Engineering evaluation of direct methane to methanol conversion

Abstract

Investigations into direct methane to methanol conversion are justified based on the avoidance of synthesis gas generation, which accounts for around 60% of the capital cost of synthesis gas to methanol conversion. A significant body of information already exists on the process chemistry, but little has been reported on the engineering of such a process. An engineering evaluation of the process was performed and the potential of this process as a platform technology for small-scale gas-to-liquids (GTL) applications was evaluated. It was found that direct methane to methanol conversion had 35% carbon efficiency and 28% thermal efficiency, which were about half of the process efficiencies of indirect methanol synthesis using synthesis gas. The poor process efficiency was mainly a consequence of the irreversible loss of carbon to CO x during conversion. The direct methane to methanol process also required an air separation unit, which eroded the stated benefit of avoiding a synthesis gas generation step in the process. The utility footprint was typical of GTL processes, with large gas compression duties and cooling duties. Overall, the engineering evaluation indicated there was no benefit to employ direct methane to methanol conversion instead of indirect methanol synthesis (the industry standard), and there was no specific benefit of direct methane to methanol conversion, irrespective of scale, for GTL applications.

The production of fuels and chemicals in the new world: critical analysis of the choice between crude oil and biomass vis-à-vis sustainability and the environment

“…The American Chemical Council estimates that as many as 148 projects totaling over $100 billion dollars in new capital investments will be floated over the next 10 years to take advantage of the shale gas boom. Methane can also be used as a feedstock for the manufacture of hydrogen (for ammonia production), syngas, methanol, gasoline and electricity (Wolf 1992 ; Hackworth et al 1995 ; Lange and Tijm 1996 ; Rostrup-Nielsen et al 2000 ; Lange 2001 ; Rostrup-Nielsen 2002 ; de Klerk 2015 ); and this proposition is corroborated by a detailed assessment of the carbon and thermal efficiencies and capital costs for a suite of methane-to-chemicals processes (Fig. 8 ).…”

Effect of Doped Metals Rh, Pd, and Cu over the IrO2(110) Surface: Improving C2 Selectivity during Oxidative Coupling of Methane

“…1,8,9 However, the low C 2 yield of OCM has long limited its economic feasibility. 1,10 The main reason is that highly efficient catalysts with high methane conversion and C 2 hydrocarbon selectivity have not been developed. 11 Methane is a highly symmetric and nonpolarized molecule, and the C−H bond dissociation energy is as high as 4.55 eV.…”

Methane C–H Activation by [Cu2O]2+ and [Cu3O3]2+ in Copper-Exchanged Zeolites: Computational Analysis of Redox Chemistry and X-ray Absorption Spectroscopy

“…Natural gas consists mostly of methane, which is a valuable source of energy and industrial chemicals. , As such, conversion of methane to liquid derivatives like methanol is the target of many research efforts. Efficient and direct conversion of methane to methanol will likely be more cost-effective than current liquefaction techniques. , Of the various systems that are active toward the methane C – H bond, copper-exchanged zeolites have garnered great interest. − The active sites for converting methane to methanol in these zeolites are known to be small copper-oxo species. There however is some debate about the exact nature of these species. − Several monocopper, dicopper, and tricopper species have been proposed. , However, invocation of a unique tricopper tri-oxo, [Cu 3 O 3 ] 2+ , − active site species complicates the established description of the Cu 2+ /Cu + redox couple as the driver for the conversion of methane to methanol .…”