(583dl) Investigation of Air-Based Oxidative Coupling of Methane. Catalysts and Products Separation

Ability to convert methane to ethylene that is the world’s most valuable chemical by oxidative coupling of methane (OCM) is highly attractive from an economic point of view. The  OCM  is  an  alternative  to  the  existing process of ethylene production by naphtha pyrolysis.

The OCM is known to represent the reaction of two СН₄ molecules in presence of oxygen with the formation of С₂hydrocarbons. The process proceeds under atmospheric pressure in the temperature range of 600-900°С in presence of a catalyst. The most active catalysts of the process are oxides of transition and rare-earth metals, and also tin and lead oxides.

In this research we have studied supported manganese catalysts as manganese oxides in the pure state function as  deep-oxidation  catalysts.  Furthermore supported catalysts have a higher mechanical strength that allows the research to be carried out in various hydrodynamic conditions.

Most of patents and publications in this field consider oxygen-based OCM reactor design due to higher conversion but air-based design is inherently safer and whole OCM technology consumes less energy if complex appropriate separation system is applied.

To reach economically feasible level of OCM technology we considered combinations of several ways:

• Co-generation of ethylene and electricity
• Carbon dioxide removal methods
• The adsorption of ethylene by zeolite
• Deep cryogenic distillation and absorption-distillation
• Nitrogen removal technologies

This research describes results of experimental investigation of manganese catalysts and ethylene adsorption by zeolite. Experimental data was used to develop integrated OCM model in Aspen Hysys and then to calculate technical and economic indices of various scheme.