抽提重组石脑油用于生产优质催化重整及乙烯裂解原料

Naphtha Recombination for the Production of High-Quality Catalytic Reforming and Ethylene Cracking Feed

摘要: 设计了一种新工艺对石脑油进行分离重组，用于生产优质重整及乙烯裂解原料。工艺包括预分馏塔和抽提蒸馏单元，抽提蒸馏原料为预分馏塔顶的轻馏分。以抽出油和预分馏塔底重组分作为重整原料，抽余油作为乙烯裂解装置原料。结果表明，最佳抽提溶剂的质量比为7:3的N-甲基吡咯烷酮、二苯甲烷复合溶剂。采用该溶剂对预分馏后石脑油轻组分进行抽提蒸馏小试实验，得到抽余油中链烷烃质量分数增至68.99%，较石脑油原料提高24.21个百分点，芳烃含量几乎为零，是优质的乙烯裂解装置原料；预分馏重组分和抽出油芳潜较石脑油原料分别增加5.7、6.5个百分点，二者混合后芳潜为57.5%，是较好的生产无苯清洁汽油或多产甲苯的重整原料。用Pro II软件对该工艺进行模拟，所得结果与实验结果基本吻合，并在此基础上优化了工艺参数，计算得工艺总能耗为20.86 MW。

Abstract: A novel process was designed to recombine naphtha in order to produce high-quality feed of cata-lytic reforming and ethylene cracking. It included a naphtha pre-fractionation column and an ex-tractive distillation (ED) unit. The light fraction from the top of the pre-fractionation column was sent into the ED column as its feed. The extracted oil together with the heavy components from the bottom of the pre-fractionation column were used as reforming feed; while the raffinate from the ED unit was used as ethylene cracking feed. The experiment results showed that the best solvent for ED unit was the mixture of N-methyl pyrrolidone and diphenyl methane (mass ratio was 7:3), and it was used in the extractive distillation trial test to separate the light fraction after pre-fractionation. The mass fraction of alkanes in the raffinate went up to 68.99%, which was 24.21 percent points higher than naphtha, and the content of aromatics was almost 0. It was good raw material for ethylene plant. The aromatic potential of pre-fractionated heavy components and the extracted oil increased by 5.7 and 6.5 percentage points respectively compared with naphtha, and the final aromatic potential of the mixture was 57.5%. It was suitable to produce benzene-free clean gasoline or to be the reforming feedstock for toluene production. The whole process was simulated by ProII software, and the simulation results were basically consistent with the experimental results. Finally, the operating parameters were optimized, and the total energy consumption was 20.86 MW.