Nitrogen-Rich Natural Gases as a Potential Direct Feedstock for Some Novel Methane Transformation Processes. Part 1: Oxidative Processes

Abstract

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 CH 4 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 CH 4 -N 2 and CH 4 -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 , C 2 H 6 -N 2 , C 3 H 8 -N 2 , and C 4 H 10 -N 2 mixtures were also performed. It was revealed that, in the irreversible processes of OCM and OCMT, no effect of CH 4 dilution with N 2 on 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 CH 4 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.

Experimental and DFT Approach on the Determination of Natural Gas Hydrate Equilibrium with the Use of Excess N2 and Choline Chloride Ionic Liquid as an Inhibitor

“…These mixtures are being used either as pipeline-quality fuel after upgrading through N 2 removal, directly as low-quality fuel, or as additives in certain amounts to the high CH 4 gas network. 17 It is interesting to note that in a recent work, Obanijesu et al 18 reported that the presence of N 2 and/or H 2 under specific conditions acts as a hydrate inhibitor for natural gas in pipelines. Although N 2 is a hydrate former itself, the pressure and temperature (P, T) conditions required for hydrate formation are relatively high (in the temperature range of −1 to 13.2 °C for the 144 to 554.2 bar pressure region) compared with those for hydrocarbons.…”

“…These nitrogen-rich natural gases contain N 2 in concentrations of approximately 10–85 vol %. These mixtures are being used either as pipeline-quality fuel after upgrading through N 2 removal, directly as low-quality fuel, or as additives in certain amounts to the high CH 4 gas network …”

Performance Analysis of a Porous Packed Bed Membrane Reactor for Oxidative Coupling of Methane: Structural and Operational Characteristics

“…However, different researchers have reported different observations with regard to the effect of diluting the feed stream in OCM reactors. The effect of gas dilution on the OCM reactor performance has been claimed to be insignificant in some reports, 15 while mostly a positive impact of this parameter on improving the C 2 yield has been observed. 16 Nevertheless, there is a general agreement that using higher dilution increases the C 2 selectivity since it reduces the partial pressure of the reactants in the gas phase and consequently the potential for the undesired gas phase reactions.…”

An Effective Approach to Synthesize High-Performance SSZ-13 Membranes Using the Steam-Assisted Conversion Method for N2/CH4 Separation

“…The unconventional natural gases in many global regions contain 10−85% of nitrogen as the main inert gas. 1 Coalbed methane by downhole extraction also has 30−70 vol % nitrogen after oxygen removal. 2 The unconventional methane needs to be upgraded before being delivered to the pipeline as commercial natural gas.…”

“…The unconventional natural gases in many global regions contain 10–85% of nitrogen as the main inert gas . Coalbed methane by downhole extraction also has 30–70 vol % nitrogen after oxygen removal .…”