DEACTIVATION OF METHANOL SYNTHESIS CATALYSTS

A novel methanol synthesis process, the liquid-phase methanol (LPMEOH) process, has been developed and scaled up to a nominal 380 kg/h (10 t on/day) pilot plant. The process is based on a gas-sparged slurry reac tor instead of a conventional, fixed-bed reactor. The use of slurry re actors, which are essentially gradientless, greatly facilitated the in terpretation and quantification of catalyst deactivation phenomena. Wi th a poison-free, CO-rich feedstream, the rate of deactivation of the Cu/ZnO catalyst increased rapidly with temperature. At constant temper ature, in the absence of poisons, the decline with time in the rate co nstant for methanol synthesis correlated with the loss of BET surface area. Iron carbonyl, nickel carbonyl, and carbonyl sulfide are severe and highly specific poisons for methanol-synthesis catalyst. There was a linear relationship between the catalyst activity loss and the conc entration of metal or sulfur on the catalyst.