Studies On The Production Of Aromatic Hydrocarbons From Algal Model Compounds Catalyzed By MoCu-loaded Hierarchical ZSM-5 Zeolites

Under the premise of resource exhaustion and environmental degradation,algae hydrothermal liquefaction is the most effective way to produce aromatics green and environmentally friendly.The development of efficient catalysts with strong hydrothermal stability and high aromatics selectivity has been a research hotspot.In this paper,the effects of the preparation of hierarchical pores,the loading of bimetals,the reaction temperature and other conditions were studied from the aspects of catalyst selection,catalyst modification and reaction process condition optimization.Firstly,the influence of different catalysts on the reaction performance of oxygen-containing algal compound stearic acid was investigated.The catalyst was selected as HZSM-5,hierarchical HZ-0.2M,Z-0.2M with single metal load and Z-0.2M with bimetal load.The activity of several catalysts was tested in the hydrothermal gasification environment,and it was found that Mo and Cu loading had a positive effect on the yield of aromatics.After the selection of load capacity and load sequence,the molecular sieve Mo0.02Cu0.01/ Z-0.2M finally showed the best deoxidizing aromatization activity due to its appropriate pore structure,appropriate acid distribution,good hydrothermal stability and more active centers.The molar yield of total toluene and ethylbenzene and xylene reached 140.73% on Mo0.02Cu0.01/Z-0.2M catalyst.The preparation of bio-oil by hydrothermal liquefaction of algae is mainly carried out in supercritical water environment,which requires the higher hydrothermal stability of catalysts.The hydrothermal liquefaction of stearic acid catalyzed by different catalysts was investigated;Since fatty acids are insoluble in water,the yield of the reaction at the same temperature and under the same catalyst condition is roughly the same as that of the hydrothermal gasification reaction,the most active catalyst was Mo0.02Cu0.01/Z-0.2M,and the total TEX yield was 138.68%.Finally,the effect of model compound hexadecanamide of nitrogen compounds in algae on the reaction was investigated.The results showed that when the reaction temperature is 450℃ and the environment is hydrothermal liquefaction,the catalyst Mo0.02Cu0.01/Z-0.2M showed the optimum catalytic activity,and the total TEX molar yield reached 100.98%.