dramatic CO2 emissions reductions for ethanol plant using renewable fuels and integrated heat and

[JohnWxy]

power configuration compared to fossil fuel usage without integrated heat and power system.

in this quote CHP means Combined Heat and Power.

"As shown in the table(Table 6_JW), CHP reduces both the total energy used by the dry mill ethanol process and the total CO2 emissions. In Case 1, overall fuel use is reduced by 13 percent on a Btu-pergallon basis, and CO2 emissions are reduced by 21 percent on a pound-per-gallon basis. As more central station power is displaced in Cases 2 and 3, overall net fuel used to produce a gallon of ethanol, and associated net CO2 emissions, are further reduced. In Case 3, CHP reduces total net fuel consumption by 55 percent; CO2 emission reductions from displacing central station power exceed the CO2 emissions at the plant itself, resulting in negative net CO2 emissions for the CHP system compared with base case conditions. (my emphasis_JW)"

EPA Study Impact of Combined Heat and Power on Energy Use and Carbon Emissions
in the Dry Mill Ethanol Process a negative carbon ethanol plant?

[kristopher]

1. It should be noted this is not representative of the state of the technology

Nor does it include the CO2 from fossil energy used to grow and transport the product to or from the plant John hopes to build.

[JohnWxy]

2. As I identified in my post this is an "EPA study". However, .....

a closed loop plant is being built in Arizona and should be finished by the end of the year.

http://www.xldairygroup.com/pressrelease.cfm?ContentKey=620

"Milk and biofuel might seem an odd combination, but a Phoenix-based company is planning to produce both at a proposed dairy/biorefinery in western Arizona. When fully built, the $260 million ag-industrial complex planned by the XL Dairy Group will produce 100 million gallons of ethanol, 25 million to 30 million gallons of biodiesel fuel and 21 million gallons of milk a year.

The concept is to use waste produced by the dairy cows to make energy that would be used to turn corn into ethanol and biodiesel, said Dennis Corderman, chief executive and chairman of XL Dairy Group. Byproducts of the ethanol and biodiesel production will be cycled back to produce internal energy for the biorefinery and to provide feed for the dairy cows, he said. "The biggest difference between us and other ethanol plants is we will use waste streams from the dairy to produce our own energy," he said. "It will provide the electrical and heat and steam energy for the entire facility." Because the plant will supply its own power, the operation will have an energy efficiency ratio of 10-to-1, he said. That means for every one British Thermal Unit of energy put into the process - including indirect energy consumption such as fuel needed to grow corn - the equivalent of 10 units of energy in the form of ethanol and biodiesel will be produced."

[kristopher]

3. What relevance does that have?

The increased efficiency of combined cycle plants isn't anything new; but there is a reason it isn't more widely used in electrical generation generally. It is often hard to find an appropriate use for the heat. It seems a good fit for biofuel production, but as I noted, there are other considerations in determining the CO2 footprint of biofuels.

It is also important to keep in mind that biofuels are energy carriers, not a means of significant energy harvesting. This severely limits their role in a renewable economy.

[JohnWxy]

4. I guess if you have a fetish for cow shit you don't see it. But try your jibberish on the people at

XL Diary group and see what they say. (lol). They might ask if you would be so kind as to supply their next operation with your bullshit. YOu ought to be able to power an ethanol plant. LOL.