Roasting Biofuel Crops Like Coffee Beans Could Boost Energy Yield by 20%
by Jeremy Elton Jacquot, Los Angeles 
on 05.22.08
Two British engineers have discovered a novel technique that could help make biofuel production cheaper and boost the energy content of some crops by up to 20%. The process, called "torrefaction," consists of slowly heating biomass in an inert atmosphere to a temperature of 300°C; it yields a solid product with a lower moisture content, minimizing transportation and storage issues.
While it's more commonly associated with coffee production, Jenny Jones and Toby Bridgeman of the University of Leeds, who led the study, published in the journal Fuel, think it'll work in a cinch for biofuel production too. They specifically tested willow, canary grass and agricultural residue wheat grass -- crops often used in the U.K. -- to see what happened when they went through torrefaction and how they performed as biofuels.
Not only did the treated biomass take less time to heat up, but it also provided higher energy yields upon combustion. Other benefits include less smoke formed during the combustion process, higher density and similar mechanical strength to the initial biomass and better stability.
Willow came out on top in the trials, boasting a 86% energy yield; by comparison, wheat straw and reed canary grass had energy yields of 77% and 78%, respectively.
Image courtesy of FreeWine via flickr
Via ::ScienceDaily: Biofuels: Process Used To Roast Coffee Beans May Give Biomass A Power Boost (news website)
See also: ::First Commercial Algae-to-Biofuels Facility Goes Online, ::Common BioFuel Myth: Corn-Based Ethanol To Blame For Global Food Shortages
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This, my Friends, is not new to me.
This technique has been used for thousands of years to make coal from wood, by heating is to high temperatures, and cover it with sand so the oxygen can not reach it and it is impossible to burn completely and lots of us use it every year on the BBQ.
No wonder the price of coffee is skyrocketing.
In stead of drinking it, it is now necessary as
research material. Ha , Ha.
I learned this technique in the first class of high school. So, sorry folks,
Ak Malten
This, my Friends, is not new to me.
This technique has been used for thousands of years to make coal from wood, by heating is to high temperatures, and cover it with sand so the oxygen can not reach it and it is impossible to burn completely and lots of us use it every year on the BBQ.
No wonder the price of coffee is skyrocketing.
In stead of drinking it, it is now necessary as
research material. Ha , Ha.
I learned this technique in the first class of high school. So, sorry folks,
Ak Malten
In no way did it increase the energy content; it says right in the abstract that you may retain up to 96% of the original energy content, not increase it. They may have increased the energy content per KG of material after the process however, which makes things more favorable if you have to ship your biomass.
What they are doing here is driving off more of the moisture content and breaking down the fuel a little. This makes the burn more efficient, quicker, and with higher temperature because you don't have to heat or vaporize the water content you've driven off.
It would be interesting to see an energy analysis from field to flame. This process costs energy, but you then can recover more energy from the biomass. Will the increase in energy recovery pay for this pre-treatment?
Ak Malten:
Actually, Torrefaction is different than carbonization, which you are thinking of. Carbonization turns it into charcoal, while this process preserves some of the oxygen content and cellulose content of the biomass.
It seems also to require less energy than carbonization, preserves more of the energy content, and makes a fuel that is more stable than carbonization.
I suspect Ak Malten has torrefaction confused with pyrolysis, the age-old method of charcoal production. The limits of said high school education, no doubt.
More importantly, as Tom points out; energy is not created here. Certainly some is actually lost at the expense of creating a more practical end-product for burning. Energy density and smoke pollution are improved, among other things.
I would appreciate a higher level of scientific analysis applied to reviews such as this, as the headline is clearly deceptive.
What isn't noted in the life cycle energy factor. Heating the biomass uses up energy too. So how far do you have to ship the resulting biomass at what cost before there is a net energy gain?
If only there was a fuel that was free and had no shipping costs... oh, yeah, that solar thingy. If we could store and retrieve the energy efficiently, there would be no energy problem.
Of course, if pigs had wings, we'd all need bigger windshield wipers too.
What isn't noted in the life cycle energy factor. Heating the biomass uses up energy too. So how far do you have to ship the resulting biomass at what cost before there is a net energy gain?
If only there was a fuel that was free and had no shipping costs... oh, yeah, that solar thingy. If we could store and retrieve the energy efficiently, there would be no energy problem.
Of course, if pigs had wings, we'd all need bigger windshield wipers too.
If only there was a fuel that was free and had no shipping costs... oh, yeah, that solar thingy. If we could store and retrieve the energy efficiently, there would be no energy problem.
right on! I still don't understand why we are even considering investing in biofuels when we can get every bit of energy we need from the sun. And all it takes is a very large 1 time investment (with some maintenace over the years) in Concentrated Solar Thermal Power.