Minimize flaring during ethylene plant startup

Abstract

Prechilling the demethanizer feed system and cold train with natural gas, a Taiwanese grassroots ethylene plant completed its first-time startup in a record 17 hours. This ethylene plant also was commissioned with virtually no flaring. Using prestart and startup checklists, ethylene operators can dramatically reduce off-spec product, which must be flared and is costly. To reduce startup emissions, operators must look within the process design and startup procedure to eliminate waste generation and implement pollution prevention techniques. Simple techniques such as recycling startup and off-spec streams can easily and cost-effectively be incorporated into the process design and greatly impact emissions during startup.