Discipline: Technology & Engineering
Subcategory: STEM Research
Ghasem Shahbazi - North Carolina A&T State University
Co-Author(s): Lijun Wang, Department of Natural Resources, NC A&T State University, Greensboro, NC
The combination of biomass gasification and subsequent Fischer–Tropsch (FT) synthesis is a promising pathway to produce liquid fuels and chemicals as alternatives to fossil-based fuels and chemicals. Biomass gasification in a fluidized bed gasifier involves complicated physicochemical and structure evolution of biomass particles, and reactive gas-particle behavior. The impurities in syngas such as nitrogen and tar can severely interfere with downstream catalytic reactions using the syngas. Syngas produced through biomass gasification contains a significant amount of CO2. This project is thus to study an integrated biomass gasification and FT synthetic process to produce liquid fuels from biomass. Five studies have been conducted, which include (1) experimental determination and mathematical modeling of physicochemical and structural evolution of biomass particles during gasification; (2) computational fluid dynamics (CFD) modeling of the multiphase reactive gas-particle flow behavior in a biomass fluidized bed gasifier; (3) investigation of a nickel-based catalyst for tar cracking and ammonia decomposition of hot syngas; (4) study of Fe-based catalyst for the F-T synthesis of liquid fuels from biomass-derived syngas with a significant amount of CO2 and (5) process simulation of the biomass-to-liquid fuel refinery. Advanced experimental and mathematical modeling techniques are used to generate fundamental knowledge and tools necessary for the development of a biomass-to-liquid fuel refinery based on gasification and FT synthesis. Specifically, experimental techniques including thermogravimetry, differential scanning calorimetry, Frontier micropyrolyzer, elemental analyzer, gas chromatograph, mass spectrometry and infrared spectrometry are used to uncover the physicochemical evolution of biomass particles during gasification. The evolution of the porous structure of biomass particles is analyzed using a B.E.T. surface area and pore analyzer. A CFD model with temperature-dependent physicochemical and structural properties is developed to analyze the behavior of multiple-phase, reactive gas-particle flow in a biomass fluidized bed gasifier. Different nickel-based low-cost catalysts are investigated to catalytically remove tar and ammonia from the syngas. The effect of promoting Fe-based F-T catalysts with various metals in hydrogenation of biomass-derived syngas is studied. A mathematical model is developed in Aspen Plus and Gabi 6 to analyze the techno-economics and assess the environmental impacts of the bio-refinery operations.
Funder Acknowledgement(s): NSF CREST Center for Bioenergy, Award #1242152
Faculty Advisor: None Listed,