乳化原料催化裂化反应行为的研究

The Emulsified Daqing VGO Catalytic Cracking Process

催化裂化是重质油轻质化的重要手段 ,催化原料雾化液滴的大小对产品分布影响很大 ,根据重油乳化燃烧过程中的“微爆”理论和“分子聚集与解聚”理论 ,开发了乳化原料冷进料催化裂化反应工艺 ,该工艺采用复合非离子表面活性剂将催化裂化原料进行掺水乳化 ,在乳化剂和剪切力的作用下 ,水以1～ 5 μm的液滴均匀地分散在油中 ,形成稳定的油包水型乳化液。乳化原料经增压泵通过雾化喷嘴进行一次雾化后 ,同高温再生催化剂接触发生二次爆破雾化 ,进一步减小液滴粒径 ,改善焦炭选择性 ,提高轻质油收率。催化裂化工艺实验结果表明 :在基本相同的操作条件下 ,与未乳化原料相比 ,乳化原料的转化率增加 0 .5 %～ 3 % ,液化气和轻质油收率提高 0 .5 %～ 3 % ,焦炭和干气产率降低 0 .5 %～ 1.5 %。实验中所用表面活性剂对催化剂的筛分组成、微反活性。

Catalytic cracking is one of the important means in the petroleum refining industry for producing gasoline from heavy oil. The size of atomized droplets has great effect on the product distribution. According to “demolition atomization” theory and “molecular aggregation and depolymerization” theory in heavy oil emulsification combustion. We develop the emulsified feedstock catalytic cracking process. FCC feedstock is emulsified by composite nonionic surfactant under the existence of water. With effect of emulsifer and shear, the water disperses uniformly in the oil as droplets from 1 μm to 5 μm and the system becomes a stable W/O emulsion. After the first atomization through the pressure pump and spray nozzle, the emulsified feedstock conducts its second explosive atomization when it contacts with the high temperature regenerated catalyst particles, with the result of lower atomized droplets diameters and improving coke selectivity and increasing light fraction oil yield. The FCC process experimental results indicate that conversion of emulsified VGO increase 0.5% to 3%, LPG and light fraction oil yield increase 0.5% to 3%, dry gas and coke yields decrease 0.5% to 1.5%, under the same operation conditions. The surfactant used in the experiment has no effect on the sieve composition,catalyst activity and metal content.