Optimal planning strategy for the supply chains of light aromatic compounds in petrochemical industries

The scope of this research is concerned with the supply chain of light aromatic compounds, i.e., benzene, toluene, o-xylene and p-xylene, in the petrochemical industries. The proper production scheme of these compounds over a specified time horizon can be configured by selecting throughput, operating conditions and technology options for each unit in the chain, by maintaining the desired inventory level for each process material, by purchasing enough feedstock, and by delivering appropriate amounts of products to the customers. A mixed-integer linear program (MILP) has been developed in this work to synthesize the best multi-period planning strategy under the constraints of given supplies and demands. By solving the proposed model, not only the appropriate inventory level of every process material and the optimal throughput and operation mode of each production unit can be determined, but also the purchase opportunities of intermediate oils can be clearly identified.