MODELING OF A PLANT LAYOUT FOR A LIQUIFIED PETROLEUM GAS REFILLING PLANT

Abstract

As a result of the volatile nature of Liquefied Petroleum Gas (LPG), the improper siting of facilities and equipment within a LPG refilling gas plant could lead to accidents with devastating effects. This study therefore seeks to lay out a LPG refilling plant such that the total risk in financial terms when the plant is exposed to an accident is minimized. This is necessary considering the conflicting objectives of reduced piping cost and increased separation distance between process units. This was achieved using the integrated approach of quantitative risk analysis and mathematical programming to the layout of a LPG refilling plant. The Dow Fire and Explosive Index was used as a quantitative risk tool to evaluate the potential hazardous units and their distances of exposure were incorporated into a Mixed Integer Linear Program (MILP). This was done to minimize the piping cost and the residual risk posed to the units in the event of an accident. It was solved using the AMPL (A Mathematical Programming Language) optimization package. The result obtained revealed a good layout characteristics such as adequate spacing between process units and good utilization of land among others. The total financial cost of USD108,640.88 which may be broken down into residual financial risk of USD106,906.08 and piping cost of USD1,734.81was obtained for the layout