Abstract:

Conversion of fatty acid methyl esters (FAMEs) to bio-paraffins and further to bio-olefins offers a potential solution to the emerging problems in the biodiesel industry due to the collapse of world oil prices. NiMo/Al₂O₃ catalyst prepared via an impregnation method was evaluated in the catalytic hydrodeoxygenation of FAMEs to bio-paraffins. The obtained paraffins were used as feedstocks to produce bio-olefins via steam cracking. The presulfided NiMo/Al₂O₃ converted the saturated FAMEs selectively to paraffins, without observable changes in the catalyst structure after reaction for 1000 h. Under the cracking conditions of coil-out temperature and pressure at 810℃ and 0.10 MPa, residence time at 0.23 s, and mass ratio of water to paraffins at 0.75, the yields of ethylene, propylene and butadiene were 36.30%, 18.14% and 7.46%, respectively. These data were much higher than the values of 27.45%, 14.74% and 5.31% obtained with naphtha as feedstocks under the similar conditions, indicating that bio-paraffins derived from FAMEs are alternative feedstocks for light olefins.

Key words: fatty acid methyl ester, hydrodeoxygenation, bio-paraffin, steam cracking, bio-olefin

摘要：

脂肪酸甲酯经生物烷烃制备轻质烯烃，有望缓解低原油价格导致的生物柴油产业发展困境。采用浸渍法制备了NiMo/Al₂O₃催化剂，首先考察其催化脂肪酸甲酯加氢脱氧制备生物烷烃的性能，然后进一步分析生物烷烃蒸汽裂解制烯烃的转化规律。结果表明，预硫化的NiMo/Al₂O₃能够高选择性地催化饱和脂肪酸甲酯加氢制备生物烷烃，并且催化剂的结构在反应1000 h后无明显改变。以上述烷烃为原料，在裂解炉出口温度为810℃，出口压力为0.10 MPa，物料停留时间为0.23 s和水油质量比为0.75的反应条件下进行蒸汽裂解，产物中乙烯、丙烯和丁二烯的收率分别达到36.30%、18.14%和7.46%，显著高于同等条件下石脑油原料得到的27.45%、14.74%和5.31%，表明源于脂肪酸甲酯的生物烷烃可以作为生产轻质烯烃的原料补充。

关键词: 脂肪酸甲酯, 加氢脱氧, 生物烷烃, 蒸汽裂解, 生物烯烃