Experimental Investigation Of Natural Coke Steam Gasification In A Bench-scale Fluidized Bed: Influences Of Temperature And Oxygenflow Rate

摘要

Natural coke was selected as a steam gasification feedstock in a bench-scale fluidized bed (i.d. 50 mm, H 1600 mm). The impacts of the gasification temperature and the oxygen flow rate on product gas composition, product gas yield, and gas heating value were investigated with a steam flow rate of 1050 g/h and a natural coke flow rate of 200 g/h. Experimental results show that gasification temperature has a significant influence on gasification properties. As the temperature goes up, the contents of H_2 and CO_2 in the product gas decline, whereas the content of CO increases. As the temperature was from 850 to 1000℃, the volume fractions of H_2, CO, and CO_2 in the product gas changed from 63.0%, 25.0%, and 9.6% to 59.8%, 20.2%, and 18.5%, respectively. The product gas yield increased by 4.3 times, the carbon conversion rate increased from 10.25% to 47.76%, and the gas heating value increased from 8.87 to 9.33 MJ/m~3. Oxygen in the oxidant reagent steam affects the gasification properties. The product gas yield and the carbon conversion increased by 1.76 times and 1.94 times, respectively, when the oxygen flow rate was from 0 to 0.2 L/min. But as it further increased to 1.0 L/min, the product gas yield increased only by 1.16 times and the carbon conversion increased by 1.34 times. The effective composition in the product gas continued to decrease from 76.0% to 54.3%, and the heating value was lowered from 9.01 to 6.35 MJ/m~3 as the oxygen flow rate was raised from 0 to 1 L/min. The CO_2 composition increased persistently from 23.1% to 37.3%.