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

 

[moltenmetal]

btrueblood: I know that heat engines waste energy. But when you convert one type of FUEL to another type of FUEL before you put it into your heat engine, you've WASTED energy on the fuel conversion process.

Until our stationary uses for bulk fuels are satisfied (i.e such as for making electricity and space heating for cities), there is basically no point in chasing transportation fuels with these renewable fuel-conversion alternatives. The automobile has arisen around the use of gasoline and diesel for a reason! The fuels have an amazing energy density per unit mass and most importantly per unit volume etc.- they're ideal for portable power applications.

If you're truly interested in improving the energy efficiency of transportation in general, the very best thing to do is to get the hundreds of thousands of single vehicle car trips daily from the outskirts of cities into the downtown core and vice versa out of their SUVs and onto public transit. You can power the subways and light rail transit systems using renewable sources of electricity. There's no easy technological fix to this problem, but there is a MARKET fix to it: make fuels expensive enough and people will find it worthwhile to conserve them. Don't do that and it's all just more hot air.

owg: if you're feeding the cattle grain anyway, what difference does it make whether you're feeding them grain or feeding them what's left over after you've made ethanol from the grain? The methane issues etc. are the same either way unless the beef consumption is somehow increased by what people put in their gastanks. If you're worried about the implications of cattle farming on greenhouse gas emissions, then you're after beef eaters, not ethanol plants!

 

[KENAT]

"Until our stationary uses for bulk fuels are satisfied (i.e such as for making electricity and space heating for cities), there is basically no point in chasing transportation fuels with these renewable fuel-conversion alternatives. "

While I tend to have leanings in your direction, though not as extreme, I think you're wrong this time.

From what is generally regarded as an 'environmental' point of view you are likely correct.

However, there are other reasons for reducing oil use. Be it just balance of payments issues or the 'oil war' issue etc. These reasons for reducing oil use are largely independant of direct environmental concerns.

One of the largest and most obvious uses of oil is as vehicle fuel...

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

 

[btrueblood]

"when you convert one type of FUEL to another type of FUEL before you put it into your heat engine, you've WASTED energy on the fuel conversion process."

That is not a given. It depends on how efficiently you can convert the fuels. Go buy a car capable of running on corn, or heck, even corn syrup. Tell me what the efficiency of that engine is. Convert electricity to what? If it's more efficient to use plant sugar, do so, if battery technology improves another close order of magnitude, it may compete or even win. Do you propose to invest in neither?

Yes, mass transit is a solution to city transport. But it doesn't help farmers plough their fields, or trucks haul the food to markets, or those of us who live in vast western spaces get around; you can't build trains everywhere, and we will always have a need for fuels. They're voting on a mass transit system here in my neighborhood. I say "they" because I apparently live just outside the boundary line -- I'll still pay the taxes, since the stores are inside the line, but I won't get a voice in it. Most of the money is going to be spent on road improvements, and some of it for a light rail going to places that an existing diesel-electric system is already serving, at lower projected costs than the new system. So we'll spend a few 100 million for a system that gets fewer drivers off the road, and probably nets out worse in greenhouse emissions, but hey it's green!

Again, I agree with you that increasing fuel costs will teach us to conserve better, and make wiser decisions re vehicles, trips, fuels used. I'd even pay a higher tax if applied across (my) country. I'd like it better if it only applied to your country and everyone elses'. So would you.

 

[zdas04]

The laws of thermodynamics would say that the act of extracting a chemical from a substance requires energy input. The number may be small, but it can't be zero. In my youth as a true hillbilly, I saw exactly how much energy input was required to convert a bushel of corn to a form of ethanol that the USDA would say was not fit for human consumption and it is a bunch of energy (back then in the form of firewood).

If you do a rigorous energy balance on the energy input to the distillation process vs. the energy that can be extracted from the ethanol you'll find that the net is less than the energy that could have been extracted from the original feedstock by burning it directly. The only reason for the distillation is to put the stored energy into a more compact and transportable form that can be used in more processes.

Energy Out = Energy in + Energy used + Energy wasted

Minimizing the "wasted" term is the goal of most fluids problems, but you never get it to zero.

David

 

[jmw]

Of course, we are talking about first generation bio-fuels.
Second Generation bio-fuels will be genetically engineered and that is a whole new ball game.... and I don't think I want to play. Not yet.

JMW

http://www.ViscoAnalyser.com

 

[YoungTurk]

Second Generation bio-fuels will be genetically engineered

Actually, it seems the thread keeps drifing back to current generation ethanol, which is almost exclusively from genetically engineered corn and sugar cane.

As the OP is suggesting, the second generation may well be cellulosic ethanol, which would not necessarily be any more genetically engineered than the current generation (with the exception of the yeast/organism used in the fermentation).

With regard to use of biofuel for stationary power generation, I think we have a much wider set of "green" possibilities for stationary power generation than for transportation (nuclear, wind, solar, etc.), so some focus on mobile power is necessary for a balanced energy policy.

 

[jeebusmn]

Here are some interesting numbers

Power plants are 30-50 percent efficient
Transmission is about 92% efficient
Electric Motors are 90%+ efficient

40%*92%*90%= 34% efficient in turning a plant joule into mechanical energy

ethanol production gets you about 30%
gasoline engines are about 20% efficient

130%*20% = 26%

So, with electicity it is about in the same ball park or better in terms of efficiency. You though don't have to create all the infrastructure you do with ethanol and you don't have to deal with rising cost of food.

 

[jmw]

Try here:

http://www.oilandgasonline.com/content/news/article.asp?docid=d1bdeae9-0c56-4511-a0dc-bc68bfa785e0

I rather think that exchanging energy dependence on middle east oil for far east palm oil isn't going to help the situation so it must be an objective to become energy self-sufficient.

Genetic engineering will most certainly be directed not just at enhanced oil production but acclimatising the crops to particular environments.

There is another aspect to this, the control of genetically engineered crops.
We have already seen the moral debate over the impact of genetically engineered food crops on third world producers and this might seem an opportunity to intensify the debate.
This is not going to be a simple solution and I may well further disadvantage economies already suffering a range of other barriers to global markets.

JMW

http://www.ViscoAnalyser.com

 

[moltenmetal]

jeebusmn: your order of magnitude calculation shows a 30% energy waste in converting the fuel, even if that 30% efficiency for ethanol conversion is correct (seems way high to me given the dehydration energy requirement). If you're talking about burning the whole corn plant- stover, cobs and all- not just the dried kernels- your calculation looks a fair bit different! Ain't no way that you'd be able to get 30% of the fuel value of the whole corn plant into product ethanol even with best imaginable cellulose ethanol production technology. Use a better source plant like switchgrass (since you no longer need starch) and the efficiency would go higher still.

The focus on replacing gasoline by any means possible except the obvious (conservation!) is a political one, not one that makes engineering or environmental sense. Sure, I'll admit as a non-US resident that it's a reasonable preoccupation of the US: I'd hate to see as much of my treasury ending up in the hands of the Saudis and others as yours does, and I'd want to do whatever I could to eliminate that. But the elephant in the middle of the room is that the obvious solution to the US dependance on Middle East oil is to stop wasting so damned much of it on the personal vehicle! If you completely eliminate city commuter trips with one person to a huge 6+ person vehicle, I bet there'd be enough continental North American oil (and natural gas) to fuel the tractors and the transport trucks etc. (those that you couldn't replace with electric trains!).

Let's face reality: the car is the source of the gasoline problem, and replacing gasoline with ethanol is NOT the solution. It's agricultural subsidy in the guise of energy policy. Not that the farmers aren't deserving of a break from the ridiculously low grain prices they've had for the past three decades- but I'd rather they get that break for producing food to feed the world rather than fuel to stuff into the tank of some dolt's Escalade!

As to who must pay for the alternatives, the answer is simple: we all must. The only question is how we'll generate the revenue. Since conservation is the desired end result, the thing that makes the best sense is a consumption tax on the FUEL and the ROADS, not on the transit system that will replace them. The more you waste, the more you pay. If the tax is used DIRECTLY to fund the alternatives, you get the social/behavioural change the planet needs by the action of market forces. Ignore the market and let politics dictate and focus on the technology only and you WILL get failure.

 

[zdas04]

moltenmetal,
Talk about quotable quotes:

It's agricultural subsidy in the guise of energy policy

and

Ignore the market and let politics dictate and focus on the technology only and you WILL get failure

Thanks for enlightening our morning.

David

 

[owg]

Thomas Friedman, Foreign Affairs Columnist for the New York Times on CNN recently: "Ethanol from corn is welfare for farmers."

HAZOP at

http://www.curryhydrocarbons.ca

 

[Gymmeh]

Molten,

great read for the morning! within the engineering community, people are assumed to have a relatively higher then average understanding of cars.

The problem is that the majority of people (out side this forum) that may not have technical aptitude are brain washed by various propaganda schemes into thinking they need an ungodly large vehicle for child safety, the adventure within, bling bling, other BS...

Currently many of the major highways (in my region) charge tolls to pay for the usage, the problem is that even with >$3 gas prices and thruway tolls, in many cases its still less expensive to drive then take a bus (which runs once or twice a day), flying and trains are not even an option unless your flying to major areas and have the money to do so. Until reasonable options are available, people almost have to drive.

 

[csd72]

A star for you moltenmetal very succinctly put.

Gymmeh,

$3 is still too low, In Australia it is currently about $4US a gallon, and in the UK I think it is about $5 to $6. Australian salaries are generally less than the US, and UK salaries are generally about the same.

Perhaps if a tax was imposed to increase these prices there could also be a refund policy for essential commercial use.

csd

 

[SomptingGuy]

In $US it's more like $8+ these days in the UK. But even that's not enough to stop the 4x4 school run with one kid and one mum in a huge car stuck in the congestion of other mums doing the same.

Personally I bicycled into the local town today for lunch and used an old bus ticket for a bookmark as I read my book.

 

[Gymmeh]

Yes, I agree with you all! I have driven around Europe...and paid the price and totally agree it could be worse in the US...

SomptingGuy, hit the nail on the head..."mums" driving around with one kid... because their kid cant walk/bike two blocks to school. Brain washed "soccer moms" are the worst!

soccer mom = 30-40yr old women with 4x4 SUV that does not understand driving, which uses the vehicle for transportation of their "1.5" kids around the block while talking on a cell phone (usually angry).

 

[csd72]

They have decided to buy the vehicle in which they can do the most damage!

 

[KENAT]

Many people justify the large vehicle by saying they are safer in a crash, and eschew small vehicles because they think in a collision with a large 4x4/SUV they'll come of a lot worse. Given some of Newton’s laws of motion one suspects they may have a point.

There are rules/tests about how 'safe' a vehicle must be in a collision. If I understand correctly these concentrate on protecting the inhabitants of the vehicle. There are also some rules for protecting Pedestrians if they get hit by that vehicle as I recall.

However, are there any rules for how much damage a vehicle can do to another vehicle in a collision?

Would introducing such rules be of benefit in increasing the (perceived) safety of small vehicles?

For instance a rule along the lines of "A large SUV should not do significantly more damage to a Super Mini/Sub compact in a given crash scenario than a typical mid size car would". Obviously, they'd need a lot more definition but hopefully you see my principle.

Just an idea, I'm wondering if more knowledgeable folks can shoot down.

Then we could have small cars burning the mystical/magical cellulose ethanol and save the planet!


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

 

[csd72]

That would eliminate trucks altogether!

 

[KENAT]

No, they'd just have to drive around with massive shock absorbing fendors/bumpers;-).

Maybe covered in bubble wrap like that car commercial.

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

 

[jmw]

I just filled up in the UK; $2.10 a litre.
In the UK motorist pays more than enough tax to pay for the entire road system and probably one other country's as well.
However, we still have bridge tolls and road tolls (Birmingham M6 toll which is damned pricey).
Of course, tolls are an excellent way to top up funding and provide employment if you pay less tax on your fuel. In the UK it is supposed to be about road use and they are contemplating satellite tolling all vehicles for all roads on a pay as you go scheme.
This proved to be the single biggest (by a long long way) no no as voted by the public on No 10's web site referenda (but Tony said he's going ahead anyway, and I guess that goes for Gordon as well).
OK, what has this to do with environment? Great, you'll say. That will encourage people to use their cars less.
Wrong.
If a punitive toll were imposed it would. Punitive tolls are great for everyone else to pay but not for you personally and it could prove, as already suggested, a great voter turn off. It is always the other guy that is the polluter, bad driver, etc.
Most importantly, governments are usually great judges of how high they can pitch charges without turning off users.
Gordon Brown inflated taxes on petrol, booze and cigs to the point where stealing fuel became almost epidemic, cigarette smuggling replaced dope smuggling as more profitable and less penalised, indeed, almost acknowledged by the populace as a sort of Robin Hood activity.
This is one outcome, and what it resulted in was an extra 1000 customs and excise staff. But would he or any politico actually increase taxation to the point where it did discourage use and, as a consequence, see a drop in tax revenue? No. These guys are tax junkies. They will never tax so much as to reduce tax revenue and will invest in measures to sustain that revenue.
Lastly, taxation is elitest when applied thus. The people who are most affected are the poorest and they may depend to a far greater extent on their cars, not 4x4s but old wrecks which get fuel but not insurance and not proper maintenance. Higher taxes just reduces the maintenance money spent. We get more uninsured drivers driving less safe vehicles.
Let's face it there is no simpe,l solution and anyone applying simple solutions is guaranteeing failure and messy failure at that.



JMW

http://www.ViscoAnalyser.com