System Analysis And Life Cycle Assessment Of Syngas-based Energy-chemical Complexes

Syngas-based energy-chemical complexes are an advanced and promising system, which is able to utilize a variety of hydrocarbon feedstocks and transformed into multiple products of power, chemicals, and fuels. Such kind of complexes, with the integrated use of multiple feedstocks and existing production infrastructure, can increase the efficiency of energy utilization by manufacturing high value-added chemicals, gaseous and liquid fuel, and electricity, with less contamination to the environment. It is a rational alternative in the respect of the conflict between economic growth and energy resource shortage in China. The initiative of this dissertationis is to apply the theory of System Engineering to research comprehensively the issue of energy-chemical system, especially for syngas-based energy-chemical complexes. The research ereas include flowsheet concept modeling, process design, process analysis and evaluation, and process optimization.With the increasing complexity and highly integration of the new energy-chemical processes, there is a need of modeling, simulation, and evaluation for such kind alternative processes. Based on technology selection, modeling and simulation for energy-chemical complexes, especially for syngas-based energy-chemical complexes, were conducted in this work. Exergy analysis and thermodynamic analysis are applied for process evaluation. This work constructs a basis of conceptual design and quantitative evaluation of energy-chemical processes.In view of energy-chemical complexes, a new evaluating method of poly-feed poly-production system is proposed. This method decides the reference performance benchmark for poly-feed poly-production complexes. The benchmark is calculated semi-theoretically with typical performance data of the reference system. The performances of complex system are quantified by energy saving ratio, investment cost saving ratio, and product cost saving ratio based on production oriented. This method is easy and exact, which provide a better way to calculate the performance for the analysis and optimization of energy-chemical complexes.Life cycle assessment (LCA) and life cycle cost analysis (LCCA) method were applied to analyze the environmental impacts and economic performance of power generation scenarios. Environmental impact potentials and life cycle cost of life cycle phases and emissions were calculated to compare conversional coal-fired (C-F) to its alternatives integrated gasification combined cycle (IGCC) and natural gas combined cycle (NGCC). Considerring economic and environmental performance, IGCC is an advanced and clean coal power generation alternative in China.To sum up, by work of this dissertation, the span and depth of research field related with energy-chemical complexes are further developed and the theory, methodology and tool of system engineering are enriched to energy-chemical field in some extent, especially for syngas-based energy-chemical complexes. This work is practically and directively significant for the implementation and promotion of energy-chemical development in China.