Warning: Offensive to creationists. Click through at your own risk.
(Orginally posted at the Pennsylvania ACLU blog
in a post about the Kitzmiller vs. Dover trial.)
While Everyman's being a dope
All right-thinking readers should hope
That his religious whine
For "intel'gent design"
Doesn't go down a slippery slope.
For there's one thing that is in no doubt;
When all of the facts have come out
Dover's ID "teaching"
Is poorly-hid preaching
Intended to please the devout.
But as sure as a bird's not a tree
There are things we're intended to see
Though there's things that we lack
We must know that the facts
Are as science reveals them to be.
While there is much hard work involved
The big puzzle's
slowly being solved
Some think it uncouth
But it shows that the truth
Is that all life on earth has evolved.
Denial will do, for a clod.
Truth's not a hard road to be trod.
This "Everyman" farce
Is just being an arse
Who thinks that his lying serves God.
When I stumble on an URL
Which makes me want to hurl
Or garbage that just fills me up with rage
I take my mouse and click myself back to the peace
Of my home page.
There wouldn't be much loss
If they got rid of Daily Kos
And lefty moonbats strutting on their stage
And one place that they will never get to post
Is my home page.
Off at WND, whose journalism's cruddy
And whose language just muddies what's so clear
I either hold my nose or laugh myself to tears
And I'd pick it all apart, but with so much where would I start?
Those mis-Anthropik freaks
Pretending that they're geeks
Who talk of doom instead of persiflage
Will never get their hateful points of view
On my home page.
Browsing Telic Thoughts, who can't see for exegesis
Think we share nothing with rhesus
They're so blind
Trying to follow them will make you lose your mind
And the irony's the clods think it's okay to lie for God.
I never will agree with adherents of P.C.
Or those who say Phil Johnson is a sage
There is one place where everything is just plain sense
At my home page!
(Tom Myers has won the "guess the tune" competition, and is owed two points.)
The collapse of Bolshevism deprived the panoply of fellow-travelers of the paradaisal vision they needed to function. To make it from one day to the next. The Worker's Paradise functioned as the Opiate of the Moonbats, vacuuming the truly insane from society and placing them in the custody of relatively functional cult leaders like Joseph Stalin and Pol Pot. Now that these worthies are gone, their former wards have all crawled out of the snakepit.
I've been relentless in my condemnation of the fuel ethanol industry for overselling its benefits while ignoring its costs. The Panda Group appears to be one of the few producers trying to get it right: instead of using scarce natural gas or LPG to run their stills, they are going to be using methane derived from animal manure. The press release states that the bio-gas will realize "an energy savings equivalent to 1,000 barrels of oil per day."
Taken at face value, this looks good. 1000 barrels of oil equivalent (BOE) at 6.1 GJ/bbl is 6.1 TJ (5.8 billion BTU), equivalent to about 5.6 million cubic feet of natural gas. Each day, it will spare enough gas to heat more than a hundred homes over a typical winter, totalling the needs of about 42,000 homes over a year. But that's the best news in it.
The first bit of bad news is the mis-statements. The plant is stated to be able to produce 100 million gallons of ethanol per year, which is claimed "will replace the equivalent of 2.4 million barrels of imported gasoline per year." This claim is exaggerated. Ethanol is not a 1:1 replacement for gasoline; a gallon of ethanol has energy equivalent to roughly 0.7 gallons of gasoline, so the plant's annual output will only replace about 1.7 million barrels of imports. This error should never have passed the company's fact checking.
The second bit is what was not done. On page 2, the release states "The Panda Group is a privately held company that has built over 9,000 MW of electric generation at a cost of $5 billion." That's about $550/kW, indicating that it is gas-turbine (possibly combined-cycle) rather than steam-turbine. The company certainly has expertise to build and operate co-generation facilities with their ethanol production. But a search of the web for "Panda Group" and "cogeneration" turns up nothing from them.
This is a significant oversight. I took a look at the GE web site, and found documentation for the LM-2000 series of gas turbines. Gas equivalent to 1000 BOE/day is about 90% of what would be needed to run an LM-2500+ turbine at continuous full power; the electric output would be about 30.5 megawatts. If the production could be sold at 5¢/kWh, it would be worth about $13.4 million/year. The conversion of energy to electricity would require more fuel to meet the 5.8 billion BTU requirements of the ethanol plant, so the potential exists to generate up to 48.5 megawatts of electricity with the addition of an 18 megawatt LM-2000 turbine. This could meet the electricity requirements of roughly 48,0000 homes; all it would require is some more biogas.
But this was not part of the plan. Panda Group, there is still more waiting to be done. You appear to be up to the task. Are you willing?
This post will collect links and calculations posted in comments elsewhere. This may become a monthly feature.
Friday the 16th: Item 3 added
Friday the 16th: Item 1 updated
Posted 2005-Sep-11 at Peak Oil Optimist in a story about biomass:
Well, let's see.
Land area of Illinois: 57918 square miles
, or about 37.1 million acres. 8% of that is 2.97 million acres; call it 3 million. (This is about 1/4 of the 11.8 million acres planted to corn in Illinois in 2004.)
Yield of Miscanthus or switchgrass: roughly 10 tons/acre/year. Call the yield 30 million tons/year.
Heat of combustion: 10 million BTU/ton?
Total available energy would be 300 trillion BTU; converted to electricity at 33% efficiency, it would yield 100 trillion BTU or 29,300 million kilowatt-hours.
Total electric consumption in Illinois in 2001 was 92,358 million kilowatt-hours
So no, growing grass to fire electrical generators wouldn't satisfy the state's needs. Not even close.
Boosting efficiency from 33% to 40% isn't going to make up for a 3:1 gap. If you can get 2.5 tons/acre of corn stover from the crop acreage, the ~30 million tons of biomass from that would get you closer but not all the way there.
But riding my hobby horse for a bit... 30 million tons of biomass with 30% conversion to char would make 9 million short tons of charcoal. If each pound of char can make 5.448 lb of zinc metal and you can get 423.6 Wh/lb out of the zinc, you'd get 41,500 million kWh out of it. That's better than 45% of requirements.
Double the 8% of land area to 16% and you've hit 90%; add 30 million tons of corn stover and you're up to 135%. That looks good, especially if you add some wind (if I were designing this I'd shoot for wind capacity of 30-50% and use zinc to run transport).
Heiko Gerhauser posted figures that I'd missed (glossed over or mis-read) or didn't have:
12-60 (!) metric tons per hectare (5.4-27 short tons/acre).
"17.4 million BTU per metric tonne" (15.8 million BTU/short ton)
Switchgrass is capable of yielding upwards of 10 short tons/acre, so the performance of Miscanthus
is less impressive than it first appears; still, 27 tons/acre is nearly twice the best prospective yield I've seen for switchgrass. However, such figures appear exceptional and may not be available absent very favorable conditions. If it is possible to get a consistent 13.5 dry tons/acre from a grass crop and it produces 15.8 MMBTU/ton, the annual available energy over 3 million acres would be 640 trillion BTU or 187,000 million kWh thermal. The electric production would be 62,500 million kWh from a 33% efficient steam plant, or 75,000 million kWh from a 40% efficient combined-cycle plant. If 30 million tons of corn stover is added to the grass and it has a similar energy content, the total electric output would be sufficient to supply Illinois' 2001 requirements.
Over at The Energy Blog, zinc got a mention... but only as a way of making hydrogen. I took issue with the concept of hydrogen as the best product:
of zinc oxide from solid zinc is 84670 cal/mol; the ΔHf
of water is 70600 cal/mol, so the conversion from metallic zinc to hydrogen is about 83% efficient. PEM fuel cells are roughly 60% efficient, so the overall efficiency of the zinc-hydrogen-PEM FC system is just about 50%.
According to Electric Fuel's published figures for their electric bus system, the efficiency of a zinc-air FC is about 62%. That's 24% more energy out of a given amount of zinc than you get by taking a detour through hydrogen.
Hydrogen is a boondoggle.
Posted 2005-Sep-15 at Green Car Congress in a story about hybrids, drifting to the suitability of zinc-air cells for running semi-tractors:
Well, let's see. If you can devote 7500 pounds of a tractor to its combined "fuel" and "engine" (electric motors are light) and you use Electric Fuel's bus cells
, you'd be able to carry 38 of them. Total energy would be 38 * 17.4 kWh = 661 kWh. If you did some aerodynamic cleanup to let the semi achieve 10 MPG and its engine efficiency is 35%, it would be using 1.5 kWh/mile  and the batteries would allow 440 miles of range. That's not much compared to what you'd get from 200 gallons of diesel at even 6 MPG, but it's clearly not impractical.
If you combined this with a dual-mode (road/rail) system like Blade Runner and electrified the rail system, you'd have unlimited range on the rails and several hundred miles off-rail range. That's sufficient for most everything.
 If diesel fuel has 19,110 BTU/lbm and 7.67 lbm/gallon, each gallon has 146,600 BTU/gallon (42.9 kWh/gallon). Conversion at 35% efficiency yields 15.0 kWh/gallon, so 10 MPG would be equivalent to 1.5 kWh/mile.
A lot of words have been written about the prospect of the USA and the world running short of oil and natural gas. Together, these supply much of the energy used in the USA for transportation, fertilizer and home heating. Word is that North American gas production has already peaked, and world production of oil is predicted to peak as early as this Thanksgiving. (Coal, which supplies half the electricity used in the United States
, shows no immediate prospect of shortages.)
Economic expansion depends on greater yield from whatever inputs are available. The energy intensity of the US economy has been falling steadily since the 1970's, yielding more and more economic output per unit of energy; still, greater efficiency can be overcome by falling supply. The alternative is to convert something else to suit. American society is no stranger to this phenomenon; in the past 229 years, US society has seen a number of transformations in its use of energy for various purposes:
- Coal replaces firewood as the primary source of space heat.
- Steam replaces draft animals for rail transport power.
- Kerosene replaces wax and tallow as the primary source of light.
- Incandescent electric lights supplant kerosene.
- Internal combustion replaces draft animals for road transport.
- Natural gas and fuel oil supplant coal as the primary source of space heat.
- Diesel engines replace steam for rail transport power.
- Fluorescent lamps supplant incandescent.
Each transformation either created a resource out of a material which had not been used widely or at all before (coal, petroleum, natural gas) or greatly increased the efficiency of use (fluorescent lighting, diesel locomotives vs. oil-fired steam). Each time, some resource was leveraged to yield more benefit.
The USA's energy supplies come mostly from fossil sources (counting nuclear as fossil), with hydropower being by far the biggest renewable contributor at 7% of electric production. The other two readily accessible and renewable energy supplies, wind and solar, contribute relatively little. Surprisingly, per the EIA
waste provides twice as much electricity as wind, and wood almost four times as much. Obviously there are resources which are not being leveraged to best advantage.
One of the principles of life is that one organism's waste is some other organism's resource. Our energy systems don't follow this; the vast majority of our energy comes from once-through handling of a single supply with the products dumped to landfills or the atmosphere, and the closest we come is with cogeneration systems which use effluent heat from power production as space heat or industrial process heat. Is it possible to do better? Looking at the electricity production statistics
and then at municipal solid waste production
, it looks like there are possibilities we might be ignoring.
So what do we have?
Lots and lots, both resources that are being somewhat underused and resources which are almost entirely ignored. In the "somewhat underused" category, we have the fuel which is burned for industrial process heat and space heat; if half of these uses were adapted to cogeneration, the additional power would amount to tens of gigawatts (perhaps 70+ GW, or almost 1/6 of current generation). But these draw from existing fuels which are rising in price and shrinking in availability; boosting efficiency can get us by for a while, but we're eventually going to have to use something else. Replacing a few percent of current inputs (a la ethanol) isn't nearly ambitious enough; ideally, it would be something we can leverage to power most of our industry and transport.
The solar-zinc process has lots of leverage; it turns a fairly small amount of carbon and roughly the same amount of solar heat into two chemical fuels, one of which (carbon monoxide) is good for gas-turbine fuel and some industrial uses, and the other (zinc) which is both portable and can be turned into either electricity or hydrogen with very high efficiency. Another virtue of the process is that it doesn't appear to care where its carbon comes from so long as it is mostly pure (coke, charcoal or even coal) by the time it gets to the input hopper. Within those limits it looks like a great many things will do as carbon sources.
A great many things are made of carbon. The ideal sources would be generated in large quantity, mostly dumped as waste products, and renewable. Biomass may not be the best of fuels, but it does make pretty good charcoal. If we needed enough biomass to get on the order of 240 million tons of carbon per year (per "Going negative"
), where could we get it?
Coming from town
Let's start with waste. The USA disposes of 237 million tons of municipal solid waste every year, or more than 1500 pounds per capita. A large fraction of this is either biomass or textiles. According to Dr. Debra Reinhart of UCF
, the various biomass components and their moisture contents
are as follows:
|| Dry mass,
% of total
|Total % dry biomass:
|Total dry biomass in MSW,
This may be a serious underestimate. It appears that some 160 million tons/annum of urban wood waste
is uncounted or partially counted in the above (perhaps because it is designated construction waste or yard waste rather than MSW). If even half of this could be captured as biomass, the impact would be very large.
This suggests that something between 120 and 280 million dry tons/year of biomass can come from cities. What else is being thrown away?
Out of the woods
One heck of a lot of wood waste is created in the forest products industry. The national total total is amazing: 178 million mettric tons/year from timber harvesting
with 86 million tons unused, and a whopping potential 110 million tons/year from thinning in national forests
What's the total which could be captured (either currently unused or diverted from their current use)? Heck if I know, but 200 million tons per year seems reasonable.
Off the back 40
Many plants are grown for fruit, seed or tubers but create a great deal of other plant matter as well. In zero-till farming this material can be problematic, as it insulates and prevents the earth from warming as desired in the spring and delays the start of growth. It is desirable to remove this excess matter, but what to do with it?
The stalks and such left over from corn (maize) is called "corn stover". The productivity of corn stover is considerable; at a harvest rate of 170 bushels/acre and allowing 1 ton/acre for ground cover, the remaining matter amounts to 3.0 dry tons/acre
. (The 2004 maize harvest was approximately 11.8 billion bu over ~80 million acres, for approximately 150 bu/ac; the corresponding production of surplus stover would be roughly 2.5 dry tons/acre.) Even if corn was reduced from 80 million acres to 60 million, corn stover could provide 150 million tons/year of dry biomass.
What could grow on 20 million idled acres? Switchgrass and Miscanthus have been advanced as biomass crops; they could be planted on buffer zones between fields and waterways to capture nitrogen in runoff and help prevent erosion. Projections of yield are variable, but 10 tons/acre appears reasonable based on some searches. 20 million acres at 10 dry tons/acre would yield 200 million dry tons.
This does not exhaust the list; crops other than maize yield stalks and straw, some of which needs to be burned or otherwise removed to eliminate pests. All of this matter is potential biomass feedstock.
Summing up: 120-280 million tons/year from cities, 200 million tons/year from forests, and 350 million tons/year from current and former maize acreage indicates a potential biomass harvest of 670-830 million dry tons per year. This is sufficient to supply the requirements projected in Going negative
. The next question: What should we do with it?
How not to get leverage
Levers can work for you or against you, by either making superior or inferior use of an input in limited supply. One example of a lever which can be disadvantageous is fermentation of carbohydrates to make ethanol. Ethanol's chemical formula is C2
O; yeasts make it from carbohydrates with a general chemical formula of CH2
O, and emit CO2
as a byproduct. If this is the only reaction going on, it balances like this:
O -> C2
O + CO2
One third of the carbon and roughly half the total mass (44 AMU out of 90) is lost as carbon dioxide in the fermentation process. It seems likely that some advocates of ethanol forget this little detail, and it throws their calculations way off. I recall a claim that 300 million tons/year of biomass would create enough ethanol to replace US gasoline consumption. After fermentation this would only yield 153 million tons/year (46.5 billion gallons) of ethanol; this is the energy equivalent of 32.6 billion gallons of gasoline, which is roughly 1/4 of annual US motor gasoline consumption. This claim is clearly false; even without allowing for the smaller energy content of ethanol it would still take upwards of 900 million tons of fermented biomass to replace gasoline, and still more to replace diesel, jet fuel and other uses of petroleum. Replacement of petroleum with ethanol made from near-term renewable biomass stocks is clearly not possible.
Forget ethanol; convert to carbon
If the purpose of the biomass collection is to produce carbon for reduction of metal, it must be pryolized. Pyrolysis produces an off-gas which contains most of the hydrogen and nitrogen and some of the carbon; the maximum recovery achievable under batch conditions using partial combustion for heat is about 30%. It may be possible to increase this yield using external heating rather than partial combustion, but the system would no longer be simple.
The feasible production of carbon from biomass appears to be 210 to 250 million tons per year. This carbon would be dry, sterile and inert, and thus could be stored easily for later use. This carbon could be fed to a thermochemical zinc reduction process, powered either by solar heat or by excess electricity from wind power.
If there was 210 to 250 million short tons per year of carbon available, it could be used to produce between 1.14 billion and 1.36 billion tons of metallic zinc per year (from zinc oxide) 
if the byproduct was carbon monoxide. If the carbon was fully oxidized to CO2
in the reduction process these amounts would be doubled to between 2.28 and 2.72 billion tons of zinc, but any production of power or chemicals from the carbon byproduct would be lost.
Where the rubber meets the road
Using Electric Fuel's figures 
, 1.14-1.36 billion tons of zinc could produce between 966 million and 1.15 billion megawatt-hours (9.66e14 WH to 1.15e15 WH) per year. This is an average power between 110 GW and 132 GW. My previous calculation
(somewhat generous) for the amount of power actually delivered to the wheels by vehicles in the USA was around 107 GW average for gasoline vehicles alone and 183 GW including trucks and other diesels; it appears that this amount of zinc could easily replace all gasoline used in the USA, and if we allow for some efficiencies of electric propulsion it could replace the rest of the motor fuel too (give or take a bit). Any extra required could be supplied by regeneration of zinc metal via electrolysis using power from wind, nuclear or any other source of electricity (preferably carbon-free). In the CO-byproduct scenario, an efficiency of 39.8 Wh/mol of CO creates an additional
632-752 million megawatt-hours (
6.32e14-7.52e14 WH) per year, or 72-86 GW of electricity. That's about 32-38% of the amount generated by coal in the USA, or roughly the production from natural gas 
. (This does not include any energy produced from the pyrolysis off-gas, which may or may not be combustible.)
It appears that a process which uses biomass to produce carbon which is then used to drive a zinc cycle for zinc-air fuel cells could replace all petroleum-based motor fuel used in the USA, and all of the natural gas burned for electric generation as well. No process for turning biomass into ethanol could accomplish anywhere near as much for the same inputs, and no alcohol process can use wind power to generate the same product. Even allowing for rather poor efficiency of zinc-air fuel cells, the zinc route gets much better leverage out of limited inputs.
UPDATE: Figures for energy from CO byproduct corrected, old figures struck out.
You find you get what you need
Zinc: Miracle metal?
A pound of carbon at molecular weight 12 can reduce zinc oxide to produce 5.448 pounds of zinc at molecular weight 65.35, with 2.67 pounds of carbon monoxide as a byproduct. If the carbon is fully oxydized to CO2
, the amount of zinc reduced doubles to 10.896 pounds. (back
Electric fuel implies an average cell potential of 1.139 volts
(17400 WH / (325 AH * 47 cells)), producing 219.8 kJ/mol or 423.6 WH/lb of zinc. (back
Everyone should read this:
Update: The principals in this story were interviewed for This American Life"
; the program name is "After the Flood".
Update: Refugees are effectively being held in prison, being deported to remote camps and not allowed to leave for the next 5 months. Link
ALCOHOLS / ETHANOL
: Can ethanol from corn or other grain replace gasoline?
Almost certainly not, for several reasons.
- There isn't enough grain. The best process we have makes about 2.66 gallons of ethanol from a bushel of corn (maize). The 2004 maize harvest was about 11.8 billion bushels; if all of it was used for ethanol, it could make a maximum of 31.4 billion gallons of ethanol (with energy equivalent to about 22 billion gallons of gasoline). US gasoline consumption in 2003 was roughly 134 billion gallons, or more than 6 times the amount which can be replaced by ethanol production from corn. Total US motor fuel consumption (gasoline and diesel fuel) is approximately 200 billion gallons per year.
- Ethanol requires too much other fuel to produce it. A gallon of ethanol (84,200 BTU) consumes about 33,000 BTU of heat in the distillation process alone. Some of this heat comes from coal or cogenerators, but most distillers burn natural gas or LPG. LPG is a petroleum byproduct, and natural gas supplies are tight and getting tighter. Ethanol producers are competing with people who need to heat their homes. The energy losses of the ethanol process make it more efficient to burn the grain for heat, and use the LPG or natural gas as motor fuel (source).
: Someone sent me an e-mail about bio-butanol as a replacement for gasoline. Could we get rid of oil this way?
No. Environmental Energy, Inc (www.butanol.com
) claims a process which yields 2.5 gallons of butanol per bushel of corn (maize). They further claim 105,000 BTU/gallon of butanol vs. 84,200 BTU/gallon of ethanol (~25% more energy) which makes it a superior fuel. This is true so far as it goes, but this also runs into limits of raw materials; 11.8 billion bushels of corn would make 29.5 billion gallons of butanol. This would displace less than 1/5 of US gasoline consumption, with nothing extra to replace diesel fuel. The major advantage of butanol over ethanol is that it would require far less energy to separate it from water; it would be worthwhile to promote butanol rather than ethanol for energy-security reasons.
Source: Environmental Energy, Inc
: Could ethanol from crop wastes replace gasoline?
Probably not; there almost certainly isn't enough biomass available. The surplus biomass of corn stalks and such (corn stover) is the largest single biomass source in the US; it yields about 2.5 tons/acre (source
) at the average yield of 146 bu/ac. The surplus biomass over the entire 80.7 million acres planted to corn is roughly 200 million dry tons per year. Even if the entire dry mass was converted to ethanol with the same efficiency as grain (2.66 gallons per 56-lb bushel, or 31.3% by weight), it would only produce 62.6 million tons (19.0 billion gallons) of ethanol, equivalent to about 13.3 billion gallons of gasoline. In practice only 30% to 60% of this biomass could be made available for fuel production, and the energy requirements for distillation come on top of this.
(corn stover yield)
(2004 corn harvest)
: How efficient are batteries?
It depends on the type of battery. Lead-acid requires equalizing charges which make it relatively inefficient overall, while modern Li-ion has over 95% efficiency
: Can cogeneration be made quiet and friendly enough to use in a dwelling?
Many generators are already quiet enough to use near a home, and the backers of Climate Energy LLC
are betting money that they can sell cogeneration systems for people to put in their homes.
: Is there any truth to the claim that oil is abiotic in origin, and we'll never run out?
Almost certainly not; there may be trivial amounts of abiotic hydrocarbons coming out of the earth, but
- All chemical and geological evidence (on-line source) indicates that the source is from ancient organisms, and
- Even the most cursory arithmetic shows that the rate of production cannot be remotely close to our rate of use.
Source: No Free Lunch, part 3 of 3
The Oil Drum
: Do solar panels ever pay back the energy needed to make them?
Yes. As of the late 1990's, systems based on crystalline silicon PV panels returned their energy of manufacture in less than 4 years (about 3 years for the module and frame), and systems based on thin-film panels in a bit over two years (2 years for the module and frame); advances were expected to reduce the system figures to about 2 years and 1 year, respectively.
: What's the skinny on vehicle-to-grid?
: See the Vehicle-to-grid
page at the University of Delaware.
: Do wind turbines ever pay back the energy needed to build them?
Yes, and very quickly too. One analysis found that a land-based wind farm would return its invested energy in a mere 0.26 years (3 months 4 days), and a sea-based wind farm would pay back in 0.39 years (less than 5 months). This analysis was for 1.5 MW turbines, which are already small compared to the 5 MW turbines which are soon to be current and will be dwarfed by the 10 MW turbines considered to be most economical.
is slightly less optimistic
about their latest, claiming a payback in 6.8 months.
A more recent summary of analyses
is not so optimistic on average, but strongly positive nevertheless.
The Oil Drum | Energy from Wind: A Discussion of the EROEI Research
: How much wind power is available, world-wide?
The latest estimate is 72 terawatts from areas of class 3 (6.9 m/sec wind speed) or greater.
Further information: Mark Z. Jacobson's wind page
Continuing previous thoughts, I decided that it would be a good thing if someone analyzed the merits of converting corn to ethanol vs. burning it directly for heat.
The heating value of shelled corn has several different values published on-line; my first two results were 314,000 BTU/bushel
and 381,000 BTU/bushel
. (Unfortunately, the graph presented in the latter is not easily examined to determine if the two calculations are actually using very similar figures and the latter is merely a character-swapped typo.) Assuming the lower figure is relatively safe (favors the status quo), so here goes.
Converting corn to ethanol at a rate of 2.66 gallons per bushel and using 33,000 BTU/gal of gas for distillation yields 2.66 gallons (224,000 BTU) of ethanol, at a cost of 87780 BTU of natural gas.
Burning shelled corn (314,000 BTU/bu) at an efficiency of 75% yields 235500 BTU of heat at zero cost in natural gas. The natural gas freed up (87,780 BTU not used in distillation + 235500 BTU not used for heat) totals 323,280 BTU/bushel, or 32% more than the heating value of the ethanol the corn would otherwise produce. The first 235500 BTU of natural gas could be used to power NGV's, and the rest would be surplus over the ethanol scenario. (This comparison would be far more lopsided in favor of burning corn if the 381,000 BTU/bushel figure was used.)
Conclusion: Not considering other value-added products, it is energetically more efficient to burn shelled corn for heating fuel and use natural gas for motor fuel than it is to use the corn and gas to make ethanol for motor fuel.
UPDATE 2005-Sep-08: temposter offers the figure of 392,000 BTU/bushel (citing an Ontario source
) in the comments. Given that maize is a natural product and the fuel value is likely to vary based on oil content (which in turn depends on the exact strain and growing conditions), the value of 381,000 BTU/bu seems realistic. At the 381,000 BTU value, each bushel burned for heat would produce 285,750 BTU of useful heat and displace 373,530 BTU of natural gas or LPG. The ethanol which could have been produced from the maize would have produced 220,400 BTU at most
, the net benefit from burning the corn as heating fuel is at least 153,000 BTU/bushel.
Labels: ethanol, ethanol mirage
Over on Winds of Change
(and probably many other places besides), some people are promoting increased ethanol production as a response to refinery outages on the Gulf coast.
This is not merely a false solution; it would be one of the worst things we could do. We can conserve gasoline and import more, but we cannot replace the fuels which would go to the distilleries. Following the mirage of ethanol will just lead us further into the desert, where we shall die of thirst.
Ethanol is no solution
If corn equal to 20% of the 2004 harvest cannot be shipped because the Mississippi ports are closed, the surplus would be 2.36 billion bushels. At a conversion rate of 2.66 gal/bu, the total ethanol production would be 6.28 billion gallons, with energy equivalent to about 3.77 billion gallons of gasoline. The US burns about 134 billion gallons of gasoline per year; that extra ethanol would amount to a mere 2.8%, when our shortage is 10%. That is assuming the ethanol could be produced, which it probably cannot.
We could save 10% or more by slowing down to 60 MPH on the freeways and removing gas-guzzling vehicles from the roads. (The people who own Hummers and Navigators can afford to rent something for the duration.) We can import gasoline from Europe, and we are doing so.
Ethanol is a problem
What we cannot do is replace the fuel needed to distill more ethanol. (We may not even be able to afford the fuel to distill what we're using.)
It takes around 33,000 BTU of fuel to distill a gallon of ethanol (which yields a mere 84,200 BTU/gallon 
). Each gallon of ethanol requires about 33 cubic feet of natural gas (or the equivalent in LPG) to distill it. This is fuel which becomes unavailable to heat homes. The hypothetical 6.28 billion gallons of ethanol would require 207 trillion BTU of natural gas. The average home which heats with natural gas uses ~50 million BTU per season; the extra gas usage would otherwise be able to heat 4.14 million homes.
At last count, Katrina damaged wells and production platforms in the Gulf and "shut in" gas production of 7.2 billion cubic feet per day. Running 20% of the US corn crop through distilleries would consume gas equivalent to another 30 days of this missing production. Using ethanol just makes a bad situation worse.
Natural gas prices have shot up to $15 per million BTU; home-heating costs are going to run to record highs this winter. The tax subsidy of ethanol distilleries uses the taxpayer's own money to increase the cost of keeping themselves warm. The public interest would be best served by cutting off natural gas and LPG supplies to all distilleries immediately. Let them burn straw or stalks.
It's time to see the ethanol lobby for what it is: leeches sucking the life's blood from the nation's taxpayers, waving flags while selling the public down the river. If we need to dispose of 2 billion bushels of corn, let's take a hint from the corn stove
sellers and use it for heat straight out of the sacks. The people who demand we use precious heating fuel to help line their pockets should be seen for what they are: traitors.
Thaw a family, shoot a distiller.
The heat of combustion of ethanol is 12,780 BTU/lbm, and 6.588 pounds of ethanol per gallon; the heat value is thus 84,200 BTU/gallon. (back)
Labels: ethanol, ethanol mirage, false firemen
Among the lessons driven home by Katrina 
is that a coastal city below sea level is a city at risk. Levees can only do so much; the only guarantee of protection from the ocean is to be above it.
New Orleans was not this way originally. The first settlers would not have put themselves in a place where levees and pumps were required just to throw up a cabin; the land on which the city was built was originally above sea level. But the construction of the city and the prevention of the normal deposition of silt which built the land halted the process which kept it that way, and the pumping of groundwater plus the normal consolidation of silt left the city sinking. I've read that some parts of the city are 16 feet below sea level, and subsidence runs as fast as a half-inch per year.
It would be desirable to have a city that is once again above the water. To do this, the land beneath it would have to be built up by an average of about eight feet and then continuously over time. But how to do that?
Let it flood, let it flood, let it flood
One possible method is to let floods do it as they did before. One way engineers have handled flooding is to lift buildings out of harm's way and otherwise let nature take its course. In some areas, houses have been raised on pilings to allow floodwaters to pass harmlessly beneath; the new basement area is enclosed with blow-out panels which prevent harm from the force of flowing water.
Allowing annual floods to pass over and through an "uplifted" New Orleans would be an inconvenience, to be sure. While it might be feasible to commute in boats during the wet season, clearing mud from streets afterward would be a chore perhaps more onerous than snow removal and most typical landscaping would suffer. Further, adding up to sixteen feet of material to bring the lowest parts up to sea level would take a very long time and require several intermediate reconstructions of roadways. Provision of utilities to buildings with "wet feet" would also be a challenge, and annual or more frequent interruptions in service would seriously affect the habitability of even dry buildings in the mean time. It would be better to do the job more quickly than that, or at least in just one step.
90% of everything is crap
Or so was the soil beneath habitations until fairly recently. In an ancient city, subsidence would not have been so much of a problem. Without garbage removal, much of the ephemeral goods which came to a city tended to remain there as refuse. It built up in layers, incorporating all sorts of bits of interest to archæologists, and elevated the entire city over time. As first floors became cellars, new buildings were constructed above the levels of the old and the entire city climbed with time. A sufficiently slovenly populace might keep pace with subsidence and maintain itself above sea level in a river delta even without the benefit of flood-borne silt.
We would never accept this today. On the other hand, it would not be necessary (or even desirable) to use garbage or compost. The river delivers huge quantities of silt each year to the area, which the Army Corps of Engineers spends an equally huge amount of effort to dredge out of shipping channels. Once dried somewhat, this silt forms excellent soil. Why not use it?
It appears likely that many of the lowest areas of the city are destroyed, perhaps beyond repair. Absent billions for higher levees they will be at high enough risk to perhaps be uninsurable, and will take tens of billions to reconstruct in any event. It makes little sense to spend so much money just to put so much property and so many people back in harm's way; the rebuilt areas should be engineered to remain safe for the useful lives of the structures. This requires an immediate lift and the capability for on-going elevation. So here is my proposal for a reconstructed New Orleans:
Buildings too damaged to be worth saving would be razed. Buildings to be saved would be jacked off their foundations, new foundation piers installed beneath, and elevated above what is to be the new ground level; in the lowest areas this would be at least 16 feet and could be much more than that. The attachments between the piers and the beams would not be permanent; they would be detachable at any time so that shims could be added to elevate the building further. At the new ground level and perhaps at intervals above, tie beams would be added to keep the piers in alignment and allow for the attachment of cross-bracing; this would keep the piers from shifting under horizontal loads such as hurricane winds.
The process would go something like this:
(images unavailable due to Blogger bug, will try to add later)
Regions due to be razed in their entirety could be filled to a considerable height above sea level and then allowed to consolidate before beginning new construction; this would give better support to new road surfaces, driveways and sidewalks. Roadways might be engineered like boardwalks, made of floating segments loosely connected to each other and adjusted by additions of semi-liquid material beneath. Foundation piers should be extended to well-settled material to prevent the need for frequent levelling. As subsidence continued, periodic road work would be accompanied by less-drastic lifts of buildings on their piers, addition of spacers in the foundation posts, and filling of yards and other areas to maintain their proper elevation. As the city's soil sank, it would shim itself up to keep pace.
Would New Orleans be quite the same after this? Probably not, but even pre-Katrina it was not exactly the same as it was 50 years ago, or even 20. A shift from levee-building to whole-city elevation would be a radical change in process, but it would allow further change to proceed by increments rather than catastrophic jumps. It would allow for a great deal more stability and less worry. Isn't that what everyone wants?
: This lesson was only driven home this time. It was learned long ago, written up dozens of times, and published in everything from government disaster-preparedness studies to glossy popular magazines. Unfortunately, the people who had taken the money and assumed the responsibility to do something about it decided to procrastinate. (back)
In the aftermath of Katrina, the utter and deadly incompetence of our top emergency management officials has become undeniable.
The aftermath of the storm left a humanitarian crisis. President Bush himself said that food and water were being mobilized to reach people in need. How could it be that reporters on site at the New Orleans convention center could be describing a scene of no food, no water and no law enforcement... on Thursday?
Hotel officials rent buses to evacuate their stranded tourists at a cost of $25,000. FEMA officials commandeer the buses... and make no arrangements for the stranded tourists who were thrown out on the street
. A 50-seat bus has a weight capacity of approximately ten tons. Ten metric tons of cargo could be taken as 8000 half-liter bottles of water and two tons of MRE's or other food. Ten buses a day could carry out a mere 500 people, but could meet the immediate needs of at least
10,000 people for food and water.
The first bus of refugees to reach the Houston Astrodome was.... a stolen school bus. The areas around New Orleans and elsewhere must use hundreds or even thousands of school buses to transport students to school and back every day. 300 school buses carrying 40 people each could move 12,000 refugees in a single convoy. Each bus could carry a week's worth of necessities for perhaps 400 people on the return trip. That would have handled the needs of the city until further assessment could be done. Yet nobody did it, despite news reports which should have caused light bulbs to go off in the heads of the people with the power to do something about it.
It's about 350 miles from New Orleans to Houston. It should be feasible for a bus to make a round trip once a day, perhaps using two drivers. Evacuating New Orleans over open roads should not be a difficult task, and neither should supplying the needs of those who must remain.
Why wasn't it done by Wednesday?
These events show a devastating lack of intelligence, imagination and basic responsibility. If these are the best people our elected officials can find for those jobs, it's time for the whole top tier to resign. State and federal. Appointed and elected. En masse. Now.
"Tell people something they know already and they will thank you for it. Tell them something new and they will hate you for it."
- George Monbiot