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Jefferson W. Tester. Johnson, Michael C., Ph. D. Massachusetts Institute of Technology Massachusetts Institute of Technology. Dept. of Chemical Engineering. Massachusetts Institute of Technology. Department of Chemical Engineering 2012-04-26T18:50:08Z 2012-04-26T18:50:08Z 2012 http://hdl.handle.net/1721.1/70402 784099822 Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2012. "February 2012." Cataloged from PDF version of thesis. Includes bibliographical references. High-lipid algae are potential sources of biofuels. Lipids in this biomass provide a straightforward chemical route to hydrocarbon-based high energy-density fuels needed for diesel and jet engines. However, current schemes for producing these biofuels require large amounts of energy and solvents to recover the oil. The feedstocks have dilute concentrations (1 wt% or less) in aqueous media, and must be dewatered significantly to form biofuels. A hydrothermal environment, utilizing a highpressure, high-temperature, water-based medium, is well-suited for processing these dilute biomass feedstocks. Conversion of high-lipid model feedstocks to bio-crude oils was investigated over temperatures from 250 to 350 C and a wide range of reaction times (from minutes to several hours). Temperature and pressure controlled batch reactions were performed on Isochrysis sp., and T. Weissflogii. Chemical analysis was performed to give a detailed characterization of the products, including fatty acid conversion and oil yields. Product analysis was thorough enough to be used for simulation of the hydrothermal process. These results were used to fit a model for lipid reactions in hydrothermal systems. Life cycle assessment (LCA) of the algal hydrothermal process was performed for comparison to conventional algal biofuel production techniques. Extraction and conversion to fuels had similar energy inputs for either hydrothermal or extracted oil. by Michael C. Johnson. Ph.D. 187 p. eng Massachusetts Institute of Technology M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 Chemical Engineering. Hydrothermal processing of high-lipid biomass to fuels Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="eb0a492d-ef42-4d24-876b-4b92b20eb28f"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Hydrothermal processing of high-lipid biomass to fuels</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2012</PublicationDate> <Authors> <Author> <DisplayName>Johnson, Michael C., Ph. D. Massachusetts Institute of Technology</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Chemical Engineering.</Keyword> <Abstract>High-lipid algae are potential sources of biofuels. Lipids in this biomass provide a straightforward chemical route to hydrocarbon-based high energy-density fuels needed for diesel and jet engines. However, current schemes for producing these biofuels require large amounts of energy and solvents to recover the oil. The feedstocks have dilute concentrations (1 wt% or less) in aqueous media, and must be dewatered significantly to form biofuels. A hydrothermal environment, utilizing a highpressure, high-temperature, water-based medium, is well-suited for processing these dilute biomass feedstocks. Conversion of high-lipid model feedstocks to bio-crude oils was investigated over temperatures from 250 to 350 C and a wide range of reaction times (from minutes to several hours). Temperature and pressure controlled batch reactions were performed on Isochrysis sp., and T. Weissflogii. Chemical analysis was performed to give a detailed characterization of the products, including fatty acid conversion and oil yields. Product analysis was thorough enough to be used for simulation of the hydrothermal process. These results were used to fit a model for lipid reactions in hydrothermal systems. Life cycle assessment (LCA) of the algal hydrothermal process was performed for comparison to conventional algal biofuel production techniques. Extraction and conversion to fuels had similar energy inputs for either hydrothermal or extracted oil.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>