Biofuel
Biofuel
(OP)
Hello,
I would kindly ask for some information regarding biofuels.
1) How much land under crops is needed for 1ton of biofuel (biodiesel, ethanol)?
2) Is there any thermal power plant built in the world that utilizes biofuels in boilers instead of oil, coil etc.
3) What is the energy efficiency of a biofuel burned in the boiler not car engine?
I have googled only information regards biofuel utilization in car engines but not in thermal plants for heat / power generation.
Thanks
I would kindly ask for some information regarding biofuels.
1) How much land under crops is needed for 1ton of biofuel (biodiesel, ethanol)?
2) Is there any thermal power plant built in the world that utilizes biofuels in boilers instead of oil, coil etc.
3) What is the energy efficiency of a biofuel burned in the boiler not car engine?
I have googled only information regards biofuel utilization in car engines but not in thermal plants for heat / power generation.
Thanks





RE: Biofuel
Bagasse from sugar cane is burned directly in many boilers at sugar refineries.
http://en.wikipedia.org/wiki/Bagasse
RE: Biofuel
"Back to Cellulose Ethanol" and "Bio-fuels.... good or bad?" where these questions are already well developed.
You can also visit the number watch website and view the thread Carbon the lifeblood of our planet where engineer David Taylor has done some rough calculations on the benefits.
http
JMW
www.ViscoAnalyser.com
RE: Biofuel
RE: Biofuel
RE: Biofuel
On a per acre basis, perhaps sawgrass or hemp might have the highest yield . May also increase the value of the houses downwind.
RE: Biofuel
See the web page for IEA bioenergy for european efforts to co-fire straw, wood, animal waste in boilers.
RE: Biofuel
Check out the US DOE energy web site where you can see what the US Governmnet is up to on biofuels:
http://www.energy.gov
Thanks,
G. Feric, PE
http://engware.i-dentity.com
RE: Biofuel
I think the biggest paybacks will ultimatly come from advances in battery technology and more efficient power generation.
RE: Biofuel
Question #1 - answered above
Question #2 - Why on earth would you take a product specifically formulated for combustion in IC engines and burn it in a boiler ? Why noy simply grow a crop and burn the biomass in a boiler ? This is probably not economic in many countries, but has been done in the past.
Question #3 - Makes no sense, an industrial boiler is designed for a specific fuel (including specific coals). Throwing something else into it (including peat, wood, bagasse, and old piping designers) it only makes the unit operate off the design point.
Do yourself a favor,... Get a copy of the superb book "STEAM" by B&W and spend a quiet productive weekend reading it..
-MJC
RE: Biofuel
- "torrefied wood" is one option of a biofuel that can be burned in a coal fired boiler with minimal impact on the boiler and mills and its air pollution equipment
-"e-grasss" or elephant grass is probably the most energy efficient biofuel for firing in boilers and provides the greatest harvest in terms of BTU/acre- the latest estimate is that there is an 8:1 ratio of energy released in the boiler vs energy consumed by planting , harvesting ,transporting , drying and pulverizing provided (a) it is burned in a fluid bed bed boiler 50% coal and 50% e-grass and (b) the crop is allowed to dry in the field over the winter season. High levels of K, Na, Cl etc cause issues with other boiler types.
RE: Biofuel
There is a large area for growing biofuels, but with little water. Or the prime areas are now used for food growth.
Interesting enough, the untillable areas in creeks, and bar ditches seem to grow weeds and trees very well, but currently are under harvested.
And why do trees grow so well under power lines?
RE: Biofuel
as per the above link, 20,000 acres of e-grass would be required in Florida to generate 130 MWe net electricity. But that scenario is not the most efficient process. See the IEA-bioenergy webpages for alternate schemes which may be more efficient.
The above link assuems multiple harvests per year, which implies more energy losses due to the need to dry the grass. It also converts the e-grass to a liquid biofuel prior to firing in a boiler, which implies more energy losses in the conversion to liquids in the prompt gasifier.
RE: Biofuel
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To maximize the ratio of usable/ input, must minmize energy for drying, transport, and grinding==> this implies drying over the winter season in the field, and combusting in a fluid bed boiler ( no pulverization)
for a good summary of the impact of co-firing biofuels in boilers, see:
<http
RE: Biofuel
We also collect our VOCs and burn them in another heater instead of flaring. There is a lot of entrained nitrogen but the HV is still ~400 btu/cf.
RE: Biofuel
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and, by the by, China is busy scooping up algae from the site of the Olympic sailing which, one guesses, they could be processing for bio-fuels...
JMW
www.ViscoAnalyser.com
RE: Biofuel
In the USA the problem also is that the time of the year that the sugar cane grind is occurring, the grid doesn't need power (fall to early winter) so the avoided cost of power is low and selling excess power isn't a profitable business. So they work hard to balance the process so that they burn what they make so that they don't have to landfill the excess bagasse.
Wood byproducts are burned by sawmills, plywood plants, OSB plants and paper mills. Sawmills and plywood plants burn bark and sawdust and planer shavings and mill waste. Some have enough excess to generate power for the grid but as a general rule, the mill consumes all the power generated.
Paper mills burn bark and the lignin chemicals "cooked" out of the wood to break down the fiber so that it can be made into paper. Again, the paper making process is so energy intensive that not only are they generating several dozen MW inside the mill with biomass and fossil fuels, they are usually purchasing up to an equal amount from the grid.
Rice hulls on the other hand are burned and all the output is sold to the grid.
But, point is they are generating power with bio mass. The question for those bio mass sources is whether there is a higher use for the bio mass. Wood in my part of the world is much more profitable made into lumber and paper than electricity.
rmw
RE: Biofuel
But , in long term steady state estimates of "sustainable" biofuel use, wood is not likely the answer- e-grass ( elephant grass , miscanthus) seems to have a much higher yield per acre per annum than wood.