This process incorporates advancements into Lurgi’s dry-ash gasifier that con­vert the system to a slagging gasifier, reduce the steam requirement to about 15% of that required by the dry-ash gasifier, provide a raw gas with higher carbon monoxide and lower methane, carbon dioxide, and moisture, and improve the capability to use caking coals and a significant amount of fines. The process affords increased gas yields by limiting the net hydrocarbon liquids to naphtha and phenols.

Winkler Process

This process converts crushed coal, oxygen, and steam at 820 to 1000°C and near-atmospheric pressure in a fluid-bed gasifier. After passage of the raw gas through a waste heat recovery section, flyash is removed by cyclones, wet scrubbers, and electrostatic precipitators. Further processing, depending on end use, yields a gas suitable as synthesis gas or pipeline gas.

High-Temperature Winkler Process

This process uses a fluid-bed unit that is especially designed for gasification of brown and hard coals, peat, and biomass. In the case of brown coal, predried feed at 12 wt % moisture is fed along with oxygen and steam to the reactor which operates at 750 to 800°C and 2.53 MPa.

TABLE 9.4 Comparison of Operating Temperatures and Pressures and Typical Product Gas Heating Values and Compositions of Selected Coal Gasification Processes Process type Process Conditions HHV, MJ/mJ (n) Raw gas composition, dry mol %" (°С) (MPa) Steam-02 Steam-air H2 CO CH4 co2 n2 Others Fixed bed Lurgi (dry ash)1′ 621-760 2.43-3.14 11.86 40 21 10 28 1 Lurgi (dry ash)“ 621-760 2.43-3.14 7.08 25 16 5 14 39 1 Lurgi (slagging)11 1296-1371 2.53 14.25 28 61 8 2 2 Ruhr 100c 1927 10.13 13.31 32 22 16 28 2 Wellman-Galusha1* 1315 30.40 6.60 15 29 3 3 50 Fluid bed Winkler1 816-982 0.10-0.61 10.80 42 33 3 21 1 0.3 Winkler* 816-982 0.10-0.61 4.63 13 21 1 7 58 0.2 Synthanef 982 3.55-7.09 15.90 28 17 24 29 0.8 1.3 C02 Acceptor® 871 1.01-1.52 17.28 54 17 21 7 0.2 1.4 U-Gas* 1038 2.43 5.89 13 19 5 10 52 0.7 Entrained Bi-Gas’ 927-1482 2.03 14.92 24 44 16 14 0.6 1.4 Koppers-TotzekJ 1816 0.10 11.78 37 56 0 6 1.1 0.3 Texaco* 1093-1371 2.74 11.78 45 45 1 9 Shell Oil Co. 1482 High 11.78 31 67 2

"Lurgi Mineraloltechnik Gmbh; commercial.

bLurgi Mineraloltechnik Gmbh, 10-min residence time; commercial. cRuhrgas AG; demonstrated.

^Wellman Engineering Company; 4-h residence time; commercial.

"Davy Powergas, Inc.; 30-min residence time; commercial; technology owned by Davy International Corp.

Aj. S. Bureau of Mines; demonstrated.

^Consolidated Coal Company; demonstrated. hIGT; commercial.

‘Bituminous Coal Research, Inc.; two-stage system with upper stage at 927°C and lower slagging stage at 1482°C; residence time of the order of seconds; demon­strated.

■’Heinrich Koppers Gmbh; 1-s residence time; commercial.

^Texaco, Inc.; commercial.

‘Applied Technology Corporation; uses molten iron; demonstrated. mM. W. Kellogg Company; uses molten sodium carbonates; demonstrated.

"Atomics International; uses molten sodium carbonates; hydrogen and carbon monoxide not differentiated; demonstrated.

"Raw gas compositions are rounded figures; raw gas from these processes usually contains small amounts of tars, oils, phenols, ammonia, sulfides, light hydrocarbons, and fines from the ash.