

It is another possibility

 

[KENAT]

Sorry had to run.

I guess the advantage of ethanol is that it's close to being a drop in replacement for gasoline/petroleum. There are a few problems but certainly Brazil seems to have managed it more or less from what I've read/seen.

The disadvantage is that I suspect it will be less efficient to 'harvest' the biomass (some more than others as some is already effectively harvested and then discarded but a major factor with say brush from forests etc), transport it to the facility, process/ferment it, transport/distribute it to end users and dispoose of waste etc; than it would be to just take it to a power plant, burn it, generate electricity, distribute the electricity, use the electricity.

Having written that down, I wouldn't mind seeing numbers as it may be closer than I first thought. Assuming you're using both in vehicles then the efficiency of the vehicle batteries or using the electricty to generate hydrogen or whatever would have to be taken into account.

What might be better is using the biomass to supplant the use of natural gas in fixed power generation and diverting the natural gas to vehicles.

So many other options and factors too. Using the biomass directly to heat/cook might even be an option.

KENAT, probably the least qualified checker you'll ever meet...

 

[btrueblood]

I think burning biomass (wood) is going to be a lot dirtier in terms of air pollution than converting it to ethanol. May or may not be "true" for large-scale boilers, but wood stoves and heaters get banned regularly here around Seattle in the winter, when inversion layers form and smoke/smog levels rise.

Energy density of alcohol is still a lot higher than natural gas, and thus it makes better sense as a vehicle fuel. Also, the conversion cost (gasoline to ethanol vs. gasoline to CNG) is lower for ethanol. If the energy economics make sense, alcohol will win.

 

[KENAT]

There are ways you can burn bio mass that make it cleaner. If I recall correctly you could burn it in a way similar to coal gasification (at least the 'wood') although I think you'd end up with a lot of charcoal! Also on large power plants filter would be an option. There are even more efficient stoves etc than the classical open fire.

However, I should have said "would burning the biomass in fixed power generation and diverting natural gas to vehicles be a better idea/more efficient?" I meant it more as a question than a suggestion.

Also, how does bio gas rank, effectively rotting the biomass to produce methane, compared to making ethanol?

Another part of the pie, though not directly related to cellulose ethanol, and something I've brought up before. Currently gas/electric hybrid technology is more expensive than regular power train. Given this wouldn't it make sense to try and concentrate hybrids into sectors that would make the most of regenerative breaking? Vehicles that make frequent stops and/or operate in heavy traffic conditions. Vehicles such as Post office delivery vans, other delivery vehicles (UPS etc), taxis, Buses etc. rather than private vehicles which may spend a lot of time on the open road etc.

Also from a 'soot' emission point of view I believe bio diesel is better. Let's use it in areas where it would make a difference. Perhaps convert all public transport that runs on diesel in major cities to run on near pure (or at least high %) bio diesel. Likewise rather than just adding 5% bio diesel to all diesel maybe have a higher concentration on that sold in city centers. There’d be distribution issues but maybe it’s worth considering.

I suspect both of my last points wont happen as such though because it would probably take strong government intervention.


KENAT, probably the least qualified checker you'll ever meet...

 

[jmw]

At a well known tractor plant many years ago there was a debate about whether to fill the windscreen wash bottles with ethanol or methanol solution. The fire safety officer declared he could handle any fire risks but the medical safety officer could not guarantee that the workforce would not drink it, and hence for safety's sake they chose the non-poisonous solution.

So let's just say that this should be a dual purpose fuel and should be safe for drinking and driving!
)

JMW

http://www.ViscoAnalyser.com

 

[KENAT]

As I recal, that's why they added the purple die and nasty taste to methanol in the UK.

On the other hand, for someonly looking to get really drunk at state expense, turn up at the hospital claiming to have drunk methanol. The treatment is supposedly to get you completely wasted on ethanol since this stops your liver absorbing the toxins in the methanol (it's too busy with the ethanol).

KENAT, probably the least qualified checker you'll ever meet...

 

[hotgas]

Gasoline is usually added to fuel-grade ethanol in order to denature it. i.e. make it bad tasting so it goes into the fuel tank and not into the employees.

 

[moltenmetal]

There are no commercial cellulose ethanol plants operating in the world right now, and it's not for lack of trying.

Harvesting and transportation of the raw biomass are significant secondary hurdles, even if the processing technology should take a sudden and gigantic leap forward. Harvesting deadfall from forests would probably take more energy than was in the feedstock, and there are other uses for this material (ie. pulp and paper production, sawdust and woodchips for building materials etc.). Then there's the tendency of any 'waste material' to instantly become a 'commodity' the second someone starts using it to make money.

The energy wasted in turning waste biomass materials into ethanol to make it into a transportation fuel is not trivial. The same goes for producing liquid fuels from biomass by pyrolysis. Burning these materials as fuels suffers from none of these drawbacks.

As far as concerns about pollution from the combustion of biomass, comparing a household wood-burning stove to a properly engineered power plant is disingenuous.

The best thing to do with these waste cellulosic materials, if they cannot be composted and used to renew the organic content of the (largely) agricultural soils from which they were produced, would be to combust them in power plants to produce heat and electricity locally. Electricity is relatively cheap to transport, relative to straw or switchgrass bales!

 

[YoungTurk]

Having worked for the Forest Service under the fire plan developing uses for underutilized biomass, I can point out that industry will not necessarily use the cellulose source you'd like them to, but rather the most economically viable one. This means that if ethanol production becomes economically viable, it is likely that the idealistic sources will be overlooked in favor of the most efficient sources. I have a feeling that the woodchips and stalks may not represent the most efficient sources for cellulosic ethanol, and we may see another form of destructive agriculture or forestry result from commercial production of cellulosic ethanol.

That being said I am optimistic for the prospects of ethanol. From a global warming perspective, any biomass fuel with a net energy gain is preferable to fossil fuel. I see the current ethanol industry (in the US) as a pilot industry, building infrastructure for the future of localized high volume ethanol production. Cellulose may or may not be the the answer in some places. The future of ethanol may come from anywhere, even elephant dung!

As I keep telling skeptical friends here in the midwest, I'm interested in any technology which makes our farmers the oil princes of this century!

 

[zdas04]

I just took a 2,500 mile road trip. The traffic on the interstate (to say nothing of the near-gridlock I saw at morning rush hour in Ft Worth, TX) is a really clear indication that liquid hydrocarbons are WAY too inexpensive for any of the above to be viable. I don't know what the number is, but I would expect that West Texas Intermediate (WTI) would have to get well above $500/bbl and stay there for a couple of years before any of the ideas above would be economic.

At $15/US Gallon for gasoline, you would start to see home biomass kits to turn underbrush into bio diesel at a retail level (the only way that that resource can be used is if you don't have to transport it long distances). You'd see city planners thinking about neighborhood shopping instead of mega-malls and super markets. You'd see the demise of the SUV. You'd see effective processes to utilize organic wastes that we mostly can't imagine today. From the looks of the highways last week I'd say that $3.00/gallon is absolutely not an incentive for any of this to happen.

A government policy that adds taxes to the retail price of fuel to force conservation is really painful, but many European governments have stepped up to the plate and imposed those taxes--the result is that the portion of GDP that goes to OPEC is significantly less than it is in the US. Our government will never have the spine to implement something that painful, so we are going to be nattering about feed stocks for ethanol plants which produce fewer BTU's of energy than it took to plant, grow, harvest, transport, and process the corn or cane. Today we have "boutique engineering" as a sop to the masses. One of these days we'll be able to come up with a viable set of technologies to replace oil, but not at today's prices.

David

 

[csd72]

America is one of the richest countries in the world with one of the cheapest gasoline prices.

Australian gasoline is around 50% more even though we have our own oil sources.

UK gasoline is twice as much as the US (as is most of europe).

It is no coincidence that the US has many very large vehicles that are seen nowhere else in the world.

The tax on gasoline in the US is too low and does not cover the environmental consequences of its consumption.

Enough of my unrelated spiel..


At the moment many sources of biofuel actually give off more carbon than gasoline, until that changes it is only an economical solution and not an environmental one.

csd

 

[YoungTurk]

It is disappointing to see the level of pessimism entering a discussion about a potential solution to one of the most significant problems facing the world. If all the negative information about ethanol were fact, why would it be necessary for anyone to spend money to publicize the information? Wouldn't economics prove enough of a deterrent to the industry (the invisible hand, anyone?)?

csd, since the carbon emitted by biofuels must first be absorbed from the atmosphere, the net carbon effect is neutral (assuming you've used other biofuels in lieu of fossil fuels in the production cycle).

David, I don't think your numbers are correct, though I agree the fuel must be produced locally. Here in the midwest, E85 is cheaper than gasoline. I know you get less mileage, but by my calculations true cost (to the consumber) is approaching the break even point. And remember, this is from a fledgling technology.

A star to 0707 for his optimistic and thorough intro to the topic. Aren't national security and enviromental responsibility good enough reasons to at least explore the potential of ethanol?

 

[0707]

Vegetal biomass can be reused with benefits for the mankind. When oil prices reach actual rates it is time to believe in the technology and go through it.
It is required political will and courageous investors

 

[zdas04]

YoungTurk,
Where are my numbers wrong? As CSD72 mentions above, motor fuel prices in the US are half of the price for similar fuels in Europe. Since the US GDP is very high by world standards, a price around 5 times greater than today's prices would be needed to drive innovation towards changes in behaviour and new technologies.

The simple reason that E85 is cheaper (in a very few markets) than gasoline is horrible government policy. The US government is providing incredible tax incentives to anyone that can demonstrate the appearance of developing a technical solution to our dependency on foreign oil. These tax incentives mask the fact that for 1 BTU of usable energy, more than 1 BTU is expended in the energy chain that got it from fallow fields to the pump. I've seen numbers as bad as 1.36 gallons of fossil fuel being consumed producing 1 gallon of (lower energy content) ethanol. The most optimistic numbers I've seen are 0.96 gallons of fossil fuel for 1 gallon of ethanol (which has 76% of the energy content of gasoline).

My comments are not meant to be negative, I firmly believe that we will run out of fossil fuel sometime and we will either revert to a subsistence economy (with a much smaller population, starvation isn't pretty) or some clever engineer will come up with a solution that is both energy and cost conservative. I despair of the government funded research ever finding that conservative technology--some geek will work it out in his basement and become the successor to Bill Gates among the richest people in the world.

David

 

[csd72]

Youngturk,

I am not against biofuels, I just think that they are currently far from the ideal that they aim to be.

I agree with the fact that the carbon is first absorbed from the atmosphere, but I think this is more than offset by emmisions of current production methods.

The government should be subsidising more research into this, not subsidising oil companies.

Here is an interesting spiel:

http://laughingwolf.net/archives/002553.html

csd

 

[btrueblood]

"As far as concerns about pollution from the combustion of biomass, comparing a household wood-burning stove to a properly engineered power plant is disingenuous."

Sorry, but I read and was responding to Kenat's post as suggesting that household burning of wood/biomass to be a better alternative than using natural gas for home heating. From this quote of his:

"Using the biomass directly to heat/cook might even be an option"

But, to take the case a bit further, do you think a wood-fired power plant, using the best available scrubbing, etc., could be "cleaner" than a natural-gas turbine? Cheaper?

 

[BrunoPuntzJones]

zdas04

0.96 gallons of fossil fuel for every gallon of ethanol certainly isn't the most optimistic estimate that has been made by a reliable source. Without wanting to get into it too much, the work of Pimentel and Patzek (and others) is really incredible sloppy stuff. Of course, it's equally true that the pro-ethanol groups also dispense a ton of garbage (in terms of data) as well.

That said, there are quite a few reputable studies out there that seem to come to a general agreement that (using current best practices for farming and processing) ethanol is certainly energy positive, albeit only in the range of 1-2 times energy input. That doesn't mean, of course, that ethanol is a viable energy option, that remains to be seen.

 

[YoungTurk]

zdas04, as said before me, most recent reputable research shows a net energy gain, albeit not a great one. I have no idea where you get the 5x figure, and I don't follow your logic, which is why I disagree. I do see long lines at the E85 station everytime gas prices spike, which is anecdotal evidence that the threshold is much lower.

Keep in mind:

- the oil industry recieves tremendous tax incentives as well, not the least of which is allowing oil companies to drill offshore without paying anything

- ethanol subsidies cover not only production but the building of an infrastructure which will improve national security and reduce the trade deficit

- farm subsidies encourage large tracts of land to be left fallow, which also artificially increases corn prices - why not spend the tax money on ethanol instead?

- bio fuels can be produced using bio fuel and bio mass, which would drive up the cost, but the net energy gain would then be 100% and the net carbon emission goes to zero

See the wonderful rant link csd72 posted, I won't repeat the substance of it here. I am skeptical of the war for oil angle, but if you google "energy task force" you may begin to wonder.

Regardless, national security (military as well as financial) and environmental responsibility are sufficient reasons for me to support the industry

"All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident."