Catalysis 2026 Issue

approximately 3.5% ethane, typical of the US Gulf Coast; the evaluated range represents additional ethane blended into this feed. Ethane was intro- duced only as part of the feed blend and was not used for firing, which continued to rely on available purge gases, with natural gas serving as the bal- ancing fuel. The R ratio (H₂- CO₂)/(CO+CO₂) in the make-up gas was maintained through- out to preserve synthesis loop stability. Process simulations assessed the combined effects of ethane addition on reforming reactions, thermal profiles, equipment constraints, and the integrated steam system. The analysis con- firmed that only a limited ethane blend could be accommodated without exceeding metallurgi- cal limits, burner constraints, or steam system capacity. Based on these considerations, the allowable ethane blend increased methanol production by approximately 60 mtpd. Although higher ethane con- centrations could theoretically provide larger capacity gains, achieving such levels would require significant modifications to the reforming section and associated systems, which were

MP steam

BFW

TCC

MUG

Purge

WCC

BFW preheat & cooling

Crude methanol

Figure 2 Existing methanol synloop

MP steam

BFW

TCC

MUG

Purge

WCC

BFW preheat & cooling

Cooling

Crude methanol

New item

Figure 3 Revamped methanol synloop

Importantly, the resulting increase in methanol produc- tion is not simply a recovery of lost performance or a cata- lyst-driven improvement; it represents throughput beyond the plant’s established hydraulic, equilibrium, and com- pression-limited maximum, which would otherwise require major equipment replacement to exceed. Controlled ethane blending The front-end upgrade introduces a controlled amount of ethane into the natural gas feed to increase syngas produc- tion while keeping all reforming equipment within estab- lished safe and reliable operating envelopes. The approach ensures that the prereformer, steam methane reformer (SMR), and ATR continue to operate within design and metallurgical limits while maintaining sufficient hydrogen availability from the existing pressure swing adsorption (PSA) system. The study assessed combined feed ethane concentra- tions ranging from 7 to 15% on a carbon basis to quan- tify impacts on the steam balance, prereformer and SMR performance, tube metal temperatures, ATR operation, and PSA capacity. The base natural gas composition contained

considered uneconomic for this study. The ethane injection strategy requires no hardware changes to the reforming equipment other than the provision of a suitable gaseous ethane tie-in. Intermediate condensation The synthesis loop upgrade introduces an intermediate condenser between the water-cooled converter (WCC) outlet and the tube-cooled converter (TCC) inlet. In the cur- rent configuration (Figure 2), effluent from the water-cooled converters flows directly to the tube-cooled converter, achieving high per-pass conversion but carrying uncon- densed methanol and water into the downstream reactor. This reduces the reaction driving force and increases overall loop circulation. The proposed upgrade (Figure 3) adds a controlled cool - ing and condensation step that removes methanol and water before the gas enters the tube-cooled converter. The modification includes cooling the reactor effluent, separat - ing the condensed liquid, reheating the cleaned vapour to the required inlet temperature, and adjusting loop control to maintain stable operation. The treated gas contains

Catalysis 2026