(51d) Profitable Emission Reduction In Petroleum Refineries

Emission reduction is becoming increasingly important for petroleum refineries, as more environmental concerns and stringent regulations have been posed.  Air emission reduction in refineries is also a very challenging task.  It involves a large-scale complex manufacturing system.  In such system, air emissions could spatially scatter at many reactors, furnaces, and flaring facilities; and temporally occurs at any time.  Thus, cost-effective emission-reduction strategies should neither depend on end-of-pipe approaches, nor focus on solutions for single units or subsystems.  The major thrusts should focus on the comprehensively study of material, energy, and information exchanges within the entire manufacturing system, so as to identify the best solutions to the entire plant.  From the systems theory point of view, it’s unnecessary to enforce emission sources from each individual facility to reach the minimum.  As long as the generated emission sources from some facilities could be appropriately reused by others facilities to the maximum extent, the entire system emissions may still have chances to approach the minimum.  Therefore, to optimally balance emission source generations and utilizations among the entire system might be the smartest way to reduce refinery emissions. 

A greedy concept of profitable emission reduction (PER) is proposed in this paper, which has merits of economically attractive, environmentally benign, and technologically viable for air emission reductions in petroleum refineries.  To identify PER strategies, a methodology framework and a new general plant-wide scheduling model have been developed, which couples generic production activities and the characterization of major air emissions from refineries, such as CO₂, VOC (volatile organic compounds), NO_X (nitrogen oxides), and PM (particulate matters).  A case study has demonstrated the efficacy of the PER concept and the developed methodologies.