A CASE STUDY OF PRODUCTION OF VALUE-ADDED LIQUID PRODUCTS FROM NATURAL GAS OF MELLITAH GAS PLANT USING GTL TECHNOLOGY: A TECHNO-ECONOMICAL STUDY

Abstract

Natural gas (NG) has assumed an extremely important status worldwide as both a source of clean energy and a major feedstock for a number of petrochemicals. Its global value can be assessed by the economic, environmental, and sometimes political future of countries being dependent on their possession or lack of natural gas for domestic and global demand. This paper analyzes the economic aspects of natural gas. It presents a study on the economic and profitable utilization of natural gas by its conversion into valueadded products. There are four most important conversion options to convert natural gas into liquids: (a) Ammonia Production, (b) Fuels Production using GTL Technology (Fischer-Tropsch Process) or Dimethyl Ether (DME) Production, (c) Liquefied Gas Production, and (d) Methanol Production. This paper presents an economic study of conversion of natural gas of Mellitah Gas Plant in Libya into value-added liquid products using Gas to Liquid (GTL) technology. The important GTL technology is conversion of natural gas into liquid products by Fischer-Tropsch synthesis process. It provides good and promising means to meet the energy needs with cleaner fuels. Development of GTL technology in Mellitah complex allows for more value of natural gas by production of readily transportable liquid products such as diesel and naphtha. The produced diesel is free of sulfur, contains no aromatics and polycyclic aromatics and having high cetane number. The combustion of FT diesel results in virtually no emissions of SO2, NOx and unburned hydrocarbons. Another product, F-T naphtha, is considered to be an ideal feedstock for ethylene production as compared to naphtha produced from crude oil due to the lack of aromatics. Absence of aromatics gives rise to higher ethylene yield as compared to ethylene from conventional naphtha. GTL technology is a downstream value added industry (economic enhancement) of natural gas. At present Libya is exporting natural gas which can be converted to value added liquid products. The installation of GTL plant in Mellitah complex will give employment opportunity to young Libyans. Another advantage is the produced diesel will help to reduce the import of diesel for local consumption and it will be a step towards self dependency of the country on fuel. At present Libya imports more than 50% liquid fuels for local consumption. GTL plant in Libya can also be a strategic new export industry. The capacity of GTL plant and its re-payback value has been calculated. The quality of liquid products have also been discussed.