Direct methane to methanol

Arutyunov V. Low-scale direct methane to methanol — modern status and future prospects. Catal Today 2013 215 243-50. 

Direct Methane To Methanol Foundations and Prospects of the Process... 

Since the predominant and most hardly convertible component of natural and associated gas is methane, with the main product of the direct oxidative conversion of methane and other light alkanes C2—C4 being methanol, the overall process of natural gas oxidative conversion to oxygenates has traditionally been referred to as Direct Methane To Methanol (DMTM), a term that will be used throughout the... 

DIRECT METHANE TO METHANOL FOUNDATIONS AND PROSPECTS OF THE PROCESS... 

In developing this next-generation direct methane to methanol process, several key considerations are important. As a general consideration it should be expected that any new process not only substantially reduces the capital costs for the process (ideally by >50%) but also meets (and desirably exceeds) the overall yield and atom-efficiency of the existing process. Significantly, giving the eco-... 

The lower than expected yields can be explained by the nature of methane oxidation to methanol in these bacteria. This reaction, catalysed by methane mono-oxygenase, is a net consumer of reducing equivalents (NADH), which would otherwise be directed to ATP generation and biosynthesis. In simple terms the oxidation of methane to methanol consumes energy, lowering the yield. 

In 1990, Schroder and Schwarz reported that gas-phase FeO" " directly converts methane to methanol under thermal conditions [21]. The reaction is efficient, occuring at 20% of the collision rate, and is quite selective, producing methanol 40% of the time (FeOH+ + CH3 is the other major product). More recent experiments have shown that NiO and PtO also convert methane to methanol with good efficiency and selectivity [134]. Reactions of gas-phase transition metal oxides with methane thus provide a simple model system for the direct conversion of methane to methanol. These systems capture the essential chemistry, but do not have complicating contributions from solvent molecules, ligands, or multiple metal sites that are present in condensed-phase systems. 

Direct oxidation of methane to methanol is an obvious dream reaction ... 

The Active Oxygen for Direct Oxidation of Methane to Methanol in the Presence of Hydrogen... 

Investigation of direct conversion of methane to transportation fiiels has been an ongoing effort at PETC for over 10 years. One of our current areas of research is the conversion of methane to methanol, under mild conditions, using li t, water, and a semiconductor photocatalyst. Research in our laboratory is directed toward ad ting the chemistry developed for photolysis of water to that of methane conversion. The reaction sequence of interest uses visible light, a doped tungsten oxide photocatalyst and an electron transfer molecule to produce a hydroxyl i cal. Hydroxyl t cal can then react with a methane molecule to produce a methyl radical. In the preferred reaction pathway, the methyl radical then reacts with an additional wata- molecule to produce methanol and hydrogen. 

A long-term goal of our research group is to explore and evaluate novel pathways for the direct conversion of methane to liquid fiiels, chemicals, and intermediates. One of our current areas of research is the conversion of methane to methanol, under mild conditions, using li t, water, and a semiconductor photocatalyst. The use of three relatively abundant... 

DMO [Direct methane oxidation] A process for converting methane to methanol or synthetic liquid fuels. Under development by Catalytica in 1997. 

R. Raja, and R. Ratnasamy, Direct conversion of methane to methanol, Appl. Catal. A158, L7-L15... 

Methane to Methanol and/or Formaldehyde Recent research indicates that a catalyst system in the presence of H2SO4 can convert methane directly into methanol. Homogeneous catalyst systems show promise. Also, heterogeneous Fe-ZSM-5 catalysts are reported to be attractive for this chemistry. Novel plasma reactors to generate hydroxyl radicals are also being investigated. 

One of the most important challenges in the modern chemical industry is represented by the development of new processes aimed at the exploitation of alternative raw materials, in replacement of technologies that make use of building blocks derived from oil (olefins and aromatics). This has led to a scientific activity devoted to the valorization of natural gas components, through catalytic, environmentally benign processes of transformation (1). Examples include the direct exoenthalpic transformation of methane to methanol, DME or formaldehyde, the oxidation of ethane to acetic acid or its oxychlorination to vinyl chloride, the oxidation of propane to acrylic acid or its ammoxidation to acrylonitrile, the oxidation of isobutane to... 

The direct catalytic conversion of methane has been actively pursued for many years. Much of the emphasis has been on the direct production of methanol via selective partial oxidation (8), coupling of methane to ethylene (9), or methane aromatization (10). At this time none of these technologies has been demonstrated commercially due to low yields of desired products due to combustion by-products or low equilibrium conversion at reasonable process temperatures and pressures. The potential benefits of a hypothetical process for the direct partial oxidation of methane to methanol (11) are presented as an example. 

Q. Zhang, D. He, Q. Zhu, Recent Progress in Direct Partial Oxidation of Methane to Methanol, 12, Journal of Natural Gas Chemistry, 81-89, (2003). 

The current two-step industrial route for the synthesis of methanol, from coal or methane to synthesis gas and then from synthesis gas to methanol, has certain drawbacks. The economic viability of the whole process depends on the first step, which is highly endothermic. Thus a substantial amount of the carbon source is burned to provide the heat for the reaction. It would be highly desirable, therefore, to replace this technology with a technically simpler, single-step process. This could be the direct partial oxidation of methane to methanol, allowing an excellent way to utilize the vast natural-gas resources. Although various catalysts, some with reasonable selectivity, have been found to catalyze this reaction (see Sections 9.1.1 and 9.6.1), the very low methane conversion does not make this process economically feasible at present. 

Oxidation of Methane. The direct selective transformation of methane to methanol and formaldehyde, two valuable industrial chemicals is a goal that is extremely... 

Direct pressurized oxidation of methane to methanol with hydrogen peroxide... 

Direct one-stage oxidation of methane to methanol is performed by two methods catalytic and thermal. Modernization of the process of methane conversion to methanol using various catalysts is ineffective, because in this case methane conversion is usually below 13%. At the present time, methane conversion to methanol has been raised to 24% [122] however, this is still insufficient for an economic assessment of the process. Hence, thermal... 

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