(248a) Region Specific Economic Modeling of Integrated Biorefining Using Process Simulation and Supply Chain Optimization
Energy dependence and pollution due to the increasing use of fossil fuels for the production of energy has become an area of concern in recent years. Most of the present research is focused on developing processes that rely on renewable resources and using existing processes in an effective and environmentally friendly manner. Feed used for these processes should be available in ample amount and should be economic compared to other fossil fuels used for energy production. Integrated biorefining is one such development which combines all the possible processes for the production of electricity, fuels and other useful products. Biomass, poultry litter and municipal waste are some of the potential feeds for biorefining. However, the density and quality of these feedstocks vary from one region to another. As such, it is necessary to develop a region specific economic model for integrated biorefining. Gasification in an integrated biorefinery is a proven method for the production of synthesis gas from coal, biomass and a combination of both. Gasification of agricultural and municipal waste is not only a good means of disposing unwanted products but can also be a source of additional revenue. Once synthesis gas is produced by gasification, selection of next process or combination of different processes depends on the local demand for a specific product. One of the concerns with gasification is that the ash content coming out of the gasifier will change with any change in the feed used. Hence, the analysis of ash content and proper disposal of it is important to make this process a clean technology. In this presentation we will show a case study on the Jackson Purchase region in Western Kentucky. The Jackson Purchase region not only has good reserves of coal but is also rich in woody biomass, crop residue and has numerous poultry farms. Process simulation models are developed for gasification of coal, biomass and chicken litter in this region. Due to local demand for fuel, gasification is followed by Fischer-Tropsch process for the production of methane, ethane and other alkanes. Ash coming out of the gasifier for different combinations of feed is analyzed and corresponding disposal techniques are suggested. The results obtained show that the operating cost of the process varies significantly with varying combinations of feedstock chosen. Geographic information system modeling is used to locate the actual distance of feedstock from the proposed plant location. Transportation of raw materials to the plant is an important criterion to propose the location of an integrated biorefinery. Most of the poultry farms present in the Jackson Purchase region were located using this technique and a site for biorefining was proposed. An economic framework is developed taking into consideration some key factors such as transportation cost, installation cost and sales revenue along with operating cost. Based on this economic framework, process models and supply chains were optimized which led to the development of a model library for conversion of biomass and other agricultural and poultry waste into fuels in the Jackson Purchase region. The library includes all possible processes and pathways corresponding to any potential feed available in that region. In a broader perspective, this approach can be applied to connect all the processes for energy and fuel production utilizing local feedstock available in a specific region.