Fundmental Study On Liquefaction Of Corn Stalk To Produce Bio-oil Via In-situ Hydrogen Supply

In recent years,the shortage of energy has become a key issue that restricts the development of the society and economy.Biomass is the only renewable energy resource that can be converted into liquid fuels.Liquefaction product bio-oil has the advantages of safety,cleanness and so on.It is expected to an alternative energy source for fossil fuels after being modified.This paper was based on hydrothermal liquefaction,with the addition of hydrogen donor in the process of hydrothermal liquefaction of straw to improve the quality of bio-oil.The obtained bio-oil was analyzed by an elemental analyzer,fourier transform infrared spectroscopy(FT-IR),gas chromatography-mass spectrometry(GC-MS)and petroleum product characterization analyzer,respectively,then the impact of hydrogen donors on bio-oil yield and physical and chemical properties was investigated based on the analysis results above.First,the effects of different reaction conditions on the yield and composition of bio-oil obtained by hydrothermal liquefaction of corn stalks was investigated.The maximum yield of bio-oil was reached to 28.13% when the reaction temperature was 320 °C and the reaction time was 60 min.Hydrothermal co-liquefaction of corn stalks and polyethylene was carried out under different reaction conditions.High-density polyethylene(HDPE)was used as hydrogen donor.The results showed that co-liquefaction increased the carbon content and hydrogen content of bio-oil,the oxygen content was reduced greatly,the maximum deoxygenation rate was reached to 48.2% and the calorific value reached 34.25 MJ/kg.The reaction of aluminum and water to produce hydrogen was studied under different conditions.The results showed that the hydrogen production efficiency can be reached more than 97%under different experimental conditions and can provide 0.5-2.1 MPa hydrogen pressure for the reactor.Therefore,aluminum is regarded as an in situ hydrogen donor is feasible.The catalytic liquefaction of corn stalk is carried out aluminum as hydrogen donor and NiS-MoS as catalyst.The total acid value,moisture content and viscosity of bio-oil decreased obviously,and the calorific value was reached to 34.55 MJ/kg.The carbon content of bio-oil was increased to more than 70.5%,and maximum deoxygenation rate was reached to 51.6%.The content of alkanes in bio-oil was increased obviously,the maximum was 36.18% when the content of aluminum was 30wt%.Therefore,the addition of aluminum in the process of hydrothermal liquefaction of corn stalks can significantly improve the quality of bio-oil.