title: Comparison of in-situ and ex-situ catalytic pyrolysis in a micro-reactor system.
abstract: In this study, we compared ex-situ catalytic pyrolysis (CP) and in-situ CP of hybrid poplar in a micro-reactor system. When both pyrolysis and catalysis were performed at 700 °C, the carbon yield of olefins was greater for ex-situ CP than for in-situ CP (17.4% vs. 5.4%). On the other hand, in-situ CP produced more aromatic hydrocarbons than ex-situ CP (26.1% vs. 18.9%). The remarkably high yield of olefins from ex-situ CP indicates the potential of exploiting the process to preferentially produce olefins as a primary product from biomass, with aromatics being the secondary products. The carbon yield of carbonaceous residues from ex-situ CP was 18.6% compared to 31.3% for in-situ CP. Substantial carbon was deposited as char during ex-situ CP, which could be easily recovered as by-product, simplifying catalyst regeneration. The effects of catalyst loading, pyrolysis temperature and catalysis temperature on product distributions for ex-situ CP were also investigated. Our results showed that catalyst temperature strongly affected product distribution. While high catalyst temperature enhanced both olefin and aromatic production, yield of olefin increased to a greater extent than did aromatics. Neither pyrolysis temperature nor catalyst loadings had significant effect on product distribution for ex-situ CP.
authors.affiliation: Center for Sustainable Environmental Technologies, Iowa State University, Ames, IA 50011, United States; Department of Mechanical Engineering, Iowa State University, Ames, IA 50011, United States.
authors.forename: Kaige
authors.initials: K
authors.lastname: Wang
authors.affiliation: Center for Sustainable Environmental Technologies, Iowa State University, Ames, IA 50011, United States.
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Johnston
authors.affiliation: Center for Sustainable Environmental Technologies, Iowa State University, Ames, IA 50011, United States; Department of Mechanical Engineering, Iowa State University, Ames, IA 50011, United States. Electronic address: rcbrown3@iastate.edu.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Brown
mesh_terms: D000475:Alkenes / Q000138:chemical synthesis*; D019149:Bioreactors; D002384:Catalysis; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006361:Heating / Q000295:instrumentation*; D006358:Hot Temperature; D008904:Miniaturization; D032107:Populus / Q000737:chemistry*; D017641:Zeolites / Q000737:chemistry*
chemical_list: D000475:Alkenes; D017641:Zeolites
keywords: Aromatics; Catalytic pyrolysis; Ex-situ; In-situ; Olefins