Posted on 01/24/2007 12:59:25 PM PST by kellynla
WASHINGTON -- The fuel ethanol boom and high crop prices will cut U.S. farm subsidy spending by $31 billion through 2016, a dramatic drop in the cost of the farm program, the Congressional Budget Office said on Wednesday.
In a semiannual report, CBO estimated farm subsidies would cost $10 billion this year and the annual cost "will range between $8 billion and $10 billion over the next decade."
The forecasts are expected to constrain this year's overhaul of farm policy by Congress. The 2002 farm law, which allocates about $20 billion a year on farm supports, expires in the fall.
Large U.S. farm groups want to maintain the current crop support system. The American Farm Bureau Federation asked on Dec. 6 that Congress and the Bush administration assure that funding "be sustained at levels authorized in the 2002 farm bill with adjustment for inflation."
Congress has a target of agreeing by April 15 on a spending outline. Leaders of the House and Senate Agriculture committees say they will not begin work on farm subsidy programs until it is clear how much money will be available.
"Projected spending . . . has declined by $31 billion for the 2007-2016 period," said the CBO report. "That reduction primarily reflects lower income-support payments to farmers for major crops because commodity prices are now expected to be higher than previously anticipated.
"In particular, CBO has reduced its estimates of support payments to corn producers as a result of stronger demand for ethanol."
Corn prices have doubled since last fall and are the highest in a decade. Soybean and wheat prices rose as well, pulled up by corn.
--Steam could very well be hot enough to use for distillation.--
I repeat: "A little research would show that the temperature of the 'spent steam' in not adequate to run a still."
Yep, I agree.
As I have repeatedly said, whatever we can do to get off our foreign oil dependency. Whether it be more drilling, solar, coal, nuclear, biodiesel, ethanol and/or a combination of all. Lets "get 'er dun!" LOL
The intensity of tillage has historically decreased with the increase in corn yields. Put another way, I get about four times the yield off my best corn field than my grandfather did when he was my age, but the soil is disturbed only about a quarter as much.
--. My uneducated bet is that the steam coming from the turbines would be hot enough to distill alcohol. --
My educated bet is that it is not.
--did not find anything that gives the temperature of steam from a nuclear power plant after it leaves the turbine but before it is cooled and reintroduced into the system.--
The link below gives the parameters of the cycle. It looks messy but down at the end there is a diagram, steam cycle on temperature and enthalpy. Look at the temperature at the exit of the turbine. About 80 degrees. That is what you would have to work with for your still.
http://www.roymech.co.uk/Related/Thermos/Thermos_Steam_Turbine.html
It is NOT "cooled" after it leaves the turbine. The thermo cycle requires it to
It is NOT "cooled" after it leaves the turbine. The thermo cycle requires it to to be condensed and then REHEATED to over 400 degrees before going back to the steam generator.
That's 80 degrees Celsius, which works out to about 176 degrees Fahrenheit, plenty hot for distillation.
Yeah, except that most of the heat in the spent steam already goes back into the system, pre-heating the feedwater into the steam generators, helping to increase the efficiency of the system.
That makes sense.
Except that, apparently, it doesn't. The spent steam still needs to be re-condensed, which requires removing heat from it, and the water that comes out of the condenser is already near boiling. So yes, I guess there is a lot of excess heat in a thermal generating station, whatever its energy source, that is normally going to waste. The question, then, is whether or not there is anything useful to be done with this excess heat. 80 degrees Celsius is still pretty damn warm, if not quite boiling.
Sorry. I was in a hurry to find a chart. I had no idea how hard it was to find the chart with temperature on it. Here is one showing the pressure at 28" Hg. I just checked ours and right now we are running about 90 degrees F.
--Yeah, except that most of the heat in the spent steam already goes back into the system, pre-heating the feedwater into the steam generators, helping to increase the efficiency of the system.--
Some of the spent steam energy goes to reheat, but not most.
see #52
I'm always reading something about them trying to figure out how to use waste heat. This isn't all tree hugger stuff, it's often about improving efficiency to cut costs. It also has environmental benefits and conserves limited energy resources, so it's win win all around. That certainly isn't always the case if it's some ridiculous government mandated program though.
No problem. You probably know a whole lot more about this stuff than I do. I was just trying to make the point that spent steam from power generating turbines might very well be hot enough to use for distillation either as the sole heat source or at least to provide a good part of the heat energy required. I don't know how practical that would be, but it may be possible.
For power plants, the maximun theroretical Carnot cycle efficiency is determined by:
1 - Tr / Ta
Where Tr is the temperature at rejection and Ta is the temperature of the source, about 560 degrees for our plant. That is why we take the Tr down as low as possible, less than 100 degrees F. If we took it down to only 200 degrees F we would lose efficiency and generate less electricity as a result. Note that the power plant actually works on the Rankine cycle which is limited in efficiency by the theoretical Carnot cycle.
Oh, I agree. The minimizing of waste heat energy is a major topic in stationary engineering. Physical plants that generate steam, for example, are optimized to minimize waste. The people who own physical plants, power plants, etc, certainly have always had a strong interest is reducing fuel costs.
How about this, then: A bank of Stirling heat engines using the waste heat. Actually, I'm not sure if 80 C is enough to run one of those, either.
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