Abstract:

Acetylene hydrogenation reactor is an important unit operation in ethylene process, whose operation deeply influences yield and purity of ethylene product. Within an operating cycle, the catalyst activity in reactor gradually declines with time, the operating point will slowly deviates from the initial steady-state design point such that the ethylene yield will drop. To implement the full-cycle operation optimization, the kinetics model of catalyst deactivation considering green oil accumulation is presented through deactivation mechanism research, then a two-dimensional heterogeneous dynamic model of acetylene hydrogenation reactor with modified catalyst deactivation equation is proposed. The full-cycle simulation on gPROMS software verifies the correctness of modified model, and the full-cycle operation optimization is solved by Matlab optimizer on upper layer interacting with gPROMS simulation. The optimization results show that, the full-cycle operation optimization is superior to the fixed value temperature compensation in regard to both the economic benefit and the regeneration cycle of reactor, and the full-cycle operation optimization simultaneously optimizing inlet temperature and hydrogen input is of greater advantage.

Key words: process systems, operation optimization, process control, acetylene hydrogenation, catalyst deactivation model

摘要：

乙炔加氢反应器作为乙烯工业流程的重要环节，其运行会很大程度上影响到乙烯产品的产量和纯度。在一个运行周期内，乙炔加氢反应器内催化剂活性会随时间推移而缓慢降低，使操作点偏移，乙烯产量会随之降低。为了实现全周期操作优化，通过研究催化剂的失活机理，提出了考虑绿油累积效果的催化剂失活动力学模型，进而改进了乙炔加氢反应器二维非均相模型。通过在gPROMS平台模拟反应器全周期运行验证了改进模型的正确性，在上层运用Matlab优化器与gPROMS平台交互求解一个运行周期的操作优化问题。优化结果表明，与定值温度补偿方案相比，全周期操作优化在经济效益和反应器再生周期两方面都要优于定值温度补偿方案，且同时优化入口温度与入口加氢量的全周期操作优化方案具有更大的优势。

关键词: 过程系统, 操作优化, 过程控制, 乙炔加氢, 催化剂失活模型