A novel lime pretreatment for subsequent bioethanol production from rice straw--calcium capturing by carbonation (CaCCO) process.
In order to establish an efficient bioethanol production system for rice straw, we developed a novel lime-pretreatment process (CaCCO process) that did not require a solid-liquid-separation step. This process adopted a step in which after pretreatment lime was neutralized by carbonation, resulting in a final pH of about 6. CaCO(3) produced by the process was kept in the reaction vessel, and no significant inhibitory effects on enzymatic saccharification and fermentation were observed. In the CaCCO process, solubilized carbohydrates, such as xylan, starch, and sucrose were also kept in the vessel, enabling high recoveries of monomeric sugars. Simultaneous saccharification and fermentation (SSF) of pretreated rice straw, 10% (g-rice straw/g-water), using Saccharomyces cerevisiae and Pichia stipitis yielded 19.1 g L(-1) ethanol that was 74% of the theoretical yield from glucose and xylose. Thus, this process represents a novel pretreatment method to utilize not only cellulose but also xylan, starch, and sucrose from biomass.
Park
Jeung-yil
JY
National Food Research Institute, National Agriculture and Food Research Organization (NARO), 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
Shiroma
Riki
R
Al-Haq
Muhammad Imran
MI
Zhang
Ying
Y
Ike
Masakazu
M
Arai-Sanoh
Yumiko
Y
Ida
Atsuhi
A
Kondo
Motohiko
M
Tokuyasu
Ken
K
D056804:Biofuels; D002119:Calcium Carbonate / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D012275:Oryza / Q000378:metabolism*; D010843:Pichia / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism
D056804:Biofuels; D000431:Ethanol; D002119:Calcium Carbonate