Pretreatment is a unit operation in the conversion of biomass to valuable products that utilizes various combinations of conditions, including chemicals, heat, pressure, and time, to reduce the recalcitrance of lignocellulose. Many such pretreatments have been developed over the years, as the operating conditions can be adapted so that lignocellulose is modified in ways unique to each pretreatment. By tailoring pretreatment conditions to achieve these modifications, the types of final products produced can be controlled. The purpose of this review is to provide a consolidated source of information for sodium hydroxide effects on lignocellulose. The structural characteristics of lignocellulose and the alterations that occur due to the application of sodium hydroxide are detailed. This review also includes a brief description of the chemical reaction mechanism that ensues during the pretreatment. Lastly, the results of studies that utilized sodium hydroxide pretreatment are discussed.

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Published in Transactions of the ASABE, v. 57, issue 4, p. 1187-1198.

© 2014 American Society of Agricultural and Biological Engineers

The copyright holder has granted the permission for posting the article here.

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The authors gratefully acknowledge the financial support of the Biomass Research and Development Initiative (Grant No. 2011-10006-30363).

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The investigation reported in this study (No. 12-05-115) is a part of a project of the Kentucky Agricultural Experiment Station and is published with the approval of the director.