458814 Emission Considered Scheduling for Crude Unloading, Transferring, and Processing
A concept of profitable emission reduction (PER) is proposed in this research, which has merits of economically attractive, environmentally benign, and technologically viable for air emission reductions in petroleum refineries. To identify PER strategies for refinery plants, a production scheduling model covers both front-end and refinery has to be involved. The key is to optimize the overall material and energy flows to make the plant net profit maximum, meanwhile to ensure emission source generations and utilizations to be smartly balanced. Other manufacturing constraints, such as operation specifications and inventory limits, should also be satisfied as well. Scheduling of front-end and refinery crude oil operations is an important part of petroleum supply-chain management.
In this research, a new methodology framework and a new general scheduling model have been developed for emission-considered crude unloading, transferring, and processing (ECUTP) system to achieve profitable emission reduction. The scope of the scheduling problem includes crude oil unloading from vessels to storage tanks at onshore berths, transfer of crude from these tanks to charging tanks, charging crude distillation units and further processing of crude inside the refinery, which includes crude distillation, cracking, coking, reforming, hydrotreating, product blending and component recovery. It also couples characterization and quantification of major air emissions from refineries, such as CO2, volatile organic compounds (VOC), nitrogen oxides (NOX), and particulate matters (PM). A general refinery process with more emphasis on air emission characterization and quantification will be introduced. The scheduling model is a large-scale mixed integer nonlinear programming problem (MINLP). The efficacy of the PER concept and the developed methodology have been demonstrated by different case studies.