(32e) Near-Zero Flaring Study for Chemical Plant Sustainability

During chemical plant turnaround operations (plant startup and shutdown) and process upset management, off-spec product streams will be produced, which usually have to be sent for flaring. Flaring is a passive and end-of-pipe means to protect personnel and equipment safety in chemical process industry (CPI). However, flaring inevitably generates huge amount of CO, CO2, NOx, and some extremely hazardous volatile organic compounds (VOCs), which will cause severe air pollution problems and negative societal impacts. Meanwhile, it also results in tremendous raw material and energy loss that could generate much needed products from the industry. Thus, flare minimization has great significance on environmental, societal, and economic advancement toward the sustainability of chemical process industry.

This paper addresses planning, scheduling, and process design opportunities on near-zero flaring for chemical plant turnaround operation to advance current endeavors on flare minimization. The key idea is to reduce the startup time and pursue the ?balanced? reuse of off-spec products from plant-wide systematic point of view. A general methodology framework has been developed. As a case study, the near-zero flaring thrusts for an ethylene plant startup have been studied.