What should be considered first when choosing a gasification process for coal-to-natural gas production?
Thread Content
It is generally said that the primary principle in choosing a coal gasification process is to select a process that is suitable for the specific quality of the coal. The second principle for selecting the gasification process is to choose it based on the products and applications of the gas processed. The primary principle is generally to determine whether it is suitable for producing water-coal slurry; if so, the water-coal slurry technology will be chosen. However, if it is used for natural gas production, is this principle also applied in that case? When producing natural gas, can the Lurgi technology be considered directly? Otherwise, why is almost all coal-to-natural gas production in China based on the Lurgi technology (or BGL)? The additional costs associated with Lucchi purification and wastewater treatment are no less than the cost increase resulting from water-coal slurry methanization. Why is it always emphasized that the methane content in water-coal slurry is low, and that this leads to increased costs in the methanation process? Has anyone done a specific comparison? Is it still because Luchi has low gasification costs? Everyone is welcome to share their opinions!
Selection of key factors for coal gasification process: 1. Coal type suitability 2. Product requirements 3. Technical specifications 4. Economic indicators 5. Level of domestic production 6. Treatment of waste gases, wastewater, and solid waste
The original poster’s question is very professional; please help to solve it! Which gasification method is reasonable to choose when considering everything as a whole?
This post was last edited by wlq1970 on 2015-7-7 at 15:31. In principle, coal resources should be utilized efficiently. When it comes to coal-to-natural gas production, pressurized coal gasification (Ruhry gasification) is a favorable option based on the composition of the gases produced during gasification; about 18% of these gases are methane. However, pressurized coal gasification requires coal particles with a diameter of 8–50 mm. Due to the high amount of ash present in the coal (indicating poor thermal stability), the particle size is often increased to 12–50 mm. As a result, large amounts of fine coal dust are generated. Although some of this dust can be used for energy purposes, a significant amount remains. Fine coal dust is often very cheap in certain places, but it is difficult to store as it tends to catch fire easily. Therefore, it is necessary to make efficient use of these resources. Stream bed gasification technology is also an option; slurry coal is the preferred choice in such cases. If the coal can be easily converted into a slurry, then slurry coal gasification should be utilized. A single furnace can process 3,000 tons of raw coal per day. An advantage of this method is that it allows for the concentration of the wastewater generated during pressurized coal gasification before it is used to create slurry. At the high temperatures involved in slurry coal gasification, tar and heavy hydrocarbons are broken down. The downside is that more methane is produced. If slurry coal isn’t suitable, powder coal gasification is usually chosen. Its advantage is that it allows for the utilization of fine coal dust, but the downside is again that more methane is produced. The wastewater from pressurized coal gasification cannot be utilized effectively, and dealing with this wastewater represents a major challenge; obtaining environmental approvals for such processes is difficult.
If the scale is large enough, is Lurgi + water-coal slurry a good choice?
In fact, any project goes through a comparison of gasification options before the gasification method is finalized. Only