Analysis For Intermittent Fixed-Bed Coal Gasification

The synthetic ammonia accounts for about half energy consumption in chemical industry. More than 75% of synthetic ammonia gas is synthesized from coal. The actual energy consumption in the coal gasification is much higher than the theoretical one. Therefore, an in-depth analysis for intermittent fixed-bed coal gasification can optimize process and save energy.In this dissertation, the data of coal gasification from Huachang Chemical Company Limited recorded by DCS was analyzed and diagnosed using the methods of practical datum calculation and partial least square.Based on the data of gasification section and using the excel tool, a four-component model was compiled to calculate intermittent coal gasification process. It was found that the production index error between the four-component model and fully component model was less than 3%. The error between the results calculated from the four-component model and the corresponding production data was less than 5%. Thus, the four-component model can be used to guide the practical production. In addition, by changing feed conditions in the calculation procedure, the change trend of the products indexes with the gasification process parameters was obtained. This provided the basis for optimizing intermittent coal gasification process.Based on partial least squares, the multiple linear regression model of up-down temperature sum, ashpan-engine speed, feeding steam pressure, feeding steam flow, steam tank's liquid level and blower current was established using MINITAB 15. Meanwhile, the variance analysis and residual analysis were adopted to analyze the fitted value of up-down temperature sum and the production data. Satisfied mathematical model was obtained after verifying the reliability and generality.