Transforming Cellulose to a Gel for Ethanol Production
01 September 2006
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| Cellulose undergoing crystalline to amorphous transformation. |
One of the barriers to the production of ethanol from cellulosic biomass is the toughness of the cellulosic structure, and its resistance to chemical and enzymatic hydrolysis and insolubility in most solvents. Accordingly, pre-treatment—such as steam explosion—to break down the structure is a necessary first step.
Now, researchers at the Japan Agency for Marine-Earth Science and Technology have discovered that cellulose undergoes a transformation from a crystalline form to an amorphous gel-like one—very similar to a starch gel—in water at high temperature (320° C) and pressure 25 (MPa).
Starch forms a gel when heated in water to around 70° C. Gelatinization is a key step in the conversion of starch to glucose, which is then fermented to create ethanol.
Up to now, it had been thought that cellulose could not gelatinize, because its crystalline structure is more stable than that of starch.
Next steps in developing the process would be to attempt it with production-grade biomass waste, and to devise a mechanism for the transformation under milder conditions.
Resources:
“Cooking cellulose in hot and compressed water”; Shigeru Deguchi, Kaoru Tsujii and Koki Horikoshi; Chem. Commun., 2006, 3293 - 3295, DOI: 10.1039/b605812d
Boil the crap out of it in a pressure cooker. Got it.
Posted by: Robert Schwartz | 01 September 2006 at 06:28 PM
Just a little pressure in the pressure cooker; at 320° C, the vapor pressure of water is over 11 MPa (something like 1600 PSI).
Posted by: Engineer-Poet | 01 September 2006 at 08:14 PM
Pressure cooker is the way to go~
Posted by: rexis | 01 September 2006 at 08:22 PM
I wonder how this will affect the overall energy return of cellulosic ethanol/butanol. On the face of it, this seems like a more efficient pretreatment process. Though I imagine the lingin has already been seperated somehow.
Posted by: Cervus | 01 September 2006 at 09:05 PM
Now, if we would just get on with building the pilot plants to prove the commercial viability and then start production, we would be on our way.
Posted by: SJC | 02 September 2006 at 08:22 AM