Winkler process

The fluidized-bed system uses finely sized coal particles and the bed exhibits liquid-like characteristics when a gas flows upward through the bed. Gas flowing through the coal produces turbulent lifting and separation of particles, and the resnlt is an expanded bed having greater coal surface area to promote the chemical reaction, but such systems have only a limited ability to handle caking coals. 

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There are three well proven processes for the gasification of coal. All three processes were developed in Germany at a time when natural gas was not available in Europe. One such process is the Winkler Process. 

HTW [High-Temperature Winkler] A process for gasifying coal, using oxygen and steam in a fluidized bed. An improved version of the Winkler process, differing from it by being operated... 

So far only the Koppers - Totzek, Texaco and Lurgi gasifiers, and probably the Winkler process in some smaller installations, have been used in ammonia plants, but the successful demonstration of the Shell process in other applications make it a potential candidate for ammonia production, too. Additional processes in different stages of technical development are the HTW and the Dow process. Information on the status and the development in the gasification of coal can be obtained from [541], [545], [548] -[554],... 

Wilson equation, activity coefficients, 374 Wilson-Lobb-Hottel eqiration, 214 application, 219 Winkler process 582 Wire mesh deentrainers, 615 calculation example, 620 disengaging space, 616 kev dimensions, 618 k-values, 615 pressure drop, 616 tvnical installations, 616 Work index, size reduction, 342 Wyssmont dryer, 237,251... 

Winkler process, the Koppers-Totzek process, and the Texaco process. Downstream adjustment and treatment of the raw product gases is required when these processes are used to supply feedstock or cofeedstock to a typical low-pressure methanol process operating at 220 to 270°C and 5.066 to 10.132 MPa (50 to 100 atm). A few of the operating details of these and other commercial coal gasification processes are presented here. 

All the industrial processes are autothermal, 30 to 40% of the coal utilized being burnt to attain the required high reaction temperatures. This is also the case for the Lurgi pressure gasification process carried out in a mechanically agitated solid bed at ca. 1200°C (as used e.g. in Sasolburg in South Africa), for the Koppers-Totzek process in which the coal is used in the form of flyash (atmospheric pressure, 1400 to 1600°C) and for the Winkler process operating with a pressureless fluidized bed at 800 to 1100°C. 

The first application of the fluidized-bed gasifier in the gasification process is the original Winkler process. In the Winkler process, steam and air (or 02) are used at atmospheric pressure. The schematic of a typical Winkler gasifier is shown in Figure 4.25. The coal (brown coal coke, subbituminous, or bituminous coals) is... 

The Winkler gasification process has many advantages such as low operating temperature, high reliability, and low tar in the gas product. However, due to the low operating pressure and temperature, the carbon conversion is also low (20%-30% carbon in ash). Most plants using the Winkler process have been shut down for almost entirely economic reasons. 

The HTW technique, developed by Rheinbraun, utilizes increased pressure (up to 3.0MPa) and operating temperature. In this process, a lock hopper and screw feeder are used to feed the coal particles into the reactor from a high-pressure charge bin. Due to the increases in both temperature and pressure, coal conversion in the HTW process is much higher than in the Winkler process. 

Figure 3.5 Gasifier of the high temperature Winkler process for the conversion of solid wastes.15...

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