Techno-Economic Analysis for the Synthesis of Downstream Processes from the Oxidative Coupling of Methane Reaction

摘要

Due to the huge methane deposits worldwide and the great need for the chemical process industry to have new alternatives for olefins production, especially ethylene as starting raw material for numerous products, the direct conversion of methane to ethylene has attracted considerable interest. The main reason that motivates the realization of this new approach is to exploit the availability of un-reacted methane, coming from the exit flue gas products of the OCM reactor, and thus, design an alternative process for methanol and formaldehyde production via OCM and the co-generation of electricity that can make the process economically attractive and designed so as to be industrially implemented. The total project investment, based on total equipment cost, as well as variable and fixed operating costs, was developed based on mass and energy balance information taken from Aspen? Process Economic Analyzer simulation results. The feasibility was evaluated in terms of energy savings, CO2-emission reductions and costs, in comparison to the separate production of methanol with conventional technology alone. Before starting the economic study of the OCM process a preliminary analysis of possible plant locations has been developed. Natural gas is a commodity which price varies strongly from one region to another. Moreover, not only the price of raw materials is affected by the location of the plant bul also the costs associated with the production, namely: steam, refrigeration, electricity, fuel, wages, etc., affecting strongly the profitability of a petrochemical project. Due to low natural gas prices in Venezuela, which has the highest production potential in South America, and the highest ethylene sales for the European market, this geographical location has been chosen for economic analysis of this project. Kinetic data of the OCM reaction were taken from the experimental fluidized bed reactor values that has been build in our facilities at TU-Berlin, which reflect promising conversion, selectivity and yield values, testing different catalysts developed at the Institute of Chemistry inside the scope of the UNICAT project. This analysis suggests areas for research focus that might improve the profitability of natural gas conversion, and the results have also been used for the design of the pilot plant which is now being operational at our department.