Aspen HYSYS’ Simulation of Ammonia Synthesis from Stranded Gas

Abstract

Companies have been finding ways stranded gas can economically be used or marketed rather than flaring it. The issue of gas flaring is being frowned upon by many regulatory bodies; hence most oil and gas operators are advised to find a better alternative. A high rate of gas flaring threatens our environment as it reduces the oxygen content in the atmosphere resulting in health issues and waste of our natural resources. However, this paper aims to simulate ammonia production from stranded gas (gas flare stream). A simulation approach was adopted using Aspen HYSYS V10 (Version 10). Three basic processes were employed during the simulation: steam reforming, carbon capturing and ammonia synthesis. The data used for the simulation were obtained from a marginal field operator in the Niger Delta region of Nigeria. Upon simulation, it was observed that the gas stream flowing at a rate of 484.13MMscf/day, with a pressure of 568.9 psig, yielded high ammonia gas of0.810829276 mole fraction at a low temperature of 30oC and pressure of 298.62 bar. High purity of hydrogen and 0% yield of carbon (IV) oxide were obtained by passing the syngas through carbon capture unit which made of absorber and desorber of packed column and MEAmine solvent for removal of CO2. In a nutshell, the result obtained from the simulation proved to be environmentally friendly as little to no greenhouse gases were expended.