Study On Pyrolysis Kinetics And Mechanism Of Rice And Corn

Typical grains,such as rice and corn,are important grain crops in the world and the most important materials in our grain storage.In view of the shortcomings in the study of typical grain thermal disasters,this paper takes two typical grains,rice and corn as research objects,to study the pyrolysis mechanism.The research progress of the thesis is summarized as follows:1.In this paper,we found that the pyrolysis activation energy of the grain was very close to the activation energy of common biomass materials,showing that when the temperature reached a high level,typical grains had higher flammability and fire risk,and the risk of rice was higher than that of corn.Attention should be paid to the fire hazards of typical grains to prevent their occurrence.The Coats-Redfern method was used to determine that the pyrolysis reaction of rice and corn was a process controlled by 3D diffusion reaction(ZH model).The thermal decomposition reaction mechanism of two typical grains at high temperature in an oxygen-containing atmosphere changes to a one-dimensional phase boundary reaction(R1 model).2.An independent parallel reaction model was used to consider the multi-component pyrolysis process of typical grain,and genetic algorithm(GA)was introduced as an optimization algorithm to solve a large number of kinetic parameters and stoichiometric parameters involved in the calculation process.The predicted DTG curves agreed well with the experimental DTG curves,indicating that the multi-component pyrolysis mechanism can describe the grain pyrolysis process well.We used the TG data of actual components to simulate the TG/DTG/DDTG curves of two typical grains for the first time,and the results proved the feasibility and application prospect of our method.3.This paper studied the formation of pyrolysis products of two typical grains by using TG-FTIR and TG-GC/MS,and explained the formation mechanism of small molecular such as CO,CO2 and alkanes.We presented a possible mechanism of the formation of methylfuran,3-penten-1-ol and 2,5-furandialdehyde,confirming that the grain pyrolysis process is not only the independent pyrolysis of their main components(starch,cellulose and protein),but also the synergy reaction between their main components.