Methane Pyrolysis with the Use of Plasma: Review of Plasma Reactors and Process Products

Abstract

With the increasing role of hydrogen in the global market, new ways of hydrogen production are being sought and investigated. One of the possible solutions might be the plasma pyrolysis of methane. This approach provides not only the desired hydrogen, but also valuable carbon-containing products, e.g., carbon black of C2 compounds. This review gathers information from the last 20 years on different reactors that were investigated in the context of methane pyrolysis, emphasizing the different products that can be obtained through this process.

Comprehensive Review on Methane Pyrolysis for Sustainable Hydrogen Production

“…12, 58 The most well-known mechanism was proposed by Chen et al 58,59 with the reactions are shown in reactions 7−10 and the net overall reaction in reaction 11 will mainly correspond to hydrogen and solid carbon, as shown in reaction 11, if the time and temperature increase. 34 Methane is known for its thermodynamic stability owing to the strong carbon−hydrogen (C−H) bonds within its molecular structure. Breaking these bonds during MP requires overcoming a considerable energy barrier, which results in an endothermic process.…”

“…56 Table 5. Comparative Analysis of Different Reactor Types for Methane Pyrolysis characteristics fixed-bed reactor 119−121 moving bed and fluidized bed reactor 11,30,102,122 liquid metal bubble column reactor 19,71,91,123 plasma reactor 34,35,111,124,125 working principle methane gas passes through a fixed bed of catalyst particles methane flows through a bed of moving particles, enhancing contact with the catalyst methane bubbles through a column of liquid metal, decomposing into hydrogen and solid carbon currently limited because of small to medium scale and high energy requirements cost moderate; catalyst cost is significant higher than fixed-bed due to complexity and moving parts high initial cost but lower operational cost due to catalyst durability relatively high due to energy consumption and maintenance advantages simple design, easy to operate. improved heat and mass transfer, longer catalyst life high conversion rates, efficient heat management high conversion rates due to high temperature and energy input limitations catalyst deactivation due to coking is a major issue more complex design and operation, higher cost high initial setup cost, handling of liquid metals electrode erosion, high operational cost, complex maintenance The techno-economic aspects of MP are complex and depend on various factors, such as the type of reactor and catalyst used, the cost of natural gas, and the type, amount, and price of solid carbon produced.…”

“…MP is an alternate method for producing hydrogen from natural gas or CH 4 through a catalytic or non-catalytic reaction at 500–1600 °C without emitting carbon dioxide. , Methane (CH 4 ) undergoes a splitting process into its elementary components: solid carbon and hydrogen gas. Numerous researchers have investigated this process, recognizing it as a promising avenue for the clean H 2 production. , …”

“…Typically, the formation of intermediate products, such as C 2 H 6 , C 2 H 4 , and C 2 H 2 , is faster than methane dehydrogenation. However, the product selectivity will mainly correspond to hydrogen and solid carbon, as shown in reaction , if the time and temperature increase …”

Study on the Value-Added Carbon Products from Methane Pyrolysis with the Thermal Plasma Process

“…During this process, various harmful substances such as carbon dioxide are emitted [22]. Consequently, if carbon black derived from plasma-based methane pyrolysis, which is simpler than the furnace black method, is utilized as a high -value-added material, it can lead to substantial energy cost sav- ings [23].…”