Sumitomo flow-sheet

Figure 14.2 shows the simplified flow sheet of the process, as reported in patents issued to Sumitomo. CO2 is maintained in the recycle loop to act as a ballast component the desired concentration of CO2 is obtained by combustion of CO, while excess CO2 is separated. Methacrolein is separated and recycled to the oxidation reactor. An overall recycle yield of 52% to methacrylic acid is reported, with a recycle conversion of 96% and a per-pass isobutane conversion of 10%. The heat of reaction produced, mainly deriving from the combustion reaction, is recovered as steam. 

Figure 14.2 Simplified flow sheet for isobutane oxidation to methacrylic acid, as stated by Sumitomo.

There are now two plants operating in Europe, both located in Switzerland. The plant developed by Batrec AG in Wimmis has been in operation since 1994 and has a nominal capacity of 2000 tonnes of UDBs per annum. This plant is based on the Sumitomo process its flow sheet is shown schematically in Fig. A3.1. 

Fig. A3.1 Flow sheet for the Sumitomo dry battery recycling process. (By permission of J. Power Sources R. Burry and A. Weber, 1995, 57, 31.)...

Figure 6.3 shows a simplified potential flow-sheet of the Sumitomo process, as inferred from the vast patent literature dating from 1999 onwards [6]. Here, two different layouts are hypothesized for the section aimed at the purification of PO in both cases, however, the key separation is an extractive distillation. It is reported that in these columns the highest temperature must not exceed 130 °C, to avoid the formation of heavy compounds. 

Figure 6.3 Simplified flow sheet of the Sumitomo process for PO synthesis, as inferred from the patent literature [5, 6]. 

This separation principle has been applied commercially at Falconbridge Nik-kelverk in Norway (Wigstol and Froyland 1972), at Sumitomo Metal Mining Co. in Japan (Suetsuna et al. 1980), and at the Societe de Nickel refinery in France (Bozec et al. 1974). More recently, this chemistry has been included in the flow sheet for the processing of a nickel laterite in the Goro process in New Caledonia (Mihaylov et al. 2000) (see Section 5.3.3.2). 

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