Published February 1988
In this review we evaluate the concept of an entrained catalyst system for methanol synthesis (originally proposed by Chem Systems) and compare its economics with those for the quench type reactor used In the ICI process. The entrained catalyst system entails syngas flowing through a circulating slurry that consists of catalyst particles (20-100 pm) suspended in an inert liquid. Unlike the heterogeneous, fixed bed, catalytic reactors used in conventional methanol processes, the entrained catalyst system can remove reaction heat externally and therefore offers the prospect of operation at higher per pass conversions without high temperature gradients. Development work is currently in progress to determine whether the concept Is both practicable and economic. Our evaluation shows that the potential cost advantage of such a system is only marginal in regard to overall production costs and even this advantage would require the attainment of ambitious research targets. With the standard methanol synthesis catalysts (which are being used in the development work), the per pass conversions are unlikely to be high enough to dispense with a syngas recycle loop. In addition, any capital investment savings that may be achieved would be limited to those associated with the synthesis reactor and its recycle loop, which together form only a small part of the total fixed capital.
