Issues regarding the requirements for raw materials in fluidized bed gasification

Feeding material with 45% water content into the furnace presents problems; firstly, feeding it is difficult, and its gasification efficiency in the gasification furnace is also low

What are the problems when the ash content reaches around 50%?

When the ash content reaches 50% during gasification, the heat loss caused by the slag removal is too high, which affects the calorific value of the gas

In my opinion, a high ash content leads to higher oxygen consumption, lower gasification efficiency, greater heat loss, and increased transportation costs. 45 units of water are added to the furnace; it seems that P is simply turned into water-coal slurry

There’s nothing to do about it – the raw material is biomass, and the cost of dehydration is very high.

The total moisture content is less than 40%, and the ash content is also less than 40%. However, when the external moisture level is high, feeding becomes difficult; it’s hard to operate in such conditions. Generally, for coal with high moisture content, a pre-drying device is needed to remove some of the external moisture first.

A fluidized bed must, at the very least, be able to accept feed material and enable fluidization once that material is inside; P

Three can maintain bed stability; four can ensure dust removal efficiency; five can...

What are the reasons for an ash content of less than 40%?

With an ash content of 40%, it is possible to apply this principle based on fluidized bed technology; on the other hand, if the ash content is too low, the coal powder cannot achieve a proper fluidized state inside the gasification furnace. However, too high an ash content presents the following main problems: 1. It places high demands on cyclone separators, and it is currently difficult for manufacturers to achieve the designed separation efficiency with existing cyclones ； 2. The unit cost of the gas produced by the gasification furnace **increases**, and scaling tends to occur easily ； 3. Excessive ash carried by syngas into the downstream system affects boiler operation ； 4. The fly ash collected by the subsequent systems has a high carbon content, and there is currently no effective way to deal with it. Only the UGS gasifier employs feedback optimization; other types of furnaces can only be used to supply boilers, which reduces the efficient utilization of the raw coal ； 5. It also puts significant pressure on the gasification gas purification system. It is understood that some fluidized bed manufacturers are currently using the raw coal used in gasification with pneumatic beds; for example, coal from places such as Yulin and Shenmu is employed, and the performance of these gasification furnaces is very good. Not only is the unit cost reduced, but some manufacturers have also seen an increase in the output of their final products, which boosts profits compared to the lower price of local coal.