燕山石化公司乙烯装置66×10^4t／a扩能改造方案的研究与决策

Scheme Study and Strategy on Expansion of Ethylene Plant to 660 kt/a at Yanshan Petrochemical Company

燕山石化公司 3 0× 10 4 t/a乙烯装置 1994年完成第一次扩能至 45× 10 4 t/a的改造后 ,仍存在原料灵活性差、能耗高、与同期建设的乙烯装置比规模偏小等问题。以全面提高技术水平、降低能耗、增加原料灵活性、尽可能扩大生产能力为目标 ,充分考虑方案的可实施性、实施时的安全性、实施后的可操作性及方案的先进性和经济性 ,对装置技术改造的方案进行了比选研究。经改造 ,实现了生产能力扩大到 66× 10 4 t/a的目标 ,实际可达 71× 10 4 t/a ,装置能耗明显下降 ,石脑油、轻柴油、重柴油、加氢裂化尾油均可作为乙烯原料。在世界上 ,首次在乙烯装置中采用混合冷剂制冷技术和碳三催化精馏加氢技术并获得成功 。

Yanshan Petrochemical Company after having expanded its 300 kt/a steam cracking unit to 450 kt/a in 1994 is still experiencing such proble ms as low feedstock flexibility, high energy consumption and smaller scale as compa red to other ethylene units constructed in the same time.In order to fully improve technical capability of steam crackers, reduce energy consumption, improve feedstock flexibility and increase production capacity, a l ot of technical revamp cases on steam cracking were studied and compared with at tention focused on the feasibility, safety, operability of the related revamp ca ses, as well as the advanced nature and economical features of the cases studied . As regards the pyrolysis-quench-compression system, the steam crackers will b e retrofitted on the site with the pyrolysis gasoline fractionation tower, quenc h water tower, pyrolysis gas compressor and steam turbine replaced by new ones, respectively. The separation system will adopt a low-pressure methane removal technology with the demathanizer tower replaced, coupled with the C 3 catalytic rectification/hydrogenation technology, while the high-pressure depentanizer w ill be replaced with the addition of a propylene rectification tower. The fract ionation flow sheet and equipment will be adjusted with the addition of a propyl ene compress or and compressor for binary mixture of methane-ethylene cooling agents. This r evamp has expanded the ethylene capacity to the target of 660 kt/a with the actu al capacity reaching 710 kt/a. This revamp project has remarkably reduced t he energy consumption, which is capable of using naphtha, light diesel fuel, hea vy diesel fuel and the hydrocracked tail oil as the steam cracking feedstock. T his project is the first to apply refrigeration by means of a mixed cooling agen t and has succeeded in using C 3 catalytic rectification/hydrogenation technolo gy, which has given an impetus to the progress of steam cracking industry in the world.