CO2 CH4 Research Articles

Co-based defect-rich nanoarchitectonics with biomass carbon materials catalysts for CH4–CO2 reforming

The synthesis and utilization of defect-rich biomass carbon catalysts with varying Co concentrations and incorporated Ce in CH4-CO2 reforming were investigated. The catalytic performance of these catalysts was found to increase with higher Co content, reaching its optimum at a Co concentration of 20 %. The presence of Ce as a promoter improved the utilization of Co precursors and enhanced the dispersion of Co sites at defective structures on the catalyst surface. The confined space within the defective structures restricted the growth of Co particles, resulting in smaller and more uniformly dispersed Co particles on the catalyst surface. Additionally, the introduction of Ce species influenced the oxygen environment on the catalyst surface. XPS analysis confirmed that the addition of Ce led to an increase in the chemisorbed oxygen content, enhancing the catalyst's ability to activate CO2. The increased percentage of chemisorbed oxygen, coupled with improved CO2 activation capacity, contributed to the Co-Ce bimetallic catalyst's ability to resist carbon deposition. The Co-Ce bimetallic catalyst demonstrated exceptional stability and performance in CH4-CO2 reforming due to its enhanced metal dispersion, reduced metal particle size, and improved CO2 activation capacity. The incorporation of Ce as a promoter played a crucial role in achieving these desirable catalytic properties.

Interfacial Electron Engineering of PdSn-NbN/C for Highly Efficient Cleavage of the C-C Bonds in Alkaline Ethanol Electrooxidation.

The splitting of the C-C bonds of ethanol remains a key issue to be addressed, despite tremendous efforts made over the past several decades. This study highlights the enhancement mechanism of inexpensive NbN-modified Pd1 Sn3 -NbN/C towards the C-C bonds cleavage for alkaline ethanol oxidation reaction (EOR). The optimal Pd1 Sn3 -NbN/C delivers a catalytic activity up to 43.5 times higher than that of commercial Pd/C and high carbonate selectivity (20.5%) toward alkaline EOR. Most impressively, the Pd1 Sn3 -NbN/C presents good durability even after 25 200 s of chronoamperometric testing. The enhanced catalytic performance is mainly due to the interfacial interaction between PdSn and NbN, demonstrated by multiple structural characterization results. In addition, in situ ATR-SEIRAS (Attenuated total reflection-surface enhanced infrared absorption spectroscopy) results suggest that NbN facilitates the C-C bonds cleavage towards the alkaline EOR, followed by the enhanced OH adsorption to promote the subsequent oxidation of C1 intermediates after doping Sn. DFT (density functional theory) calculations indicate that the activation barriers of the C-H bond cleavage in CH3 CH2 OH, CH3 CHOH, CH3 CHO, CH3 CO, CH2 CO, and the C-C bond cleavage in CH3 CO, CH2 CO, CHCO are evidently reduced and the removal of adsorbed CH3 CO and CO becomes easier on the PdSn-NbN/C catalyst surface.

Numerical study on effects of CH4–CO2 internal reforming on electrochemical performance and carbon deposition of solid oxide fuel cell

CH4–CO2 fueled solid oxide fuel cells (SOFCs) are the high-efficiency and low-carbon power generation technology. However, carbon deposition severely hinders its application. Here, the numerical model considering the complex anode CH4 internal reforming reactions, H2 electrochemical reaction, gas diffusion and charge transfer of SOFC using CH4–CO2 fuel has been established. The CH4–CO2 internal reforming and electrochemical reactions of SOFC under different CO2/CH4 ratios and temperatures are studied to reveal the optimal operating conditions. The distributions of different reaction rates, gas components and carbon deposition activity at the anode are analyzed. The results show that the increase of CO2 concentration can decrease the carbon activity but also cause the decrease of electrochemical performance. It is found that the good comprehensive performances including power density, carbon activity and methane conversion rate can be achieved under the CO2/CH4 molar ratio of 1. The thermodynamic calculation of three different methane reforming modes shows that CH4–CO2 reforming leads to the greatest carbon deposition risk compared with CH4–H2O and CH4–O2 reforming, implying the importance of anti-carbon for CH4–CO2 fueled SOFC.

Emission characteristics of typical gas pollutants during oxygen-enriched waste incineration process

Oxygen-enriched waste incineration can improve incineration efficiency and reduce pollutant generation, while greenhouse gases and pollutant emission characteristics of different wastes are still unclear. In this study, pollutant emission characteristics of actual municipal solid waste (MSW) and typical components at different oxygen concentrations and moisture content were investigated to reveal the pollutant generation mechanism. The results illustrated that when oxygen concentrations increased from 21% to 30%, CO, CH4 and HCN emissions decreased by 95%, 95.5% and 96.5%, respectively. NO emissions increased by 75% due to the promotion of oxygen on fuel NO and rapid NO. The slight increase in SO2 (from 25.8% to 26.87%) was due to the promotion of oxygen on organic S and the reaction between SO42− and HCl. The decrease in HCl emissions (from 78.42% to 76.85%) was caused by the increasing deacon reaction. Besides, with increasing moisture content, CO, CH4 and HCN generation decreased first because of the CO oxidation and CH4 reforming reaction, and then increased due to the water–gas reaction between fixed carbon and water. Furthermore, the moisture content contained (66%) would promote NO and HCl generation by 35.7% and 9.1% through fuel N oxidation by OH radicals and hydrolysis of chlorine salt at high temperatures. The increased oxygen concentration would inhibit the moisture influence and improve applicability for different MSW. In addition, 25% oxygen-enriched incineration was selected as the most suitable parameter for improving combustion efficiency and reducing pollutant emissions of MSW with high moisture content.

Sensitivity analysis of nucleation and droplet growth models in the prediction of natural gas non-equilibrium condensation in Laval nozzle

Supersonic separation is a promising technology for purifying natural gas by removing impurities like H2O and heavy hydrocarbons. The condensation process of natural gas has obvious non-equilibrium characteristics, the accurate prediction of which is challenging and essential for efficient separators design. Euler-Euler two-fluid model was developed to investigate non-equilibrium condensation of four two-component gas mixtures: H2O, CO2, H2S and n-C9H20 in CH4. Various nucleation and droplet growth models were employed to analyze the sensitivity in predicted results. The obtained results show significant differences in condensation characteristics among four gas mixtures due to varying isentropic expansion coefficients. The choice of nucleation models had a pronounced impact on H2O and n-C9H20, especially using the internally consistent classical theory(ICCT). However, noticeable differences emerged for CO2 and H2S only when using ICCT compared to classical nucleation theory (CNT). Furthermore, results for H2O and n-C9H20 exhibits high sensitivity to calibration factors in the Gy and Yg droplet growth models. Conversely, due to the essentially continuous flow of initial droplet sizes for CO2 and H2S, the Nusselt number and results show minimal response to such calibrations. These results can provide a reference for determination or development of nucleation and droplet growth model for natural gas non-equilibrium condensation.

Methane deflagration promoted by enhancing ignition efficiency via hydrogen doping, with a view to fracturing shales

The enhancement of shale gas explosion pressure is an unresolved issue in the emerging in-situ methane explosive fracturing. An effective approach to further enhance combustion and explosion characteristics is to promote ignition via improver doping. In this work, the enhancement of EIE (excess ignition energy) on the deflagration characteristics of CH4–CO–H2 mixtures was tested using a 20 L spherical setup, whereby the contribution of hydrogen, as an improver with higher thermal conductivity, to the enhanced effects was first explored. It is discovered that hydrogen doping contributes to thermal expansion and combustion, and the explosion pressure, rise rate and laminar burning velocity of methane at 0.6 equivalence ratio have been increased by 1.2%, 19.7% and 3.9% after loading 1 kJ EIE compared to loading minimum ignition energy, and can be further enhanced by 0.2%, 7.2% and 2.8% via hydrogen doping. Moreover, the promotion of hydrogen doping on ignition efficiency was demonstrated by quantitatively analyzing the underlying heat loss of EIE. Results indicate that even at 1.0 equivalence ratio, EIE would experience a significant heat loss of 54% in methane, whereas more energy would be used to promote combustion after hydrogen doping, ultimately achieving an ignition efficiency of up to 87%.

Highly permeable DDR membranes

In this study, DDR membranes with a layer thickness of approximately 700 nm were studied for separation feeds comprising mixtures of CO2 and CH4. The membranes displayed the highest CO2 over CH4 permselectivity and CO2 permeability reported in literature. This was ascribed to a defect-free and ultra-thin zeolite film as well as an open and highly permeable support. For equimolar mixtures, the highest CO2 over CH4 permselectivity of 727 was observed when the pressure at the feed side was 5 bar(a) and the permeate pressure was 1 bar(a) at 25 °C. At these conditions, the CO2 permeability was very high at 45 × 10−7 mol/(m2 s Pa). Separation experiments for 80/20 and 20/80 mixtures were also performed, and in these cases, CO2 over CH4 permselectivities of 1011 and 622 were observed, respectively. For all feeds, the membrane permselectivity decreased slightly at higher temperature and in all cases, higher permselectivity was observed when vacuum was applied at the permeate side. One-stage membrane processes for upgrading biogas to biomethane at three different operating pressures were designed based on the experimental data. In all cases, a quite low membrane area, methane slip and power need were observed.

Investigation of oxy-fuel combustion for methane and acid gas in a diffusion flame

Co-combustion of methane (CH4) and acid gas (AG) is required to sustain the temperature in Claus reaction furnace. In this study, oxy-fuel combustion of methane and acid gas has been experimentally studied in a diffusion flame. Three equivalence ratios (ER = 1.0, 1.5, 2.0) and CH4-addition ratios (CH4/AG = 0.3, 0.5, 0.7) were examined and the flame was interpreted by analyzing the distributions of the temperature and species concentration along central axial. CH4-AG diffusion flame could be classified into three sections namely initial reaction, oxidation and complex reaction sections. Competitive oxidation of CH4 and H2S was noted in the first section wherein H2S was preferred and both were mainly proceeding decomposition and partial oxidation. SO2 was formed at oxidation section together with obvious presence of H2 and CO. However, H2 and CO were inclined to be sustained under fuel rich condition in the complex reaction section. Reducing ER and increasing CH4/AG contributed to higher temperature, H2S and CH4 oxidation and CO2 reactivity. Hence a growing trend for CH4 and AG to convert into H2, CO and SO2 could be witnessed. And this factor enhanced the generation of CS2 and COS in the flame inner core by interactions of CH4 and CO2 with sulfur species. COS was formed through the interactions of CO and CO2 with sulfur species. The CS2 production directly relied on reaction of CH4 with sulfur species. The concentration of COS was greater than CS2 since CS2 was probably inhibited due to the presence of H2. COS and CS2 could be consumed by further oxidation or other complex reactions.

Permeability properties of hydrate-bearing sediments: Competition and conversion in hydrates growth

The permeability of reservoirs is an important factor restricting CO2 sequestration and CH4 hydrate exploitation, which is predicted by the hybrid models. However, these hybrid models fail to provide the calculation method and physical meaning of the weight parameters. Additionally, pore structure controls permeability by affecting the hydrates growth modes. In this work, a competition parameter was used to describe the modes evolution with increasing saturation, and its value range was determined using natural and laboratory samples. Then, the relationship between saturation, competition parameter, newly formed hydrates, and cumulatively formed hydrate was analyzed, respectively. The results indicate that a competitive cumulative effect exists in hydrates growth. Sh corresponding to the first derivative (equal to 1) of the ratio of PF hydrates in the newly formed hydrates is twice the first derivative maximum value of weighting parameter. This competition model could predict the mode evolution in hydrates growth and provide a new idea for industrial exploitation and simulation calculation.

(Invited) Plasma Catalysis: An Emerging Electrification Technology for Sustainable Production of Fuels and Chemicals

The conversion of inert molecules (e.g., CO2, CH4, and N2) with strong chemical bonds for the synthesis of value-added synthetic fuels and platform chemicals has attracted significant interest. However, the activation of these molecules remains a great challenge as they are thermodynamically stable and require a significant amount of energy for activation. Non-thermal plasma (NTP) is an emerging and attractive technology for gas conversions under ambient conditions. The combination of NTP with heterogeneous catalysis has great potential to generate a synergistic effect from interactions between the plasma and catalysts, which can activate catalysts at low temperatures and improve the activity and stability of the catalysts, resulting in a remarkable increase in conversion, selectivity, and yield of end-products, as well as the energy efficiency of the process. Moreover, plasma processes can be switched on and off instantly, allowing for great flexibility in decentralised chemical production using renewable energy sources, particularly intermittent renewable energy. The potential of plasma-catalytic technologies for the synthesis of fuels and chemicals via various chemical processes such as CH4 activation, CO2 conversion, and ammonia synthesis will be discussed in this presentation.

Optimization of Discharge Plasma Reactor for Dry Reforming of Methane using Response Surface Methodology

This research provides a study of the dry reforming of methane (DRM), which converts two main greenhouses gases (CO2 and CH4) to synthesis gas (H2 and CO) by a Dielectric Barrier Discharge (DBD) plasma reactor at atmospheric pressure. The Box-Behnken Design (BBD) method based on the Response Surface Methodology (RSM) was applied to determine the optimum experimental conditions on the plasma stability and the synthesis gas production. The synergistic effects of input power (P), CO2/CH4 ratio (R), and flow rate (FR) on the CO2, CH4 conversions, H2, CO yields, and the syngas ratio of H2 to CO were studied. With the desirability value of 0.97, the optimum values of 10.05 W (P), 1.03 (R), and 1.58 L.min−1 FR were identified with CO2 conversion of 48.56% and CH4 conversion of 86.67%; H2 and CO yields of 45.87% and 39.43% respectively; and syngas ratio of H2 to CO of 0.88. The study shows that both P and FR have a major significant effect on the reactant conversions and syngas ratio, followed by R. Meanwhile, the value of R has a significant impact on the H2, CO yields followed P and FR. In contrast, the synergistic effects between P-R, P-FR, and R-FR had a weak significant on the CO2 and CH4 conversions, H2 and CO yields, and H2 to CO ratio respectively. The quadratic term coefficients of P, R, and FR had a remarkable effect on all responses. Thus, the synergistic effect of the most important parameters improves the process efficiency. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Molecular insights on influence of CO2 on CH4 adsorption and diffusion behaviour in coal under ultrasonic excitation

Decoupling the molecular structure from the pore structure is challenging under experimental conditions; this hinders the independent investigation of the effect of the changes in molecular structure on methane (CH4) transport. In this study, the molecular model of coal was reconstructed based on the test results of X-ray photoelectron spectroscopy (XPS) and 13C nuclear magnetic resonance (13C NMR). A grand canonical Monte Carlo (GCMC) based molecular dynamics (MD) simulation method was used to independently investigate the effect of CO2 on CH4 adsorption and diffusion behaviour in coal under changes in the molecular structure of coal after ultrasonic excitation. The experimental results show that, under ultrasonic excitation, the proportion of oxygen content in the coal increases and the oxygen-containing functional groups (carboxyl groups, ether bonds/hydroxyl groups) increase compared to the original coal. The simulation results show that the amount of CH4 adsorbed, the isosteric heat and the proportion of low-energy CH4 in the coal sample decrease after ultrasonic excitation for the same pore size. Furthermore, for the same pore size and CO2 partial pressure ratio, adsorption selectivity factor increases after ultrasonic treatment. Additionally, for the same pore size and the same CO2 partial pressure ratio, the interaction energy between CH4 and coal in the CH4–CO2–coal mixed system decreases and the density of high-energy CH4 increases after ultrasonic excitation; this leads to an increase in CH4 self-diffusion and transport diffusion coefficient. The presence of oxygen-containing functional groups causes a significant increase in the electrostatic potential difference between CO2 and coal as compared to that between CH4 and coal, which is the fundamental reason for the change in the effect of CO2 on the adsorption-diffusion behaviours of CH4. Our findings revealed the micro-mechanism of ultrasonic-assisted coalbed methane extraction and demonstrated the effectiveness of ultrasonic-CO2 collaborative technology.

Pd/P–CeO2–Al2O3 coatings supported on foam ceramic with controlled morphology for high-performance CO2 methanation

Converting CO2 to highly demanded fuels or chemicals is able to achieve substantial economic and environmental benefits. Herein, a series of Pd/P–CeO2–Al2O3 coatings on foam ceramics with particular morphologies including mesh, rod, plate, as well as mixed mesh and plate, are successfully prepared. The mesh Pd/P–CeO2–Al2O3 coatings (MC) supported on ceramic displayed much higher catalytic activity and better selectivity than those of catalysts with other morphological Pd/P–CeO2–Al2O3 coatings. The CO2 conversion and CH4 selectivity of MC were up to 85.9% and 100%, respectively. The superior catalytic performance was ascribed to the strong MSI effect, high hydrogen storage capacity, abundant oxygen vacancies, and metal sites, as well as moderately basic sites, which were characterized by TEM, XPS, CO2-TPD, and H2-TPD. More importantly, the intermediates and possible reaction pathways were systematically investigated by in situ FTIR. And the high performance of MC mainly comes from the accelerated conversion of carbonate and the hydrogenation of the generated monodentate formate. Overall, the catalytic performance of Pd/P–CeO2–Al2O3 coatings supported on ceramic can be facilely regulated and optimized by accurately devising the morphology of the Pd/P–CeO2–Al2O3 coatings, which offers a novel perspective for high-performance CO2 methanation.

Enhancing the catalytic performance and coke reduction using low-cost Ni-based promoted catalyst for hydrogen production

Dry reforming of methane (DRM) is a highly promising reforming technology that facilitates converting CO2-rich natural gas into synthesis gas. However, the commercial application of DRM has concerns such as carbon deposition and sintering of the catalyst at high temperatures, leading to catalyst deactivation. This study aimed to determine the effect of an alkaline promoter addition on the amount of carbon deposited and activity test of alkaline-promoted nickel-based catalysts. Alkaline-promoted nickel-based catalysts were prepared using the incipient wetness impregnation method, followed by characterization using X-ray diffraction, N2 physisorption, H2-TPR, CO2-TPD, and thermogravimetric analysis. The performances of the catalysts were tested in a fixed-bed reactor under atmospheric pressure at 700 °C for 240 min. The Mg-promoted catalyst yielded the highest CH4 conversion (78%), CO2 conversion (64%), and H2 to CO ratio (1.52) compared to the non-promoted nickel-based and other alkaline-promoted catalysts. Furthermore, the thermogravimetric analysis revealed the Mg and Na-promoted catalyst produced 1.2 and 3.5 times less carbon than a commercial steam reforming catalyst.

Synergistic effect of coal and biomass gasification and organo-inorganic elemental impact on gasification performance and product gas

The current study demonstrates the synergistic effect of co-gasification of high-ash Indian coal and biomass (press mud and sawdust) blends in varying proportions in a pilot-scale bubbling fluidized bed gasifier (BFBG) with a capacity of 20 kg/h. The effect of blending on product gas yield, composition and heating value, carbon conversion, and cold gas efficiency was critically analyzed. Mineralogical transformations and catalytic effects were investigated during co-gasification, wherein minerals in ash residue, such as hematite, sylvite, chlorite, K-feldspar, CaO, and MgO, showed a catalytic role in co-gasification, increasing the product gas compositions, and reverse the trend for kaolinite and phosphate minerals. Blending coal with biomass enhances the porosity and reactivity of blends, surface morphology, gasification performance, and product gas yield. So, high ash coal and biomass are suitable for gasification. The high ash coal gasification comprises the volumetric product gas composition (%) of CO (9.79), CO2 (8.75), H2(13.6), and CH4(1.12) with the maximum blends (40%) of biomass, the volumetric composition (%) is enhanced comprising CO (17.71), CO2 (14.8), H2(19.9) and CH4(2.05) for press mud blend, and CO(15.84), CO2(14.2), H2(18.3) and CH4(2.29) for sawdust blend, respectively, and HHV increases from 3.42 (MJ/Nm3) to 5.59(MJ/Nm3).

Investigation of influence factors on CO2 flowback characteristics and optimization of flowback parameters during CO2 dry fracturing in tight gas reservoirs

CO2 dry fracturing is a promising alternative method to water fracturing in tight gas reservoirs, especially in water-scarce areas such as the Loess Plateau. The CO2 flowback efficiency is a critical factor that affects the final gas production effect. However, there have been few studies focusing on the flowback characteristics after CO2 dry fracturing. In this study, an extensive core-to-field scale study was conducted to investigate CO2 flowback characteristics and CH4 production behavior. Firstly, to investigate the impact of core properties and production conditions on CO2 flowback, a series of laboratory experiments at the core scale were conducted. Then, the key factors affecting the flowback were analyzed using the grey correlation method based on field data. Finally, taking the construction parameters of Well S60 as an example, a dual-permeability model was used to characterize the different seepage fields in the matrix and fracture for tight gas reservoirs. The production parameters after CO2 dry fracturing were then optimized. Experimental results demonstrate that CO2 dry fracturing is more effective than slickwater fracturing, with a 9.2% increase in CH4 recovery. The increase in core permeability plays a positive role in improving CH4 production and CO2 flowback. The soaking process is mainly affected by CO2 diffusion, and the soaking time should be controlled within 12 h. Increasing the flowback pressure gradient results in a significant increase in both CH4 recovery and CO2 flowback efficiency. While, an increase in CO2 injection is not conducive to CH4 production and CO2 flowback. Based on the experimental and field data, the important factors affecting flowback and production were comprehensively and effectively discussed. The results show that permeability is the most important factor, followed by porosity and effective thickness. Considering flowback efficiency and the influence of proppant reflux, the injection volume should be the minimum volume that meets the requirements for generating fractures. The soaking time should be short which is 1 day in this study, and the optimal bottom hole flowback pressure should be set at 10 MPa. This study aims to improve the understanding of CO2 dry fracturing in tight gas reservoirs and provide valuable insights for optimizing the process parameters.

Linking soil dissolved organic matter characteristics and the temperature sensitivity of soil organic carbon decomposition in the riparian zone of the Three Gorges Reservoir

Soil dissolved organic matter (DOM) is highly sensitive to external interference. However, little attention has been paid on how soil DOM characteristics in the dry period affect the warming response of soil organic carbon (SOC) decomposition in riparian ecosystems under flooding conditions. The temperature sensitivity (Q10) of SOC decomposition was determined by incubating 99 riparian soils under flooding across 11 transects of the Three Gorges Reservoir. Soil DOM characteristics in the dry period were measured by ultraviolet–visible spectroscopy (i.e., a254, a350, SUVA254 and SR) and 3D-fluorescence spectroscopy (such as FI, β:α, BIX, and HIX). The fluorescence components of C1, C3, and C4 were determined by parallel factor analysis. SOC decomposition was sensitive to warming with a higher Q10 value for CH4 (2.34 ± 1.30) and lower for CO2 (1.37 ± 0.23) under flooding. The soil DOM in dry period was mainly autochthonous with FI > 1.9 and 90% of BIX > 0.7. The humification of soil DOM was relatively weak at ∼ 95% of HIX < 0.8. The Q10 value of CO2 was positively correlated with Ln (SUVA254) and Ln (HIX) whereas negatively correlated with Ln (DOC), Ln (a254), and Ln (a350). The Q10 of CH4 was positively related to Ln (HIX), while on the contrary, negatively related to Ln (C4). These variations in Q10 were mainly driven by the aromaticity and humification degree of DOM. Out of all DOM characteristics, the lignin component was the key predictor of the Q10 variation. Overall, findings of this study indicate that soil DOM characteristics in dry period are closely linked with the response of SOC decomposition to warming during the reservoir impoundment.

Kinetic model of CO2 methanation in a microreactor under Power-to-Gas conditions

The kinetics of CO2 methanation using a 12%Ni/γ-Al2O3 catalyst was modeled in a catalytic microreactor, considering the three-dimensional momentum, heat and species continuity balances in stationary state. The microreactor consisted of 80 microchannels with dimensions 0.45 × 0.15 × 50 mm3 in each one with an average 0.04 mm catalytic thickness. Several experimental tests were carried out at various conditions of flow rate (110, 130 and 140 mL/min), temperature (275, 300, 325 and 350 °C) and reactants partial pressure. Kinetic parameters were modeled and fitted using COMSOL Multiphysics 6.0 and Matlab 2021 R. Using the corrected Akaike information criterion (AICc), it was determined that a power kinetic model with a low kinetic exponent, 0.12 ≤ n ≤ 0.18, is adequate to represent a wide range of experimental CO2 conversion and CH4 yield (up to 86%) data. An activation energy around 83–85 kJ/mol was estimated, as well as a correlation between the different parameters of the power rate law. The temperature raise significantly increases the CO2 conversion and methane yield under the operational conditions used, due to the distance from thermodynamic equilibrium. It was numerically verified that under the experimental conditions the microchannels operate isothermally. Using this model, it is possible to evaluate the effect of operational variables (temperature, volumetric flow and H2/CO2 ratio) and reactor design (microchannel surface/volume ratio) on methane production, proving potential application in catalytic efficiency studies for Power-to-Gas applications. It is clear that processes intensification is useful to achieve higher CO2 conversions fostering sustainable development of closed-carbon production cycles.

FTIR- based serum structure analysis in molecular diagnostics of essential thrombocythemia disease.

Essential thrombocythemia (ET) reflects the transformation of a multipotent hematopoietic stem cell, but its molecular pathogenesis remains obscure. Nevertheless, tyrosine kinase, especially Janus kinase 2 (JAK2), has been implicated in myeloproliferative disorders other than chronic myeloid leukaemia. FTIR analysis was performed on the blood serum of 86 patients and 45 healthy volunteers as control with FTIR spectra-based machine learning methods and chemometrics. Thus, the study aimed to determine biomolecular changes and separation of ET and healthy control groups illustration by applying chemometrics and ML techniques to spectral data. The FTIR-based results showed that in ET disease with JAK2 mutation, there are alterations in functional groups associated with lipids, proteins and nucleic acids significantly. Moreover, in ET patients the lower amount of proteins with simultaneously higher amount of lipids was noted in comparison with the control one. Furthermore, the SVM-DA model showed 100% accuracy in calibration sets in both spectral regions and 100.0% and 96.43% accuracy in prediction sets for the 800-1800cm-1 and 2700-3000cm-1 spectral regions, respectively. While changes in the dynamic spectra showed that CH2 bending, amide II and CO vibrations could be used as a spectroscopy marker of ET. Finally, it was found a positive correlation between FTIR peaks and first bone marrow fibrosis degree, as well as the absence of JAK2 V617F mutation. The findings of this study contribute to a better understanding of the molecular pathogenesis of ET and identifying biomolecular changes and may have implications for early diagnosis and treatment of this disease.

Effect of the Ni-to-CaO Ratio on Integrated CO2 Capture and Direct Methanation

Direct methanation in an integrated CO2 capture and utilization system has recently gained considerable attention as a promising approach owing to its simplified process and lower requirement of total thermal energy as compared to conventional CO2 capture and utilization techniques. This study formulated macroporous structured Ni/CaO catal-sorbents by controlling the Ni-to-CaO ratio. The influence of this ratio on the CO2 capture (capacity and kinetics) and direct methanation performances (productivity and kinetics) was evaluated at 500 °C. CO2 capture combined with direct methanation experiments revealed that 10Ni/CaO exhibited the best CO2 capture capacity, kinetics, and CH4 productivity with the thermal stability of Ni and CaO species.