PRENFLO™ is a pressurized (>40 bar), entrained-flow gasification technology first demonstrated in the late 1980s, and currently offered by Uhde (Krupp Koppers merged with Uhde in 1997). Notably, PRENFLO™ is the gasification technology used at the world's largest solid feedstock-based gasifier at ELCOGAS's Puertollano IGCC plant in Spain (which is fueled with a 50%/50% mix of petcoke and coal). PRENFLO™ is offered in two varieties, the PRENFLO™ PSG (with steam generation) depicted in Figures 1 & 2, and PRENFLO™ PDQ (direct quench) as depicted in Figures 3 & 4. The gasifier conditions and feed characteristics are similar, but PRENFLO™ PSG includes an integrated waste heat boiler and uses compressed recirculated quench gas as illustrated in Figure 2, resulting in relatively low moisture raw syngas at relatively high exit temperature. PRENFLO™ PDQ uses direct quench, resulting in considerably lower raw syngas exit temperature (200-250°C) which is saturated. Uhde notes that PDQ has lower investment cost and shorter construction and supply schedule than PSG, though this would be at the performance expense of somewhat lower thermal efficiency and slightly higher concentration of carbon dioxide (CO2) in raw syngas.
Currently, several new implementations of PRENFLO™ gasification technology have been underway or are contemplated: