Material and Energy Flow Analysis (Mefa) of the Unconventional Method of Electricity Production Based on Underground Coal Gasification

Abstract

In this paper, the application of Umberto NXT LCA software to devise a Material and Energy Flow Analyses (MEFA) for the technology of producing electricity from gas extracted in the process of shaftless underground coal gasification is presented. The Material Flow Analyses of underground coal gasification includes a range of technology, through obtaining process gas and its purification, to electricity production, and, additionally, the capture of carbon dioxide. To evaluate electricity production based on Underground Coal Gasification, Material and Energy Flow Analyses (MEFA) was used. Modeling material and energy flow helps a high level of efficiency or technology of a given process to be reached, through the effective use of resources and energy, or waste management. The applied software for modeling material flow enables, not only, the simulation of industrial processes, but also the simulation of any process with a material or energy flow, e.g. in agriculture. MEFA enabled the visualization of material and energy flow between individual unit processes of the technology of electricity production from UCG gas. An analysis of material and energy flow networks presented in the form of Sankey diagrams enabled the identification of unit processes with the biggest consumption of raw materials and energy, and the greatest amount of emissions to the environment. Thanks to applying material and energy flow networks with Umberto software, it is possible to visualize the flow of materials and energy in an analyzed system (process/technology). The visualization can be presented in the form of an inventory list of input and output data, or in the form of a Sankey diagram. In the article, a Sankey diagram has been utilized. MEFA is first stage of the plan to conduct analyses using Umberto software. The analyses performed so far will be used in the following stages of the research to assess the environmental impact using the LCA (Life Cycle Assessment) technique, to analyze costs using the LCC (Life Cycle Cost) technique, and to analyze eco-efficiency. It is important to highlight the fact that this is the first attempt of material and energy flow analysis of electricity production from UCG gas. This is the first approach which contains a whole chain of electricity production from Underground Coal Gasification, including stages of gas cleaning, electricity production and the additional capture of carbon dioxide.