Large‐scale Continuous Production of Single Cell Protein

The PRUTEEN plant represents a major innovation in the green field of biotechnology. The 50 000-t/a-plant was sanctioned in 1976 as a £40-million-project and built by contractors John Brown. The 600 t fermenter vessel in particular was an impressive piece of engineering: fabricated in Dunkirk, it was transported to the Billingham site in one piece. This paper illustrates why, given the risks of innovation on such a scale, ICI chose a novel fermentation process. Particular reference is made to the pressure cycle fermenter and how it works, and to the product recovery stage. The approach to sterile engineering, which is crucial to the effective operation of the fermentation process, is also discussed. Faced with unique technical challenges, ICI pioneered practical solutions, and, through operational experience, has arrived at the point today of being able to license the process.