Major Chemical Safety Incidents – A Review of Common Causes

Yeochun NCC Co., Ltd (YNCC) Ethylene Plant No. 2 is located near Yeochun, Korea. The plant No. 2 ethylene technology was licensed by Technip Energies Process Technology (formerly Stone and Webster) in 1992. The original capacity of this plant was 350 KTA of polymer grade ethylene with the equipment designed for capacity of 450 KTA (based on 8,000 operating hours per year). YNCC#2 revamped plant on various occasions to 543 KTA. In 2009 Technip Energies Process Technology performed a feasibility study to identify the bottlenecks and required scope of modifications. The objective was to increase the operating capacity of the plant from 543 KTA to 859 KTA. In 2018, YNCC decided to implement 859 KTA expansion and contracted Technip Energies Process Technology to provide Basic Engineering Package (BEP) and Ethylene Technology Licensing for the planned capacity, as well as efficiency increase for YNCC No. 2 Ethylene Plant. This important plant revamp had many challenges due to the large capacity increase of ~160% from the current capacity.

This paper will discuss the various revamp techniques and construction challenges in this large capacity increase. Few examples are:

• Addition of two 192U furnaces and a gas turbine on a tight plot space.
• All three major compressors (Cracked Gas, Ethylene Refrigeration and Propylene Refrigeration) had a foot print replacement on the same foundation.
• High capacity trays were used in many towers.
• Parallel towers were added for few services where required capacity increase was beyond capacity limit of the high capacity trays.
• Efforts were done to minimize the parallel equipment addition due to the limited availability of the plot space. Many equipment were therefore replaced on the same foundation instead of adding a parallel equipment.

YNCC along with its construction partners Daelim and Hanwha successfully completed the construction in December 2020 and plant was started up and achieved the targeted ethylene production in January 2021.