Co-hydrothermal liquefaction of spirulina + corn straw: Reaction mechanism, pathways and kinetic studies

In this work, a global kinetic pathway network and quantitative reaction kinetic model have been proposed and applied to accurately present the product changes and migratory behavior in co-hydrothermal liquefaction (co-HTL) of spirulina + corn straw. The reaction kinetic model involves the decomposition of feedstock to produce water-insoluble biocrude, as well as the mutual transformation processes between several different products. Moreover, the proposed model can accurately describe the temporal variation trends of different product yields. By analyzing reaction rate constant k_i and activation energy E_a, the rate-controlling steps for the non-catalytic and catalytic systems are determined as the pathway of water-insoluble biocrude to solids and that of aqueous-phase products converting to water-soluble biocrude, respectively. Finally, the optimal kinetic parameters obtained from model fitting outcomes were used to accurately predict the distribution and variation of different product yields over a wider range of temperature and time.