Mitigating Risk: A Commercializing New Catalyst Technology in a World Scale Ethylene Plant

Bringing a new ethylene plant on stream and to full capacity quickly and smoothly is a tremendous undertaking. This is especially true in ethylene plants which employ “Front End” acetylene hydrogenation reactors which have traditionally been prone to run away at transient conditions common during streaming, such as:

• Low (or no) forward Cracked Gas feed flow, with catalyst temperatures at or near reaction initiation level
• Low inlet CO concentrations (e.g. 50-150 ppmv prevalent with new furnace designs)
• CO fluctuations
• Inlet temperature fluctuations

With ethylene plant capacities hitting record highs, the cost of an off-spec incident during startup is substantially higher than even five years ago. As such, the market began to demand an ultra-stable front-end selective hydrogenation catalyst.

Utilizing their Innovation Process, Clariant has identified a new catalyst formulation and applied High Throughput Experimentation to optimize a new, multi-component Front End catalyst. OleMax^®260 shows greatly reduced reactivity of ethylene relative to that of acetylene. It is also highly stable at very low and fluctuating CO levels. Along with achieving maximum selectivity, its unique performance characteristics deliver significant operational risk mitigation.

The Dow Chemical Company partnered with Clariant toward the new catalyst’s commercialization throughout several years of extensive laboratory and pilot testing. Despite what might be considered significant risk in selecting an unproven catalyst for use in a world-scale ethylene plant, Dow elected to proceed as the first adopter of this exciting catalyst technology at their new world scale cracker in Freeport, TX.

OleMax^®260 was successfully commercialized in September 2017. The catalyst was very quickly and smoothly brought on specification despite low inlet CO levels and process variability which could have easily resulted in a runaway. Performance data to date confirm both its high activity and exceptional selectivity to ethylene.