Technological Conditions For Bio-oil Hydrogenation Upgrading By Commercial Ni Based Catalyst

Due to rapid economic development, human`s demand for energy has increaseddramatically, and energy shortages has become a major factor restricting economicdevelopment. The burning of fossil fuels results in a dramatic increase in carbondioxide emissions. The greenhouse effect, air pollution and other environmentalproblems have become increasingly prominent. So biomass energy, as a clean andrenewable energy, has gradually been paid attention by people. Biomass, as a carbonsource, becomes a traditional raw material of the petrochemical industry in the future.And the global carbon cycle with zero carbon dioxide emission could be seen due tothe joining of the renewable biomass sources.It is found that in the biomass pyrolysis oil(bio-oil) hydrodeoxygenationupgrading process with commercial Ni-based catalyst RZ409for oil reforming, such acatalyst shows not only good hydrodeoxygenation activity for bio-oil, but also verygood acid resistance and hot water resistance. By adding a certain amount of organicsolvent under the optimization of experimental conditions, the calorific value of thebio-oil increases from14~18MJ/kg to36~37MJ/kg, oxygen content reduces fromabout50%to10~15%, water content also reduces from20~35%to1~2%, hence, thequality of bio-oil can be greatly improved. The optimum experiment conditions are asfollows: the solvent ratio of bio-oil: n-butyl alcohol: xylene=3:1:1, the experimenttemperature is300℃, the reaction timeis1h, the heating rate is3.0℃/min.Under the optimum conditions, the yield of the oil phase upgraded by RZ409is56.6%, and the deoxidation rate is55.2%, the moisture content of the oil phase is1.83%, the heat value is36.23MJ/kg, pH increases from2.3to4.8. Acidity is notonly improved, but also bio-oil can achieve a good solubility with diesel oil. And thecoke amount of RZ409catalyst is25.07mg/100mg. XRD analysis show that, in thesame experimental conditions, the support structure of ICI46-1catalyst is destroyed,while of RZ409catalyst is still complete. The results indicate that rare earth elementssuch as Ln added in RZ409catalyst could make the phase of γ-Al2O3in the catalystsupport more stable, and, the same time, effectively inhibit the Ni sintering and loss,hence, such a catalyst has a better carbon deposition resistance.The coke kinetics analyses of RZ409catalyst indicate that the activation energyand the deposition amount both first increase and then decrease, finally increase again with the increasing reaction temperature. The value of coke combustion activationenergy can reflect the stability of the coke. The higher the value is, the highertemperature the coke combustion requires. It means that the catalyst regeneration ismore difficult. What’s more, dealumination and dehydroxylation phenomenon ofcatalyst support easily happen in such a high temperature, leading to low acidity, andthen seriously affecting the catalyst regeneration. In a word, the regeneration ability ofdifferent catalysts through comparing the coke burning kinetic parameters can beobtained, which is beneficial to develop more effective and stable catalysts.