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

 

[btrueblood]

"If we were to rely on photovoltaics for all of the world's (non-transportation) energy needs, assuming 10% efficient solar cells, we would require an area of roughly 200,000 square miles, or roughly 5% of the USA landmass. It's big, but it's reasonable."

No arguement from me there.

But photovoltaics don't work well for transportation. And there aren't any efficient methods to store excess electrical power in a portable, energy-dense fuel.

 

[BrunoPuntzJones]

btrueblood,

I was trying to agree with you. Ethanol doesn't have to take care of all our energy needs, just our transportation fuel needs. Combined that with good farming practices and higher efficiency vehicles (and smarter use of those vehicles) ethanol may very well be able to meet our needs without consuming all of our farmland.

 

[btrueblood]

BPJ, and I agree right back. Not trying to be argumentative here, I really would like to see some discussion of alternate fuel/energy storage systems for vehicles. Is a natural gas to octane conversion plant competitive (with ethanol) at todays prices? Can lithium cells compete with fuels?

 

[jmw]

Er,
if we do away with mineral oil for fuel, we can also say goodbye to plastics and if the planet has a hard time to lose its dependence on petrol/gasoline, just think how hard it would be to get by without plastics.

Oh, It's OK, worry not, we just synthesise the feed stocks from our bio-fuels.....ironic, nes pas? But just think what doesn't use plastics today/
But heh, that's just another competing force for our bio-fuels. At least we can look forward to an end of persecuting fat people, there won't be enough food for people to over-indulge, not with rationing coming in and countries that now exercise population control insisting the rest of us do too just as we insist they stop adding CO2 to the atmosphere (they may be more right than the AGW people that it is population that is the problem not anthropogenic global warming).

But I think CD72 has the right answer. Nuclear (better yet, fusion) power.
In fact, if we think about it the paranoids amongst us who turned anti-nuclear into a religion and have left us far more dependent on fossil fuels than we ought otherwise to have been.

The UK is now poised to have no nuclear power just when we have the end of North Sea Oil and Gas, (at the moment some are down through faults in the external systems and some are down for maintenance. Some and some means nearly all because unlike France, we bowed to the anti-nuclear campaigners and now will be hostage to who ever has the oil fields, the palm forests, the sugar cane plantations or whoever. It is said that even if the UK decides to invest in nuclear it will take 50 years to make an impression. But heh, Three Mile Island, Chernobyl etc. Engineers have not moved beyond that have they? ...

Not exploiting nuclear due to the Frankenstein complex fostered on the population, means we have used fossil fuels for all power generation whereas, what Bruno suggest for ethanol, should have been true for crude oil... transportation only.
We wouldn't have an AGW anti-CO2 religion (top add to anti-nuclear), we wouldn't be forever worrying about running out of oil (we can put that off for a few more years) and we could be using bio-fuels as part of a balanced fuel/plastics production plan. As it is we may be forced into total dependence on bio-fuels whether we like it or not.

And food... Soylent Green anyone?


JMW

http://www.ViscoAnalyser.com

 

[SnTMan]

BrunoPuntzJones and others, neither the author nor myself was suggesting replacing all the US energy needs with corn-based ethanol, I just used that statement from the book because it was convenient, another way of saying I was too lazy last night to do the arithmetic

Well tonight I'm not. Using figures from the Energy Information Agency "Annual Energy Outlook 2002" the US used 103 EJ (103 x 10^18 J) of energy per year, 27.9% for transportation. At a year-round, round the clock average that figures to just under 1 TW per year (0.92*10^12 J/s). At the author's figure of 0.047 W/m^2 net (again a year-round, round the clock average) for ethanol from corn and a US "land only" area of 9.162*10^6 km^2, it only uses about 2.4 times the US land area for transportation energy.

What to do?

Regards,

Mike

 

[GregLocock]

So far as pV being no good for transportation, I can't help feeling that that is not true for a significant proportion of transport. Electric railways could at least perform long distance haulage, and of course some commuter transport, and, if push comes to shove, electric cars and buses may make some inroads.

In my opinion the really tricky ones are aircraft, tractors, and trucks.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[GMcD]

Rail and trains, the most economical expenditure of fuel per pound mile. The North American rail system isn't much better than Lower Bulgaria, and in fact, I'd probably give the nod to Lower Bulgaria due to the ability to get from city to city, downtown to downtown, by walking and taking a train. North America is in lust with the car and highway culture, and when fossil fuels become scarce and expensive enough to be used for "essential" products like your plastics and other products, then the happy motoring public will have to look towards other ways of getting around. I wonder why Warren Buffet is making large investments in railways these days?

 

[Rjeffery]

Hmmmm. When beer is made, what happens to the grain when the fermentation is finished? It should be higher in protein as a percentage of mass than the un-malted grain, right? Does that mean that the grain can be now used as a high(er) protein food stuff? (for Humans?) Truely, does the process of making ethanol commercially harm the grain in some way that would make it unfit for human consumption?

In the process of converting cellulose to ethanol is there a residue and if there is can it be burned to assist in the production of the ethanol?

 

[moltenmetal]

rjeffery: yes, the brewer's mash from corn ethanol production is used to feed CATTLE which are used to feed humans, and their dogs and cats etc. Some new ethanol units are being co-located with huge beef feedlot operations for this reason. Forgetting about the energy benefit of the byproducts is how people end up calculating that grain-derived ethanol is fossil fuel replacement negative rather than modestly positive. Mind you, eating animals is incredibly energy-inefficient relative to eating their feed grains! The true dyed-in-the-hemp greenies are vegetarians for this reason amongst others...

But what you don't get back is the ENORMOUS energy it takes to distill and then de-hydrate a weak ethanol solution in fermenation broth to produce an ethanol stream dry enough for fuels use. This energy is WASTED and it's gone forever, regardless what you burn to produce it.

Sure, you could burn the lignin and other crap that's left over after you've made as much sugar from the cellulose as you can- but the same problem is there- this material is now saturated with water and needs to be dried before it's burned, resulting in yet more energy wasted. And your product is still ethanol in dilute solution in water- yet more energy wasted. Burning the feedstock outright eliminates this energy waste entirely.

If you believe the stat given earlier, transportation is only ~28% of US energy use. Why then do we try to jam every other kind of fuel into something we can dump into our gastanks, throwing away half its energy content or more in the process, when it could be used to replace the remaining 72% of our energy needs instead with ZERO losses? Is this good engineering? Is it good public policy? And isn't the market that rewards such behaviour entirely screwed up?

There ultimately is only one solution to this problem: fuels need to be taxed to make them expensive enough that people will find it worthwhile to conserve them. Even at $100/barrel, oil prices in North America are not sufficient deterrent from excessive consumption. Even if the tax revenue is "wasted" on schools and hospitals and the like rather than being used to fund energy efficiency initiatives and public transit etc., it will still influence the market in the correct direction. Market forces will then permit EXISTING technologies to help people wean themselves from their fuels addiction. People's behaviours and expectations and purchasing decisions will change based on the new reality. The market will reward development of alternative energy technologies that are truly source energy efficient, rather than those which have the right political backing and public relations hype associated with them.

 

[csd72]

Moltenmetal,

Bravo, A high five for that one.

It is about time that modern economies take into account the true cost of any given resource, not just the monetary cost. The health of the population and the environment needs to be taken into account in any cost comparison between fuels.

This cost to society needs to be reflected by taxes on the consumption.

csd

 

[zdas04]

Moltenmetal,
That's my argument--motor fuels are outrageously cheep and the US needs a real energy policy that raises the price high enough to be a driver in changing behaviour. A major side benefit of this is that the trade deficit with the Middle East becomes less of a blood letting than it is today.

Yeah, there will be real short-term hardships. The cost of everything will go up. People stuck with gas guzzler vehicles will not be able to sell them. Maybe local governments would be forced to develop/improve mass transit.

But this is just a pipe dream. If the elected idiots had started working a real energy policy in 1974 (with the Arab Oil Embargo) and increased the fuel taxes in increments then we would have fuel prices at least 2-3 times today's rates and a vastly different energy use profile. Today the problem is so broken that the politician who can fix it doesn't exist. It will require something awful like a supertanker sunk in the Straight of Hormuz that shuts down the Persion Gulf of a few months.

David

 

[csd72]

Shortsightedness,

The typical American voter is so anti-tax that any raising of taxes is political suicide.

csd

 

[btrueblood]

Greg, pV = photovoltaics? I don't disagree about electric trains, and possibly short-distance commuter cars with decent batteries...but the Big 5 keep backing away from lithium-ion storage cells, and other candidates are still too heavy? Here in rainland, pV won't get us very far, although it's still a possibility for fixed sources, if prices drop a bit more (at least relative to other sources). It may get there, someday.

molten, "Why then do we try to jam every other kind of fuel into something we can dump into our gastanks, throwing away half its energy content or more in the process, when it could be used to replace the remaining 72% of our energy needs instead with ZERO losses?"

Uh, zero losses? How are you going to convert biomass to energy (presumably electric) at zero loss? Or even at less than 50% loss? Or do you mean replace cornfields with photovoltaic power fields?

 

[btrueblood]

"The typical American voter is so anti-tax that any raising of taxes is political suicide."

True. I'd rather have you, or moltenmetal, or jmw, pay for my fuel than me. If the US economy keeps on the way it's going, moltenmetal's higher cost for oil solution will happen on its own anyway.

I think I'll go buy a horse, and invest in a buggy whip factory.

 

[SnTMan]

zdas04, we in the US have had a "real" energy policy since way back before the embargo years, its called "cheap oil". Not everybody agrees with the policy though. I have said for years that cheap oil is the main barrier to alternative enegy.

csd72, you think raising taxes is political suicide, try raising gas prices. Why do you suppose the politicans investigate the oil companies for "price gouging" every time gas goes up? That way they can be seen to be doing something for Mr. Average American, but they haven't made it stick yet, and I doubt they ever will. Not really in their interest.

Frankly, the only thing I have against the "oil economy" it that these days we have to buy it all from people that hate us.

Regards,

Mike

 

[zdas04]

I guess by "real" I mean "an explicitly stated" energy policy that moves the country toward a desirable and clearly defined goal. Won't happen. We'll have cheep oil until we have no oil, then Congress will jump into high gear to find someone to blame. By then the railroads will be in total disrepair, no one will live close enough to their job to be able to commute, and it will get hungry in the cities.

I'm going to go consume some grain in the form of beer.

David

 

[owg]

Moltenmetal - I need time to figure out how many cows to place around a 100 million gallon per year ethanol plant to eat the mash. Then multiply that by 300 pounds of methane per cow. But fortunately there are ways to cut down all that cow belching. And if the cows were just moved in from somewhere else there could be a methane credit.

HAZOP at

http://www.curryhydrocarbons.ca

 

[csd72]

SnTman,

Oil is only cheap in terms of monetary price, the true cost of oil is far greater.

I was referring to taxes on gasoline which obviously would raise gas prices.

csd

 

[SnTMan]

csd72, agreed, so is the cost of many other things as well.
If only there were some way to get it all out in the open.

zdas04, don't want to ruin your day, but I just read an article that says BEER PRICES are going to go up because of...ETHANOL. This is just intolerable

Regards,

Mike

 

[zdas04]

Luckily, I'm at the stage of life where I don't look at beer prices--the price isn't going to change my behaviour and knowing what it is is depressing.

David