Grace----you need to define what you call food. Do you define starch and sugar as "food"? It is possible to eat that is true, however, there is very little to no nutritional value.
Or do you define protein and vitamin content as food?
Corn and sugarcane don't grow very well in Vermont.
Switch grass can be a very important source of renewable fuels because it is a naturally evolved grass that is basic to the ecology of large areas of North America. It is a high density grass that forms cover and diet for many species of animals, birds, reptiles etc. Unlike grasses that are imported and/or genetically selected and altered----it follows the local seasons, and wildlife's adapted life timing and movements have co-evolved with it.
Since switch grass is locally evolved it is adapted to the prevailing conditions----it requires no cultivation other than original starter planting, it is evolved to self propagate, requires no fertilization or irrigation and is evolved to be active and dormant according to local climatic conditions, primarily prairie----which can be a monsoon climate, very wet at times, separated by long sometimes very hot and dry seasons. Prairie grasses can put down extremely long root systems, 12 to 14 feet with highly dense mat formation that can store and access water, resist drought and preserve topsoil, and are impervious to fire. Annual seed crops can not do this, they don't live long enough, only perennial grass can do this. Native plants are also evolved to handle local pests and diseases so they require a bare minimum of herbicides and pesticides unless dealing with a species imported by man.
Due to timing of growth and wildlife cycles---it is even possible to get crops from wildlife reserves without disturbing the natural life cycles of wildlife. For instance, ground nesting birds have cover and grain in the spring when it is needed for mating and nesting seasons, and crops can be mowed in the fall when the fledglings are reared and most species migrate.
Switch grass is also highly suited for areas where agriculture is not generally suited----for instance, growing in the medians and right-of-ways of highways.
Switchgrass and other hays(switch grass is a type of hay) depending on local climate and terrain type, can produce anywhere from 3 to 7 tons per acre of cutting with up to 3 or 4 cuttings per season.
We have three different processes to produce ethanol from cellulose, going back 120 years. The Scholler process using heat and acid to break down the cellulose. This produces "black liquor"---essentially biologically based crude oil. Anything made from crude petroleum can be made from black liquor, including fuels and even plastics. Black liquor is a by-product of paper pulp production. Currently pulp production produces roughly 36 billion gallons per year of black liquor. High temperature "fast pyrolysis" can also be used to produce black liquor, and this is the process that is ordinarily used for solid wastes such as MSW(municipal solid waste).
Fischer-Tropsch uses heat and pressure to break down cellulose into carbon monoxide and hydrogen "synthgas" which is then recombined using catalyst beds, heat and pressure to produce any type of organic molecule desired from simple methane(CH4) to complex long chain hydrocarbons up to 43 carbons long, which would be highly heat resistant lubricating oil range. Varying heat, pressure and catalysts makes it possible to control the desired output.
Several plants are opening right now that use certain bacterial enzymes to break down the cellulose to pure sugars which can then be fermented into ethanol. DuPont, POET, and Abengoa are opening three plants in Iowa and Kansas by the end of this summer that will have a combined capacity of over 100 million gallons per year of ethanol using enzyme fermentation. They will be producing ethanol using waste corn stover(non grain parts of the corn plant)----as well as other agricultural waste such as wheat straw----and they could also handle switch grass.
The goal of most projects using cellulose to produce ethanol is 75-100 gallons per ton.
For Tom Clark:
-----------" Paying $200/ton for wood pellets is the same as paying:
• $1.67 per gallon for heating oil
• $1.18 per gallon for propane
• $12.50 per (1,000 ft3) for natural gas
• $0.04 per kWhr for electricity"-------------
Biomass Energy------Georgia Forestry Commission
You will notice when you visit the page and compare the various options that kiln dried biomass has significantly higher energy content. That is because a greater % of the weight is usable fuel in relation to overall weight. Using renewable energy to dry the biomass(solar or wind for instance) is actually "storing" energy by reducing water content, and thus increasing the working temperatures of the biomass.
This is where grasses have a large advantage. Grasses are relatively very quick and easy to mow, sun dry and bale----then make into pellets. This creates pellets that are dense and hard, and very similar to the dried buffalo dung that the Plains Indians used as fuel in the absence of trees to provide wood. In which case, the buffalo acted as four legged pelletizing machines for the Indians. Energy content is very similar and NO, there is no smell to burning dried buffalo dung-----not even as much smell as burning a similar amount of dried grass.
@ Brian, we can make ethanol out of almost anything....................including desert plants............Agave, it is called tequila, we've been making it for centuries.
Brian: ------" Fred, alcohol is a low density fuel,............:------------
That will come as a surprise to the people who race the fastest, most advanced race cars in the world, the Indy League Racing Circuit. All Indy cars run on 100% ethanol. And they have over twice the thermal efficiency of gasoline powered vehicles, over 50%. Thermal efficiency wins races, not fuel density.
----------" The ethanol conversion methods do not work with cellulose."---------
Maybe you should be telling DuPont instead of me. DuPont is opening their new 50Mgallon/yr cellulosic ethanol plant in Nevada Iowa by the end of summer. DuPont is betting $200 million that they can produce ethanol cheaper than gasoline using enzyme technology. They are also betting that it will be so successful that they can sell turn key production facilities throughout the world as well. With no subsidies. They have been doing it for several years at test facilities in Tennessee.
Not only that, POET and Abengoa are opening facilities on roughly the same schedule and size. (Abengoa's in Hugoton KS, is already up and running).
Brian----that is an elaborate test. But it is set up to test gasoline. Not ethanol. Gasoline has an octane rating of 85-87. Ethanol has an octane rating of ~115. The key to thermal efficiency with internal combustion engines is compression. The higher the compression, the greater the power output and efficiency.
Using gasoline, the upper compression ratio limit is 10.5:1 : using ethanol, the upper compression ratio is 24:1. The upper limit of thermal efficiency Work/BTU = 20% with gasoline. With ethanol the thermal efficiency is close to 50%.
Water affinity is how you remove water from gasoline systems.
DI can give you marginally more compression use-----but when you push it too far there is a sudden power drop off----fuel /air don't adequately mix.
If you don't like ethanol made from corn, make it from something else----we can make it from almost anything.
What cars is that put into Brian?
Unproven tinkering Brian.
Diesel engines routinely run 40% TE, and over. Scania and Mann diesels run 45% and over TE. Indy League Racing Circuit cars run between 50-55% TE(all ILRC car run on 100% ethanol.)
Any diesel engine can run without modification on ethanol with the addition of 5% ignition enhancer. It is designated ED95 (ethanol diesel 95%)
I am right, you are wrong. The fastest most advanced race cars in the world run on ethanol, Indy League Racing Circuit. Indy cars run on 100% ethanol, and have run on nothing but alcohol base fuels since 1963.
Scania maintains a fleet of over 1,000 buses world wide that run on ethanol (ED95)----and has for over 20 years. They maintain buses in Sweden, UK, Brazil and Hong Kong.
The Model T Ford when introduced in 1908 could be ordered with an adjustable carburetor that could be set to run on either gasoline or ethanol.