Ekwueme, Stanley Toochukwu2025-02-182025-02-182022-02Ekwueme, S. T. ( 2022). Development of optimal gas- to liquids ( GTL) plant using steam/Co2 reforming for synthesis gas production . (Unpublished Masters thesis), Federal University of Technology, Owerri.https://repository.futo.edu.ng/handle/20.500.14562/1627The Degree of Master in Engineering ( M.Eng) in Petroleum Engineering Department . It contains tables, graphs, pictures and mathematical formulas.This research work is on method for optimisation of GTL plant using Steam/CO2 reforming for syngas generation. Extensive modeling of GTL plant has been done. Two cases were considered during the simulation of the GTL plant. The first case being the base case was the use of oxygen gas as the feed reactant gas using an auto-thermal reformer for the production of synthesis gas. The alternative case which is the proposed method in this work uses CO2 in lieu of oxygen for the production of synthesis gas. CO2 method was chosen because of its cheap availability and the ability to be recycled from purge gas and reused reducing pollution. Honeywell’s Unisim software was used for the simulation and the Peng-Robinson equation of state was chosen as the fluid property package. The simulation was done unit by unit and integration of all units was made. The synthesis gas unit was simulated in Unisim as a conversion type reactor using two separate reactors while three equilibrium reactors were used to control the water gas shift reaction to maintain favourable H2/CO ratio. The FT reactor was modeled as a multi-tubular bed reactor and simulated as a plug flow reactor (PFR) in Unisim using heterogeneous catalytic reaction type. Technical and economic performances were analyzed for both methods. The technical analyses revealed that the proposed steam/CO2 method gave a H2/CO ratio of 2.17 compared to 2.21 obtained for the autothermal reformer (ATR). Furthermore the carbon efficiency of the two methods revealed 77.68% and 92.17% for base case and the proposed method respectively making the proposed method more efficient. The liquid yield shows that the proposed method has a liquid yield of 5730b/d over the 5430b/d obtained from the base case representing an increase in product yield of 5.5%. The economic analyses show a quicker pay-out time of 4.9 years from the proposed model as against 5.9 years from the base case. Using the proposed method gave an annual cashflow increase of 20.9% and NPV increase of 59.7% at 10% discount rates. Thus the proposed method is more profitable in terms of NPV. This project will be suitable for application in the Niger Delta stranded and remote gas locations which are known for gas flaring leading to environmental pollution.enAttribution-NonCommercial-NoDerivatives 4.0 InternationalAutothermal reformingfischer-tropschgas-to-Liquidssteam/CO2 reformingsynthesis gasDepartment of petroleum engineeringMaster’s Thesis