Decarbonizing Natural Gas: A Review of Catalytic Decomposition and Carbon Formation Mechanisms

Abstract

In the context of energy conservation and the reduction of CO2 emissions, inconsistencies between the inevitable emission of CO2 in traditional hydrogen production methods and eco-friendly targets have become more apparent over time. The catalytic decomposition of methane (CDM) is a novel technology capable of producing hydrogen without releasing CO2. Since hydrogen produced via CDM is neither blue nor green, the term “turquoise” is selected to describe this technology. Notably, the by-products of methane cracking are simply carbon deposits with different structures, which can offset the cost of hydrogen production cost should they be harvested. However, the encapsulation of catalysts by such carbon deposits reduces the contact area between said catalysts and methane throughout the CDM process, thereby rendering the continuous production of hydrogen impossible. This paper mainly covers the CDM reaction mechanisms of the three common metal-based catalysts (Ni, Co, Fe) from experimental and modelling approaches. The by-products of carbon modality and the key parameters that affect the carbon formation mechanisms are also discussed.

First-Principles Microkinetic Modeling Unravelling the Performance of Edge-Decorated Nanocarbons for Hydrogen Production from Methane

“…H 2 is becoming ever more relevant as a promising candidate to replace fossil fuels, which are rapidly depleting and cause global warming . In fact, the major source of H 2 production is via methane steam reforming (SMR), resulting in large emissions of greenhouse gases . Therefore, the reduction of the CO x as a byproduct for hydrogen production is pointed to as critical to reducing costs and energy consumption …”

“… 2 In fact, the major source of H 2 production is via methane steam reforming (SMR), resulting in large emissions of greenhouse gases. 21 Therefore, the reduction of the CO x as a byproduct for hydrogen production is pointed to as critical to reducing costs and energy consumption. 22 …”

“…2 the major source of H 2 production is via methane steam reforming (SMR), resulting in large emissions of greenhouse gases. 21 Therefore, the reduction of the CO x as a byproduct for hydrogen production is pointed to as critical to reducing costs and energy consumption. 22 Metal-based catalysts are the most commonly employed for the CMD process, with nickel-and iron-based catalysts being the most economically viable and possessing high selectivity for hydrogen production.…”

Thermocatalytic Decomposition of Methane: A Review on Carbon-Based Catalysts

“…Carbon formation in a CDM reaction is a multistage process that initiates with the CH 4 adsorption, and then various dehydrogenation steps conclude the formation of a conically ordered graphitic filamentous carbon over suitable catalysts and under the required reaction conditions. Attempts to understand the thermodynamics and driving force for carbon filament growth are widely reported in the literature . The gradients in temperature and/or concentration across the catalyst are believed to drive the carbon diffusion process through the catalyst .…”

Bubble‐Mediated Mass Production of Graphene: A Review

“…[ 113 ] In past years, the pursuit for a higher conversion of CH 4 is the most important topic in this area. [ 114 ] In 2017, Upham et al. proposed a recorded conversion rate of CH 4 (95% at 1065 °C in a 1.1 m bubble column) in molten Ni 27 Bi 73 system (Figure 11b).…”