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methane conversion, processes such as partial oxidation of methane into methanol/
formaldehyde, oxidative coupling of methane-producing ethylene and MDAproducing aromatic compounds have been explored. Thermodynamically, direct
conversion of methane into other commodity chemicals is favourable in presence of
oxidants and hence methane oxidation has been widely studied in direct methane
utilization. In this reference, methane oxidation to methanol, formaldehyde and
other oxygenates constitutes an important thrust in the research area of petrochemical industries [6]. However, lower methane conversion with poor methanol yield is
the major limitation which does not make this process successful in comparison to
syn-gas route.
Another prominent route using methane oxidation was claimed by Lunsford in
1985 reporting that methane could be converted into ethane/ethylene via oxidative
coupling using magnesium oxide catalyst at 600 °C [7]. To date, oxidative coupling
of methane (OCM) has been broadly studied and a maximum methane conversion
up to 25% with 80% of C 2 selectivity has been reported [8]. A major drawback with
OCM observed is further oxidation of C 2 hydrocarbons in the presence of oxygenproducing carbon dioxide, carbon monooxide and water which results in lower ethylene selectivity at high conversion. These limitations restrict for OCM
commercialization. In the pursuit to conduct direct methane upgradation, another
route involves methane transformation into liquid aromatic hydrocarbons under
non-oxidative conditions. Wang et al. in 1993 firstly investigated methane to aromatic reaction on ZSM-5-supported molybdenum catalyst producing mainly benzene with hydrogen as by-product under oxygen-free environment [9]. As the
process (later known as MDA) marks higher selectivity towards aromatic compounds (mainly benzene) using direct methane activation, several investigations
have been carried out on MDA reaction up to date [10]. Common challenges and
Fig. 1 Different routes of methane conversion producing value-added chemicals
Thermocatalytic Conversion of Natural Gas to Petrochemical Feedstocks…
methane conversion, processes such as partial oxidation of methane into methanol/
formaldehyde, oxidative coupling of methane-producing ethylene and MDAproducing aromatic compounds have been explored. Thermodynamically, direct
conversion of methane into other commodity chemicals is favourable in presence of
oxidants and hence methane oxidation has been widely studied in direct methane
utilization. In this reference, methane oxidation to methanol, formaldehyde and
other oxygenates constitutes an important thrust in the research area of petrochemical industries [6]. However, lower methane conversion with poor methanol yield is
the major limitation which does not make this process successful in comparison to
syn-gas route.
Another prominent route using methane oxidation was claimed by Lunsford in
1985 reporting that methane could be converted into ethane/ethylene via oxidative
coupling using magnesium oxide catalyst at 600 °C [7]. To date, oxidative coupling
of methane (OCM) has been broadly studied and a maximum methane conversion
up to 25% with 80% of C 2 selectivity has been reported [8]. A major drawback with
OCM observed is further oxidation of C 2 hydrocarbons in the presence of oxygenproducing carbon dioxide, carbon monooxide and water which results in lower ethylene selectivity at high conversion. These limitations restrict for OCM
commercialization. In the pursuit to conduct direct methane upgradation, another
route involves methane transformation into liquid aromatic hydrocarbons under
non-oxidative conditions. Wang et al. in 1993 firstly investigated methane to aromatic reaction on ZSM-5-supported molybdenum catalyst producing mainly benzene with hydrogen as by-product under oxygen-free environment [9]. As the
process (later known as MDA) marks higher selectivity towards aromatic compounds (mainly benzene) using direct methane activation, several investigations
have been carried out on MDA reaction up to date [10]. Common challenges and
Fig. 1 Different routes of methane conversion producing value-added chemicals
Thermocatalytic Conversion of Natural Gas to Petrochemical Feedstocks…