(136b) Linde’s EDHOXTM Technology: Commercial Ethylene and Acetic Acid Production without Direct CO2 Emissions

Linde’s EDHOXâ„¢ technology is the first commercial process to produce ethylene (polymer grade) by the oxidative dehydrogenation of ethane, offering significantly lower specific energy consumption and lower CO₂ emissions than conventional ethane-steam cracking (E-SC). In addition, the EDHOXâ„¢ technology co-produces acetic acid (glacial purity) and is the ideal choice for downstream processes requiring both ethylene and acetic acid, such as VAM (Vinyl Acetate Monomer), EVA (Ethylene Vinyl Acetate) copolymer, PVOH (Polyvinyl Alcohol products), PTA (Terephthalic Acid), ethyl acetate and similar derivatives.

The Linde EDHOXâ„¢ technology provides a wide flexibility range of ethylene to acetic acid production (2.5-4.5 t/t) and an overall selectivity towards these products above 93% under safe and reliable oxidative conditions. This is achieved with a multitubular reactor at low pressure and moderate operating temperature (300-350°C), which can be materialized in a wide range of production capacities up to world scale ethylene plant capacities. Furthermore, its oxidative route is exothermic and consequently does not require additional heat input by firing or electricity. The high selectivity to ethylene and acetic acid is achieved with a solid catalyst, producing, in turn, less by-products than conventional E-SC and simplifying product separation and purification. CO₂ is only formed as a reaction by-product and captured as part of the EDHOXâ„¢ process prior to the ethylene purification. These unique features of the EDHOXâ„¢ technology result in more than three times lower specific energy consumption than conventional E-SC. With utilization or storage of the captured CO₂ and the usage of renewable power the Linde EDHOX^TM technology can effortlessly attain “Zero Scope 1 & 2 Emissions”.

The EDHOX™ technology performance has been verified in a demonstration plant under commercial conditions at Linde’s Pullach (Munich) Engineering center in Germany, with a commercial size reactor tube, separation-purification and closed-loop operation to recycle non-converted ethane. Linde is currently working on several early phase projects for the first commercial scale application of the EDHOX™ technology.

The paper describes in detail the Linde EDHOXâ„¢ technology and highlights its “Zero Scope 1 & 2 Emissions” features. It consequently focuses on its significant economic advantages in comparison to conventional E-SC. This includes up to 20% lower CAPEX, 40% lower ethylene production costs per ton of ethylene and significantly higher net present value (NPV) within historic feed and product prices, regardless of CO₂ credits.