Basic Research Of Bio-oil Preparation From Plant Biomass Waste Of Hydrothermal Liquefaction

Plant biomass waste,as one of the most important renewable energy resources,has a wide variety of sources that are readily available and inexpensive with sustainable regeneration advantages.In current studies,sugarcane bagasse is used as plant biomass waste materials prepared by hydrothermal conversion to bio-oil fuels.The reaction temperature,time and material ratio effects on the distribution of liquefaction products are noted.The effects of solutions like Na OH and Na2CO3 on the distribution of sugarcane bagasse liquefaction products are witnessed.Similarly,the effects of KBH₄,ZSM-5 zeolite and Ni-ZSM-5,Na-ZSM-5 modified zeolite catalysts are also observed on these sugarcane bagasse liquefaction products.Finally,the oil 1,oil 2 and heavy oil（HO）components are analyzed by GC-MS,and the various reaction conditions effects on the various types of compounds distribution of oil phase are observed.The gas products are analyzed by GC-TCD,which aim to explore various reaction conditions effect on gas composition of the gas phase.The reaction temperature,reaction time and the material ratio have significant influence on the hydrothermal liquefaction products distribution of sugarcane bagasse.When the reaction temperature is 285 ℃,reaction time is 30 min and sugarcane bagasse/ deionized water = 10: 200,the total oils get a maximum production rate of 46.9 %.The main compounds of oil 1 are phenols,ketones,furans,acids,aldehydes and alcohols.Phenols,ketones,furans,acids,esters and alcohols are the main compounds of oil 2.Whereas,the main compounds of HO are phenols,acids and hydrocarbons.According to GC-TCD analysis,CH₄ proportion in the gases products increases with the increasing reaction temperature,reaction time and growth of material ratio.While the H2 proportion in the gases products increases with the increasing the reaction time,but decreases with the growth of material ratio.On one hand NaOH solution can reduce the yield of solid residue and improve the sugarcane bagasse hydrothermal liquefaction rate,while on the other hand it can reduce the reaction temperature and reaction time for the highest rate of the total oil production.At different concentrations,NaOH solution is conducive to phenols generated of oil 1,oil 2 and HO,especially in the oil 2 and HO.Na2CO3 solution can increase the peak area ratio of phenols and reduce the peak area ratio furans in the oil 1.However,the phenols peak area ratio can be greatly improved in HO phase.The esters and acids are affected larger by Na2CO3 solution in the oil 2,where acids peak area ratio is decreased with the increasing Na2CO3 concentration.When using KBH₄ added in the hydrothermal liquefaction of sugarcane bagasse,the phenols and furans are significantly influenced in the oil 1,but aldehydes and other compounds are less influenced.Furans are not detected in the oil 2 when KBH₄ was used.The ketones and acids peak area ratio decreased with the addition of KBH₄ while the peak area ratio of phenols increased.However,the hydrocarbons and acids peak area ratio substantially reduced,and the peak area ratio of phenols greatly improved in the HO during the process.According to GC-TCD analysis,the more amounts of KBH₄ added,the more significant influence on the content of H2 in the gas phase and vice versa.The ZSM-5 zeolite can increase phenols and ketones peak area ratio in the oil 1,and reduce the peak area ratio of furans.With the increase of ZSM-5 amounts,the phenols peak area ratio gradually reduce in the oil 2.But however,the acids peak area ratio decreased significantly while esters peak area ratio increased significantly.Acids and hydrocarbon peak area ratios significantly reduced and the peak area ratio of esters increased in the HO when ZSM-5 added.The modified Ni-ZSM-5 and Na-ZSM-5 zeolite has a greater effects on the components of bio-oil,especially in phenols,furans,acids and esters.According to GC-TCD analysis,ZSM-5,Ni-ZSM-5 and Na-ZSM-5 zeolite has caused decrease in the H2 contents and whereas,the significant increase in CH₄ content occurred in the gas phase.