Process design gasification

Gasafi et performed LCA in combination with a dominance analysis in order to identify hot-spots in process chains in early phases of process design to efficiently improve the environmental performance. The authors illustrated their approach on the example of super-critical water gasification for the treatment of organic feedstock with high moisture content. 

Gasafi, E., Meyer, L., Schebek, L. (2004) Using Life-Cycle Assessment in Process Design Supercritical Water Gasification of Organic Feedstocks. Journal of Industrial Ecology, 7(3M), 75-91. 

The model and the results presented here illustrate the physicochemical processes involved in char gasification with simultaneous sulfur capture. In particular, they demonstrate that diffusion limitations in the gasification reactions enable the conversion of CaO to CaS within the char even though CaS formation is not feasible at bulk gas conditions. Furthermore, this first version of the model correctly predicts the trends observed experimentally. Future effort in this area will focus on quantitative comparisons of model predictions with results from carefully designed gasification experiments. 

The technology of gasification is under active development in both equipment and process design to reduce capital costs, and in the chemistry of the process to improve yields and obtain more favorable gas ratios. The latter includes the use of catalysts to enhance the process and to promote the formation of specific products, such as methane or ethylene for increased thermal efficiency or for feedstocks for chemical synthesis. 

MHI [Mitsubishi Heavy Industries] A coal gasification process designed for coals whose ash has a high melting point. Piloted at Nakoso, Japan. 

Recent years have seen vast experimentation with many different process designs for the liquefaction of coals. The degree of coal conversion and composition of the product oil vary with both the coal rank, maceral composition, mineral matter content, and conversion process. Whereas much attention has been focused on the separation and characterization of the product oil by chromatographic and spectroscopic means, less work has been done on the unconverted or process altered residues from liquefaction processes. Although many of the processes do incorporate some sort of bottoms processing , other possible uses of these residues include road materials, carbon electrodes, coal gasification feedstocks, and as direct combustion fuels. Recently, coal conversion by-products have been used as raw materials in the synthesis of thermosetting polyesters. ... 

On the other hand, the potential benefits that could arise from the presence of this same mineral matter should not be ignored catalytic effects in processes designed for the liquefaction (Chapters 18 and 19) and the gasification (Chapters 19 and 20) of coal may be cited as examples. 

Wen, C. and Chaung, T. (1979) Entrainment coal gasification modeling. Industrial Engineering Chemistry Process Design and Development, 18 (4), 684-695. 

Mild gasification is a pyrolysis-based process designed to produce a product slate of alternative fuels by decomposing coal at relatively mild conditions of temperature and pressure. The idea is to produce the most profitable combination of products with a given feedstock and associated operating, distribution, and capital costs. ... 

Boerrigter H, UU H, Cahs HP. 2003. Green diesel from biomass via Eischer-Tropsch synthesis new insights in gas cleaning and process design. In Bridgwater, AV (editor). Pyrolysis and gasification of biomass and waste. Newbury, UK CPL Press, pp. 371-383. 

Dutta, A., Takaadge, M., Hensley, J. et al. (2011) Process Design and Economics for Conversion of Lignocellulosic Biomass to Ethanol Thermochemical Pathway by Indirect Gasification and Mixed Alcohol Synthesis, NREL/TP-5100-51400. Available at http //www.nrel.gov/biomass/pdfs/51400. pdf (accessed on 29 August 2015). 

Luterhacher, J.S., et al., 2009. Hydrothermal gasification of waste biomass process design and life cycle asessment. Envirorunental Science Technology 43 (5), 1578—1583. 

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