Experimental Study On Catalytic Pyrolysis Of Biomass Over La Semi-Coke-Based Catalysts

In this era of energy shortage,it is a hot issue to explore new energy and improve energy efficiency.Using a large number of easily available forest waste biomass for pyrolysis and reforming to produce hydrogen as a clean fuel is a hot issue.In terms of the research progress in this field at home and abroad,the main research focus in the field of biomass pyrolysis is to find efficient pyrolysis reforming catalysts to improve the production of pyrolysis gas and hydrogen.At present,the main problems in the research are:unstable catalyst performance,high cost,easy carbon deposition or deactivation,and the tar produced by pyrolysis process is difficult to purify or remove.Looking for a catalyst,with abundant resources and low price,Looking for a resource-rich,low-cost catalyst to improve the catalyst efficiency and remove tar more efficiently is a research hotspot of biomass pyrolysis reforming.On this premise,this paper used pine fuel rods as biomass raw materials,used self-designed reforming furnace for the two stages of pyrolysis experiment platform,and presented the preparation of catalyst and carrier lanthanum semi-coke base catalyst,surveied the biomass pyrolysis reforming reaction.The effects of reforming temperature and two catalysts on the gas,liquid and solid products of biomass pyrolysis reforming are briefly analyzed.?1?Compared with the simple pyrolysis test,under the condition of reforming,the gas yield increases from 437g/kg?at 650??to 497g/kg?at 850??,which are all higher than the maximum yield at 900?,and the H₂ volume fraction significantly increased,both higher than the H₂ volume fraction during pyrolysis at 800?.The production amount of tar also decreased under the condition of reforming.The extended exposure time of the liquid phase products under the reforming conditions to the high temperature environment,which is conducive to the more adequate removal of carboxyl group and the more thorough decomposition of phenols and alcohols.With the increase of pyrolysis temperature,the surface of residual carbon gradually becomes uneven,and its strength also decreases slowly?2?After adding semi-coke catalyst for catalytic reforming,the gas production rate increases significantly and H₂ volume fraction increases.With the addition of a semi-coke catalyst,the amount of tar generated decreases significantly.After high temperature catalytic reforming of gaseous liquid products with semi coke catalyst,the compounds of O-H functional groups decreased significantly,and the characteristic peak area of C-H,C-O,C=O and other stretching vibration is strengthened,and the number of characteristic peaks and peaks decreased.The semi-coke catalyst participates in the reaction during the catalytic reforming process,the surface fracture increases the ash accumulation and blocked the channel phenomenon,and the catalytic activity decreased.?3?When the catalytic reforming temperature was 800?,the maximum yield of pine wood pyrolysis gas reaches 531g/kg,and the minimum yield of tar is 90g/kg.The volume fraction of H₂ increases from 20.42%?at 650??to 32.66%?at 850??.Compared with the conditions of catalyst free and semi-coke free,the volume fraction of H₂ at 800?is significantly higher than 16.77%without catalyst and 20.06%when semi-coke free as the catalyst.The decline trend of tar production is obvious.After catalytic reforming,the catalyst showed agglomerated with metal elements,and the active components La₂O₂CO₃and La in the catalyst are converted into La₂O₃.With the carbon deposition and ash clogging,some pores on the catalyst surface are blocked,and the catalytic activity is somewhat reduced.The new La-loaded semi-coke based catalyst developed in this project shows better catalytic pyrolysis performance of pine wood,which is of great practical significance for improving biomass pyrolysis efficiency and reducing pyrolysis energy consumption.