Regarding Hitachi gasifiers

I haven’t heard much about Hitachi gasifiers; could any fellow sailor give me some information on them?

Hitachi’s research on coal gasification began in 1982, with basic laboratory studies conducted. A gasifier with a processing capacity of 1 ton per day was developed, using a one-chamber two-stage design concept. The upper and lower nozzles have different swirl diameters; the upper nozzle creates downward swirls, which prolongs the residence time of the coal in the furnace and facilitates its gasification. Meanwhile, the efficiency of cold gas production is significantly improved during gasification in these two stages. Another unit with a capacity of 3 tons per day has been built and put into operation. This one-chamber, two-stage gasification method has been adopted by the Industrial Technology Agency of the Ministry of International Trade and Industry and NEDO for the development of coal-to-hydrogen technology with a capacity of 50 tons per day. After numerous experiments, Hitachi constructed a pilot plant capable of processing 50 tons of coal per day. The structure of the two-stage gas flow bed gasifier developed by this research institute is shown in Figure 11; it adopts a design concept of one chamber with two stages of gasification, and 4 burners are arranged at the upper and lower parts of the furnace in the tangential direction. Figure 11 shows the structure of the two-stage gas flow bed vaporizer. The flow pattern and reactions within this vaporizer are depicted in Figure 12. As shown in Figure 12, pulverized coal and the gasification agent oxygen are injected into the furnace chamber through upper and lower nozzles respectively and flow in a spiral pattern; the pulverized coal is gasified, while the ash is discharged in a molten state. This fluidized bed is characterized by a high carbon conversion rate, high thermal efficiency, and stable slag. Figure 12 Flow conditions and reaction processes in a two-stage gas flow bed gasifier. Pilot plant: Preliminary design began in 1985, and actual operation started in 1990. This process is characterized by a high gasification rate, wide suitability for different coal types, the ability to operate on a large scale, low environmental pollution, high reliability, and a long service life. The structure of its gasification furnace is shown in Figure 13. Figure 13 Schematic diagram of the structure of a two-section spiral gas flow bed gasifier