Coal gasification

Gas production from bituminous coal for fixed-bed use is a mature process. As long as the sulfur and harmful elements in the syngas are within acceptable limits, on the one hand, the sulfur and harmful elements in the raw coal are also within acceptable limits ； Or reduce the content of sulfur and harmful elements through other measures.

It should be possible; as mentioned above, emphasis should be placed on effective sulfur recovery and the recovery and conversion of other harmful substances. Of course, the operating parameters need to be adjusted slightly depending on the situation. This post was last edited by wbp on 2009-2-21 14:02]

The fixed-bed system has shifted from using coke and lump coal for gas production to small-grained coal and briquetted coal, mainly due to the high price of lump coal and difficulties in obtaining it. However, the gasification intensity and gas quality of gas produced from briquetted coal are far inferior to those of lump coal, and it causes severe erosion of the equipment; only some manufacturers have achieved economic benefits. Using bituminous coal to produce briquettes is a good idea; I’ve heard of it for the first time. Bituminous coal has a high volatile content, and when used to make briquettes, it tends to break down and turn into powder more easily once it enters the furnace, making it harder to control the furnace operation. I hope that manufacturers who have succeeded in using this method can share their experience. Thank you.

The fixed-bed batch gas production process and desulfurization are part of the ammonia aqueous-phase process. Last year, we also tried to use bituminous coal in the production process; the sulfur content in this coal was around 7%, while the sulfur content in the coal fed into the furnace was about 2%. The volatility of the coal increased to around 7 as well. Within less than three days of operation, an oil foam formed on the surface of the circulating water used for desulfurization and gas production, and the water had a strong diesel-like odor. After continuing operations for another two days, no bubbling occurred in the desulfurization regeneration tank. Even after replacing the ammonia solution, no bubbling occurred again within just one shift. Finally, once bituminous coal was stopped from being used for one day, normal operation was restored immediately. So, in addition to sulfur treatment, there is also oil treatment.

As a supplementary point, bituminous coal has a high volatilization content, which is indeed beneficial for coal gasification. Especially when bituminous coal is mixed with lignite, the gas production volume in gas generators increases significantly, and the problem of pulverization mentioned earlier no longer exists. However, the tar content in the gas is difficult to remove; we installed electrostatic tar removal towers before and after desulfurization, but neither of them was able to effectively eliminate the tar. In short, if one wants to use bituminous coal for gas production, these issues must be resolved first.