Biomass pretreatment with ammonium bicarbonate / carbonate expansion process
First Claim
1. A method for pretreating a biomass to improve the susceptibility of the biomass to hydrolysis, comprising the steps of:
- (a) blending and/or mixing the biomass with one or more solid, nitrogen-containing compounds having a decomposition or melting point in the range 35 to 80 degrees C. within a mixing/blending vessel at any desired feed ratio to produce a blended, mixed feedstock;
(b) transferring said blended, mixed feedstock into a pressure reactor;
(c) sealing the pressure reactor;
(d) heating the feedstock within the pressure reactor to a temperature sufficient to decompose said nitrogen-containing compounds into gaseous ammonia, carbon dioxide and water vapor, thereby increasing pressure within the reactor;
(e) holding the feedstock within the pressure reactor at a desired pressure and temperature for a desired time interval;
(f) unsealing the pressure reactor by releasing the carbon dioxide, water vapor, and ammonia gases therefrom;
(g) conducting the released carbon dioxide, water vapor and ammonia gases from the pressure reactor into the interior of a precipitation reactor, thereby leaving residual contents in the pressure reactor;
(h) cooling said released carbon dioxide, water vapor and ammonia in the precipitation reactor sufficiently to precipitate ammonium bicarbonate/carbonate therein;
(i) conducting some or all of the precipitated ammonium bicarbonate/carbonate away from the precipitation reactor; and
(j) removing the residual contents of the pressure reactor from the pressure reactor.
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Accused Products
Abstract
A simple, inexpensive, and benign process to pretreat lignocellulose biomass for the economical production of biofuel and extraction of organic chemicals. Lignocellulose solids are mixed or blended with ammonium bicarbonate/carbonate and heated within a pressure reactor. At elevated temperature (e.g., >35° C.), the ammonium bicarbonate/carbonate dissociates into ammonia and carbon dioxide gases and water vapor, thereby causing a rise in pressure within the pressure reactor. Rapid release of the gases from the pressure reactor then ruptures biomass cell wall structures, which facilitates conversion of the cellulose and hemicellulose in the pretreated biomass to sugars that are fermentable into ethanol or other liquid fuels. Optionally, ammonia bicarbonate/carbonate can be reconstituted by cooling and precipitating the carbon dioxide and ammonia gases released from the pressure reactor for further use in the pretreatment process or sequestered as an end product.
13 Citations
28 Claims
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1. A method for pretreating a biomass to improve the susceptibility of the biomass to hydrolysis, comprising the steps of:
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(a) blending and/or mixing the biomass with one or more solid, nitrogen-containing compounds having a decomposition or melting point in the range 35 to 80 degrees C. within a mixing/blending vessel at any desired feed ratio to produce a blended, mixed feedstock; (b) transferring said blended, mixed feedstock into a pressure reactor; (c) sealing the pressure reactor; (d) heating the feedstock within the pressure reactor to a temperature sufficient to decompose said nitrogen-containing compounds into gaseous ammonia, carbon dioxide and water vapor, thereby increasing pressure within the reactor; (e) holding the feedstock within the pressure reactor at a desired pressure and temperature for a desired time interval; (f) unsealing the pressure reactor by releasing the carbon dioxide, water vapor, and ammonia gases therefrom; (g) conducting the released carbon dioxide, water vapor and ammonia gases from the pressure reactor into the interior of a precipitation reactor, thereby leaving residual contents in the pressure reactor; (h) cooling said released carbon dioxide, water vapor and ammonia in the precipitation reactor sufficiently to precipitate ammonium bicarbonate/carbonate therein; (i) conducting some or all of the precipitated ammonium bicarbonate/carbonate away from the precipitation reactor; and (j) removing the residual contents of the pressure reactor from the pressure reactor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification