Methane Activation by Heterogeneous Catalysis

Abstract

Methane activation by heterogeneous catalysis will play a key role to secure the supply of energy, chemicals and fuels in the future. Methane is the main constituent of natural gas and biogas and it is also found in crystalline hydrates at the continental slopes of many oceans and in permafrost areas. In view of this vast reserves and resources, the use of methane as chemical feedstock has to be intensified. The present review presents recent results and developments in heterogeneous catalytic methane conversion to synthesis gas, hydrogen cyanide, ethylene, methanol, formaldehyde, methyl chloride, methyl bromide and aromatics. After presenting recent estimates of methane reserves and resources the physico-chemical challenges of methane activation are discussed. Subsequent to this recent results in methane conversion to synthesis gas by steam reforming, dry reforming, autothermal reforming and catalytic partial oxidation are presented. The high temperature methane conversion to hydrogen cyanide via the BMA-process and the Andrussow-process is considered as well. The second part of this review focuses on one-step conversion of methane into chemicals. This includes the oxidative coupling of methane to ethylene mediated by oxygen and sulfur, the direct oxidation of methane to formaldehyde and methanol, the halogenation and oxyhalogenation of methane to methyl chloride and methyl bromide and finally the non-oxidative methane aromatization to benzene and related aromates. Opportunities and limits of the various activation strategies are discussed.

Methane dehydroaromatisation and methanol activation over zeolite catalysts: an overview

“…There has been interest in its conversion into products which are more valuable and/or more easily transportable [2]. In general, it is an indirect feedstock for the production of various target products through its conversion to syn gas by steam reforming and associated technologies.…”

Molten salt chemical looping for reactive separation of HBr in a halogen-based natural gas conversion process

“…Economical use of methane in natural gas as a feedstock for liquid chemicals and fuels continues to be a long-term scientific and engineering challenge [1][2][3]. Demonstrated processes have high capital costs and require large scales to be profitable.…”

Application of POSS Nanotechnology for Preparation of Efficient Ni Catalysts for Hydrogen Production

“…resources, nuclear energy (high-temperature water splitting) and electricity (electrolysis of water) [3][4][5][6][7][8][9]. Although the "green" or carbon-neutral path from current fossil-based to future hydrogen economy is preferable and provides sustainable development [1][2][3][4], to date H 2 is usually produced from fossil fuels without CO 2 capture and storage [16,10,13]. Natural gas remains main feedstock for hydrogen production [8,13,14,16,17].…”

“…Although the "green" or carbon-neutral path from current fossil-based to future hydrogen economy is preferable and provides sustainable development [1][2][3][4], to date H 2 is usually produced from fossil fuels without CO 2 capture and storage [16,10,13]. Natural gas remains main feedstock for hydrogen production [8,13,14,16,17]. The typical technologies for production of hydrogen from natural gas are steam methane reforming (SMR), partial oxidation (POX) and autothermal reforming (ATR).…”

“…The generated heat from POX is used for an endothermic SMR reaction, thus providing advantages of ATR technology for hydrogen production. Ni-based catalysts have been used and widely studied in methane reforming because of their high catalytic activity and low price [16][17][18][19][20][21][22][23][24]. But under long exposure [44], co-precipitation [45], deposition-precipitation [46], combustion [47,48], sol-gel [49], surfactant assisted and polyol [50] methods.…”