To study the effects of operational parameters on gasifying characteristics in the jet-fluidized-bed reactor and illustrate the scaling relationships of jet-fluidized-bed coal gasifier in a scale-up process, we established an equivalent reactor network model for the gasifier using CHEMKIN 4.1 software. The model is based on hydrodynamic properties in the gasifier and knowledge of the burning zone and gasifying zone of the reactor. It involves two-phase flow between materials, heat and mass transfer, as well as the coal gasification process in the presence of mixed gases, most notably H 2 O, O 2 , N 2 , etc. The model was validated by comparing it to the experimental data of outlet gas compositions. To optimize characteristics of the jet-fluidized-bed coal gasifier, the influence of the oxygen feed rate into the center nozzle and the coal feed rate on the gasification process and gas composition were studied by the equivalent established reactor network. Within the calculation range, with the increase of the oxygen feed rate into the center nozzle, the jet region nearly doubled, the temperature increased by 306 K, carbon conversion efficiency rose from 68 to 97%; however, the temperature of the jetting region should be controlled within the coal ash-softening temperature, and in generated gases, the CO and H 2 contents had clearly changed. With the increase of the coal processing capacity, the jet region temperature decreased by 252 K, the gasifier overall temperature decreased, and carbon conversion reduced from 98 to 74%.

To study the influence of fluidized-bed reactor scale-up on coal gasification characteristics, a model of the ash agglomerating fluidized-bed reactor has been developed using an equivalent reactor network method. With the reactor network model, the scale-up effects of a gasifier were studied in terms of the characteristics of the chemical reactions in the jet zone, the annulus dense-phase zone and the freeboard zone. Results showed that the changes occurred in the inequality proportion of the volume of the jet zone during the reactor scale-up. Taking into consideration the utilization of a portion of the backflow gas, the expansion of the jet zone volume and the coal particle residence time, the temperature of the jet zone was increased from 1592 to 1662 K. Also, both the annulus dense-phase zone temperature and the freeboard zone temperature decreased, causing subsequent decrease in the carbon conversion efficiency.