Correlation of biomass quality using htp assay to enzymatic hydrolysis and micropyrolysis products and the importance to the biofuel industry
Abstract
Human induced climate change and dependence on non-renewable resources are two of the most serious issues facing society today. Substitution of renewable fuels produced from biomass addresses both of these issues. In the production of biofuels, it is important to know the biochemical make-up of the biomass feedstock. A high throughput assay developed by Murphy et al., provides a faster method than traditional methods and the standard developed by the National Renewable Energy Laboratory. The purpose of this study was to explore relationships of biomass quality to process variables in the production of ethanol and to pyrolysis products. Corn stover samples from Iowa and Wisconsin with varying biomass quality were used for the study. The samples were pretreated with dilute acid liquid hot water in stainless steel reactors and sand baths at four severity levels and two solids loadings. Samples underwent enzymatic hydrolysis using Genencor's Accellerase 1500 and XY at three different loadings. Combined sugar yields were determined at 0 hr and 24 hr hydrolysis time. These results were correlated to biomass quality as determined by the HTP assay. The result of correlation showed that severity is the most important factor in combined sugar yield, enzyme loading the second most important factor, and solids loading is not important. In the correlation to biomass quality, this study showed no strong correlations exist. The same corn stover samples were pyrolyzed using pyrolysis gas chromatography, mass spectrometry, and flame ionization detection. Twenty four compounds were found and these were correlated to biomass quality parameters. Important compounds were shown to be levoglucosan, acetaldehyde, and multiple phenols (lignin derived compounds). Important correlations were found between biologically available carbohydrates and levoglucosan and acetaldehyde, along with unavailable carbohydrates and lignin with phenols. Biologically available carbohydrates correlated negatively to levoglucosan, the primary product of pyrolyzed cellulose, and positively to acetaldehyde, a secondary product. Unavailable carbohydrates and lignin correlated with various lignin derived products, including phenol, 4-vinylphenol, and vanillin.
Degree
M.S.A.B.E.
Advisors
Murphy, Purdue University.
Subject Area
Agricultural engineering|Civil engineering
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