Experimental Study On Catalytic Pyrolysis Of Biomass With Ce Bio-char Catalysts

With the rapid development of industrialization and the improvement of people's living standards,the continuous consumption of fossil energy has led to serious environmental pollution and the exhaustion of fossil energy.Therefore,how to make the environment and energy develop harmoniously is getting more and more attention.Biomass is a kind of renewable energy with very wide distribution and abundant resources.It is an environmentally friendly low-carbon energy and plays an important role in the sustainable development of social economy.As far as the development and utilization of biomass energy in China is concerned,the utilization level is low and it is not possible to make full use of its energy.Therefore,the effective conversion of low-grade energy into high-grade energy in biomass energy has always been the concern of the majority of researchers problem.In this project,Ce-supported biomass char catalysts were prepared,and a two-stage biomass catalytic pyrolysis fixed furnace experiment system was used to conduct biomass pyrolysis experiments.Through pyrolysis tests on pine sticks,analyze the composition,morphology and pore change of pyrolysis reaction products and catalysts.According to the reaction mechanism of biomass pyrolysis,it provides important basic data for the optimization and research of thermochemical conversion process.1.The thermal weight loss process of pine wood particles can be divided into three main stages:dehydration,volatilization analysis and carbonization.The bio-char catalyst and a small amount of Ce supported on the metal will cause thermal hysteresis,which will cause the starting temperature and ending temperature of the main stage of pyrolysis to move to the high temperature region.Hemicellulose pyrolysis is mainly an endothermic reaction,cellulose pyrolysis is a strong endothermic reaction.Lignin pyrolysis has a wide temperature range and emits a lot of heat,which is the main source of biomass char formation.2.As the temperature of catalytic reforming increases,the volume fraction of H₂increases from 14.65%at 650?to 26.04%at 850?.The increase in temperature is conducive to the reaction equilibrium towards the endothermic reaction,which in turn promotes the secondary cracking reaction and reforming reaction of tar.The increase of Ce addition increased the overall volume fraction of H₂ from 20.06%of Ce-2/char to 27.35%of Ce-8/char.The Ce-supported biomass char catalysts crack large organic compounds into small hydrocarbon gas to promote the production of H₂.When the catalyst was used 4times,it was found that the volume fraction of the gas was significantly weakened.With the increase in the number of times the catalyst was used,carbon deposition and ash deposition occurred in the biomass pyrolysis catalysis process,which affected the bio-char catalytic activity.At the same time,the catalyst had Long service life and strong regeneration performance.3.With the increase of metal Ce loading,the specific surface area of semi-coke based catalysts gradually decreases?Ce-2/char-618.69m²/g,Ce-4/char-516.52m²/g,Ce-6/char-514.54m²/g?.The specific surface area after use at 800?is 494.14m²/g,which is a slight increase from 456.75m²/g at 650?,because the accelerated catalytic cracking reaction of biomass at high temperature makes the carbon deposition rate slower.After the catalyst is used,a part of Ce²⁺and CeO₂ undergo a reduction reaction to generate elemental Ce,but at the same time,a large amount of CeO₂ still exists,which proves that the catalyst can be recycled and recycled.4.The relative content of LPAHS in tar increases with increasing temperature,which is 35.80%,47.16%,58.03%,54.46%,61.80%,indicating that it is difficult to remove at higher temperatures and will stimulate the formation of polyaromatic compounds at higher temperatures.The relative contents of HPAHS with increasing temperature are 13.49%,8.83%,12.00%,16.88%,and 21.35%,respectively.It needs to be cracked at a higher temperature.After the fourth use,HPAHS increased significantly,and heterocyclic aromatic hydrocarbons and monocyclic aromatic hydrocarbons no longer showed a downward trend,indicating that the catalytic performance decreased with the increase of the number of catalysts used,which affected the cracking behavior of polycyclic aromatic hydrocarbons and the tendency of monocyclic aromatic hydrocarbons to increase.Cyclization of cyclic aromatic hydrocarbons.This topic proposes effective solutions to alleviate global energy tensions through the use of waste.A bio-char-based catalyst is used as the catalytic raw material to conduct biomass pyrolysis test,analyze the catalytic performance and regeneration performance of the catalyst,and provide a reasonable basis for selecting the optimal catalyst to fully pyrolyze the biomass.