[Gasification] Ecoethanol

[Harmon Seaver]

   Pray tell -- what does this have to do with gasification? I really
don't get it -- why do people keep cluttering up the gasification list
with totally irrelevant topics? Do you have any idea how many people
interested in gasfication have been driven off this list by the signal
to noise ratio? Repp has two other lists where this would have been
more than welcome -- bioconversion and bioenergy, please use them.

On 7/23/06, Kermit Schlansker <kssustain at provide.net> wrote:
>                                         Ecoethanol
>
>         The following defense of corn to ethanol is by no means meant to indicate that it is the solution for all of our problems. It also doesn't indicate that there couldn't be a better process. However our first task is to make farming independent of oil. We can't possibly power all of the big cars. In addition to all of the advantages cited here, making ethanol can be done without high pressures and temperatures. It can easily be done within a building or in an insulated outbuilding. It is a well-known primitive process.
>           It is possible to show the power of the Ecomindium with the following example. The making of ethanol from corn is a reviled process because the energy efficiency is so low. It has been said that it takes about 4 lbs of coal to process one gallon of ethanol. This would be about 40,000 btus/gallon. To get another angle on input energy, joedoves says that it takes 12000 kj/kg to process ethanol. This is also about 40,000 btus/gallon. This energy is probably used in grinding, steaming, and distilling the corn.
>         According to "Ethanol 101", one bushel of corn makes 17.6 lbs of ethanol, weighs 56 lbs, gives 6000 btus of heat, and 17 lbs of distiller's grain.  The 6000 btus/bushel seems to be incorrect. Also the 17.6 lbs of ethanol does not seem to jibe with the 2.5 gallons per bushel that is frequently given.
>           At 56 lbs /bushel and 8000 btus/lb the overall energy value of the corn bushel is 448000 btus. If the Stover is 2 tons/acre, at 120 bushels/acre and 6000 btus/lb of Stover the energy value per bushel is 200000 btus. This works out to a total of 77.8 million btus/acre.
>            Ethanol has a high heat value of 12770 btus/lb. This means that the heat value of the ethanol/bushel is 224752 btus. At 72000 btus/gallon we are getting 3.12 gallons/bushel. This seems high. If we subtract the 17 lbs leftover solids from distillation from the weight per bushel we get 39 lbs/bushel.  At 8000 btus/lb the remaining heat value is 312000 btus. If we subtract the heat of the ethanol from this we get 87248 btus. This is probably the heat lost during fermentation and is 29000 btus/gallon.
>            To sum it up we are getting 224752 btus of ethanol energy plus 87248 btus waste heat from a bushel of corn. We are putting 120000 btus into it for processing. This means a total of 207248 btus/bushel of waste heat that can be used for space heating in winter. We can add to this the 200000 btus/bushel of Stover energy. This can be gasified and used for cogeneration to produce about 15 kwhrs of electricity and about 160000 btus of waste heat. The total value of waste heat is then 367248 btus/bushel, which is greater than the heat of the alcohol. Making 1000 gallons of ethanol would contribute about 122 million btus to space heating. This is what I call comanufacturing and the Ecomindium would excel at it. If we add waste heat from gasification, cogeneration, and biodigestion, the heating and hot water heating bill for the Ecomindium is eliminated.
>            It is the 17 lbs of good processed food that makes corn to ethanol into a superior process. If this food is fed to people, chickens, rabbits, or fish it becomes really valuable and the cost of processing replacement food is eliminated. Ethanol from cellulose in large facilities is not as useful a process.  In an Ecomindium, corn would produce food, tractor fuel, and space heating.  In the Ecomindium culture it would also be possible to generate the 40000 btus needed to process the corn from solar mirror energy.
>           The plowing energy might come from the ethanol but could come from biodiesel or a cellulose fired, tractor mounted gasifier system. Nitrogen is made by crop rotation with clover, soybeans, other leguminous plants, manure, or biodigester residues. Ashes are used to return minerals to the soil. Alfalfa has deep roots that probably would put carbon into the soil. In a biodigester the alfalfa can also be used to make gaseous energy, space heating, and fertilizer. The whole process should work for a long time.
>
>                                                                                    Kermit Schlansker
>
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-- 
Harmon Seaver