CO Syngas Research Articles

Direct liquefaction behavior of Shenhua Shangwan coal under CO containing atmosphere

Direct coal liquefaction (DCL) under CO or syngas atmosphere is beneficial to reduce the cost of hydrogen production. Effects of CO on liquefaction process of Shangwan coal were investigated by comparing the liquefaction behavior in three atmospheres of CO, H2, and N2. Then, effects of different CO/H2 ratios and catalysts on the liquefaction process in syngas were investigated. The results indicated that the oil yield under CO atmosphere reached 43.1%, which was 4.2% lower than that under H2, but 10.2% higher than that under N2. The liquefaction performance was further improved by adding the Shenhua 863 catalyst. It is analyzed that CO promoted liquefaction in two ways: water-gas shift reaction and the reaction between CO and organic structures of coal. Through characterization of the products by GC-MS and FT-IR, it was found that CO makes benzenes, aliphatics, and oxygen-containing compounds in liquefied oil simultaneously increased. The effect on functional groups and free radicals concentration in the solid products was not obvious. The experimental results under syngas showed that the highest oil yield, 57.4%, can be obtained in DCL with 20% CO syngas, and further improved by increasing moisture content of coal appropriately. In addition, the Shenhua 863 catalyst had a good catalytic effect on the liquefaction process and also water-gas shift reaction.

Exsolved NiRu bimetallic nanoparticles induced by Ru doping in LaBaMn1.6Ni0.3Ru0.1O5+δ as a coking resistant anode catalyst layer for direct-methane solid oxide fuel cells

Due to its abundant resources and advantages in transportation and storage, methane fueled solid oxide fuel cells (SOFCs) are highly needed. In this work, an exceptional internal reforming catalyst comprising in-situ exsolved NiRu bimetallic nanoparticles and oxygen-deficient layered double perovskite LaBaMn1.6Ni0.3Ru0.1O5+δ (r-LBMNR) was prepared. Compared to the cell with LaBaMn1.6Ni0.4O5+δ (r-LBMN) catalyst, the cell with a Ru-doping r-LBMNR catalyst layer, exhibits superior peak power output of 336 mW cm−2 and better durability with a less decay rate of 0.014% per hour in CH4 fuel. The enhanced electrochemical performance can be attributed to the high oxygen ion and electron conductivities of the catalyst and the coupling of Ni and Ru sites with the oxygen-deficient r-LBMNR matrix This coupling activates CH4 and H2O, promotes the oxidation of C atoms in CH4 molecules, and enables reversible hydrogen spillover, ultimately leading to the production syngas of CO(g) and H2(g).

Selective Hydrogenation of Aldehydes under Syngas Using CeO2-Supported Au Nanoparticle Catalyst.

Chemoselective hydrogenation of aldehydes to alcohols is of importance in synthetic chemistry. Here, we report a reusable CeO2-supported Au nanoparticle catalyst for the selective hydrogenation of aldehydes using syngas as the hydrogen source for which CO in syngas works as a site blocker to prevent side reactions. In particular, the hydrogenation of aldehydes with an easily reducible alkene, alkyne, or halogen moiety under syngas gave the corresponding alcohols with high selectivity, while the hydrogenation under pure hydrogen resulted in overreduction or dehalogenation. Of particular interest is that CO works as a site blocker but does not affect the hydrogenation rate significantly. A potential application of the present catalyst system was demonstrated by the conversion of terminal alkenes to alcohols via a one-pot hydroformylation/hydrogenation sequence.

Photocatalytic CO2 reduction to syngas using nickel phosphide-loaded CdS under visible light irradiation

Photocatalytic CO2 reduction is a sustainable pathway to produce syngas (H2 + CO), which is a key feedstock for the production of several important liquid fuels on the industrial scale. However, achieving an appropriate tunable ratio of H2:CO in syngas for commercial purposes is a challenging task. In this work, we present a low-cost and non-noble metal, phosphide-based co-catalyst—Ni2P-loaded cadmium sulfide (CdS) photocatalyst system, for photocatalytic CO2 reduction. As a co-catalyst, Ni2P fosters an efficient charge separation of photoexcited charges generated in the CdS production of syngas. In total, 3 wt.% Ni2P/CdS exhibited exceptional performance of 50.6 µmol g−1 h−1 in the CO evolution rate and 115 µmol g−1 h−1 in the H2 evolution rate, with a syngas composition varying from 2 to 4 in the H2:CO ratio. Furthermore, first-principles density functional theory calculations were performed to study the surface energetics of the catalyst system and the results are found to be consistent with our experimental findings. Indeed, they establish that the composite favors CO2 photoreduction into syngas more efficiently than pure surfaces.

Enhancing CO and H2 Production in Propane Dry Reforming in Excess of CO2.

This study focuses on addressing the challenges in the dry reforming of propane, a process historically marked by low syngas yields and only moderate conversions of CO2 and propane. The primary objective was to enhance CO2 utilization and boost the selectivity of syngas (CO and H2) production using titania-based catalysts. For synthesizing these catalysts, an impregnation method was employed with subsequent characterization through X-ray diffraction (XRD), N2 adsorption-desorption, ammonia temperature-programmed desorption (TPD), and hydrogen temperature-programmed reduction (TPR). The titania-based catalysts generally possess weak acidic strength, with each catalyst displaying a unique reduction profile. The dry reforming process using these catalysts resulted in varying levels of propane conversion, with V/Ti, Ir/Ti, Al/Ti, and Zr/Ti catalysts showing distinct efficiencies. Notably, the Ir/Ti and V/Ti oxide catalysts achieved the lowest selectivity for generating intermediate byproducts such as methane, ethane, ethylene, and propylene while successfully promoting higher syngas CO and H2 production alongside stable propane conversion. When exposed to excess CO2, each catalyst consumed differing amounts of CO2 molecules. Particularly, the Ir/Ti and V/Ti oxide catalysts demonstrated enhanced activity in promoting CO2 reactions with intermediate radical species, facilitating carbon-carbon (C-C) bond dissociation and leading to increased syngas production. This study offers valuable insights into the potential of titania-based catalysts in improving the efficiency and selectivity of propane dry reforming processes for blue hydrogen.

Continuous H-B-E fermentation by Clostridium carboxidivorans: CO vs syngas

Leveraging renewable carbon-based resources for energy and chemical production is a promising approach to decrease reliance on fossil fuels. This entails a thermo/biotechnological procedure wherein bacteria, notably Clostridia, ferment syngas, converting CO or CO2 + H2 into Hexanol, Butanol and Ethanol (H-B-E fermentation). This work reports of Clostridium carboxidivorans performance in a stirred tank reactor continuously operated with respect to the gas and the cell/liquid phases. The primary objective was to assess acid and solvent production at pH 5.6 by feeding pure CO or synthetic syngas under gas flow differential conditions. Fermentation tests were conducted at four different dilution rates (DL) of the fresh medium in the range 0.034–0.25 h−1. The fermentation pathways of C. carboxidivorans were found to be nearly identical for both CO and syngas, with consistent growth and metabolite production at pH 5.6 within a range of dilution rates. Wash-out conditions were observed at a DL of 0.25 h−1 regardless of the carbon source. Ethanol was the predominant solvent produced, but a shift towards butanol production was observed with CO as the substrate and towards hexanol production with synthetic syngas. In particular, the maximum cell concentration (0.5 gDM/L) was obtained with pure CO at DL 0.05 h−1; the highest solvent productivity (60 mg/L*h of total solvent) was obtained at DL 0.17 h−1 by using synthetic syngas as C-source. The findings highlight the importance of substrate composition and operating conditions in syngas fermentation processes. These insights contribute to the optimization of syngas fermentation processes for biofuel and chemical production.

Unlocking long-chain hydrocarbons (C2–7) via direct electrochemical CO2 and CO reduction on balanced Au/Ni electrodes

Electrochemical (EC) CO2 reduction method has been widely used as a green energy and environmental solution strategy. The use of Au/Ni electrodes was introduced to showcase a new concept of the direct EC Fischer-Tropsch (dEC F-T) synthesis pathway. This pathway involves the combination of electrodes that produce H2 and CO (syngas) during electrochemical CO2 reduction. The introduction of Au on the Ni electrode surface led to an increase in CO production and a gradual decrease in H2 production. When the interface was balanced, a pronounced F-T synthesis pathway was observed, resulting in the production of a series of hydrocarbons (CnH2n and CnH2n+2, n = 2–7). The dEC F-T synthesis was evaluated under different conditions, including electrolytes, concentrations, metal supports (Co and Fe), various overlayer metals (Ag and Cu), light irradiation, and isotope effects. The process was elucidated through surface C−C coupling polymerization reactions based on Anderson-Schulz-Flory weight distribution analysis. Additionally, the F-T synthesis was demonstrated through EC CO reduction via direct CO and H adsorption. The dEC F-T path provides a novel strategy for energy and environment by producing high-value long-chain hydrocarbons.

The conversion mechanism of syngas CO and H2 under Au and Au-CCo-doping catalysts

The relative stability, reaction potential energy surface, NBO charge analysis and kinetic properties of Au, Au-C co-doping catalysts in CO and H2 syngas catalytic reactions were studied by density functional theory calculation. The calculation results indicate that the reaction energy barrier and reaction rate showed a consistent pattern of change. NBO charge analysis indicates the feasibility of the catalytic reaction of syngas. We also calculated the rate constant which indicates that the rate constant has a positive temperature dependence. Our calculations show that the reaction is an exothermic reaction catalyzed by Au and Au-C co-doping.

Clean Energy from Poplar and Plastic Mix Valorisation in a Gas Turbine with CO2 Capture Process

The objective of this paper is to explore the utilisation of plastic waste via the gasification process to produce electricity with low carbon dioxide emissions. Worldwide, plastic production has increased, reaching 390 million tons in 2021, compared to 1.5 million tons in 1950. It is known that plastic incineration generates approximately 400 million tons of CO2 annually, and consequently, new solutions for more efficient plastic reuse in terms of emissions generated are still expected. One method is to use plastic waste in a gasifier unit and the syngas generated in a gas turbine for electricity production. The co-gasification process (plastic waste with biomass) was analysed in different ratios. Gasification was carried out with air for an equivalent ratio (ER) between 0.10 and 0.45. The volume concentration of CO2 in syngas ranged from 2 to 12%, with the highest value obtained when the poplar content in the mix was 95%. In this study, the option of pre- and post-combustion integration of the chemical absorption process (CAP) was investigated. As a result, CO2 emissions decreased by 90% compared to the case without CO2 capture. The integration of the capture process reduced global efficiency by 5.5–6.1 percentage points in a post-combustion case, depending on the plastic content in the mix.

Effect of H2 and CO in syngas on oxy-MILD combustion

This paper investigates the effect of adding H2 and CO to a syngas on oxy-MILD combustion. This work employs a Perfectly Stirred Reactor (PSR) model to calculate the autoignition temperature and the critical oxygen concentration for different component fuels under oxy-MILD conditions. Our investigation obtains the critical O2 concentration for oxy-MILD combustion of various H2/CO/CH4 component fuels. The results indicate that adding H2 to CH4 significantly reduces the minimum O2 concentration required for achieving the MILD state while adding CO has little effect. Furthermore, using the novel PCA method, we analyze characteristic chemical time scales for oxy-MILD combustion for different fuel ratios. We conclude that the mixture containing H2 and CO can be used as fuel for oxy-MILD combustion, as its characteristic chemical time scale is comparable to the turbulent time scale, resulting in Da number close to unity. However, achieving a steady MILD combustion state is more challenging than methane due to reduced ignition delay times. Moreover, syngas with various ratios of H2/CO presents the potential for controlling the MILD combustion process.

The influence of Co nucleation in Co[sbnd]Ni single atom alloy on low-temperature methane dry reforming with DFT simulations and microkinetic modeling

CO2 reacting with CH4 to produce value-added syngas CO and H2 is an attractive approach to utilize CO2 and achieve carbon neutralization. The present work employed the dispersion corrected density functional theory (DFT) and microkinetic modeling to investigate the influence of Co nucleation in CoNi single atom alloy (SAA) on low-temperature methane dry reforming (DRM). It is found that the Co nucleation in CoNi SAA did not alter the most favorable reaction path. That is, CH4 is dehydrogenated to CH* step by step, then CH* is oxidized by O* from CO2 direct decomposition to obtain CHO*, and finally CHO* is dehydrogenated to produce CO. For the decomposition of CO2, the direct decomposition of CO2 prefers over the assisted decomposition of CO2 by H* via COOH* or HCOO* intermediates decomposition to obtain the final product CO. Microkinetic modeling results reveal that the nucleation of single Co atoms to Co dimer or a surface Co layer favors the conversion of methane and CO2 at 773 K but reduces the coke-resistance ability. Reverse water-gas shift does not change the key species on the surface but interferes the product distribution and surface rate-limiting step.

Insights into syngas-fueled Wankel rotary engine performance from varied CO/H2 ratio

Syngas is a fuel with a huge market and low carbon emission, which has been proven to be well applied to internal combustion engines. WRE with high power density can effectively improve the power characteristic when syngas is employed as fuel in engines, however, which has not been reported publicly. This work aims to provide insights into the performance of syngas-fueled WRE under different CO/H2 ratios and thus gives theoretical guidance for its application. The test is done at 1500 r/min and part load. It is found that with the increase of the volumetric ratio of CO in syngas (CO%), the efficiency, torque and carbon emissions are deteriorated, however, the NO emission is significantly improved and the knock level is also reduced. In addition, on the premise of constant CO%, a high brake thermal efficiency, low NO emission and knock intensity can be achieved at lean combustion. In particular, when CO% is 10%, the combustion efficiency of CO is independent of the excess air ratio, while when CO% is 20%, that is decreased with increasing excess air ratio. In summary, the syngas-fueled WRE is recommended to adopt the qualitative control and the syngas with low CO%.

Techno-economic analysis of the co-gasification of sewage sludge and petroleum coke

In this study, the co-gasification of sewage sludge and petroleum coke is assessed with equilibrium and numerical modeling. The gasification process of these binary wastes provides a potential pathway for waste management and environmental sustainability. First, the thermodynamic equilibrium approach is used to calculate the maximum cold gasification efficiency (CGE) at different mixture ratios in an attempt to narrow down and focus on the appropriate composition of the two kinds of feedstock within the entrained flow gasifier. Furthermore, a parametric study is conducted to show the gasification metrics, i.e., CGE and feedstock conversion, and the syngas composition at different gasification conditions. The equilibrium model is based on eight unknowns in the gasification product, namely, H2, CO, CO2, H2O, CH4, O2, Csolid, and the temperature, under variable O2 and H2O molar ratios. Using three elemental mass balances, four equilibrium (Csolid) constant relations, and energy balance, the mathematical model is developed. The model incorporates the solid unburnt carbon in the product species. The temperature of gasification is determined through an iterative process. Using the result of the equilibrium model, a high-fidelity reactive flow model that accounts for the reactor geometry and the devolatilization kinetics is developed. This model accounts for an extended set of reactions covering the char combustion, water and gas shifts, Boudouard and devolatilization. Finally, economic analysis is carried out to assess the conditions when such a process can be deemed to be profitable. The result of the model shows that the maximum CGE is achieved when all the solid carbon is converted into carbon monoxide with nearly all hydrogen present in the feedstock converted into hydrogen gas. The maximum conversion was attained with sewage sludge and petroleum coke ratio of 1 at 1,200°C. The mole fraction of the syngas species obtained is XH2 = 0.4227 and XCO = 0.5774 and a small fraction of XCH4 = 0.0123. Moreover, the cold gasification efficiency (CGE) measures 87.02% for the H2 and CO syngas species and reached 91.11% for the three species, including CH4. The gasification of the sewage sludge and petroleum coke at 50:50 is economically viable at temperatures higher than 950°C. A peak net gain of 0.16 $/kg of fuel blend was achieved at 1,250°C. At temperatures lower than 950°C, net losses were realized. This could be associated with less product gas yield, which is not significant enough to counteract the input costs. For instance, the net losses were −0.03 and −0.17 $/kg of feedstock at 950 and 800°C, respectively.

Removal of Organic Sulfur Pollutants from Gasification Gases at Intermediate Temperature by Means of a Zinc–Nickel-Oxide Sorbent for Integration in Biofuel Production

Production of renewable fuels from gasification is based on catalytic processes. Deep desulfurization is required to avoid the poisoning of the catalysts. It means the removal of H2S but also of organic sulfur species. Conventional cleaning consists of a several-step complex approach comprising catalytic hydro-treating followed by H2S removal. In this work, a single-stage process using a zinc and nickel oxide sorbent has been investigated for the removal of organic sulfur species present in syngas. The process is called reactive adsorption and comes from the refinery industry. The challenge investigated by CIEMAT was to prove for the first time that the concept is also valid for syngas. We have studied the process at a lab scale. Thiophene and benzothiophene, two of the main syngas organic sulfur compounds, were selected as target species to remove. The experimental study comprised the analysis of the effect of temperature (250–450 °C), pressure (1–10 bar), space velocity (2000–3500 h−1), tar components (toluene), sulfur species (H2S), and syngas components (H2, CO, and full syngas CO/CO2/CH4/H2). Operating conditions for removal of thiophene and benzothiophene were determined. Increasing pressure and temperature had a positive effect, and full conversion was achieved at 450 °C, 10 bar and 3500 h−1, accompanied by simultaneous hydrogen sulfide capture by the sorbent in accordance with the reactive adsorption desulfurization (RADS) process. Space velocity and hydrogen content in the syngas had little effect on desulfurization. Thiophene conversions from 39% to 75% were obtained when feeding synthetic syngas mimicking different compositions, spanning from air to steam-oxygen-blown gasification. Toluene, as a model tar component present in syngas, did not strongly affect the removal of thiophene and benzothiophene. H2S inhibited their conversion, falling, respectively, to 2% and 69% at 350 °C and 30% and 80% at 400 °C under full syngas blends.

Fe-based oxygen carrier for the chemical looping combustion of CO, H2, and CH4 syngas in fluidized bed reactor under interruption of H2S

Chemical looping combustion (CLC) reduces the CO2 capturing cost, elevates combustion efficiency, and prevents NOx formation. This study applied Fe2O3/SiO2 and Fe2O3/Al2O3 oxygen carriers to react with H2, CO and CH4 under different operating setup and examined the interference of H2S. Examination was also conducted on the reaction kinetics, cycle test, and characterization of oxygen carriers. Reduction of oxygen carrier from Fe2O3 to between FeO and Fe occurred during the reaction. The higher syngas concentration led to higher diffusion capacity and promoted utilization of oxygen carriers. Carbon deposition was enhanced by excess concentration of CO and CH4. Involvement of H2S led to declining of performance due to the presence of carbonyl sulfide (COS) and FeS. With Fe2O3/SiO2, application of multiple redox cycles reduced the utilization value to 43 % due to formation of Fe2SiO4. Analysis of exhausted gas after reaction was applied in study of proposed reaction mechanism. Study of reaction kinetics using Type I deactivation test indicated a well fitted result with experimental data with R2 in the range of 0.9605–0.9976. Thus, compared to other studies with discussion only on CO, H2, or CH4 in CLC, this study offered a comprehensive research on interruption of H2S, characterization, and reaction kinetics.

Plasma-Catalytic CO2 Reforming of Toluene over Hydrotalcite-Derived NiFe/(Mg, Al)O x Catalysts.

The removal of tar and CO2 in syngas from biomass gasification is crucial for the upgrading and utilization of syngas. CO2 reforming of tar (CRT) is a potential solution which simultaneously converts the undesirable tar and CO2 to syngas. In this study, a hybrid dielectric barrier discharge (DBD) plasma-catalytic system was developed for the CO2 reforming of toluene, a model tar compound, at a low temperature (∼200 °C) and ambient pressure. Periclase-phase (Mg, Al)O x nanosheet-supported NiFe alloy catalysts with various Ni/Fe ratios were synthesized from ultrathin Ni-Fe-Mg-Al hydrotalcite precursors and employed in the plasma-catalytic CRT reaction. The result demonstrated that the plasma-catalytic system is promising in promoting the low-temperature CRT reaction by generating synergy between DBD plasma and the catalyst. Among the various catalysts, Ni4Fe1-R exhibited superior activity and stability because of its highest specific surface area, which not only provided sufficient active sites for the adsorption of reactants and intermediates but also enhanced the electric field in the plasma. Furthermore, the stronger lattice distortion of Ni4Fe1-R provided more isolated O2- for CO2 adsorption, and having the most intensive interaction between Ni and Fe in Ni4Fe1-R restrained the catalyst deactivation induced by the segregation of Fe from the alloy to form FeO x . Finally, in situ Fourier transform infrared spectroscopy combined with comprehensive catalyst characterization was used to elucidate the reaction mechanism of the plasma-catalytic CRT reaction and gain new insights into the plasma-catalyst interfacial effect.

Formate-induced CO tolerance and methanogenesis inhibition in fermentation of syngas and plant biomass for carboxylate production

BackgroundProduction of monocarboxylates using microbial communities is highly dependent on local and degradable biomass feedstocks. Syngas or different mixtures of H2, CO, and CO2 can be sourced from biomass gasification, excess renewable electricity, industrial off-gases, and carbon capture plants and co-fed to a fermenter to alleviate dependence on local biomass. To understand the effects of adding these gases during anaerobic fermentation of plant biomass, a series of batch experiments was carried out with different syngas compositions and corn silage (pH 6.0, 32 °C).ResultsCo-fermentation of syngas with corn silage increased the overall carboxylate yield per gram of volatile solids (VS) by up to 29% (0.47 ± 0.07 g gVS−1; in comparison to 0.37 ± 0.02 g gVS−1 with a N2/CO2 headspace), despite slowing down biomass degradation. Ethylene and CO exerted a synergistic effect in preventing methanogenesis, leading to net carbon fixation. Less than 12% of the electrons were misrouted to CH4 when either 15 kPa CO or 5 kPa CO + 1.5 kPa ethylene was used. CO increased the selectivity to acetate and propionate, which accounted for 85% (electron equivalents) of all products at 49 kPa CO, by favoring lactic acid bacteria and actinobacteria over n-butyrate and n-caproate producers. Inhibition of n-butyrate and n-caproate production by CO happened even when an inoculum preacclimatized to syngas and lactate was used. Intriguingly, the effect of CO on n-butyrate and n-caproate production was reversed when formate was present in the broth.ConclusionsThe concept of co-fermenting syngas and plant biomass shows promise in three aspects: by making anaerobic fermentation a carbon-fixing process, by increasing the yields of short-chain carboxylates (propionate and acetate), and by minimizing electron losses to CH4. Moreover, a model was proposed for how formate can alleviate CO inhibition in certain acidogenic bacteria. Testing the fermentation of syngas and plant biomass in a continuous process could potentially improve selectivity to n-butyrate and n-caproate by enriching chain-elongating bacteria adapted to CO and complex biomass.

Synergistic effects during co-pyrolysis and co-gasification of polypropylene and polystyrene

The thermal conversion of waste plastic products can provide a promising solution to the issues of environmental pollution, waste management, and energy needs. However, our present understanding on the thermal reforming of different kinds of plastic wastes mixtures during their co-pyrolysis and co-gasification for syngas production and energy recovery is insufficient. Non-selective urban polypropylene (PP) and polystyrene (PS) waste plastics were chosen for the investigations reported here. Thermal degradation properties of PP and PS as well as their blends in different mass ratios were investigated via thermogravimetric (TG) analysis. Co-pyrolysis and CO2-assisted co-gasification of PP-PS blends were then conducted using a fixed-bed reactor at a temperature of 1173 K. Experimental results from the blends were then compared with the weighted value calculated from their component feedstocks to quantify the degree of synergistic effect. TG results showed that the co-treatment of PP and PS enhanced the respective devolatilization process. The co-pyrolysis of PP and PS enhanced their thermal cracking, leading to synergistic increases in the yields of H2, light hydrocarbons (HC) and total syngas. In co-gasification, the reforming reaction involving CO2 was synergistically enhanced, resulting in the increased yields of H2 and HC. The gasification reactivity of carbon black improved during the co-processing of PP and PS due to the synergistic effect between the two different kinds of plastics. Higher synergistic effects were observed from the plastic mixtures having higher PS content that resulted in increased yield of syngas. Co-gasification of PP-PS blends having 40% PP content (2P3S) exhibited the maximum synergistic effect on H2, CO, and total syngas showing increased yields by 88.8%, 77.7%, and 74.2% respectively. The lowest synergistic effect was observed for HC that showed increased yield of only 25.1%. The optimal CO2 consumption was also observed from the co-gasification of 2P3S. Each gram of 2P3S feedstock consumed approximately 1.80 g of CO2 to result in highest recovered energy of 27.49 kJ/g and the maximum overall energy efficiency of 43.2%. The results revealed that enhanced thermal cracking and CO2 reforming reaction, along with the improved reactivity of carbon black were mainly responsible for increased yields of H2, HC, CO and total syngas during co-gasification. This study contributes to the fundamental understanding of co-processing of non-separated waste plastics for enhanced syngas production and energy recovery, elucidating the synergistic effect between the various kinds of plastics during their co-pyrolysis and co-gasification.

New molten metal catalysts for CO2 and CH4 conversion to 2 : 1 H2 : CO syngas.

Activity trends for 22 metals and metal alloys are reported for the conversion of CO2 and CH4 to 2 : 1 H2 : CO syngas and carbon. A correlation is observed between CO2 conversion and the free energy of oxidation by CO2 on pure metal catalysts. Indium and indium alloys activate CO2 at the highest rates. We identify a new bifunctional 20 : 80 mol% Sn-In alloy that activates both CO2 and CH4 while catalyzing both reactions.

Optimization of operating conditions of an internal combustion engine used as chemical reactor for methane reforming using ozone as an additive

Internal combustion engines can be used as chemical reactors exploiting the high temperature and pressure as well as short residence time for chemical conversion. For instance, methane and CO2 can be efficiently converted to H2 and CO (syngas). The process can be boosted by additives such as dimethyl ether (DME). In this paper, the focus is on optimizing the operating conditions for the use of ozone, O3, as an alternative fuel additive for dry reforming of methane. Furthermore, methane can be converted to C2 hydrocarbons, which is also studied numerically to find optimized operating conditions, again using O3 as an additive. The engine is modelled as a single-zone batch reactor under ideal gas assumptions with a variable volume profile. An elementary-step reaction mechanism consisting of 749 reactions among 132 species and including O3 chemistry was used for the simulations. CO2 conversion of over 70% is possible using O3 as an additive, whereas the maximum achievable using DME was around 50%. The optimized yield of C2H4 is higher with O3 as an additive as compared to DME, at all the inlet gas temperatures, whereas it is lower for CH2O and comparable for C6H6 and CH3OH.