Enhanced Catalytic Pyrolysis of Biomass for High-Quality Biofuel Production

The rapid increase in energy demand, the extensive use of fossil fuels, and the urgent need to reduce carbon dioxide emissions have raised concerns in the transportation sector, since transportation has been primarily dependent on fossil fuels. Biofuel from biomass can make significant contributions to overcome the expected depletion of fossil fuels and reduce carbon emissions. The availability and wide diversity of biomass resources have made them an attractive and promising source of fuels. Biomass can be converted into biofuel by thermochemical pyrolysis process. Improvements on the pyrolysis process of biomass fuels are needed to obtain a high-quality of bio-oil. Pre-treatment by acid leaching prior to the pyrolysis process is considered to remove Alkali and Alkaline Earth Metal (AAEM) from the biomass, since AAEM adversely affect the catalytic pyrolysis process. Information about biomass pyrolysis kinetics is also important to evaluate biomass as a feedstock for fuel or chemical production as well as efficient design and control of thermochemical processes. Further, the use of H-ZSM-5 and Al-MCM-41 as a mesoporous and a microporous catalyst has been proved to improve the quality of bio-oil. The influence of a catalyst regeneration on the chemical composition of the upgraded oil is also one of the factors pertaining to the catalytic process.In this study, the catalytic pyrolysis kinetics of lignocellulose biomass with a mixed catalyst of H-ZSM-5 and Al-MCM-41 at different ratios for both, un-leached and leached biomass, is analyzed. The derived activation energies are determined based on the solid-state reaction mechanism. Bench-scale experiments have also been investigated to improve the quality of bio-oil, in terms of Organic Fraction (OF), water content, acidity, favorable fractions, as well as gasoline-range chemicals. The effect of a mixed-catalysts and staged-catalysts consisting of H-ZSM-5 and Al-MCM-41 at different ratios in a lignocellulose biomass pyrolysis has been compared. The ratio of H-ZSM-5 and Al-MCM-41 in the catalyst mixtures for lignocellulose biomass catalytic pyrolysis has also been optimized. Further, the effect of sequential catalyst regenerations of H-ZSM-5 and Al-MCM-41 catalyst mixtures on the obtained catalytic pyrolysis products has been analysed.The bench-scale experiments of lignocellulosic biomass pyrolysis and catalytic pyrolysis were performed using a fixed bed reactor equipped with oil condensers and a gas collection