Sarnia Refinery TGCU Reduces Sulfur Emissions and Provides Operating Flexibility

摘要

In response to Ontario Canada's tightening sulfur emission regulations, Imperial Oil's Sarnia Refinery implemented a project to add a Tail Gas Cleanup Unit (TGCU) downstream of their two existing Claus Sulfur Recovery Units (SRUs). Imperial Oil contracted URS (formerly Washington Group Northern) for the basic design, engineering, procurement, and construction management of the project. The new unit successfully commenced operation in June of 2010. The TGCU design is a hydrogenation - quench - amine configuration utilizing FLEXSORB® SE solvent, which is licensed by ExxonMobil Research and Engineering Company (EMRE). Several aspects of the project required novel engineering solutions to fulfill project goals, including: 1.Addition of a new TGCU between the existing two SRUs and incinerator, without the need of a tail gas blower 2.Meet <250 ppmv H_2S specification in the tail gas with upstream sulfur throughputs ranging from 65 tonnes/day to 241 tonnes/day 3.Quench tower to reduce tail gas ammonia content to <20 ppmv 4.Very limited plot space Both Imperial Oil and EMRE described the startup of the new TGCU as one of the smoothest in recent history. Furthermore, the refinery has gained operational flexibility and improvements as the unit is outperforming both the targeted sulfur removal and expected hydraulic capacity. This paper discusses the unique and challenging aspects of the TGCU design and the benefits the refinery has gained from the unit's addition. An overview of the startup is also provided.