Skip to Main Content
 

Global Search Box

 
 
 

ETD Abstract Container

Abstract Header

Kinetics of the Hydro-Deoxygenation of Stearic Acid over Palladium on Carbon Catalyst in Fixed-Bed Reactor for the Production of Renewable Diesel

Vam, Albert
http://rave.ohiolink.edu/etdc/view?acc_num=dayton1373313020

Abstract Details

2013, Master of Science (M.S.), University of Dayton, Chemical Engineering.
Biological oils are potential sources of liquid transportation fuels. In the presence of a precious metal catalyst under reducing conditions, the transformation of biological oils to liquid fuels proceeds sequentially. First, any double bond is quickly saturated. The double bond saturation is followed by the hydrogenolysis of the ester linkages which releases the saturated fatty acids from the propane backbone. The fatty acids are then deoxygenated producing n-alkanes. Typically, the n-alkanes are further treated to meet the required physical properties of a particular fuel fraction. Although important, the deoxygenation of the fatty acid had not yet been studied in production-like conditions. For this reason, in this study, a comprehensive investigation of the deoxygenation of a representative fatty acid was carried out by studying stearic acid (S.A.) diluted in a highly isomerized C24 solvent. The deoxygenation of stearic acid was studied in the presence of hydrogen, in a trickle-bed reactor by using a 3 wt % carbon-supported palladium catalyst. In order to simplify the study of the kinetics of the S.A. deoxygenation, a uniform S.A. concentration across the catalyst bed was desired. For this reason, the entire study was conducted under differential conditions, by limiting the S.A. conversion to 10 percent. The limited conversion allowed me to assume uniform S.A. concentration across the catalyst bed. The liquid products were identified early on as n-heptadecane, n-octadecane, and stearyl stearate. The rate of formation for each liquid product was examined over wide-ranging sets of temperature, initial S.A. concentration and hydrogen pressure. Kinetic data for the different products were graphically derived and rate expressions were developed and presented. The S.A. deoxygenation reaction network in the presence of hydrogen was found to be rather complex. The observed rate of n-heptadecane production was a combined rate of two reactions, the stearic acid decarboxylation and the octadecanal decarbonylation. Likewise, the observed rate of n-octadecane production was the sum of the rates of octadecanol reduction and stearyl stearate hydrogenolysis. In order to estimate the contribution of each of the rates of S.A. decarboxylation and octadecanal decarbonylation to the total rate of n-heptadecane production, the relative rate of CO/CO2 production was studied over a range of temperature and hydrogen pressure. And, in order to estimate the contribution of the rate of alcohol reduction and the rate of stearyl stearate hydrogenolysis to the total observed rate of n-octadecane production, a complete study of palmityl stearate hydrogenolysis was carried out to estimate the stearyl stearate hydrogenolysis partial contribution to the overall rate of n-octadecane production.
Heinz Robota, J. (Advisor)
Kevin Myers, J. (Committee Chair)
Amy Ciric, R. (Committee Member)
130 p.
Alternative Energy; Chemical Engineering; Chemistry; Energy; Materials Science; Organic Chemistry; Physical Chemistry
Deoxygenation; Pd on C; Stearic acid; Renewable diesel fuel; Green diesel; Fatty acids; hydrogenation of fatty acids; palladium catalyst; decarboxylation of fatty acid; decarbonylation; hydrocarbons production; algae oil refining;

Recommended Citations

Citations

  • Vam, A. (2013). Kinetics of the Hydro-Deoxygenation of Stearic Acid over Palladium on Carbon Catalyst in Fixed-Bed Reactor for the Production of Renewable Diesel [Master's thesis, University of Dayton]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1373313020

    APA Style (7th edition)

  • Vam, Albert. Kinetics of the Hydro-Deoxygenation of Stearic Acid over Palladium on Carbon Catalyst in Fixed-Bed Reactor for the Production of Renewable Diesel. 2013. University of Dayton, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=dayton1373313020.

    MLA Style (8th edition)

  • Vam, Albert. "Kinetics of the Hydro-Deoxygenation of Stearic Acid over Palladium on Carbon Catalyst in Fixed-Bed Reactor for the Production of Renewable Diesel." Master's thesis, University of Dayton, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1373313020

    Chicago Manual of Style (17th edition)

dayton1373313020
2,850
© 2013, all rights reserved.
This open access ETD is published by University of Dayton and OhioLINK.