Search

Methanol is favored for its excellent physicochemical properties, becoming an ideal alternative fuel for engines. Adopting a dual-fuel injection mode of methanol port injection and gasoline direct injection (MPI + GDI) allows for more flexible injection strategies, enhancing the engine's power, efficiency, and emission performance. However, observing the processes of fuel injection, atomization, mixing, flow, and combustion in real engine cylinders is challenging, and controlling the fuel–air distribution and turbulence before engine ignition is difficult. Therefore, after validating the simulation model through optical engine bench experiments, this study investigated the performance and emission characteristics of MPI + GDI engines under various injection strategies. The results indicate that delaying the GDI injection timing decreases the uniformity of the fuel–air mixture and reduces cylinder pressure, corresponding to a retarded crank angle. Increasing GDI injection pressure enhances the fuel–air mixing, especially when the injection timing is later. Employing secondary injection and increasing the proportion of the second injection lead to poorer fuel–air uniformity in the cylinder, a decrease in peak pressure value, reduced nitrogen oxides (NOx) emissions, and a gradual increase in carbon monoxide (CO) and total hydrocarbons (THC). [ABSTRACT FROM AUTHOR]

Expanding the application of methanol fuel cells in the energy economy is only feasible when a low-cost or highly CO-tolerant electrocatalyst replaces Pt catalysts to enhance the electrocatalytic properties of Pt. In this study, a PtAu thin film was produced at the liquid-liquid interface through the simple reduction of [Pt(cod)Cl2] and [Au(PPh3)Cl] complexes. The resulting thin film was directly transferred onto a glassy carbon electrode (without the application of Nafion™) and used as an electrocatalyst in the methanol oxidation reaction. Experimental and theoretical results both confirmed that PtAu exhibits lower CO poisoning compared to PtPd or Pt films. The high jf/jb ratio (where jf is the maximum current of the anodic peak in the forward route and jb is the maximum of peak current in the backward route), and theoretically calculated adsorption energies for PtAu thin film showed higher CO tolerance compared to Pt or PtPd thin film electrocatalysts. [ABSTRACT FROM AUTHOR]

Methanol is industrially generated from non-renewable fossil fuel sources. Owing to its widespread use in all domains, from synthesis of various chemicals to its use as an alternative fuel in the SI engines, finding a sustainable and renewable way of generating methanol would be one of the key achievements. Biomass-derived syngas for methanol generation would be one such example. However, bio-syngas has few drawbacks like (a) lower H 2 content when compared to the traditional SMR syngas, (b) the impurities present in bio-syngas are higher and need removal, (c) the biomass availability is scattered, just to name a few. In this work, we will be addressing the low H 2 -containing syngas for methanol generation process. Since limited literature is available on the experimental work on methanol generation from bio-syngas (without H 2 adjustment), this work aims to bridge the research gap by presenting experimental results on direct bio-syngas to methanol generation process. This work will address the experimental comparison between two syngas compositions: one H 2 excess and the other H 2 deficient. The composition of the first syngas, namely syn-1, used is like the one obtained from the SMR process. The composition of the second syngas, syn-2, is via the biomass gasification process. The H 2 /(CO+ CO 2 ) values in syn-1 and syn-2 were 3.54 and 1.08, respectively. The experimental setup consisted of a high-pressure microreactor, and a Cu/ZnO/ Al 2 O 3 commercial catalyst was used for the methanol generation process. The results from the experimental work were used to develop and validate the Aspen Plus® kinetic model. The validated model for lower H 2 -containing syngas for methanol generation process would be further used for the formulation of mathematical equation for methanol yield predictions. The experiments performed indicated that the methanol yield is favored at lower temperatures and higher pressure values of 483 K and 5 MPa for both syn-1 and syn-2. The results also indicated that the high CO 2 /CO ratio results in increased side reactions. The observed increase in the CH 4 selectivity in syn-2 when compared to syn-1 was the evidence for this increased side reactions. This is one of the key highlights as for SMR syngas-to-methanol conversion the CH 4 is sometimes assumed to be inert. Finally, the developed mathematical model predicted a maximum methanol yield of 21.06% for lower H 2 syngas at a temperature of 483 K, a pressure of 5 MPa and a space velocity of 1650 ml/h(g cat). The mass balance analysis suggests using 2.27 kg of syn-1 and 5.67 kg of syn-2 for production of one kg of methanol under a similar condition of 483 K, 5 MPa and 1650 ml/h(g cat). This validated model for methanol production will find its utility for methanol yield optimization and techno-economic analysis. [ABSTRACT FROM AUTHOR]

The exergy analysis of a direct method for the conversion of natural gas to methanol is reported in this work. The study is part of a process development effort to identify areas of improvement to the technology of direct conversion of natural gas to methanol. Prior to the exergy analysis, different configurations of the direct conversion process were developed and simulated. Two heat-integrated configurations designated as Case I and Case II were considered plausible. The exergy efficiency, excluding exergy of the rejected heat, of Case I and Case II were determined as 33% and 36%, respectively. The 9% increase in efficiency of Case II relative to Case I did not justify the installation of an expander and was therefore screened out. Exergy balance in Case I showed that a total of 56% of the exergy input was lost to internal consumption. The majority of exergy destruction was found to be due to the methanol synthesis reactor (36.0%), heat exchangers (30.1%) and combustion (25.0%). Further analyses of the losses across all heat exchangers indicated a nonlinear relationship between exergy destruction contribution and minimum approach temperature (ΔTmin), with a minimal at ΔTmin of 10 °C. The methanol product was determined to represent 18% of exergy input, excluding the air separation unit. The overall process efficiencies were found to be 18% (LHV) and 24% (LHV) for recycle split fractions of 90% and 98%, respectively. The results of this work would provide further insight into the exergy viability of the technology of direct conversion of natural gas to methanol. [ABSTRACT FROM AUTHOR]

This article explores the challenges and potential solutions for decarbonizing marine transportation. It discusses the environmental impact of the industry, including greenhouse gas emissions and pollution, and the need for alternative fuels. The advantages and disadvantages of hydrogen, ammonia, methanol, and battery energy storage systems are examined as potential alternatives. The article also addresses the challenges and considerations associated with each fuel, such as cost, storage, safety concerns, and infrastructure requirements. The ongoing research and development efforts in these areas are emphasized, as well as the need for comprehensive solutions to achieve zero-emission vessels. The article showcases various projects focused on advancing the use of methanol fuel in maritime transportation, including the production of methanol from renewable sources, the development of methanol-fueled ships, and the testing of methanol fuel cells. The potential of e-methanol, a carbon-neutral synthetic methanol, as a promising maritime fuel is also discussed. E-methanol is produced using renewable energy and carbon capture technologies, and it can blend with existing fuels without requiring significant modifications to vessels. The importance of using low-cost, biogenic carbon dioxide as a carbon source for e-methanol production, as well as the utilization of byproducts such as waste heat and dioxygen, is emphasized. Overall, the adoption of methanol and e-methanol as marine fuels can contribute to decarbonization efforts and reduce the carbon footprint of the maritime industry. [Extracted from the article]

Anaerobic, acetogenic bacteria are well known for their ability to convert various one-carbon compounds, promising feedstocks for a future, sustainable biotechnology, to products such as acetate and biofuels. The model acetogen Acetobacterium woodii can grow on CO2, formate or methanol, but not on carbon monoxide, an important industrial waste product. Since hydrogenases are targets of CO inhibition, here, we genetically delete the two [FeFe] hydrogenases HydA2 and HydBA in A. woodii. We show that the ∆hydBA/hydA2 mutant indeed grows on CO and produces acetate, but only after a long adaptation period. SNP analyzes of CO-adapted cells reveal a mutation in the HycB2 subunit of the HydA2/HydB2/HydB3/Fdh-containing hydrogen-dependent CO2 reductase (HDCR). We observe an increase in ferredoxin-dependent CO2 reduction and vice versa by the HDCR in the absence of the HydA2 module and speculate that this is caused by the mutation in HycB2. In addition, the CO-adapted ∆hydBA/hydA2 mutant growing on formate has a final biomass twice of that of the wild type. Many acetogens, including Acetobacterium woodii, cannot grow on carbon monoxide and thus cannot be used as platform to detoxify industrial waste gas streams. Here, the authors solve the problem by knocking out the two [FeFe] hydrogenases HydA2 and HydBA in A. woodii. [ABSTRACT FROM AUTHOR]

To promote the efficient and clean application of low-carbon alcohol fuels in internal combustion engines, this article compares and studies the effects of three internal EGR strategies, including exhaust valve lift strategy (EVVL), exhaust timing advance strategy (EVT), and intake valve timing advance strategy (IVT), on the combustion, performance, and emissions of gasoline, methanol, and ethanol. Under the same internal EGR rate, the internal EGR temperature generated by the three valve strategies is, from highest to lowest, as follows: EVT, EVVL, and IVT. With an increase in internal EGR in the cylinder, the ignition delay and combustion duration under the EVVL and IVT strategies increase progressively, whereas the ignition delay under the EVT strategy tends to first shorten and then lengthen. Methanol has the shortest combustion duration. Furthermore, methanol and ethanol have lower heat transfer and exhaust losses than gasoline. The thermal efficiency of methanol, ethanol, and gasoline can be raised by 7.7%, 7.5%, and 7.2%, respectively, using the IVT strategy; 3.1%, 3.9%, and 4.6% using the EVVL strategy; and 6.82%, 6.85%, and 7% using the EVT strategy. The combination of methanol and ethanol with internal EGR technology greatly reduces NOx emissions, with an 84.5% reduction under the EVVL strategy. [ABSTRACT FROM AUTHOR]

Catalytic conversion of CO2 to methanol with H2 from renewable energy has attracted increasing interest as a promising strategy for reducing excessive CO2 emissions. However, the performance of reported various catalysts still suffers from low methanol yield with a passable CO2 conversion. In this work, Cu–ZnO–La2O3 interfaces are constructed with various La2O3 mole ratio. Compared to Cu/ZnO, the optimized catalyst (i.e., Cu0.6Zn0.2La0.4) exhibits a much higher mass-specific methanol formation rate (159.3 gMeOH/kgcat/h) at 240 °C and 3 MPa. A series of ex-situ and in-situ characterizations, such as X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), N2O titration measurements, and in-situ diffuse reflectance Fourier transform infrared spectroscopy (in-situ DRIFTS) study, are used to investigate its structure and mechanism study. The dispersion of Cu over Cu/ZnO/La2O3 catalyst is significantly enhanced, forming more Cu–ZnO–La2O3 interfaces. LaOx species favor CO2 activation and generate more carbon intermediates species for CO2 hydrogenation. Furthermore, more Cu+ is bonded, which stabilizes the key intermediate, inhibits its desorption, and facilitates its further hydrogenation to methanol. This work is expected to offer an effective strategy to develop new catalysts with high performance for CO2 hydrogenation to methanol. [ABSTRACT FROM AUTHOR]

Asymmetric bioreductions have the potential to synthesize chiral alcohols when catalyzed by biocatalysts. Nevertheless, the (S)-phenyl (pyridin-2-yl)methanol ((S)-2) analgesic synthesis poses significant challenges concerning unsatisfactory substrate amount and production method. Thus, this study proposes an inscribed design-focused multi-response nonlinear optimization model for the asymmetric reduction of the phenyl(pyridin-2-yl)methanone (1) with Leuconostoc pseudomesenteroides N13 biocatalyst. From the novel inscribed design-focused multi-response nonlinear optimization model, optimization conditions of the reaction, such as pH = 6, temperature = 29 °C, incubation time = 53 h, and agitation speed = 153 rpm, were found. Also, the reaction conversion was predicted to be 99%, and the product of the enantiomeric excess (ee) was 98.4% under the obtained optimization conditions. (S)-2 was obtained with 99% ee, 99% conversion, and 98% yield while performing a validation experiment using the determined optimized conditions. In addition, 1 with the amount of 11.9 g was converted entirely to (S)-2 (11.79 g, 98% isolated yield) on a high gram scale. Also, this study is noted as the first example of the gram-scale production of (S)-2 using an optimization strategy and biocatalyst. Further, the applicability of the inscribed design-focused optimization model in biocatalytic reactions has been demonstrated and provides an effective process for the analgesic synthesis of (S)-2, which is a green, cost-effective method of producing chiral aryl heteroaryl methanol. [ABSTRACT FROM AUTHOR]

Nafion membranes are commercially available for the application of direct methanol fuel cells (DMFCs) due to their unique nano-porous structure, high wettability, high ion exchange capacity due to sulfonic groups and high mechanical strength. However, its high cost and high swelling in water result in high methanol crossover, low chemical stability and low ion conductivity at elevated temperatures that limit its usage. Moreover, in commercial membranes when the thickness increases, the ion conductivity compromises and when the thickness decreases, the fuel crossover increases which disrupts the performance of the fuel cell. The modification of pre-existing Nafion membrane such as Nafion 115, Nafion 117, Nafion 212, Nafion 112 and laboratory recasted Nafion membrane is a promising requirement for their future applications. Additives such as organic, inorganic nanoparticles and polymers apply to the Nafion membrane that not only tune the physical aspects of the membrane but also improve the electrochemical properties of the membrane. This review article focuses on advances in different Nafion commercial membranes and laboratory recasted non-commercial Nafion membrane that make under special conditions after modifications. This paper provides challenges, advantages, and disadvantages, as well as future advances in the application of composite membranes in direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

The catalytic conversion of carbon dioxide is one of the important ways to achieve the goal of carbon neutralization, which can be further divided into electrocatalysis, thermal catalysis, and photocatalysis. Although photocatalysis and electrocatalysis have the advantages of mild reaction conditions and low energy consumption, the thermal catalytic conversion of CO2 has larger processing capacity, better reduction effect, and more complete industrial foundation, which is a promising technology in the future. During the development of new technology from laboratory to industrial application, ensuring the safety of production process is essential. In this work, safety optimization design of equipment, safety performance of catalysts, accident types, and their countermeasures in the industrial applications of CO2 to methanol are reviewed and discussed in depth. Based on that, future research demands for industrial process safety of CO2 to methanol were proposed, which provide guidance for the large-scale application of CO2 thermal catalytic conversion technology. [ABSTRACT FROM AUTHOR]

Modification of photocatalysts to improve their adsorption and photocatalytic activity in the oxidative desulfurization of liquid fuels has been reported by many investigators. In this study, Pt-decorated carbon-doped TiO2 nanoparticles were synthesized by hydrothermal and photo-deposition techniques and were subsequently used in photocatalytic oxidative desulfurization of dibenzothiophene (DBT) in n-heptane as a simulated liquid fuel with methanol as the extracting solvent. Carbon-doped TiO2 was first synthesized by a simple self-doping method. Pt was then loaded by a photo-deposition technique. The synthesized photocatalysts (labeled as YPt-CT where Y is percent Pt loading) were characterized by of X-ray diffraction (XRD), photoluminescence (PL), field emission scanning electron microscopy (FESEM), N2-physisorption, UV-Vis diffusive reflectance spectra (UV-Vis DRS), transmission electron microscopy (TEM), Fourier transform infrared spectra (FTIR), and nitrogen sorption measurements. The removal efficiency of DBT was 98% in the presence of 2 g/l of 0.5Pt-CT catalyst under visible-light irradiation (λ > 400 nm), ambient pressure, and reaction temperature of 40°C. [ABSTRACT FROM AUTHOR]

Reaction mechanisms of direct conversion of methane to methanol (DCMM) catalyzed by single vacancy graphene supported single Cu atoms (Cu/C3-Gr and Cu/N3-Gr) were investigated using first principles calculations, taking N2O as the oxidant. The catalytic performance was tuned drastically by replacing three coordinated carbon atoms of active center Cu (Cu/C3-Gr) with three nitrogen atoms (Cu/N3-Gr). For Cu/N3-Gr catalyzing DCMM, a crossing between potential energy profiles of the triplet state and the singlet state occurs after transition state of C–H activation. It makes the reaction energy profile downhill and the free energy barrier of C–H activation is only 0.4 eV. The calculation results indicate that Cu/N3-Gr is likely to be an excellent catalyst for DCMM at room temperature, more superior to Cu/C3-Gr. By modulating micro-coordination environment of single atom Cu, both reactivity and selectivity of DCMM were improved remarkably. [ABSTRACT FROM AUTHOR]

In consideration of the increased activity of Pt-based catalysts for methanol oxidation in direct methanol fuel cells, it is necessary to apply an ideal support in the construction of Pt-based catalyst for methanol oxidation. In this study, Ag/g-C3N4 nanosheets (Ag/GCNN) nanocomposites with different Ag contents were synthesized and used as the progressive support to construct Pt/Ag/GCNN catalyst. As a nitrogen-rich polymeric semiconductor, GCNN is easily coordinated with various metals. The introduction of Ag nanoparticles can improve the electrical conductivity of the catalyst and cooperate with Pt for optimizing the performance of electrocatalytic oxidation of methanol. The electrochemical experiment results demonstrated that Pt/Ag/GCNN has higher electrocatalytic activity and stability for methanol oxidation than Pt/GC and Pt/GCNN. The mass activity of Pt/Ag/GCNN-0.6 (18.66 mA mgPt−1) is 7.07, 4.60 and 1.26 times that of Pt/GCNN (4.06 mA mgPt−1), Pt/Ag/GCNN-0.4 (4.06 mA mgPt−1) and Pt/Ag/GCNN-0.8 (14.76 mA mgPt−1) at the forward peak potential. The Jf/Jb ratio of Pt/Ag/GCNN-0.6 is 3.31, which is bigger than that of Pt/GCCN (2.62), Pt/Ag/GCNN-0.4 (2.69), and Pt/Ag/GCNN-0.8 (2.56). A suitable mechanism was proposed to explain that Ag/GCNN supported Pt catalyst can improve the CO toxicity resistance and electrocatalytic performance. Based on the coordination of GCNN, Ag was first modified to form a support, and then the remaining coordination sites were used to support Pt. It provided a new strategy for the design of catalysts for methanol electrooxidation. [ABSTRACT FROM AUTHOR]

Alternative fuels in spark-ignition engines significantly reduce engine exhaust emissions and improve fuel efficiency. This research investigates the performance of a multicylinder SI engine using 10%, 20% (ethanol, methanol, methyl acetate), and 100% compressed biomethane gas (CBG) as alternative fuels. Engine performance parameters (BTE, ITE, ME, BP), BSFC, ISFC, FF, combustion phenomenon (cylinder pressure, crank angle, cylinder volume, mass fraction burned, net heat release, mean gas temperature, cumulative heat release, rate of pressure rise), and emission characteristics (HC, CO, CO2, NOx) are measured. CBG achieved a maximum BTE of 23.33% compared to all other fuels. Minimum fuel consumption rate of 1.72 kg/h at maximum rpm achieved BSFC value of 0.44 kg/kWh and ISFC value of 0.261 kg/kWh. The highest cylinder pressure of 6.79 bar was achieved in the G90M10 with a cylinder volume of 48.58 cc. NHR of 3.08 j/deg was found in the G80M20 at a crank angle of 376°, and the maximum MGT was 390.20 °C in the G80E20. The highest CHR values of 0.12 kJ at crank angles of 432°, 420°, 422°, and 427° were achieved in the G100, CBG, G80E20, and G90E10. G90M10 reached a maximum value of 0.14 bar/degree of rate of pressure rise at a crank angle of 374°. Average minimum emission gas was found in CBG at a minimum and maximum RPM, indicating that CBG gives the best emission result with engine performance compared to all alternative fuels. [ABSTRACT FROM AUTHOR]

The combustion of rich mixtures of methanol and hydrogen with air has been studied by experimental and numerical methods. It has been shown that the deviation from Le Chatelier's principle for the rich flammability limits is due to two factors: flame inhibition by methanol in rich mixtures of hydrogen and the presence of superadiabatic temperatures in rich mixtures of methanol. It has been found that the effect of adding small amounts of hydrogen to rich methanol mixtures is the same as the effect of adding inert nitrogen and carbon dioxide. Numerical simulation has shown that the addition of small amounts of hydrogen to rich methanol mixtures has only a physical effect on the normal flame speed. The addition of H2 affects the occurrence of superadiabatic temperatures in methanol flames in the same way as the addition of inert CO2 and N2. [ABSTRACT FROM AUTHOR]

The direct formation of dimethyl carbonate (DMC) from methanol and CO2 becomes a promising method, which can effectively utilize carbon resources and reduce greenhouse gas emissions. In this paper, we first developed a novel oxide-zeolite composite catalyst based on the incorporation of ceria and zeolite Beta (CB), which could significantly modify the suitable concentration of surface acid–base sites and hoisting the number of surface oxygen vacancies or defects, which further improved DMC yield in the direct synthesis of DMC from carbon dioxide and methanol. In particular, the CB-5 composite catalysts hydrothermally prepared by grafting the Ce onto alkali-treated zeolite Beta exhibited the best activity for the direct synthesis of DMC from CO2 and CH3OH than both single component CeO2 and zeolite Beta catalysts, which reached a DMC yield of 1.5 mmolDMC/gCat. With N2 sorption, XPS, CO2-TPD, NH3-TPD and other characterization methods, the excellent activity of CB composite catalysts benefited from the synergistic effect of the suitable concentration of surface acid–base sites and increased surface oxygen vacancies. These findings highlighted a feasible approach for the design of high-efficient composite catalysts. [ABSTRACT FROM AUTHOR]

Fluorite high entropy oxides (HEOs) were synthesized by anchoring method and Ce0.5(LaPrSmY)0.5O2-y used as catalysts for synthesis of dimethyl carbonate (DMC) from methanol (CH3OH) and carbon dioxide (CO2), the yield of DMC was up to 7.6 mmol/g at 140 ℃ and 8.0 MPa. Under the same reaction conditions, the time to reach reaction equilibrium was reduced by half compared HEOs with CeO2. The structure of HEOs were characterized by X-ray diffraction (XRD), specific surface area and pore size analyzer (BET), high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). The results showed that there are five metal elements of Ce, La, Pr, Sm and Y in the lattice of layered fluorite-type HEOs Cex(LaPrSmY)1-xO2-y. The synergistic effect among the elements led to the lattice distortion and the generation of a large number of oxygen vacancies, which improved the reaction rate. The rare earth metal ions were anchored on the graphene oxide by electrostatic interaction and then calcinated to obtain fluorite high entropy oxides (HEOs) Cex(LaPrSmY)1-xO2-y. Ce0.5(LaPrSmY)0.5O2-y were used as catalysts for synthesis of dimethyl carbonate (DMC) from methanol (CH3OH) and carbon dioxide (CO2), the yield of DMC was up to 7.6 mmol/g at 140 °C and 8.0 MPa. Under the same reaction conditions, the time to reach reaction equilibrium was reduced by half compared with CeO2 attributed to the abundant oxygen vacancies on the surface and the excellent electron transfer ability. [ABSTRACT FROM AUTHOR]

The direct oxidation of methane to methanol under mild conditions is challenging owing to its inadequate activity and low selectivity. A key objective is improving the selective oxidation of the first carbon-hydrogen bond of methane, while inhibiting the oxidation of the remaining carbon-hydrogen bonds to ensure high yield and selectivity of methanol. Here we design ultrathin PdxAuy nanosheets and revealed a volcano-type relationship between the binding strength of hydroxyl radical on the catalyst surface and catalytic performance using experimental and density functional theory results. Our investigations indicate a trade-off relationship between the reaction-triggering and reaction-conversion steps in the reaction process. The optimized Pd3Au1 nanosheets exhibits a methanol production rate of 147.8 millimoles per gram of Pd per hour, with a selectivity of 98% at 70 °C, representing one of the most efficient catalysts for the direct oxidation of methane to methanol. The direct oxidation of methane to methanol occurs in two steps that are difficult to control. Here, the authors use the OH binding strength as a descriptor to optimize the trade-off effect between the two pathways over PdxAuy catalysts. [ABSTRACT FROM AUTHOR]

Burning hydrocarbon fuels at ever-increasing rates and producing huge amounts of carbon dioxide emissions are the root causes of the global energy problem and climate change. The transformation of CO2 into other forms of energy, such as CO, CH4, and CH3OH, is one potential approach to the complex problems of environmental pollution, climate change, and global warming. Methanol is one of these goods that is one of the most significant and highly adaptable chemicals regularly used in industry and daily life. Methanol is one of the most important and widely used chemicals. Photocatalysis answers the present problems facing the environment and the energy sector. This article explores recent developments in the photocatalytic conversion of CO2 to CH3OH using catalysts based on plasmonic TiO2 and TiO2 nanomaterial. The process involves converting carbon dioxide into methanol. [ABSTRACT FROM AUTHOR]

This paper focuses the study of nonlinear absorption (NLA) features of anthraquinone dye namely, acid blue 129 with different polar solvents including ethanol, methanol, acetone, 1-proponal and DMSO. The acid blue 129 dye in polar solvents is characterized by UV–Visible absorption and fluorescence study. The NLA measurements of acid blue 129 dye is examined via open aperture (OA) Z-scan method employing at 650 nm wavelength. The OA Z-scan curve of the experimental dye exhibits both saturable absorption (SA) and reveres saturable absorption (RSA) signature, which results from negative and positive NLA coefficient (β). The order of ground and excited state absorption cross-section is measured to be 10˗22 m2 and 10˗18 m2, respectively and proved the existence of RSA in acid blue 129 dye. The order of NLA coefficient and imaginary component of the third-order nonlinear susceptibility of acid blue 129 dye in polar solvents is calculated to be 10˗3 cm/W and 10˗5 esu, respectively. The multi-parameter scale viz., Kamlet-Abboud-Taft is used to measure the influence of solvent parameters on solute molecule. The results from the experiments suggest that the acid blue 129 is a suitable candidate for nonlinear optical (NLO) applications. [ABSTRACT FROM AUTHOR]

Polyoxymethylene dimethyl ether (PODE) and methanol are important low-carbon substitutable fuels for reducing carbon emissions in internal combustion engines. In the research, the impacts of methanol ratio, injection timing, and intake temperature on HCHO generation and emission were investigated using both engine tests and numerical simulations. Results suggest that an increase in methanol ratio suppresses auto-ignition tendency of PODE, leading to the increase of ignition delay period, pressure peak, and heat release rate peak inside the cylinder. The decrease in in-cylinder combustion temperature contributes to an increase in HCHO emission due to partial oxidation of methanol in the cylinder and exhaust pipe. While the injection timing is gradually postponed from −10 °CA ATDC to 2 °CA ATDC, in-cylinder high-temperature area decreases, the quantity of unburned methanol increases, but part of HCHO is converted to HCO due to H radical influence, resulting in 72% increased HCHO emission. With the increment of intake temperature, the oxidation and decomposition of in-cylinder methanol accelerate, leading to an improvement in combustion stability, more uniform temperature distribution, and a decrease in unburned methanol, which results in lower HCHO emission. When the intake temperature is rose from 30 to 60 °C, HCHO emission decreases by 11.2%. [ABSTRACT FROM AUTHOR]

The direct oxidation of methane to methanol has been spotlighted research for decades, but has never been commercialized. This study introduces cost-effective process for co-producing methanol and sulfuric acid through a direct oxidation of methane. In the initial phase, methane oxidation forms methyl bisulfate (CH3OSO3H), then transformed into methyl trifluoroacetate (CF3CO2CH3) via esterification, and hydrolyzed into methanol. This approach eliminates the need for energy-intensive separation of methyl bisulfate from sulfuric acid by replacing the former with methyl trifluoroacetate. Through the superstructure optimization, our sequential process reduces the levelized cost of methanol to nearly two-fold reduction from the current market price. Importantly, this process demonstrates adaptability to smaller gas fields, assuring its economical operation across a broad range of gas fields. The broader application of this process could substantially mitigate global warming by utilizing methane, leading to a significantly more sustainable and economically beneficial methanol industry. Conversion of methane to methanol via methanol derivatives such as methyl bisulfate (MBS) allows to achieve high selectivity and yield, but separating MBS from oxidizing agents such as sulfuric acid is an energy-intense step. Here, the authors eliminate the need for separation of MBS from sulfuric acid by replacing the former with methyl trifluoroacetate, which is subsequently hydrolyzed into high-purity methanol. [ABSTRACT FROM AUTHOR]

This paper focuses on enhancing the performance of electrocatalytic CO2 reduction reaction (CO2RR) by improving the dispersion of cobalt phthalocyanine (CoPc), especially for the methanol formation with multi-walled carbon nanotubes (CNTs) as a support. The promising CNTs-supported CoPc hybrid was prepared based on ball milling technique, and the surface morphology was characterized by means of those methods such as scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FT-IR) and X-ray photoelectron spectra (XPS). Then, the synergistic effect of CNTs and ball milling on CO2RR performance was analyzed by those methods of cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), gas chromatography (GC), and proton nuclear magnetic resonance spectroscopy (1HNMR). Subsequently, the reduction mechanism of CO2 on ball-milled CoPc/CNTs was revealed based on the DFT calculations. The results showed that the electrocatalyst CoPc/CNTs hybrid prepared with sonication exhibited a conversion efficiency of CO2 above 60% at -1.0 V vs. RHE, accompanied by the Faradaic efficiencies of nearly 50% for CO and 10% for methanol, respectively. The addition of CNTs as the support improved the utilization efficiency of CoPc and reduced the transfer resistance of species and electrons. Then the ball-milling method further improved the dispersion of CoPc on CNTs, which resulted in the fact that the methanol efficiency was raised by 6% and partial current density was increased by nearly 433%. The better dispersion of CoPc on CNTs adjusted the reduction pathway of CO2 and resulted in the enhancement of methanol selectivity and catalytic activity of CO2. The probable pathway for methanol production was proposed as CO2 → *CO2− → *COOH → *CO → *CHO → *CH2O → *OCH3 → CH3OH. This suggests the significance of the ball-milling method during the preparation of better supported catalysts for CO2RR towards those high-valued products. [ABSTRACT FROM AUTHOR]

Nanocomposite membranes of average thickness 100 µm were successfully fabricated using a phase inversion method which involved use of sulfonated polyether ether ketone (SPEEK) incorporated with nanoclays of cloisite 30B and bentonite. The membranes were characterized for their organic functional groups, morphological structure, thermal and physical properties under the influences of cloisite 30B and bentonite addition in SPEEK matrix. The presence of nanoclays was confirmed by the changes observed in the membrane morphology and improved glass transition temperature in pristine SPEEK membrane. The fuel cell performance of the membranes was determined by their water uptake capacity, methanol permeability and proton conductivity. The 0.5 wt% addition of cloisite and bentonite in SPEEK showed 2.1% reduction of water uptake as compared to the pristine SPEEK membrane. The cloisite-added SPEEK membrane showed the average proton conductivity of 3.05 × 10–5 S cm−1 at 80 °C. Nevertheless, cloisite- and bentonite-incorporated SPEEK nanocomposite membranes demonstrated the reduced proton conductivity of 6.14% in the methanol permeability as compared to the pristine SPEEK membrane. Hence, the modified SPEEK nanocomposite membranes with cloisite and bentonite are being suggested to be a promising proton exchange membrane for direct methanol fuel cell. [ABSTRACT FROM AUTHOR]

Reducing carbon dioxide emissions during production is one of the main trends in modern oil and gas chemistry. One of the most realistic possibilities for achieving this is to involve carbon dioxide generated in technological processes as a feedstock for producing gas chemical products. The maximum effect can be achieved in the production of large-scale chemicals, such as syngas, hydrogen, and methanol. We consider such possibilities and present a new combined autothermal process for the joint production of hydrogen and methanol based on non-catalytic matrix conversion of natural gas into syngas, which allows one to almost avoid CO2 emissions. [ABSTRACT FROM AUTHOR]

In this study, the production of two-stage metal-free catalysts from pistachio shells, which are abundant in Turkey and the world, is designed. The first stage of the study includes activated carbon(AC) production, and the second stage includes the production of heteroatom-doped catalysts as a result of hydrothermal heating of the obtained activated carbon with nitric acid. These metal-free catalysts obtained were used for the production of hydrogen (H2) from sodium borohydride (NaBH4) in methanol. In H2 production experiments, the NaBH4 concentration effect, temperature effect and catalyst amount effect and catalyst reusability parameters were investigated. HGR values obtained from the methanolysis using metal-free catalysts treated by the nitric acid/water ratio: 1:2, 1:3, 1:4, 1:5 are 8041, 8955, 10600 and 8333 ml min−1 g−1, respectively. The activation energy (Ea) of the production of H2 from NaBH4(NaBH4–H2–P) in methanol by the metal-free catalyst was 18.19 kJ mol−1. Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), CHNS elemental analysis, scanning electron microscopy (SEM), and nitrogen adsorption analyses were performed for the characterization of the metal-free catalysts obtained. In addition, the mechanism of the obtained metal-free catalysts on the NaBH4–H2–P in methanol is discussed. [ABSTRACT FROM AUTHOR]

This research reports the application of recursive neural network–particle swarm (RNN–PS) and nonlinear multivariate rational function (NLMRF) algorithms for optimization of biodiesel derived from non-edible feedstock of Hevea brasiliensis. Nonlinear auto-regressive with external input (NARX) model was applied with four input variables: time (45–65 min), process temperature (45–65 °C), methanol/oil molar proportion (4:1–12:1) and catalyst dosage (0.5–1.5 wt%), one target (biodiesel yield) and two delays. The RNN showed better correlation (SSE = 21.14 and R2 = 0.98) than the three NLMRFs (SSE > 300 and R2 < 0.63). Optimum conditions obtained with RNN–PS hybrid heuristic model were 60.55 min, 70 °C, methanol/oil molar ratio of 6.89 and catalyst concentration of 1.5wt% with a maximum biodiesel yield of 92.77wt% and experimental validation of 92.52 wt%. Sensitivity analysis result shows that the level of the impact of the input variables on the independent responses follows the order: catalyst concentration (43.77%) > reaction time (24.22%) > methanol/HBSO molar ratio (21.89%) > reaction temperature (10.12%). RNN–PS exhibited high capability in excellent capturing of mapping, great diversity trajectory search, rapid convergence and intrinsic guidance strategy. Functional groups, fatty acid compositions and physicochemical characteristics of the biodiesel obtained using Fourier transform infrared (FTIR), gas chromatography flame ionization detector (GC-FID) and American Standard for Material Testing (ASTMD) methods show that the quality of the biodiesel agreed with international standards. RNN–PSO is therefore proposed as a meta-heuristic and reliable optimization tool for developing a viable and sustainable route for biodiesel fuel production. [ABSTRACT FROM AUTHOR]

Direct methanol fuel cells (DMFC) has proven to be the most promising option for charging portable electronic devices. The performance of a DMFC depends mainly on methanol crossover (MCO) and elimination the pumping power to pump fuel greatly enhances cell performance. Hence, the current study is aimed at achieving two objectives: delivery of fuel without any parasitic power consumption (losses) and reduction of MCO; the performance of a DMFC was analyzed experimentally at different operating conditions. To pump the fuel without any external power source, the inherently developed CO2 bubbles at the anodic flow channel were utilized. In other words, byproduct of the fuel cell reactions provided the required power for pumping and hence the requirement of an external pump was eliminated. The effect of the working parameters such as reactants 'methanol concentrations, flow rates and incorporation of liquid electrolyte (LE) between two half membrane electrode assemblies was examined on the performance of DMFC. It is observed that the incorporation of LE between two half Membrane Electrode Assembly (MEAs) electrolyte assemblies reduced the MCO in an LE-DMFC and better performance was reported when compared to conventional DMFC, at an optimal flow rate of 2 ml/min with 3M methanol concentration. Further, the effect of methanol concentration and flow rates on the cell performance is also compared and analyzed. The better performance was achieved in a conventional DMFC (8.09 mW/cm2). The corresponding LE maximum power is 8.8 mW/cm2, which is 9.14% higher in comparison with conventional DMFC value. The piled hydrophilic LE layer thickness of 1.5 mm and H2SO4 (diluted sulfuric acid) is used as LE layer and electrolyte respectively. [ABSTRACT FROM AUTHOR]

Methanol, the simplest aliphatic molecule of the alcohol family, finds diverse range of applications as an industrial solvent, a precursor for producing other chemicals (e.g., dimethyl ether, acetic acid and formaldehyde), and a potential fuel. There are conventional chemical routes for methanol production such as, steam reforming of natural gas to form syngas, followed by catalytic conversion into methanol; direct catalytic oxidation of methane, or hydrogenation of carbon dioxide. However, these chemical routes are limited by the requirement for expensive catalysts and extreme process conditions, and plausible environmental implications. Alternatively, methanotrophic microorganisms are being explored as biological alternative for methanol production, under milder process conditions, bypassing the requirement for chemical catalysts, and without imposing any adverse environmental impact. Methanotrophs possess inherent metabolic pathways for methanol production via biological methane oxidation or carbon dioxide reduction, thus offering a surplus advantage pertaining to the sequestration of two major greenhouse gases. This review sheds light on the recent advances in methanotrophic methanol production including metabolic pathways, feedstocks, metabolic engineering, and bioprocess engineering approaches. Furthermore, various reactor configurations are discussed in view of the challenges associated with solubility and mass transfer limitations in methanotrophic gas fermentation systems. [ABSTRACT FROM AUTHOR]

A series of CuO-ZnO–ZrO2 (CZZ) catalysts were synthesized via a solvothermal method. The effects of four saturated monohydric alcohols (methanol, ethanol, n-propanol, and n-butanol) as solvents on the physicochemical properties and catalytic performance for the direct synthesis of methanol from CO2 hydrogenation of the prepared catalysts were investigated. N2 physical adsorption, X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy mapping, reactive N2O adsorption, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction by H2 (H2-TPR), and temperature programmed desorption (H2-TPD, CO2-TPD) techniques were used to characterize the catalysts. The results indicate that the catalyst prepared with methanol as solvent (CZZ-M) has the smallest Cu crystallites and the largest metallic Cu surface area, thus exhibiting the highest methanol yield of 7.4% at 240 °C, 3.0 MPa, H2:CO2 of 3 (v/v), and GHSV of 2400 mL/(gcat·h). [ABSTRACT FROM AUTHOR]

Tandem catalysis as an exciting research frontier has recently aroused wide attention due to the eliminated intermediate work-up, improved production efficiency, decreased production cost and reduced waste discharge. The main challenge in this tandem catalytic approach is the exploiting of a bifunctional catalyst that can be effective for both reactions processed under the same reaction conditions in a single reactor. We herein report for the first time that in the presence of in-situ generated Co3O4/CuCo2O4 heterostructures (CCHS) as a heterogeneous catalyst, α-methoxyphenylacetic acid (MTPAA) can be produced via tandem catalysis from styrene and methanol by integrating the styrene epoxidation and subsequent nucleophilic ring-opening of styrene oxide (SO). The styrene conversion of 94.8% accompanied with a selectivity of 62.5% to MTPAA was achieved under the optimal reaction conditions. Consequently, a simple heterogeneous approach for the highly efficient and selective production of MTPAA has been established. This study highlights the great potential of bifunctional heterostructures composed of earth-abundant elements for the synthesis of valuable chemicals via tandem conversion of styrene and subsequent diverse SO ring-opening reactions. In the presence of in-situ generated Co3O4/CuCo2O4 heterostructures as a heterogeneous catalyst, α-methoxyphenylacetic acid can be produced via tandem catalysis from styrene and methanol by integrating the styrene epoxidation and subsequent nucleophilic ring-opening of styrene oxide. [ABSTRACT FROM AUTHOR]

The industrial utilization of methane to methanol is based on the indirect pathway with syngas as an intermediate product, but the reaction conditions are very harsh and the costs in equipment and operations are extremely high. Therefore, the direct oxidation of methane to methanol (DOMTM) under mild conditions is more desirable. In this paper, coupling of non-thermal plasma and Cu–zeolite (Cu–ZSM-5 and Cu–S-1) catalysts have been studied for DOMTM. The effect of Si/Al ratios (Cu–ZSM-5 and Cu–S-1 catalysts) on the reaction performance has been investigated. Cu–S-1 catalyst exhibited the best catalytic performance, i.e., 5.8% methane conversion and 50.6% methanol selectivity. The employed catalysts have been characterized by XRD, UV–Vis, XPS and FT-IR. The results show that Cu–ZSM-5 catalysts with high Si/Al ratio are conducive to the formation of isolated Cu2+ species, and Cu–S-1 catalyst exhibits the most abundant isolated Cu2+ species. Furthermore, Cu–S-1 catalyst shows the most abundant Oads species. The plentiful surface silicon defects on S-1 is the reason why Cu–S-1 catalyst shows the most abundant isolated Cu2+ and Oads species, and these two species are interdependent to form a Si–O–Cu species, which may be the active site for DOMTM. Based on these findings, the possible catalytic mechanism was proposed. [ABSTRACT FROM AUTHOR]

Electro catalysts play a vital role in facilitating the reaction process in the oxygen reduction reaction (ORR) of fuel cells. In methanol fuel cells, methanol easily penetrates the diaphragm rendering the ORR catalyst inactive. Although commercial platinum exhibits excellent ORR catalytic activity, its poor methanol resistance and long-time durability severely restrict its sustainable development and application. This work synthesized Ti4O7/CNT nanocomposite electrocatalysts by using the sol-gel method followed by high-temperature carbothermal reduction. The obtained catalysts exhibit a large electrochemically active surface area (347.89 cm2) and low interfacial charge transfer resistance (64.5 Ω). The reduction potential (0.73 V), onset potential (0.93 V), half-wave potential (0.73 V), and electron transfer number (3.7) of this electrocatalyst are all close to those of the Pt/C electrocatalysts in alkaline medium. Simultaneously, it also possesses remarkable methanol tolerance and long-term durability, whose relative current density can maintain above 74% after cycling for 24 h. [ABSTRACT FROM AUTHOR]

The aim of this research to assess the thermal performance of a locally developed two-phase closed thermosyphon system charged with methanol. The performance of the system is examined through experiments to determine the impact of changes in the electrical heat power, liquid charge, flow rate, inclination angle, and cooling water temperature on the output temperature. Temperatures at various points of the heat pipe, as well as cooling water, are recorded. Several fluid loadings are examined, ranging from 4 to 9 ml, which corresponds to the limits of the half full and overfilled evaporator. Different flow rates in the interval 0.2–0.7 kg/min, heat input in the interval 13.0–41.4 W, and cooling water temperature in the interval 15–35°C are considered. According to the findings, the ideal liquid fill ratio provides the best results in terms of the output temperature, and the heat transfer coefficient is between 64 and 71%. The impact of the adiabatic zone insulation on the temperature distribution along the heat pipe is illustrated. [ABSTRACT FROM AUTHOR]

The present work deals with the fabrication of cost-efficient nanocomposite proton exchange membrane (PEM), prepared by incorporation of nanoparticles of Fly Ash (FA) collected from M/s Bina thermal power plant Madhya Pradesh India; within the host PVDF [poly(vinylidene fluoride)] polymer matrix. Subsequently, the nanocomposite membranes are treated with the well-known sulfonating agent chlorosulfonic acid at 60˚C for 1.5 h. The successful incorporation of FA nanoparticles within the host polymer structure along with the sulfonation of the nanocomposite membranes was confirmed by using FTIR, XRD, FESEM-EDX, and AFM studies. The ion exchange capacity (IEC) and proton conductivity (PC) of nanocomposite membranes are observed to be 0.58 meq g−1 and 3.30 × 10−2 S cm−1 respectively. Further, it was interesting to note that the fabricated membranes exhibited enhanced water uptake capacity up to 19.6% with supressed methanol crossover (1.7 × 10−7cm2/s). Among all the fabricated membranes, the membrane SPF-5 (containing 5% w/w FA), exhibited significantly high membrane selectivity 1.94 × 105 Scm−3 s over corresponding Nafion-117 (2.47 × 104 Scm−3 s), which clearly indicates its potency towards an alternative to costly Nafion-117 for DMFCs (direct methanol fuel cells) application. [ABSTRACT FROM AUTHOR]

It has recently been shown that CO 2 hydrogenation to methanol over PdIn and In 2 O 3 depends critically on the adsorption energy of hydrogen. Here we use density functional theory calculations to investigate hydrogen adsorption over Pd–In intermetallic compound surfaces with different Pd:In ratios. The electronic structure and properties of hydrogen adsorption are investigated for a range of surface facets and compared to the corresponding results for the pure parent metals and Cu. Increased In content is found to shift the Pd(d) density of states away from the Fermi level, making the intermetallic Pd–In compounds to appear "Cu-like". We find a linear correlation between the hydrogen binding energy and the d-band center of surface Pd atoms. Understanding of how the hydrogen adsorption energy depends on composition and structure provides a possibility to enhance the performance of CO 2 hydrogenation catalysts to methanol. [ABSTRACT FROM AUTHOR]

In order to improve the extraction ability of carbon fibers (CFs) for microextraction of polycyclic aromatic hydrocarbons (PAHs), biochar nanospheres derived from glucose were in-situ grown onto the surface of CFs via hydrothermal synthesis. The surface morphology and elemental composition of biochar nanospheres-CFs were investigated by scanning electron microscopy and X-ray photoelectron spectroscopy. Thereafter, the biochar nanosphere-CFs were pulled into the polyetheretherketone tube for solid-phase microextraction, and the tube was combined with high-performance liquid chromatography-diode array detector to online detect PAHs. With the help of π-stacking, hydrophobic, and hydrophilic effect of biochar nanospheres, the extraction efficiency of CFs was greatly enhanced (enrichment factor increased by 293% compared with the original). The conditions affecting the analytical performance (sampling volume, sampling rate, methanol content, and desorption time) were investigated. Under the optimal conditions, an online analytical method for microextraction and determination of several PAHs was developed, and satisfactory results were achieved. The limits of detection were 0.003-0.010 ng mL-1 owing to high enrichment effect (2973-3600), linearity ranged from 0.010-15.0 ng mL-1, and relative standard deviations were 0.4%-1.6% (intra-day) and 2.4%-4.4% (inter-day), respectively. The method was applied to analyze environmental water samples (rain water, snow water, and river water), and spiked recoveries within 80.0%-119% were obtained. [ABSTRACT FROM AUTHOR]

In the present study, the effects of biodiesel-methanol blends on the performance and emissions of diesel engine at an altitude of 2400 m, were investigated experimentally and using response surface methodology (RSM). The RSM models were developed using experimental data. Methanol ratio, injection pressure (IP) and injection timing (IT) were selected as the input parameters, while power output, brake specific energy consumption (BSEC), nitrogen oxides (NOx) and smoke emissions were chosen as the response parameters. The desirability approach of the RSM was used to optimize the methanol ratio and injection system parameters for improved engine performance and lower emissions at high alitiude. The optimum values of input parameters were 95.27 MPa of IP, 15.13 BTDC of IT and 17.32 % methanol ratio, and the corresponding responses of power output, BSEC, NOx and smoke with a high desirability of 0.767 were 23.7 kW, 9.94 MJ/kWh, 7.08 g/kWh NOx and 0.020 g/kWh, respectively. [ABSTRACT FROM AUTHOR]

In this study, stir bar sorptive extraction as an easy to use, solventless, and novel sample enrichment technique combined with thermal desorption (TD)-gas chromatography triple quadrupole mass spectrometry (GC-MS/MS) was applied to determine cresols in wastewater samples for the first time. The analytical method is based on effortless extraction followed by TD-GC-MS/MS detection not requiring derivatization. The design of experiment procedure was utilized for improved extraction and analytical conditions. In this regard, the major sample extraction parameters (extraction time, salt addition, methanol content, pH, and stirring rate) and TD parameters (desorption flow, desorption temperature, desorption time, and cryo-focusing inlet temperature) were scrutinized and optimized. The fractional factorial design showed that stirring rate, extraction time, and methanol content were the major influential factors for extraction. While desorption flow, desorption temperature, and cryo-focusing inlet temperature significantly affected the instrumental analysis conditions. The optimized methodological conditions for the stir bar coated with polydimethylsiloxane were as follows: sample volume of 20 mL, methanol addition of 10%, stirring rate of 1200 rpm, desorption time of 10 min, desorption temperature of 240°C, desorption flow of 20 mL/min, and cryo-focusing inlet temperature of ‒20°C. The analytical characteristic of the proposed methodology presents good linearity (0.9909–0.9918), repeatability (11.5–15.1%), recovery (104.78 ± 0.27 to 106.19 ± 0.16%), and low detection limits (0.020–0.04 ng/mL). The established method was employed to measure trace levels of cresols in several wastewater samples taken from Istanbul. [ABSTRACT FROM AUTHOR]

Although it is an environmental threat, the flue gas of a combined cycle power plant can be a good motivation to produce methanol due to its high carbon dioxide richness. This paper includes a simulation and comprehensive technical, economic, and environmental analyses of the methanol production process through CO2 capture. In other words, an improved and modified power plant (plus version) is introduced through structural optimization. At first, the combined cycle power plant was simulated, and thermoeconomic and environmental evaluations were performed. Then, it was found that its energy and exergy efficiencies were 44.87 and 42.86%, respectively, and its annual profit was approximately equal to 1.96 M$. In the second stage, in addition to the power generation section, two sections of carbon dioxide capture and methanol production were simulated, which showed that the performance of the power plant plus was improved compared to the conventional system. Energy and exergy analysis for the power plant plus demonstrated that the total energy and exergy efficiency, in this case, was 58.22 and 97.47%, respectively. From the environmental viewpoint, it was found that the power plant plus could reduce the net carbon dioxide emission by 58.84% compared to the simple system. Economic estimations explained that despite the 116.09% increase in the investment cost of the power plant plus compared to the combined cycle power plant, the annual revenue and profit increased by 182.03 and 116.08%, respectively, and the payback period also decreased by 0.66 years. [ABSTRACT FROM AUTHOR]

The effects of air and exhaust gas recirculation (EGR) dilution of a spark ignition engine fueled with methanol under different loads were studied by experiment in this paper. Such as ignition delay, combustion center (CA50), IMEP, break thermal efficiency (BTE) and other parameters were investigated to assess the combustion performance. And discussed in depth the balance between NOx emissions and economic performance represented by brake specific fuel consumption (BSFC). The results showed that combustion progress such as ignition delay, combustion duration and CA50 were more sensitive on the changes of EGR, introducing EGR under the same dilution rate prolonged combustion process. Air-EGR dilution showed the best improvement of IMEP and break thermal efficiency, except the optimal area, increasing EGR rate will decreased IMEP and BTE. Air-EGR dilution strategy showed the best improvement on BSFC than air dilution than EGR dilution. Under light load and high load, when the lowest BSFC was obtained, NOx emissions were less than 0.5 g/kWh with air-EGR dilution strategy. [ABSTRACT FROM AUTHOR]

The present study provides the first information on the chemical composition, antimicrobial and antioxidant potentials of the essential oil and methanol extract from the stems of Dasymaschalon rostratum Merr. & Chun. Gas chromatography and gas chromatography-mass spectrometry analysis revealed that the main components of the D. rostratum essential oil were β-caryophyllene (27.4%), β-pinene (12.8%), α‑copaene (11.7%), α-pinene (8.4%), and α-humulene (6.2%). The antimicrobial assay showed that the essential oil had better activity against all tested microorganisms with lower minimum inhibitory concentration (MIC) ≤ 500 μg/mL compared with methanol extract. In turn, methanol extract was distinguished by the higher antioxidant potential in comparison to the essential oil in both DPPH and ABTS assays with IC50 values of 119.3 and 76.2 μg/mL, respectively. Furthermore, the total phenolic content of methanol extract was determined as 32.5 μg/mg. The results of the present investigation demonstrated significant variations in the antimicrobial and antioxidant activities of the essential oil and methanol extract from the stems of D. rostratum. In addition, complementary investigations should be conducted to identify phenolic compounds of these plant extracts as well as to evaluate the antimicrobial mechanisms of essential oil against bacteria and fungi. [ABSTRACT FROM AUTHOR]

In this study, manganese-coated cerium oxide was synthesized by impregnation method, and the effect of Mn coating CeO2-NS catalyst on the methanol oxidation reaction was investigated.The results show that Mn coating can significantly improve the methanol oxidation performance of CeO2-NS catalyst, and the difference in Mn/Ce ratio will also dramatically affect the physicochemical properties of MnOx/CeO2 catalyst, and 30% MnOx loading is more favorable for better catalytic performance. A series of characterizations revealed that the better performance of 30-MnOx/CeO2-NS catalyst can be attributed to the increase of oxygen vacancies and a more suitable valence state distribution, which is intrinsically related to the suitable Mn/Ce ratio, resulting in excellent methanol oxidation performance (T50 = 134 °C, T90 = 148 °C). This work may provide a fundamental insight for the rational design of manganese-cerium oxide catalysts for methanol oxidation. [ABSTRACT FROM AUTHOR]

In this study, manganese-coated cerium oxide was synthesized by impregnation method, and the effect of Mn coating CeO2-NS catalyst on the methanol oxidation reaction was investigated.The results show that Mn coating can significantly improve the methanol oxidation performance of CeO2-NS catalyst, and the difference in Mn/Ce ratio will also dramatically affect the physicochemical properties of MnOx/CeO2 catalyst, and 30% MnOx loading is more favorable for better catalytic performance. A series of characterizations revealed that the better performance of 30-MnOx/CeO2-NS catalyst can be attributed to the increase of oxygen vacancies and a more suitable valence state distribution, which is intrinsically related to the suitable Mn/Ce ratio, resulting in excellent methanol oxidation performance (T50 = 134 °C, T90 = 148 °C). This work may provide a fundamental insight for the rational design of manganese-cerium oxide catalysts for methanol oxidation. [ABSTRACT FROM AUTHOR]

A novel grafting polymer was synthesied via the grafting of itaconic acid (IA) and co-acrylamide (Am) onto sodium alginate (NaAlg) for direct methanol fuel cell (DMFC) application. Optimization of the copolymerization factors affecting polymerization, including initiator concentration, monomer concentration, temperature, and time, has been investigated. Functionalization with polyaniline (PANI) on grafted polymer has been done. The FT-IR, X-ray, thermogravimetric analysis (TGA), and scanning electron microscope were used to characterize newly fabricated materials. These grafted polymers based on sodium alginate acted as electrocatalysts in the methanol oxidation reaction (MOR). NaAlg-g-Am-co-IA-g-PANI/graphite electro-catalyst for MOR demonstrated exceptional electrochemical activity, delivering a high current density of about 20 mAcm2 and long-term stability. This remarkable electro-catalytic performance towards MOR of NaAlg-g-Am-co-IA-g-PANI is due to its unique fibrous structure, which facilitates electron transport and increases electrocatalyst porosity, allowing charge carriers to move to its matrix, which is the main reason for this improvement in electrochemical performance. This research focuses on a simple method for creating grafted polymer-based electrocatalysts for DMFCs in industrial applications. [ABSTRACT FROM AUTHOR]

The aerobic granular biomass technology was optimized for treating nitrate-polluted groundwater based on the biological denitrification processes in order to provide drinking water. Reactors inoculated with granular biomass were operated at progressively lower C/N rate using acetate and methanol to encourage heterotrophic denitrification, in order to meet the recommended requirements described by European Drinking Water Framework Directive. The granulation and long-term stability of granular biomass under low C/N were successful for all stages, demonstrated compactness of granules and absence of filamentous microorganisms. The nitrate removal was similar in methanol- and acetate-fed reactors, occurring in both cases nitrate removal ratios > 80%, and fact allows the selection of one of both depending groundwater polluted case. Also, feeding reactors with 2 C/N ratio showed nitrate removal values of ≥ 95%, treating highly polluted groundwater (100 mg·L−1). The microbial diversity was higher in the methanol-fed reactor with representative phylotypes as Flavobacterium, Cytophagaceae, NS9 marine group, while species richness was higher in the acetate-fed reactor, which was mainly represented by Flavobacterium genus. Statistical analyses revealed the higher resilience of bacterial population on granules fed with acetate, showing more resistance under drop C/N ratio. Oscillating pollution in groundwater during seasonal periods should be treated using acetate as carbon source for denitrification carried out by granular biomass, while stable pollution concentrations over time allow the use of methanol as a carbon source since the greater microbial diversity allows the elimination of other contaminants present in groundwater. [ABSTRACT FROM AUTHOR]

One of the significant drawbacks of the Direct Methanol Fuel Cells is the overpotential for the methanol oxidation reaction, which strongly limits the efficiency of this fuel cell. Furthermore, CO poisoning of Pt is considered to be a severe problem for these devices. In this work, electrocatalysts with suitable properties and outstanding performance have been developed for the oxidation reaction of methanol. PtCu and PtCuRu type materials have been synthesized through a relatively uncomplex, fast, highly reproducible, and easily scalable method. In turn, these materials have been subjected to a selective chemical dissolution process to enrich their surface with a higher density of active sites and surface defects. Evidence of alloy formation was found, specifically through XPS measurements on Ru 3d level. Besides, it was observed that with the trimetallic catalysts, which contain not only Cu but also Ru, the onset of CO electrooxidation is substantially reduced. Moreover, the leaching treatment further improves this value. This same trend was observed in the evaluation of methanol oxidation. Regarding the specific and mass activities, PtCuRu-le exhibits almost 240% and 195% higher SA and MA than commercial Pt, respectively. [ABSTRACT FROM AUTHOR]

Exploiting inexpensive and effective nickel-based catalysts that produce hydrogen from liquid organic hydrogen carriers (LOHCs) is crucial to alleviating the global energy and environmental crisis. In this study, we report a rational strategy that can realize atomically dispersed Ni atoms anchored on vacancy-abundant boron nitride nanosheets (Ni1/h-BNNS) with high specific surface area (up to 622 m2·g−1) and abundant hydroxyl groups for high efficient hydrogen production. Methanol dehydrogenation results show an excellent hydrogen production performance catalyzed by this Ni1/h-BNNS, as evidenced by a remarkably high H2 yield rate (1684.23 ), nearly 100% selectivity toward hydrogen and CO, and high anti-coking performance. Density functional theory (DFT) calculations reveal that the outstanding catalytic performance of Ni1/h-BNNS primarily originates from the unique coordinated environment of atomically dispersed Ni (Ni-B2O2) and the synergistic interaction between Ni single atoms and the h-BNNS support. Specifically, the coordinated O atoms play a decisive role in promoting the activity of Ni, and the neighboring B sites significantly decrease the energy barriers for the adsorption of key intermediates of methanol dehydrogenation. This study offers a novel strategy for developing high-performance and stable single-atom Ni catalysts by precisely controlling single-atom sites on h-BN support for sustainable hydrogen production. [ABSTRACT FROM AUTHOR]

The present study analyzes the emission mitigation ability of a porous media combustion (PMC) technology-based cookstove compared to a free flame combustion (FFC) technology-based cookstove. Emission of pollutants, i.e., PM2.5, PM10, and CO, caused due to burning of fuels, namely, methanol, ethanol, kerosene, and LPG in the kitchen environment are measured. The study incorporated exhaustive real-time indoor air quality (IAQ) measurements and presented the temporal variation of measured pollutant concentrations for 2 h (morning meal duration). In addition, 24 h average concentration of the measured pollutants is also compared with the limits prescribed in WHO guidelines for domestic settings. The results emphasized that the utilization of cookstove based on PMC would help in improving the IAQ of the kitchen area by decreasing the concentrations of PM2.5, PM10, and CO. For 2 h duration measurements, the methanol cookstove based on PMC reduced the concentrations of PM2.5, PM10, and CO by 7.7%, 8.1%, and 17.2%, respectively, compared to FFC cookstove. Similarly, in the case of PMC-based LPG cookstove and kerosene cookstove, the respective values were 11.7%, 20.4%, and 41.6% and 55.3%, 62.6%, and 66.6%. Among all the tested cookstoves, PMC-based LPG cookstove achieved the lowest emission values (PM2.5: 20.6 μg/m3, PM10: 31.3 μg/m3, and CO: 1 ppm) which are lower than the prescribed WHO values (PM2.5: 25 μg/m3, PM10: 50 μg/m3, and CO: 6 ppm). [ABSTRACT FROM AUTHOR]