Lurgi-Ruhrgas process

In this process (Nowacki, 1979), crushed coal is fed into a mixer where it is heated rapidly to 450°C-600°C (840°F-1110°F) by direct contact with hot, recirculating char particles which have 

FIGURE 19.1 Relative costs over time for the development of a concept from bench-scale to commercialization. 

The char forms approximately 50% of the products while the liquid yields are on the order of 18%, and the remainder (approximately 32%) are gases having an approximate calorific value of 700-850 Btu/ft3. 

The high gas yield is due to the relatively long residence times of the products in the reactor by virtue of which thermal decomposition occurs to yield gaseous products that are, in actual fact, a secondary product insofar as they are not formed from the coal. The majority of the sulfur originally in the coal occurs in the char. 

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The Lurgi-Ruhrgas process is a direct retorting operation which has been proposed for use on the Alberta oil sands. It is the view of the Authority that the next step in the further development of the Lurgi process is to carry out a test run on... 

Two indirectly heated oil shale retorting technologies employing solid-to-solid heat transfer have been described in connection with coal pyrolysis. They are the TOSCOAL process, called the TOSCO process when used with oil shale, and the Lurgi-Ruhrgas process. The former process was fully developed before operations were terminated, and the latter has been commercialized in connection with coal devolatilization and hydrocarbon pyrolysis. 

Rammler, A. W., "The Production of Synthetic Crude Oil from Oil Sand by Application of the Lurgi-Ruhrgas Process," Canadian Journal of Chemical Engineering, 48 (October 1970) 552-560. 

The Lurgi-Ruhrgas process (Figure 19.2) was developed as a low-pressure process for the production of liquids from lower rank coals in Europe. It is based on the premise that when coal is heated very rapidly to temperatures in excess of those required for decomposition, fragmentation is very extensive (Weller et al., 1950) to the point of being explosive. ... 

The liquid products are filtered to remove particulate matter and then hydrotreated (370°C-425°C [700°F-800°F] 1750-2500 psi hydrogen) to produce a synthetic crude oil (Table 19.1) from whieh the majority (90%) of the nitrogen, oxygen, and sulfur have been removed. As already noted for the Lurgi-Ruhrgas process, the majority of the sulfur originally in the coal occurs in the char and, therefore, combustion of the char may be an environmental problem unless there is some effort made to install stack gas cleaning equipment. 

The Biolig process of the research center Karlsruhe FZK, Germany. Here, flash pyrolysis, with emphasis on straw as feedstock, is tested to produce a bio-oil-char slurry. The pyrolysis reactor compares to the ER reactor (Lurgi-Ruhrgas) by which sand as heat carrier is mixed and transported together with biomass in a double (twin) screw feeder. A novel unit is constructed with a biomass processing capacity of 12 t/day. 

Lurgi-Ruhrgas Also known as LR. A process originally intended for pyrolizing fine-grained solids, such as coal, peat, shale, and tar sands, to produce mixed hydrocarbons. The process is based on flash heating in a mixer by means of circulated hot powders, usually obtained from the... 

I) Pyrolysis and Hydropyrolysis Processes (Lurgi-Ruhrgas COEd/ Occidental etc.)... 

Ruhrgas (2) A process for thermally decomposing oil shale, developed by Lurgi. 

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