Energy & Fuels, Vol.23, 4438-4448, 2009
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-N-2 and CH4-N-2-(C-2-C-4) mixtures of different composition, modeling some degasolined and non-degasolined raw dry and wet NRNGs, containing up to about 90 vol% of N-2, were used in investigations carried out under applied conditions. Experiments with (C-2-C-4)-N-2, C2H6-N-2, C3H8-N-2, and C4H10-N-2 mixtures were also performed. It was revealed that, in the irreversible processes of OCM and OCMT, no effect of CH4 dilution with N2 oil the reactant conversions and the yields and selectivities of the main products was observed with up to about 80% of the N-2 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,is a direct feed in the investigated oxidative methane transformation processes.