| Mathematical models were developed to characterize the technical and economic performance of integrated gasification combined. cycles (IGCC) and integrated gasification humid air turbine (IGHAT) cycles. The models provide technical performance data, inventories of capital and operating costs, as well as levels of gaseous emissions and solid wastes. The models comprise numerous sub-models for the major elements of the integrated cycles such as coal gasification, syn-gas cooling, cold gas cleaning, energy conversion, sulfur removal, and NOx emission abatement. While the models are simple enough for use in parametric, sensitivity, and optimization studies of integrated gasification power production systems, they are sensitive to variations in coal characteristics, design and operating conditions, part load operations, and financial parameters.; This approach provides the flexibility necessary to accommodate a wide range of technical options and emission constraints, and takes into account the various component interactions encountered in different technologies. Also, this approach makes it possible to estimate capital and operating costs of the overall cycles based on the costs of the major components. This allows for calculation of the revenue requirement and levelized electricity cost for different systems under different financial scenarios.; The models may be used as versatile decision making tools for a wide variety of purposes such as: (1) Analyzing the impact of environmental policies on the cost of power generation, (2) Predicting the thermal, environmental, and economic performance of conventional and advanced power production schemes operating at full and part loads, (3) Identification of the most appropriate power generation schemes for both new capacity and retrofit options that can meet technological, economic, and environmental constraints, (4) Predicting the operational flexibility of advanced power production schemes regarding fuel switching, phased construction and part load operation, (5) Quantitative evaluation of the impact of changes in design and operating conditions on the levelized cost of electricity and pollution emissions, (6) Identifying potential operating problems and defining limits of safe operation, (7) Performing environmental and thermo-economic optimization studies of advanced energy conversion systems to identify areas of potential improvement.; To demonstrate the capabilities of the models, case studies were conducted to investigate the thermal, environmental, and economic performance of four advanced power generation technologies: IGCC with moving bed gasifier (BGL design), IGCC with slurry fed entrained bed gasifier (Texaco design), IGCC with dry feed entrained bed gasifier (Shell design) and IGHAT with slurry fed entrained bed gasifier. The results verify favorable characteristics of IGCC and IGHAT cycles namely: high thermal efficiency, low levelized unit electricity costs, and low emissions. All four technologies achieved SO x and NOx emissions of 32 × 10−6 and 40 × 10−6 kg s−1 MW −1, respectively, which are about a quarter of the values stipulated by the current Canadian power plant emission standards. The best environmental performance was achieved by the IGHAT unit. The results of the exergy analysis indicated that the most significant improvement may be achieved by increasing the temperature of syn-gas cleaning and by increasing the maximum firing temperature in the gas turbine. (Abstract shortened by UMI.)... |
