【摘要】 生物油酸类和酮类化合物具有较高的裂化活性,而使用分子蒸馏技术能将这些组分富集到蒸出馏分中,因此蒸出馏分相比原始生物油具有更好的裂化特性.为了模拟实际蒸出馏分的组成,本文将生物油模化物(羟基丙酮(HPO)、环戊酮和乙酸)进行配比混合,在固定床反应器上对其与乙醇的共裂化行为进行了研究,考察了不同反应温度和压力对混合反应物的转化率、粗汽油相的选择性和组成的影响.研究发现,当反应温度在340℃时,乙酸和乙醇的转化率分别仅为67.9%和74.4%,同时得到的油相产物中烃类含量仅为59.8%,并含有大量的含氧副产物.常压裂化同样生成了低品质的油相产物,同时油相选择性仅为10.8%.提高反应温度能促进反应物的转化,提高裂化过程中的脱氧效率,而提高反应压力对液体烃类的生成有明显的促进作用.在400℃和2MPa时,酸类和酮类都有良好的裂化表现,反应物接近完全转化,粗汽油相选择性达到31.5%,且全部由烃类组成,其中芳香烃含量高达91.5%.此外,反应后催化剂表征和稳定性测试结果表明,催化剂在较长时间反应后会失活,但通过催化剂再生能够很好地恢复催化剂活性.更多还原

【Abstract】 Acids and ketones in biomass pyrolysis oil(bio-oil) can be readily cracked to produce hydrocarbons.They can also be enriched in the distilled fraction using molecular distillation techniques.To simulate the actual composition of the distilled fraction,the co-cracking performance of mixtures of hydroxypropanone,cyclopentanone,and acetic acid with ethanol in a fixed-bed reactor over an HZSM-5 catalyst was studied.The influences of reaction temperature and pressure on the reactant conversion,selectivity,and composition of the oil phase were investigated.At a low reaction temperature of 340 ℃,the conversions of acetic acid and ethanol were as low as 67.9%and 74.4%,respectively,and the oil phase had a low hydrocarbon content of 59.8%,with large amounts of oxygenated byproducts.Cracking under atmospheric pressure also generated a low-quality oil phase with a very low selectivity of only 10.8%.Increasing the reaction temperature promoted reactant conversion and improved the deoxygenation efficiency,whereas increasing the reaction pressure significantly promoted hydrocarbon production.The optimum conditions for biogasoline production were 400 ℃ and 2 MPa.Under these conditions,the reactant conversion reached 100%and the oil phase selectivity was 31.5 wl%.This oil phase consisted entirely of hydrocarbons,91.5wt%of which were aromatic hydrocarbons,indicating that the HZSM-5 catalyst had high activity for deoxygenation and aromatization reactions during cracking.In addition,characterization of the spent catalysts and stability tests showed that the catalyst was deactivated after a long reaction time.However,the catalytic activity was recovered by catalyst regeneration.更多还原