A new route to syngas-combined conversion of carbon dioxide and ethane on zeolites

Towards maximizing conversion of ethane and carbon dioxide into synthesis gas using highly stable Ni-perovskite catalysts

Boosting CO2 Conversion with Terminal Alkynes by Molecular Architecture of Graphene Oxide-Supported Ag Nanoparticles

Pulsed-corona plasma has been used as a new method for ethane dehydrogenation at low temperature and normal pressure using carbon dioxide as an oxidant in this paper. The effect of carbon dioxide content in the feed, power input, and flow rate of the reactants on the ethane dehydrogenation has been investigated. The experimental results show that the conversion of ethane increases with the increase in the amount of carbon dioxide in the feed. The yield of ethylene and acetylene decreases with the increase in the yield of carbon monoxide, indicating that the increased carbon dioxide leads to the part of ethylene and acetylene being oxidized to carbon monoxide. Power input is primarily an electrical parameter in pulsed-corona plasma, which plays an important role in reactant conversion and product formation. When the power input reaches 16 W, ethane conversion is 41.0% and carbon dioxide conversion is 26.3%. The total yield of ethylene and acetylene is 15.6%. The reduced flow rate of feed improves the conversion of ethane, carbon dioxide and the yield of acetylene, and induces carbon deposit as well.

Thermodynamic analysis of syngas production via tri-reforming of methane and carbon gasification using flue gas from coal-fired power plants

The utilization of carbon dioxide for the production of valuable chemicals via catalysts is one of the efficient ways to mitigate the greenhouse gases in the atmosphere. It is known that the carbon dioxide conversion and product yields are still low even if the reaction is operated at high pressure and temperature. The carbon dioxide utilization and conversion provides many challenges in exploring new concepts and opportunities for development of unique catalysts for the purpose of activating the carbon dioxide molecules. In this paper, the role of carbon-based nanocatalysts in the hydrogenation of carbon dioxide and direct synthesis of dimethyl carbonate from carbon dioxide and methanol are reviewed. The current catalytic results obtained with different carbon-based nanocatalysts systems are presented and how these materials contribute to the carbon dioxide conversion is explained. In addition, different strategies and preparation methods of nanometallic catalysts on various carbon supports are described to optimize the dispersion of metal nanoparticles and catalytic activity.

Ethylene is the most significant product that is being used in different sectors. The demand for ethylene is increasing year by year as it is the preferred raw material in the production of various industrially important products such as HDPE, LDPE, PVC, ethylene glycol, styrene, and ethylene dichloride. Carbon dioxide is a promising oxidant for the dehydrogenation of ethane. The global consumption of ethylene has increased to approx. 160 million ton per year with an annual growth rate of 4%. A significant amount of ethylene is produced by pyrolysis of various hydrocarbon stocks using steam, which is a highly energy-intensive process. Oxidative dehydrogenation of ethane using carbon dioxide is considered as one of the alternative methods for obtaining ethylene with higher yield. This chapter explores the effectiveness of metal oxide catalysts, with a particular interest in achieving higher selectivity to ethylene and better conversion of ethane and carbon dioxide. Various methods of preparation and physicochemical characterization techniques of catalysts were analyzed in detail. Performances of metal oxides and metal oxide-supported Cr2O3 catalysts were evaluated in a fixed-bed quartz reactor at 550–675 °C. Cr2O3 on metal oxide catalysts is suitable for oxidative dehydrogenation of ethane in the presence of CO2. CO2 which acts as a diluent for enhancing the equilibrium conversion of light alkanes and as an agent for the removal of coke formed on the catalyst thus acquires enormous importance.

Conversion of methane to syngas via plasma technology is a cost-effective approach to obtaining syngas. Methane conversion by means of ceramic electrodes was significantly increased. In plasma reformer, while electrical discharge is available in gas, very active species such as electrons, radicals, ions, atoms, and excited molecules are produced and they function as catalysts. Methane and carbon dioxide gases at atmospheric temperature and pressure in the non-thermal with TiO2-coated electrode plasma reactor with an inner diameter of 9 mm are converted to hydrogen and carbon monoxide (syngas) through one chemical step. The main objective of this research was to investigate the effects of changes in feed flow rate and feed ratio on methane conversion and product selectivity, as well as product distribution. Furthermore, the results were obtained when three synthesized catalysts were inserted in a section (3 mm) of plasma length (100 mm). The obtained results demonstrated that the voltage of 15 kV was required for methane conversion and hydrogen production. Reducing voltage and/or increasing the partial pressure ratio of methane to carbon monoxide in the reactor inlet resulted in the reduction of methane conversion rate. Moreover, according to the findings, increasing the ratio of carbon dioxide to methane would increase methane conversion and consequently, decrease the conversion of carbon dioxide. The conversion of methane and carbon dioxide was higher for co-precipitated Ce-Mn oxide support than those using the two other methods.

The concentration of carbon dioxide in the atmosphere is increasing, leading to a rising demand for its conversion. It is the growing demand for carbon dioxide (CO2) conversion that drives research into various innovative technologies. There are many existing methods for the catalytic conversion of carbon dioxide, such as electrocatalysis and chemical catalysis. However, each technology has its own sets of advantages and disadvantages. Among these, the electro-catalytic conversion of carbon dioxide, combining enzymatic catalysis and electrocatalysis, stands out for its potential to provide efficient and clean solutions. Writing a relevant literature review is meaningful in this context. This article commences by examining the electron transfer mechanisms between NAD(P)H-independent and NAD(P)H-dependent redox enzymes and electrodes, with the aim of exploring the mechanisms and efficiencies of enzymatic electrocatalytic systems in carbon dioxide conversion. In addition, an innovative technology is discussed, which is notable for successfully developing a new electro-enzyme coupling pathway. This innovation enhances the high activity between NADH and the enzyme, providing a new pathway for efficient and environmentally friendly carbon dioxide utilization. This process is capable of synthesizing high-value chemicals while minimizing environmental impact.

Review: Opportunities for simultaneous energy/materials conversion of carbon dioxide and plastics in metallurgical processes

Conversion of carbon dioxide (CO2) and water (H2O) to methanol (CH3OH) is achieved through an artificial photosynthesis procedure utilizing cobalt (Co) micro-particle based photocatalyst and solar energy in a simple, closed reactor. The photocatalyst is fabricated by exposing the surfaces of cobalt microparticles to femtosecond laser irradiation in a gold chloride (AuCl) solution. The morphology and composite of the photocatalyst surfaces were observed and detected to be a layer of cobalt dioxide (CoO) nano-flakes on which some gold (Au) nanoparticles were deposited. The Au nanoparticles harvest the Sunlight energy through a plasmonic effect. The energy absorbed by Au nanoparticles creates electrons and holes which excite the H2O and CO2 molecules adsorbed on CoO nanostructure surfaces to form excited hydrogen (H2)* and excited carbon monoxide (CO)* on the CoO surface. The excited molecules combine to form CH3OH on the CoO surface. The Au/CoO/Co nanostructured surfaces are useful for developing a low-cost method to convert solar energy to chemical energy in the form of methanol.

Multi-criteria decision approach to select carbon dioxide and hydrogen sources as potential raw materials for the production of chemicals

A new strategy to remarkably improve the low-temperature reversible hydrogen desorption performances of LiBH4 by compositing with fluorographene

The tri-reforming process was employed for syngas production from biogas at elevated pressures in this study. In the tri-reforming process, air and water were added simultaneously as reactants in addition to the main biogas components. The effects of various operating parameters such as pressure, temperature and reactant composition on the reaction performance were studied numerically. From the simulated results, it was found that methane and carbon dioxide conversions can be enhanced and a higher hydrogen/carbon monoxide ratio can be obtained by increasing the amount of air. However, a decreased hydrogen yield could result due to the reverse water–gas shift reaction. A higher level of methane conversion and hydrogen/carbon monoxide ratio can be obtained with increased water addition. However, negative carbon dioxide conversion could result due to the water–gas shift and reverse carbon dioxide methanation reactions. The dry reforming reaction resulting in positive carbon dioxide conversion can only be found at a high reaction temperature. For all cases studied, low or negative carbon dioxide conversion was found because of carbon dioxide production from methane oxidation, water–gas shift, and reverse carbon dioxide methanation reactions. It was found that carbon dioxide conversion can be enhanced in the tri-reforming process by a small amount of added water. It was also found that first-law efficiency increased with increased reaction temperature because of higher hydrogen and carbon monoxide yields. Second-law efficiency was found to decrease with increased temperature because of higher exergy destruction due to a more complete chemical reaction at high temperatures.

Collaborative conversion of methane and carbon dioxide into sustainable chemicals is an appealing solution to simultaneously overcome both environmental problems and energy crisis. However, this reaction is limited to the preparation of syngas with the unfavorable feature for transportation and storage. Herein, liquid formaldehyde as product is fabricated by the collaborative conversion of methane and carbon dioxide using anatase phase titanium dioxide as photocatalyst. The productivity reaches 14.65 mmol g−1 with 88.32% selectivity. In situ diffuse reflectance Fourier transform infrared spectroscopy, isotope testes, and theoretical calculation clarify that the photoexcited holes and electrons engage into methane oxidation and carbon dioxide reduction over anatase using surface hydroxyl species and oxygen vacancy as active sites, respectively. The consumption of surface hydroxyl species on methane oxidation promotes the oxygen vacancy formation for carbon dioxide adsorption, mutually the carbon dioxide provides the oxygen atom for surface hydroxyl species facilitating methane oxidation. The consumption of photoelectrons and photoholes on carbon dioxide reduction and methane oxidation balances the number of photogenerated carriers and ensures the catalytic system stability. In this work, the avenue is broadened toward the co‐conversion of greenhouse gas into desirable chemical products in a sustainable way.

MXene - A frontier exploiter in carbon dioxide conversion: Synthesis and adsorption