| Biomass pyrolysis catalytic technology is an important way to prepare biomass vehicle alternative fuel.The principle and structure design of the reactor is particularly important.For the characteristics of the traditional reactor including complex structure and poor stability,a collaborative enhancement reactor was designed based on the principle of Dielectric Barrier Discharge(DBD).Using three components of biomass(cellulose,xylan and lignin)and polyethylene as raw materials and modified HZSM-5as catalyst,a study on the synthesis of alternative fuel for automobiles by combining different biomass components and polyethylene was carried out.The main contents are as follows:(1)A collaborative quality improvement reactor based on DBD was designed,and a pyrolytic-DBD collaborative quality improvement reaction system was built.The reactor adopted a tubular structure,featuring uniform discharge and high strength,which was more suitable for biological refining reactions.In addition,Ti and Ni were modified by impregnation method using HZSM-5 as base material.After modification,the crystal structure of the catalyst remained unchanged,and the physical and chemical properties of the catalyst were improved by the support of metal elements.(1)A collaborative quality improvement reactor based on DBD was designed,and a pyrolytic-DBD collaborative quality improvement reaction system was built.The reactor adopted a tubular structure,featuring uniform discharge and high strength,which was more suitable for biological refining reactions.In addition,Ti and Ni were modified by impregnation method using HZSM-5 as base material.After modification,the crystal structure of the catalyst remained unchanged,and the physical and chemical properties of the catalyst were improved by the support of metal elements.(2)Analyze the pyrolysis characteristics of different raw materials,including pyrolysis weight loss characteristics and pyrolysis liquefaction characteristics.The results show that the weight loss temperature is polyethylene > cellulose > xylan >lignin,the maximum weight loss rate is polyethylene > cellulose > xylan > lignin,and the total weight loss is polyethylene > cellulose > xylan > lignin.Cellulose is similar to the pyrolysis oil of xylan,and the products mainly include phenols,aldehydes and ketones,with the total content of the three products reaching 66.76% and 56.78%respectively.Due to the various free radicals containing benzene ring in its structure,the content of aromatic organic compounds reaches 84.43%,while the pyrolysis of polyethylene generates various small olefin molecules.(3)Using cellulose and polyethylene as raw materials,the experiment of automobile alternative fuel preparation was carried out.The results showed that the oil phase yield of cellulose and polyethylene combined conversion was significantly higher than that of cellulose alone conversion,and the oil phase yield increased from 30.12%to 36.67%.With the increase of polyethylene content,the oil phase yield increased significantly to 48.32%,and the oxygen-containing organic matter decreased significantly.After using Ti modified catalyst,the oil phase yield increased to 38.86%,and the monocyclic aromatic hydrocarbon content increased from 12.23% to 42.55%.The amorphous coke decreases from 1.44% to 0.90% and the graphite-type coke increases from 0.32% to 3.20% on the Ti-modified catalyst.After using Ni modified catalyst,the oil phase yield decreased to 33.35% and the monocyclic aromatic hydrocarbon content increased to 44.36%.Amorphous coke and graphite-type coke increased to 4.81% and 1.53% on Ni-modified catalyst,and the total coke content increased from 1.76% to 6.34%.(4)Using xylan and polyethylene as raw materials,the preparation experiment of automobile alternative fuel was carried out.The results showed that the addition of polyethylene increased the oil phase yield from 24.15% to 40.67%,and the oxygen-containing organic matter in the oil phase decreased significantly.The use of Ti modified catalyst increased the oil phase yield from 29.93% to 33.30%,the single cyclic aromatic hydrocarbon content from 17.09% to 22.55%,the light coke from 1.23% to1.96%,the amorphous coke from 3.43% to 4.10%,and the graphite coke from 0.84% to0.35%.With the addition of Ni modified catalyst,the oil phase yield decreased to28.17%,the single cyclic aromatic hydrocarbon content increased to 40.90%,the light coke increased to 3.09%,the amorphous coke increased to 6.75%,the graphite coke increased to 1.13%,and the total coke content increased from 5.50% to 10.97%.(5)Using lignin and polyethylene as raw materials,the experiment of automobile alternative fuel preparation was carried out.The results showed that the oil phase yield of lignin was significantly lower than that of cellulose and xylan,and the highest oil phase yield was 29.25%.Using Ti modified catalyst,the oil phase yield increased from20.10% to 22.72%,and the content of single cyclic aromatic hydrocarbons decreased from 59.22% to 39.58%.The amorphous coke increased from 1.80% to 4.03% and the graphite-type coke increased from 3.20% to 7.80%.When Ni modified catalyst was used,the oil phase yield increased to 24.00% and the single cyclic aromatic hydrocarbon content increased to 71.95%.On the Ni-modified catalyst,amorphous coke increased to 7.03%,graphite coke increased to 9.80%,and the total coke content increased from 5.00% to 17.10%.(6)In conclusion,the oil phase yields of the three components of biomass transformed alone were cellulose > xylan > lignin,and the oil phase yields increased after adding polyethylene.The oil phase yields were cellulose > xylan > lignin after using Ti modified catalyst,and cellulose > xylan > lignin after using Ni modified catalyst.The contents of monocyclic aromatic hydrocarbons in the oil phase obtained by three groups of biomass conversion alone were: lignin > xylan > cellulose.After adding polyethylene,monocyclic aromatic hydrocarbons were lignin > xylan > cellulose.After using Ti modified catalyst,the contents of monocyclic aromatic hydrocarbons were cellulose > lignin > xylan.After using Ni modified catalyst,the content of monocyclic aromatic hydrocarbons was lignin > cellulose > xylan.The coke amount of the three components was lignin > xylan > cellulose,and the coke amount of the Ti modified catalyst was lignin > xylan > cellulose.The coking amount of Ni modified catalyst was lignin > xylan > cellulose. |
