Published February 1997
Neste Oy started up the first commercial operation of the NExTAME process in March 1995 at its Porvoo refinery in Finland. The NExTAME process achieves 90% isoamylene conversion to tert-amyl-methyl ether (TAME) and eliminates the need for methanol recovery. This process exceeds the thermodynamic equilibrium conversion level of about 70% by continuously circulating a side stream that is withdrawn above the feed point of the distillation column to the etherfication reactors. The methanol is concentrated in the side stream together with the C5s and thus cannot leave the system either through the overhead or the bottoms of the distillation column. The amount of methanol in the overhead product is low enough so that it can be blended directly into the gasoline pool.
In this review, we evaluate the technical and economic aspects of TAME production using the NExTAME process. Our evaluation shows the NExTAME process is economically feasible for producing 2,500 b/d of TAME, based on isoamylene derived from a 65,000 b/d FCC unit. The estimated product value for TAME in gasoline is similar to its octane blending value.