What are the advantages and disadvantages of water-coal slurry and pulverized coal fluidized bed?
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This post was last edited by lflsedin on 2015-8-18 08:02. This morning, when I learned that the world’s first water-cooled wall coal-water slurry gasifier had been developed successfully, I wanted to ask everyone about the advantages and disadvantages of using coal-water slurry compared to pulverized coal. I’m also interested in the environmental aspects, as well as any differences in terms of technical complexity (or operational difficulty).
The water-coal slurry gasification furnace has a simple process and can handle a wide range of coal types; the output per furnace can now reach 2,000–2,500 t/d. However, the burners and refractory linings need to be replaced frequently, and the carbon dioxide content in the produced crude gas is relatively high, resulting in an overall carbon conversion rate that is lower than that of pulverized coal gasification furnaces.
Thank you. I just saw the moderator’s comment and realized I made a mistake; it should read \"The world’s first water-cooled wall coal-water slurry gasifier was successfully developed.\" Sorry for that
Thank you. I just saw the moderator’s comment and realized I made a mistake; it should read \"The world’s first water-cooled wall coal-water slurry gasifier was successfully developed.\" Sorry for that
I’m sorry; based on the information available, it seems there may be differences in this regard. If a water-cooled wall is used in a water-coal slurry gasification furnace, the following problems arise: (1) There are no refractory bricks to store heat, which makes it more difficult to ignite the water-coal slurry during feeding. (2) Both the energy consumption per unit of gas produced and the oxygen consumption are much higher. From the perspective of the principles of water-coal slurry gasification, the excessive amount of moisture introduced into the system forces some of the carbon in the coal to be oxidized into carbon dioxide, in order to provide sufficient heat for the gasification process. This is why the concentration of carbon dioxide in the crude syngas produced by water-coal slurry gasification is much higher than that in syngas produced by pulverized coal gasification. If water-cooled walls are used, the gasification system loses an additional amount of heat to these walls, which leads to a further increase in carbon dioxide levels and a further decrease in the ratio of useful gases, thereby affecting the efficiency of gasification. This is very different from pulverized coal gasification.
Water-coal slurry gasifiers are currently widely used and their technology is mature. Compared with coal powder gasifiers, the differences are as follows: a) In terms of investment, coal powder gasification is more expensive than water-coal slurry gasification. b) In terms of operating costs, coal powder gasification results in lower expenses, mainly due to the high heat efficiency of Shell gasification, which allows for greater heat recovery. c) The coal powder gasifier must be assembled on-site due to its excessive diameter; it has a complex structure, making it difficult to manufacture.
I’ve learned it; everyone here is an expert! :)