Low Temperature Steam Research Articles

Biocompatibility Study of Purified and Low-Temperature-Sterilized Injectable Collagen for Soft Tissue Repair: Intramuscular Implantation in Rats.

The clinical application of collagen-based biomaterials is expanding rapidly, especially in tissue engineering and cosmetics. While oral supplements and injectable skin boosters are popular for enhancing skin health, clinical evidence supporting their effectiveness remains limited. Injectable products show potential in revitalizing skin, but safety concerns persist due to challenges in sterilization and the risk of biological contamination. Traditional methods of sterilization (heat and irradiation) can denature collagen. This study addresses these issues by introducing a novel technique: the double filtration and low-temperature steam sterilization of a collagen gel. In vitro tests documented the sterility and confirmed that the collagen did not show cytotoxicity, degradation, integrity, and viscosity characteristics changes after the processing and sterilization. The collagen gel induced new collagen expression and the proliferation of human dermal fibroblasts when the cells were cultured with the collagen gel. An in vivo study found no adverse effects in rats or significant lesions at the implantation site over 13 weeks. These results suggest that this novel method to process collagen gels is a safe and effective skin booster. Advanced processing methods are likely to mitigate the safety risks associated with injectable collagen products, though further research is needed to validate their biological effectiveness and clinical benefits.

Co–Fe/Al2O3 catalyst for low-temperature steam reforming of phenol for hydrogen production

In this study, a series of high-efficient catalyst, Co–Fe/Al2O3, were synthesized via the sol-gel method for low-temperature phenol steam reforming (PSR). The optimized catalyst, 15Co–2Fe/Al2O3, exhibited a remarkable phenol conversion of 95.3%, a H2 yield of 92.1% at 450 °C, GHSV = 7500 h−1 and a steam-to-carbon (S/C) ratio of 10. Furthermore, the catalyst activity was maintained for 660 min before a gradual decline was observed. The NH3-TPD analysis revealed that the addition of Fe enhanced the surface acidity of the catalyst, providing more active sites for phenol adsorption and activation. This study aims to address the challenges associated with high reaction temperatures and poor catalyst stability in PSR. Various characterization techniques have been employed to investigate the reaction mechanisms of bimetallic catalysts in low-temperature PSR.

Novel Ni–Ru/CeO2 catalysts for low-temperature steam reforming of methane

Upgrading of biogas and biomethane into H2-rich streams by steam reforming is regarded as an effective strategy to reduce fossil fuel consumption contributing to the transition towards a green energy system. In this context, novel reactor configurations such as membrane reactors appear a promising route for process intensification, but they require novel catalysts more active at low temperatures, stable, and resistant to coke formation. In this work, we prepared and tested structured catalysts characterized by a low Ni content (7 wt%) and a very low Ru content (≤1 wt%) supported on ceria and deposed onto SiC monoliths. Catalysts were tested at low temperatures (<600 °C), i.e. at temperatures suitable for applications in Pd-based membrane reactors. Fresh and used catalysts were characterized by ICP-MS, N2 physisorption, XRD, TEM, SEM-EDS, XPS and H2-TPR to identify the physicochemical properties affecting the catalytic activity. The catalysts showed good activity towards methane reforming, stable performance, and good resistance to coke formation. Ruthenium affects both the intrinsic catalytic activity and the resistance to the inhibiting effect of steam on the reaction rate. This is related to improved redox properties due to the intimacy between the active metals and their strong-metal-support-interaction with the ceria. Finally, our catalysts show self-activation under reaction conditions, which is an interesting property for applications.

Effective direct steam regeneration of bis-iminoguanidine solid sorbent used for carbon dioxide capture

A cost-effective, energy-efficient sorbent regeneration process for phase-changing guanidines used for CO2 capture was developed based on direct-steam stripping. This approach enhances the regeneration rate, simplifies the overall CO2 capture process, and reduces the energy cost compared to conventional conductive thermal regeneration. A direct-steam sorbent regeneration reactor was developed, demonstrating that aqueous bis(iminoguanidines) (BIG) sorbents, e.g., methylglyoxal-bis(iminoguanidine) (MGBIG) and glyoxal-bis(iminoguanidine) (GBIG), could be efficiently regenerated with up to ∼ 99 % CO2 recovery through direct-steam stripping. Using low-temperature steam at 100 °C, a 4.5 times faster regeneration rate for GBIG carbonate sorbent (e.g., 30 min for 10 g) was demonstrated compared to conductive-heating (e.g., 135 min for 10 g) at 130 °C. Additionally, fully regenerated MGBIG converts into an aqueous MGBIG solution when the steam condenses onto the sorbent surface. Condensed steam with the guanidine can be easily recycled as an aqueous solution into the gas–liquid contactor to achieve a continuous-flow CO2-capture process. Molecular dynamics simulation was employed to provide a better understanding of the process. Higher heat transfer rates from steam to guanidine carbonate, compared to air heating, were attributed to the vibration resonance of water molecules within MGBIG with that of vapor molecules and the effective transfer of kinetic energy from vapor to solid. Technoeconomic analysis demonstrated that direct-steam stripping significantly decreases the CO2 capture cost by 50 % compared to traditional conductive heating methods. Enhanced mass transfer facilitated by low-temperature steam and subsequent condensation effectively heats up the H2O-containing BIG-carbonate crystals, facilitating the desorption of CO2 from the solid crystals, thereby leading to fast, effective, and energy-efficient sorbent regeneration.

Small iridium clusters supported on TiO2 as catalysts for intensifying low-temperature methane activation and reforming

Hydrogen production via low-temperature (<550 °C) steam reforming of methane (SRM) has attracted increasing research attention due to its importance as an alternative, efficient, and environmentally benign energy carrier. The thermodynamic limitation of low-temperature SRM can be eased by process design such as using a membrane reactor or an adsorption-enhanced reforming process, and an active low-temperature SRM catalyst with high stability would be indispensable. Herein, we report a 2 wt% Ir/TiO2 catalyst that exhibits high methane conversion activity in low-temperature SRM with a relatively high turnover frequency (TOF) and a low activation energy in comparison with the literature. Long-term catalyst stability test demonstrates a good resistance to coking and sintering during low-temperature SRM reactions. In situ spectroscopy analyses and density functional theory (DFT) calculations reveal that the small Ir clusters and Ir single atoms (SAs) are both active for methane conversion, while the clusters exhibit higher activity than SAs for low-temperature SRM reaction. Microkinetic simulation based on DFT calculations shows consistent product formation temperatures and the simulation nicely reproduces the product distribution observed in experimental analysis, which confirms the superior SRM activity of the TiO2-supported Ir clusters in this work.

Gasification of Liquid Hydrocarbon Waste by the Ultra-Superheated Mixture of Steam and Carbon Dioxide: A Thermodynamic Study

The thermodynamic modeling of waste oil (WO) gasification by a high-temperature gasification agent (GA) composed of an ultra-superheated H2O/CO2 mixture is carried out. The GA is assumed to be obtained by the gaseous detonation of fuel–oxidizer–diluent mixture in a pulsed detonation gun (PDG). N-hexadecane is used as a WO surrogate. Methane or the produced syngas (generally a mixture of H2, CO, CH4, CO2, etc.) is used as fuel for the PDG. Oxygen, air, or oxygen-enriched air are used as oxidizers for the PDG. Low-temperature steam is used as a diluent gas. The gasification process is assumed to proceed in a flow-through gasifier at atmospheric pressure. It is shown that the use of the detonation products of the stoichiometric methane–oxygen and methane–air mixtures theoretically leads to the complete conversion of WO into a syngas consisting exclusively of H2 and CO, or into energy gas with high contents of CH4 and C2-C3 hydrocarbons and an LHV of 36.7 (fuel–oxygen mixture) and 13.6 MJ/kg (fuel–air mixture). The use of the detonation products of the stoichiometric mixture of the produced syngas with oxygen or with oxygen-enriched air also allows theoretically achieving the complete conversion of WO into syngas consisting exclusively of H2 and CO. About 33% of the produced syngas mixed with oxygen can be theoretically used for PDG self-feeding, thus making the gasification technology very attractive and cost-effective. To self-feed the PDG with the mixture of the produced syngas with air, it is necessary to increase the backpressure in the gasifier and/or enrich the air with oxygen. The addition of low-temperature steam to the fuel–oxygen mixture in the PDG allows controlling the H2/CO ratio in the produced syngas from 1.3 to 3.4.

Inhalation exposure to nanosized aerosols of disinfectants for the application of continuous releasing sprayers and fogger

ABSTRACT This study aimed to investigate the airborne exposure to aerosols according to the particle size distribution of three different spray types (nano-nozzled spray gun, low-temperature steam spray, and fogger) and compare the concentrations of inhaled aerosols between children and adults. Airborne aerosols released from three products were observed using size-segregated particle measurements, and particle concentrations deposited in the respiratory tracts of adults and children were estimated using multi-path particle dosimetry lung deposition models. All types of sprayers generated the most nanoparticles (~100 nm). Due to their higher respiratory rate than adults, a larger number of particles <1.0 μm deposited in the children’s respiratory tracts was higher. The sequences of the total number of particles in the respiratory regions after spraying nano-nozzled spray gun and fogger were alveolar (AL)>tracheobronchial (TB)>head airway (HA) in adults and AL>HA>TB in children. Meanwhile, the trend of low-temperature steam spray was AL>TB>HA in adults and AL>TB>HA in children.

Analysis of sterilization efficiency and application cost of three low temperature sterilization methods.

This paper discusses the sterilization efficiency of three low temperature sterilization methods used in thermosensitive medical devices and makes a preliminary analysis of sterilization costs so as to provide the basis for reasonable selection of low temperature sterilizer in Central Sterile Supply Department. Medical devices compatible with the three sterilization methods were selected for sterilization, and two packaging materials were selected for the three low-temperature sterilization equipment according to the compatibility of the packaging materials. The equipment packed with the same packaging materials were sterilized for five times, and each low-temperature sterilizer was sterilized for a total of ten times. The sterilization effect, sterilization cycle time, energy consumption, and cost of the three sterilizers were compared. The cycle time of ethylene oxide sterilizer was 393.6min, and the cycle time of hydrogen peroxide low temperature plasma sterilizer was 56.1min. The cycle time of low temperature steam and formaldehyde sterilizer was 105.7min. The hydrogen peroxide low temperature plasma sterilizes single cycle power consumption at a maximum of 5 kWh. The single cycle energy consumption of compressed air ethylene oxide sterilizer is up to 12 l. In terms of sterilization application cost, hydrogen peroxide low temperature plasma sterilization has the highest cost, followed by ethylene oxide sterilization, and low temperature steam and formaldehyde sterilization is the lowest. The sterilization efficiency of hydrogen peroxide low temperature plasma sterilization is the highest, followed by low temperature steam and formaldehyde sterilization, and the lowest is ethylene oxide sterilization. The three low temperature sterilization methods can achieve effective sterilization of devices. Each hospital can choose an appropriate low temperature sterilization method according to the characteristics of thermosensitive instruments, turnover efficiency requirements, and financial status.

Tin and lanthanum modified Ni/CeO2 catalyst systems for low temperature steam reforming of ethanol

This work examines the Ni–Sn/Ce–La–O catalyst systems for low-temperature stream reforming of ethanol. Catalysts of 5 and 20 wt% metal loading, and different Ce:La ratios are prepared by ultra-sonication assisted solution combustion synthesis method. Catalysts at total metal loading 5 wt% with 33 and 67 at. % La and optimum Sn (Ni:Sn = 14:1) demonstrate better efficiency compared to the Ni/CeO2 catalysts. At 20 wt% metal loading and Ni:Sn = 1:1 atomic ratio, catalytic activity degrades. The best activity and stability are revealed for the N14S1(5)/CL21 catalyst with 5 wt.% total metal loading, Ni:Sn = 14:1, and Ce:La = 2:1 mol ratio. Physico-chemical characterizations (XRD, H2 -TPR, NH3-TPD, Raman, FESEM, TEM, XPS, N2 adsorption-desorption, DTA/TGA, etc.) are performed to understand the role of the metal loading, Sn, and La in the catalytic activity and coke deposition behavior.

Nature-inspired Apatite Production: Steam Processing of Calcium Carbonate and Tricalcium Phosphate Nanosized Powder Blends

Green production of materials is crucial to protect the environment. In this article, a low-temperature steam synthesis strategy for apatite production is shown for limiting chemical pollution and enabling the control of crystallinity. Steam processing produced apatite from calcium carbonate and tricalcium phosphate nanosized powders. Interdiffusion between amorphous precursors gave hydroxyapatite accompanied by calcium-deficient hydroxyapatite. This study unfolds the potential of hydrothermal processing in steam as a synthesis strategy that has been forgotten since the 1950s showing where two solid nanosized powders react to form a new product without creating waste, thereby emulating the clean processing route found in nature. This research reopens the consideration of steam processing for more chemically diverse alternatives and processing of various calcium resources readily available in nature, such as eggshell waste, for greener production. Furthermore, it presents a rarely found combination of apatite forms.

Thermodynamic and economic evaluation on a novel cogeneration system based on energy sectionalized closed utilization method

Based on the characteristics of temperature evolution during steam energy release, the idea of energy sectionalized conversion is proposed, and a dual-stage organic Rankine cycle (DORC) that can be respectively matched with varying temperature process and constant temperature process of the steam is constructed to enhance effective energy input from the energy input end. Besides, an absorption heat pump (AHP) is considered as the bottom cycle to recycle all exhaust vapor waste heat of DORC to achieve closed utilization of heat energy. The coupling of DORC and AHP to form a DORC-AHP cogeneration system can simultaneously improve the energy conversion efficiency of medium–low temperature steam from both the energy quality and quantity perspectives. Energy, exergy and economic assessments are carried out to disclose the superiority of the new energy utilization method. Compared with the singular-stage organic Rankine cycle (SORC) and DORC, the thermal efficiency of DORC-AHP is enhanced by 84.74% and 84.15%, the exergy efficiency is enhanced by 10.48% and 8.36%, and the exergy loss is decreased by 912.15 kW and 687.25 kW as the saturation temperature of the steam, superheat degree and mass fraction of R600 are 132℃, 40℃ and 0.10. Furthermore, there is an optimal saturation temperature and superheat degree of the steam to make the exergy efficiency of new cogeneration system the highest. Meanwhile, there is an optimal steam saturation temperature that enables AHP to assimilate all the exhaust vapor waste heat of DORC with the lowest driving heat source flow rate ratio between AHP and DORC. In addition, compared with the SORC and DORC, the exergy cost of new cogeneration system is decreased by 0.0007 $/kWh and 0.0006 $/kWh, multiple of investment cost (MOIC) is increased by 5.02 and 5.35, and dynamic payback period (DPP) is shortened by 2.46 years and 3.00 years. The DPP and MOIC of DORC-AHP system are both gradually close to those of SORC and DORC with the rise of electricity price. The results indicate that the new energy sectionalized closed conversion pattern demonstrates distinct superiority in the thermal and economic performance. The study achievement can lay a theoretical foundation for improving medium–low temperature steam energy utilization degree.

Inactivation kinetics of a surrogate yield conservative predictions of foodborne pathogen reductions from low water activity foods of varying size and composition during low-temperature steam processing

There is a growing interest in using models to predict foodborne pathogen inactivation as a way to validate or verify preventive controls. Unlike liquid foods, solid, low water activity foods (LWAF) are heterogenous in composition and structure and do not transfer heat uniformly. Using models constructed from one food to predict pathogen inactivation on another LWAF is complex and may not always be possible, even if the foods have similar composition. Using models constructed from inactivation kinetics of three foodborne pathogens and a surrogate from vacuum-steam-pasteurized (72 and 82 °C) whole macadamia nuts and dried apricot halves, 3-log reductions were predicted for the same pathogens and foods of reduced size. Model fits (First-order, Weibull, and Gompertz) were significantly impacted by the food type regardless of particle size. Despite the foods being identical in composition with particle size as the only altered characteristic, best-fit models accurately predicted the 3-log reductions only 50% of the time, but the surrogate inactivation models provided conservative predictions for pathogen reductions, highlighting that a surrogate's model may be a suitable tool for predicting pathogen reduction on LWAFs.

Optimization of Rh-containing Catalysts for Low-temperature Steam Reforming of Light Hydrocarbons

Rhodium-containing catalysts on various carriers (Ce0.75Zr0.25O2, Ce0.5Zr0.5O2, Ce0.4Zr0.5Y0.05La0.05O2, γ-Al2O3, TiO2) produced by various methods (sorption-hydrolytic precipitation and incipient wetness impregnation) and differing by mass content of rhodium (from 0.5 to 4 % by mass) were studied. The dependence of the catalytical efficiency of rhodium catalysts on composition, texture, and redox properties of the carrier was studied. The prospect of using associated petroleum gas at Russian deposits was confirmed.

Cycle Characteristics of a New High-Temperature Heat Pump Based on Absorption–Compression Revolution

A large amount of the waste heat generated during industrial production is not used, which leads to a low energy utilization rate. The recovery of industrial waste heat using heat pumps has the advantages of low energy consumption, high efficiency, safety, and environmental protection. Industrial waste heat has a wide temperature distribution range. Traditional absorption and compression heat pumps can only work in a narrow temperature range due to the thermodynamic cycle, the thermal properties of the working medium, the temperature and pressure resistance of the compressor, and other factors; they cannot simultaneously meet the requirements of a “high heating temperature” and “wide temperature-range heat transfer”. To solve the above problems, this paper proposes a high-temperature heat pump unit based on a coupled cycle of absorption and compression, which can recover low-temperature steam and 50 °C waste heat and produce hot water at 110–130 °C. EES software is used for the mathematical modeling and simulation analysis of the heat pump unit. The results show that, when the driving steam temperature is 140 °C and the waste heat temperature is 50 °C, the heating temperature can reach 110~130 °C and the COP of the system can reach 4.22. Increasing the waste heat outlet temperature and the condensation temperature of the absorption cycle strengthens the COP of the coupled cycle; meanwhile, increasing the evaporation temperature and heating temperature of the absorption cycle reduces the COP of the coupled cycle. The results of this study significantly broaden the operating temperature range and heating temperature of electric heat pumps; our findings therefore have essential research significance for improving energy efficiency in industrial fields.

The impact of accelerated maintenance system on alkali-activated mortar incorporating ultra-fine dredged sand

Alkali-activated concrete mixed with waste dredged sand (DS) is a new type of green concrete. In addition to reducing resource consumption and CO2 emissions, this approach is also cost-effective. Therefore, the ongoing research on its application in real industrial production is of great importance. This study examined the impact of the steam curing system on the mechanical properties and microstructure of alkali-activated dredged-sand concrete (AADSC). Different alkali equivalents and DS contents were used to produce AADSCs, and such AADSCs were cured using different steam curing schemes. The results show that steam curing significantly improves the early strength and 28-day strength under low alkali equivalent. The curing promotes the 1-day strength at 3% alkali equivalent from 2.1 MPa to 27 MPa after steam curing, and the 28-day strength increase was 7.8%. It is also found that the rise in compressive strength does not have a direct correlation with the energy consumption of steam curing. Even though the energy consumed by steam curing at 40 °C was 67% more than that at 60 °C, the 1 d strength under 40 °C steam curing was 7.5% lower. However, low-temperature steam curing retains more room for concrete strength increase. These results indicate the importance of a reasonable steam curing regime for the strength of AADSC.

Experimental and Simulation Study on the Direct Contact Condensation of Saturated Steam on Moving Droplets at Sub-Atmospheric Pressure

The recovery of low-temperature steam is of great significance to the effective utilization of energy. Direct contact condensation (DCC) technology is an effective heat recovery method with a low initial investment. An evaluation of the direct contact condensation heat transfer technology of water droplets and low-temperature saturated steam (at an absolute pressure of 7.3–19.9 kPa) was performed using both experimental and computational approaches. In the experiment, an experimental device based on the weighing method was set up, and the direct contact heat transfer process between droplets with a normalized diameter of less than 21.7 and saturated pure steam at 40–60 °C was experimentally investigated. The transient condensation efficiency and heat transfer coefficient were calculated by the real-time mass variation. The rapid condensation stage was classified to discuss the effects of initial droplet diameter, pressure, temperature, and mass flow rate on the heat transfer process. A two-dimensional model was developed using computational fluid dynamics techniques and verified by experimental results. The results indicated that when the normalized diameter of the droplet is less than two, 1.6 is the optimal value for DCC. For droplets with a normalized diameter greater than two, the optimal droplet temperature and mass flow rate are 15 °C and 10 g/s, respectively.

Numerical investigation of hydrogen production from low-pressure microwave steam plasma

Hydrogen is recognized as a suitable energy carrier that can facilitate the storage and transport of renewable energy. In this context, hydrogen production from microwave-excited steam plasma is one of the least researched techniques and lacks numerical study due to the complex plasma kinetics and difficullty of the simulation process. Therefore, in this study, a kinetic model is developed for steam plasma, considering forty-one reactions and fourteen species. Two-dimensional microwave steam plasma is modeled using COMSOL Multiphysics software for the first time. At a microwave power of 800 W, plasma formation and hydrogen production from low pressure (1 Torr) and high temperature (150 °C) steam plasma are numerically studied within the time domain of 10−10 to 10−4 s. The presented results demonstrate that the maximum electron density reaches 5 1017m−3 at 10−4s, and 16.8% of the water molecules dissociate to form various species. The conversion rate of water molecules to hydrogen is calculated as 24%. According to the thermodynamic evaluations, the proposed system's energy and exergy efficiencies are 10.31% and 10.14%, respectively, with a hydrogen production rate of 0.68 μg/s. Furthermore, the effect of the applied microwave power on plasma properties and hydrogen production is parametrically studied. Despite the proportional relationship between the input power and hydrogen production, no correlation is found between microwave power and system efficiency.

Моделирование и расчет процесса тепломассообмена в многоступенчатых многопоточных испарителях мгновенного вскипания

Thermal methods that have several environmental and economic advantages are widely applied for water treatment at thermal (TTP) and nuclear power plants (NPP) along with chemical methods. Multistage flash evaporation plants are important in case of use of thermal methods for desalinated water treatment as they can use low-temperature steam of thermal power plants. Despite the considerable number of scientific papers on this issue, the effective performance and improvement of the heat and mass transfer process in evaporator plants remains an urgent task, especially with variable operating modes of the technological equipment of TPPs and NPPs. On the one hand, it is due to the need to match the variable parameters of steam and the variable flow rates of make-up water for the process needs of the station. On the other hand, it is due to the lack of universal methods to calculate and design the equipment. Thus, the development of new methods to model and improve heat and mass transfer processes in thermal water treatment plants of thermal power plants and nuclear power plants is an urgent task for the power energy industry and related ones. To solve the problems of modeling heat and mass transfer processes in flash evaporation plants, models based on the mass and energy balance equations have been used. The obtained differential and linear equations are solved by analytical methods and methods of mathematical programming. A matrix model of the process of heat and mass transfer in a multi-stage multi-flow evaporative flash installation has been developed, considering evaporation of part of the water when it enters the low-pressure region. The steady-state pressure distribution over the stages and the performance of each stage of the evaporative installation have been found. Comparison of the calculated and known results have shown an adequate description by means of the model of the real process of heat and mass transfer in flash evaporation plants. It makes possible to set and solve problems to choose the optimal design and operating parameters of equipment for multi-flow evaporation plants. The proposed method to solve the problem of modeling heat and mass transfer provides the possibility of simultaneously search for acceptable values of design and operating parameters of multistage evaporative plants for various purposes.

Double oxalates of Rh(III) with Ni(II) and Co(II) – Effective precursors of nanoalloys for hydrocarbons steam reforming

Heteronuclear coordination compounds of d-metals are suitable single-source precursors for bimetallic nanoalloys, which often show extraordinary catalytic properties due to synergetic effect. In particular, Ni- and Rh-based catalysts are highly effective in low temperature steam reforming processes. Double oxalates of Rh with Ni and Co of the formula {[Rh(H2O)2(C2O4)μ-(C2O4)]2M(H2O)2}·6H2O (M = Ni, Co) were synthesized and structurally characterized. According to thermogravimetric analysis, the complexes decompose completely in He and H2 atmospheres to form corresponding nanoalloys at ∼300 °C. The calcination in O2 atmosphere leads to formation of spinel type mixed oxide. The supported Co–Rh/Al2O3 and Ni–Rh/Al2O3 catalysts were prepared by impregnation of double oxalate complexes in porous support with subsequent calcination and tested in propane low temperature steam reforming in CH4 excess. The Co-containing catalyst showed comparable activity regarding to pure Rh/Al2O3 sample, while bimetallic Ni–Rh/Al2O3 catalyst revealed to be appreciably more active, than monometallic catalysts with higher active component loadings. Rh–Ni catalyst allowed for complete propane conversion at T ≈ 350 °C, whereas for Rh catalyst the temperature was T ≈ 410 °C, and Rh–Co did not reach complete C3H8 conversion at all.

Effects of metal loading and support modification on the low-temperature steam reforming of ethanol (LTSRE) over the Ni–Sn/CeO2 catalysts

This article presents the effect of metal loading and support modification with MgO on low-temperature steam reforming of ethanol (LTSRE) over Ni–Sn/CeO2 catalysts prepare by a single-pot solution combustion synthesis (SCS) method. Atmospheric pressure activity study of these catalysts (0.5 g) is performed at different temperatures (200–400 °C), H2O:EtOH = 12: 1 mol ratio, and feed flow rate 0.1 ml/min. After 10 h TOS at 400 °C, NiSn(5)/CM12 catalyst with 5 wt.% total metal loading, optimal Sn (Ni:Sn = 14:1), and Ce:Mg = 1:2 mol ratio shows EtOH conversion 100% and H2 selectivity 70% with low coke deposition. Physicochemical characterizations (XRD, Raman, FESEM, TEM, and N2 adsorption-desorption) reveal that addition of MgO in CeO2 and an optimal amount of Sn decrease both Ni and support particle sizes while oxygen storage capacity (OSC) of the support increases (by XPS). Alkaline characteristics of MgO reduces support's acidity and improves active metal-support interaction, as evaluated by NH3-TPD and H2-TPR.