Page 168 - Synthetic Fuels Handbook

154 CHAPTER FIVE

The molten salt system employs a bath of molten salt to convert coal (Cover et al., 1973;
Howard-Smith and Werner, 1976; Koh et al., 1978).

Fixed-Bed Processes
The Lurgi Process. The Lurgi process was developed in Germany before World War II
and is a process that is adequately suited for large-scale commercial production of synthetic
natural (Verma, 1978).
The older Lurgi process uses a dry ash gasifier (Fig. 5.14) which differs significantly
from the more recently developed slagging process (Baughman, 1978; Massey, 1979). The
dry ash Lurgi gasifier is a pressurized vertical kiln which accepts crushed [¼ × 1¾ in
(6 × 44 mm)] noncaking coal and reacts the moving bed of coal with steam and either air

Coal

Coal lock
Wash water
Jacket steam
Coal distributor drive

Coal distributor
Wash
cooler
Drying zone
Devolatilisation zone
Gasification zone
Crude gas
Combustion zone

Grate
Grate drive
Water jacket

Steam + oxygen

Ash lock

Ash
FIGURE 5.14 The Lurgi dry-ash gasifier.