Full-scale process considerations

When the membranes are used on an industrial scale, a considerable amoimt of surface area will be necessary to process the gas stream involved. A typical surface area necessary is 1500 m for a 300 MW class power plant. For ceramic membranes this is a rather large surface area. Considering that permselectivity is already good for this application, it seems reasonable to direct research towards enlargement of the permeation or explore module concepts with a high surface area to volume ratio (e.g. monolytic systems) next to selectivity improvement. 

When membranes are produced in a tubular geometry, which seems the most feasible currently, all membranes have to be sealed separately. This favours tubes with large diameters to reduce the number of seals. On the other hand, the smaller the tube diameter, the higher the specific surface area attainable in a module. 

High pressure, high temperature membrane sealing is an important aspect of the full scale modirle and this hurdle has been taken for laboratory and bench scale [16,28,31,57]. The membranes can be sealed gas-tight to a stainless steel tube by a special joining technique. Experiments will be carried out initially for the so-called passive reactor concept in which a high selective membrane is surrounded by catalyst. 

Dead end tube configuration, in which only one end of the membrane tube is connected and the other end is closed [14], seems favourable since it needs one ceramic to metal joint less than two-side connected tubes. A drawback of this option is the large force that will act upon the dead end side of the membrane when the process works with a considerable pressure drop as in this application. These aspects show that it is important to realise for which application the membranes are being developed and to consider scaling up in an early stage. 

Through membrane reactor model calculations it has been shown that membranes can enhance the conversion of a WGS membrane reactor and concurrently separate hydrogen from carbon dioxide. This system can be used to control the release of CO2 to the atmosphere from a IGCC power plant. Through process 

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The plant began full-scale operation in 1962 and produced acetic, adipic, and propionic acids acetaldehyde butanol hexamethyldiamine vinyl acetate nylon and other chemical products from petroleum-base stocks. The effluent was collected at waste treatment facilities as two separate mixtures. Because mixing two wastestreams produced considerable precipitation, the wastestreams were processed and injected separately into two wells. 

Various industrial pilot plants and full-scale operations, using radiation-chemical processing have been reported, with production rates -50 to -1000 tons per year (Spinks and Woods, 1990 Chutny and Kucera, 1974). Production rates less than -50 tons per year are not considered viable. These operations are or have been conducted in countries such as the United States, the former U.S.S.R., Japan, and France. However, some operations have also been reported in the former Czechoslovakia and Romania, especially in connection with petroleum industry. In the United States, chlorination of benzene to gammexane (hexachlorocyclohexane) was hotly pursued at one time by radiation or photoinitiation. Since the early seventies the activity has dwindled, presumably due to lack of demand and environmental considerations. 

These anaerobic processes have been investigated under sewer conditions (Tanaka and Hvitved-Jacobsen, 1998, 1999, 2000 Hvitved-Jacobsen et al., 1999 Tanaka et al., 2000a, 2000b). The results from experiments in the laboratory, in a pilot sewer and under full-scale sewer conditions combined with theoretical considerations have provided knowledge on the anaerobic transformations of carbon that can be expressed conceptually (Figure 6.8). 

Rapeseed. one of the five most widely produced oilseeds, is cultivated mainly in India. Canada, Pakistan, France, Poland, Sweden, and Germany. Past objections to using rapeseed as a source of edible protein has been its content of deleterious glucosinolales. Considerable research has been conducted in Sweden to develop a rapeseed protein concentrate. The first full-scale production plant using a new process was installed in Alberta, Canada. The plant, with a capacity of 5000 tons/year produces a material containing 65% protein. Rapeseed is rich in essential amino acids, with exception of methionine, which soybeans also lack. 

In scaling up a process from the laboratory to the full-scale version, besides the geometrical similarity, process-related and material similarity must also be considered. In examining the demand for material similarity, it is expedient for the determination of model substances to start from a material data chart T = Ba x Pr 1/3, Pr with a parametrical temperature indication, see Fig 17. From this representation it can be discerned that mixtures of different materials are particularly suitable as model substances because they cover entire areas in this diagram and can therefore considerably widen the scope of material numbers. 

Interest in the Fischer-Tropsch synthesis was manifested by Russian investigators soon after the first information about it was published the synthesis was discussed at the Mendeleev Chemical Congress in 1934, and reviews were published both in book (148) and in journal (73,74,75, 82,84,146,234) form. The work has led to pilot plant studies full-scale industrial development of this process may have been achieved by 1950. There has been considerably more attention given to the performance of various catalysts and to the reaction mechanism, and, recently, to related processes, such as the hydropolymerization, mentioned above, and the hydrocondensation of olefins, rather than to such aspects of this process as preparation of synthesis gas,... 

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