Commercial and environmental benefits have made carbon dioxide (CO2) methanation one of the topmost research projects all over the world both at the pilot plant and commercial scale. Mitigation of CO2 via carbon capture and storage (CCS) routes have less motivation from a commercial point of view. Therefore, an integrated system is of paramount importance to convert CO2 into value-added products such as methane (CH4) using solar energy (photosynthesis) or surplus electrical energy in hydrolysis for production of reactant hydrogen to use in CO2 methanation. To date, great efforts have been made to investigate both the reaction mechanism and catalysts development for methanation. Here in this review, up to date references have been cited, which are aimed at giving researchers a comprehensive overview of CO2 methanation with respect to the recent advancements in reaction mechanism, catalytic materials, and the novel combination of metal active phase and its synergy. Both thermochemical and electrochemical ro...

Recent Advancements, Fundamental Challenges, and Opportunities in Catalytic Methanation of CO2

Adsorption of CO2 from flue gas by novel seaweed-based KOH-activated porous biochars

Anaerobic digestion produces biogas, a mixture of CH4 and CO2, where CH4 is a low cost, environmentally friendly, and renewable energy source. The application of biogas production is increasing rapidly as a means of reducing the pollution impact of organic biomasses. However, biogas contains unwanted elements such as hydrogen sulfide, carbon monoxide, siloxanes, and carbon dioxide. To remove these elements, several biogas upgrading technologies like water scrubbing, amine scrubbing, pressure swing adsorption, and membrane separation have been developed and are being used at various commercial scales. Problems with these methods are high energy consumption, the use of expensive chemicals, and high operating cost. Therefore, a major effort is currently underway to improve the design of existing methods as well as developing innovative new upgrading technologies such as cryogenic separation and biological upgrading. This review intends to provide a comprehensive overview of the limitations with the existing upgrading technologies along with recent advances in physical, chemical, and biological biogas upgrading technologies (e.g., pressure swing adsorption, membrane separation, biochar adsorption and CO2 conversion by biological organisms) and further into possible future solutions, such as hybrid systems. Comparative studies of process complexities and associated economic concerns are also provided, and future perspectives that may facilitate research into sustainable biogas upgrading technologies are discussed, focusing in particular on cryogenic separation, novel biological techniques, biochar based upgrading and hybrid technologies incorporating two or more different methods seamlessly integrated.

Current status of biogas upgrading for direct biomethane use: A review

Porous carbon with both high CO2 uptake and CO2/N2 selectivity is desired for reducing the cost of carbon capture. Here, we report the preparation of N-enriched porous carbons (NPCs) derived from the low-cost triazine-based porous organic polymers using KOH as the activating agent under N2. The results indicate that the nitrogen content and textural properties of the NPCs can be effectively adjusted by the polymer precursors and the carbonization temperature. Impressively, the NPCs have an enriched N content (5.56–11.33 wt %) and abundant porosity (BET surface area: 394–1873 m2/g, pore volume: 0.27–1.56 cm3/g), endowing them with high CO2 uptake (120–207 mg/g at 273 K and 1.0 bar) and acceptable CO2/N2 selectivity (Henry’s law: 14.3–16.8). In particular, the ultra micropore volume (d ≤ 0.8 nm) is proven a key factor for the CO2 uptake, while both the ultra micropore volume and N content contribute the CO2/N2 selectivity. Our described work will provide a strategy to initiate developments of rationally des...

Synthesis of Triazine-Based Porous Organic Polymers Derived N-Enriched Porous Carbons for CO2 Capture

Triazine-based hyper-cross-linked polymers derived porous carbons for CO2 capture

In the last few decades of industrialization, the concentration of CO2 in the atmosphere had increased rapidly. Different organizations have invested considerable funds in research activities worldwide for CO2 capture and storage. To date, significant work has been done and various technologies have been proposed for CO2 capture and storage. Both adsorption and absorption are promising techniques for CO2 capture, but low-temperature adsorption processes using solid adsorbents are the prevailing technique nowadays. In this review paper, a variety of adsorbents such as carbonaceous materials, dry alkali metal-based sorbents, zeolites, metal–organic frameworks (MOFs) and microporous organic polymers (MOPs) have been studied. Various methods of chemical or physical modification and the effects of supporting materials have been discussed to enhance CO2 capture capacity of these adsorbents. Low-temperature (<100 °C) adsorption processes for CO2 capture are critically analyzed and concluded on the basis of information available so far in the literature. All the information in CO2 adsorption using different routes has been discussed, summarized and thoroughly presented in this review article. The most important comparative study of relatively new material MOFs and MOPs is carried out between the groups and with other sorbent as well.

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M. Jk Bashir

Papers

Feasibility of CO2 adsorption by solid adsorbents: a review on low-temperature systems

Advanced treatment of poultry slaughterhouse wastewater using electrocoagulation and peroxidation: parametric analysis and process optimization

Enhancing solar water heater system for utmost useful energy gain and reduction in greenhouse gas emissions in Gaza