Nitrogen-rich natural gases as a potential direct feedstock for some novel methane transformation processes. Part 1: Oxidative processes

Nitrogen-rich natural gases (NRNGs) constitute a substantial part of the world's natural gas resources. The present work (parts 1 and 2) is concerned with the prospects for their possible future use, without separation and nitrogen removal, as a direct feedstock in some novel CH₄ conversion processes. Part 1 examines the possibility of using NRNGs as a direct feedstock in two oxidative processes: the methane oxidative coupling (OCM) to ethylene and ethane and the methane and toluene oxidative cross-coupling (OCMT) to styrene and ethylbenzene. Various CH₄-N₂ and CH₄-N ₂-(C₂-C₄) mixtures of different composition, modeling some degasolined and non-degasolined raw dry and wet NRNGs, containing up to about 90 vol%of N₂ , were used in investigations carried out under applied conditions. Experiments with (C₂ -C₄ )-N₂ , C₂ H₆ -N₂ , C₃ H₈-N2, andC₄ H₁₀-N₂ mixtures were also performed. It was revealed that, in the irreversible processes of OCM and OCMT, no effect of CH₄ dilution with N₂ on the reactant conversions and the ields and selectivities of the main products was observed with up to about 80% of the N2 content. The behavior of large amounts of CH4 homologues present in some feedstocks and their individual and collective influence on the yields of desirable products were examined. Some other observations were also reported. It was confirmed that NRNGs of different composition could be used as a direct feed in the investigated oxidative methane transformation processes.