(374az) Sustainability Assessment of Different Schemes of Syngas Production From Coal and Natural Gas

The development of a methodology for sustainability assessment facilitates the comparison of alternative processes, and enables the development of processes towards sustainability. In this work, a methodology for sustainability assessment has been applied to a syngas production system. Syngas, a mixture of hydrogen and carbon monoxide, can be produced from coal, natural gas, heavy hydrocarbons, etc., as a feedstock. Syngas can be characterized by its H2/CO ratio. Higher H2/CO ratios are needed for the downstream synthesis of chemicals and fuels. Coal is a cheap, abundantly available fuel and is the most commonly used feedstock for gasification. Typically, the H2/CO ratio is lower in syngas produced from coal. To overcome this, syngas produced from coal can be mixed with that produced from natural gas, which has a higher H2/CO ratio and is also the cleanest fossil fuel resource, in order to obtain the exact ratio necessary for a specific application. In this paper, three different arrangements have been assessed: using natural gas as a fuel in coal IGCC, co-gasification of coal and natural gas, and adding H2 produced from natural gas to adjust the syngas ratio. These processes have been modeled in Aspen Plus. Sustainability assessment has been carried out to determine the most sustainable pathway, taking into consideration the economic, environmental, efficiency and societal aspects.