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This study aims to investigate the effects of different catalysts on biomass gasification. Therefore, red mud (RM) and Aluminum–Nickel alloy were used as catalysts with biomass mixture (BM) for the lab-scale gasification studies by using an updraft and a modifiable-downdraft fixed bed reactor. The maximum volumetric percentage of H 2 , ranging from 51% to 65%, was achieved at 900 °C in both gasifiers. Al–Ni catalyst significantly boosted H 2 content, reaching 65% in the updraft gasifier at 900 °C with 0.05 L/min dry air. H 2 /CO ratio varied from 2 to 4 for BM, while catalyst use expanded the range to 1.6–7 with the Al–Ni catalyst demonstrating the most effective performance. In general, it was seen that RM increased the H 2 component in the syngas between 1 and 7 vol% at 900 °C in updraft gasifier. In the modifiable-downdraft reactor, on the contrary, H 2 concentration in the syngas decreased by 2–6% with the addition of RM. [Display omitted] • Red mud and aluminum - nickel alloy were added to biomass as catalysts. • Two different fixed-bed gasifiers were operated under the same conditions. • The use of the catalyst increased the H 2 vol% in the syngas. • The max. volumetric percentage of H 2 gas was found to be in the range of 51–65%. [ABSTRACT FROM AUTHOR]

The work is devoted to the development of a thermal scheme for the conversion of a cogeneration power plant to threegeneration with the production of hydrogen as a new product. The purpose of the work is to assess the possibility and potential of hydrogen production from MSW at the existing thermal power plants of St. Petersburg. To achieve this goal, it is necessary to develop a methodology for selecting the site of an existing thermal power plant in order to integrate a hydrogen production complex by the MSW gasification method, as well as a methodology for estimating the amount of hydrogen that can potentially be obtained from a given amount of MSW. The research methods include simulation of the thermal circuit of a steam power plant in the United Cycle program. The paper proposes an algorithm for selecting the site of an operating thermal power plant for the integration of a complex for the production of hydrogen by the method of MSW gasification. The algorithm can be applied to any subjects of the Russian Federation, and its relevance is confirmed by strategic documents. Potential locations for the new TPP are being considered in the territories of TPP-21 and TPP-22, which have the necessary resources and good infrastructure. As a result of the study, the site of TPP-22 was selected as the most suitable for the placement of new facilities. A new thermal scheme of a threegeneration power plant has been developed, including a hydrogen generation unit by the MSW gasification method. This allows the production of hydrogen in parallel with the production of electricity and heat. The efficiency evaluation criterion is the fuel heat utilization factor (FHUF). Regardless of the hydrogen content in the generated synthesis gas, the integration of the synthesis gas cooler into the thermal circuit of the TPP leads to an increase in the FHUF and an additional energy effect. This scheme increases the efficiency of existing TPP plants, regardless of the morphological composition of municipal solid waste. [ABSTRACT FROM AUTHOR]

Today, conversion of hydrocarbons is one of the most common hydrogen production technologies. This paper presents a design of a high-temperature reactor — the main component of a hydrogen production unit using partial oxidation of hydrocarbons — as well as a physical model of gas generation. It also presents a schematic diagram of an experimental setup as well as results of experimental studies on steady-state modes of partial oxidation in the combustion chamber of a high-temperature reactor for various hydrocarbon feed/oxidant combinations. In the course of the study, we identified patterns that describe how the excess oxidant ratio affects the composition of products of incomplete combustion of hydrocarbons to obtain hydrogen-containing gas of the required composition and parameters for hydrogen production. We propose a method to calculate nominal geometric dimensions of a high-temperature reactor, which makes it possible to estimate its weight and size at the design stage. The paper presents results of experimental studies confirming the adequacy of the proposed method. • Production of hydrogen by the method of partial oxidation of hydrocarbons. • Design of a high-temperature reactor and a physical model of the gas generation process. • The design of the main units and the method for calculating the nominal geometric dimensions of a high-temperature reactor. • Scheme of the experimental setup and results of experimental studies. • Patterns of the influence of the oxidizer excess coefficient on the composition of products of incomplete combustion of hydrocarbons. [ABSTRACT FROM AUTHOR]

This study aims to investigate the gasification potential of olive pomace with using different fixed-bed gasifier systems. Olive pomace as a dried form was supplied from a chemical industry plant working on olive oil soap, located in Izmir, Türkiye. After a complete characterization of olive pomace, gasification experiments by using fixed bed reactor systems were done at three different gasifier temperatures as 700, 800 and 900 °C. As a gasification agent, dry air was used with four different flowrates (0.4, 0.2, 0.1, 0.05 L/min) while pure oxygen experiments were carried out with a flow rate of 0.01 L/min. Syngas with H 2 content of 48% and 45% (volumetric) were obtained in updraft and downdraft gasifiers, respectively, by using dried air as a gasifying agent. Heating value of syngas was around 12.4 MJ/Nm3. In the pure oxygen atmosphere, H 2 contents of the syngas were measured as 53% and 39%vol. In the updraft and downdraft gasifiers. This paper presents the research results on the olive pomace gasification study as a part of a large-scale research project and discuss them in the context of hydrogen production from the fixed bed reactors. [Display omitted] • Pomace gasification process was carried out in two different fixed bed reactors. • The volumetric percentage of H 2 gas was found to be in the range of 40–50%. • The maximum volume of methane was measured approximately as 20%. • The maximum volume of CO was measured in the range of 20–30% in both reactors. • The maximum volume of hydrogen in the updraft gasifier was measured as 48%. [ABSTRACT FROM AUTHOR]

The research status of traditional gasification technology for hydrogen production from organic solid waste are reviewed, the influence of three main factors, gasification medium, gasification temperature and catalyst, on hydrogen production effect is analyzed in detail, by analyzing the action mechanism and summarizing the advantages and disadvantages in the application process, the technical disadvantages of this technology are put forward purposefully, it is pointed out that the technology should be developed from four aspects: mechanistic exploration, development of high-performance composite catalyst/catalyst with special structure, development of hydrogen production technology by co gasification with coal, and coupling with other new gasification hydrogen production technologies in the future, so as to better promote the industrial application of the technology. [ABSTRACT FROM AUTHOR]

A gasification plant may partially replace an industrial thermal plant and hydrogen production plant by polygenerating valuable products (hydrogen, power, steam) from low-value materials. Carbon energy analysis is one way of conceptually evaluating such processes. In this paper, the integration of a heavy residue (HR) gasification plant into a mid-size oil refinery (5 million t per year crude processing rate) is conceptually assessed via the comparison of electricity, natural gas and heavy residue consumption, and CO2 emissions. The main purpose of the integration is to reduce the consumption of natural gas currently used for hydrogen production at the expense of increased HR consumption and to achieve a reduction in CO2 emissions. Two case studies with different modes of operation were compared to base case showing that annual reduction of 2280 GWh in natural gas consumption with constant heat and hydrogen production is possible, accompanied with a slight increase in electricity purchase by 28 GWh per year. HR processing in the refinery increases by over 2800 GWh per year. The refinery's CO2 emissions increase by more than 20% (up to 350 kt per year) as a result, while, after incorporating external emissions into the balance, a decrease of more than 460 kt CO2 per year can be achieved. This confirms that the integration of gasification plants within industrial enterprises and clusters has a positive environmental and energy impact and supports the idea of converting low-value material to more valuable products in polygeneration plants. The economics of HR gasifier integration in varying operations under real refinery conditions remain to be explored. [ABSTRACT FROM AUTHOR]

This study reports the dry reforming of methane (DRM) using non-thermal plasma in a swirl-induced point-plane electrode discharge reactor to produce syngas. This reactor geometry facilitates better mixing of the reactant gases in the plasma region, thus increasing the residence time and conversion of the reactants. The effect of varying flow rates and compositions of CO2/CH4 (v%/v%) on conversion was studied. A high-voltage AC power input of 50 W and 70 W at a frequency of 19 kHz was provided. The voltage–current characteristics with respect to time were studied. The results show that with an increase in the flow rate of the gas mixture from 0.5 to 2 LPM the conversion of both CO2 and CH4 decreases, while an increase in the concentration of CO2 or CH4 (from 25 to 75%) increases the conversion of the respective reactant. The products, viz. syngas (CO and H2), C2 hydrocarbons, and solid carbon, were characterized and quantified. The maximum total conversion of 44% was obtained for a CO2:CH4 ratio of 25:75 (v%/v%) at a flow rate of 0.5 LPM. The solid carbon collected from the reactor walls was analyzed, and it was found to be 89.9% pure with traces of oxygen functionality. The increase in flow rate decreased the specific energy input, which eventually resulted in lowering the energy cost. [ABSTRACT FROM AUTHOR]

Hydrogen is increasingly being viewed as a significant fuel for future industrial processes as it offers pathways to zero emission. The UK sees hydrogen as one of a handful of low-carbon solutions for transition to net zero. Currently, most hydrogen production is from steam reforming of natural gas or coal gasification, both of which involve the release of carbon dioxide. Hydrogen production from mini decentralised grids via a thermochemical process, coupled with electricity production, could offer favourable economics for small modular reactors (SMRs), whereby demand or grid management as a solution would include redirecting the power for hydrogen production when electricity demand is low. It also offers a clean-energy alternative to the aforementioned means. SMRs could offer favourable economics due to their flexible power system as part of the dual-output function. This study objective is to investigate the critical performance parameters associated with the nuclear power plant (NPP), the cycle working fluids, and control-system design for switching between electricity and hydrogen demand to support delivery as part of a mini grid system for a reactor power delivering up to approximately 600 MWth power. The novelty of the work is in the holistic parametric analysis undertaken using a novel in-house tool, which analyses the NPP using different working fluids, with a control function bolt-on at the offtake for hydrogen production. The results indicate that the flow conditions at the offtake can be maintained. The choice of working fluids affects the pressure component. However, the recuperator and heat-exchanger effectiveness are considered as efficiency-limiting factors for hydrogen production and electricity generation. As such, the benefit of high-technology heat exchangers cannot be underestimated. This is also true when deciding on the thermochemical process to bolt onto the plant. The temperature of the gas at the end of the pipeline should also be considered to ensure that the minimum temperature-requirement status for hydrogen production is met. [ABSTRACT FROM AUTHOR]

• The SE-CL-SMR potentially offers feeds of H 2 , CO 2 , and N 2 , application for urea production plant. • CaO, steam, metal oxide, and oxidising agent affect process performance. • Bi-metallic NiO:CuO appear to be interesting oxygen and heat transfer materials for H 2 production via SE-CL-SMR. • Using air as oxidising agent allows the utilisation of the hot gas stream. • Using O 2 as oxidising agent demands low energy for a less complex purification system. An intensified hydrogen production steam reforming process named 'Sorption-Enhanced Chemical Looping Steam Methane Reforming' (SE-CL-SMR) was studied. Aspen Plus was used to carry out a thermodynamic investigation into the influence of various operating conditions on hydrogen production and process thermal efficiency. The steam to carbon molar ratio (S/C), the CaO to carbon molar ratio (CaO/C), the metal oxide to carbon molar ratio (MeO/C), the metal oxide composition (NiO:CuO), and the oxidising agent species were all shown to influence the process performance. The main findings were that; (1) the introduction of CaO reduces the potential for coke formation with predicted zero coke formation for CaO/C ratios > 0.4; (2) increasing amounts of metal oxide (MeO/C) and steam (S/C) enhance the hydrogen production yield and purity; (3) due to its involvement in an exothermic reaction, the presence of CuO allows for the reforming reactor to operate as an adiabatic reactor with an operating temperature within the range of 600 °C–700 °C; (4) an increase in the NiO:CuO ratio leads to an increase in methane conversion. With the operating conditions of S/C = 3, CaO/C = 1, MeO/C = 1, NiO:CuO = 0.9 and air as the oxidising agent, a hydrogen purity as high as 98% was predicted for the SE-CL-SMR process, along with the lowest observed CO 2 production rate. Under the same conditions and using pinch analysis, the thermodynamic model prediction of the thermal process efficiency is reported as ca. 86%. This is significantly higher than the reported efficiency of 79% for the 'Sorption-Enhanced Steam Methane Reforming' (SE-SMR) process, predicted using similar thermodynamic models. [ABSTRACT FROM AUTHOR]

This work presents advances in OSU's BTS technology, targeted explicitly toward hydrogen production from experimental and process simulation results. Two experimental parameters: residence time and enhancer steam flowrate, are explored. A volume reduction of ∼67 % can be achieved in Reducer while ensuring high char conversion. The steam injection enhances char gasification and H 2 content; however, it may lead to increased tar content due to decreased gas residence time. The steam injection of ∼5 % of the inlet carbon flow rate can be adequate for efficient biomass gasification and injecting additional steam downstream into the WGS unit is optimal for H 2 generation. Two cases that implement modularization for tighter process integration are compared with the conventional BTS and BDCL processes for H 2 generation. The application of modularization eliminates the energy-intensive AGR unit and increases ETE by ∼17 % over the BTS process. Modularization offers product flexibility and increased control with lower operational risks over the BDCL process but at 7 % lower ETE, which can be attributed to the high amounts of oxygen present in the biomass, leading to decreased syngas purity. H 2 yield can be further increased by co-injection of low oxygen feedstocks such as plastics, which can increase H 2 yield by ∼12 %. • Demonstrated ∼67 % reduction in the reactor volume for gasification of woody pellets. • Minumum 5 % steam adequate as an enhancer triggering heat savings. • Modularization offers increased flexibility, with a lower carbon carryover risk. • ∼17 % increase in ETE with modularization for biomass to H 2 generation. • 7 % lower ETE compared to the BDCL system, due to high O content in biomass. [ABSTRACT FROM AUTHOR]

The catalytic performances in steam reforming (SR) and aqueous phase reforming (APR) of glycerol of a bimetallic Pt-Mn catalyst supported on activated carbon are investigated and correlated with the surface properties of the catalyst. Under SR conditions, Mn showed a significant promoting effect over Pt/C, both in terms of hydrogen production rate and conversion, with a higher selectivity toward the glycerol dehydration products. Upon addition of Mn the amount of strong Lewis acid sites increased, promoting the dehydration of glycerol and favoring the C O over C C cleavage at expenses of hydrogen selectivity. Conversely, under APR conditions, a slightly higher hydrogen selectivity and only minimal enhancement in hydrogen production were found, while the products selectivity was comparable to Pt/C. Most of Mn leached into the aqueous media, but the remaining (<5% of the fresh parent sample) might be alloyed with Pt and promote the CO desorption from neighbor Pt sites. [ABSTRACT FROM AUTHOR]

In this study, an experimental investigation of photosensitive material copper oxide electrodeposition on various substances is performed under different experimental conditions in order to evaluate the effects on photoelectrochemical hydrogen production system. The experimental setup consists of solar simulator, electrodeposition chemicals, hydrogen sensor, pH meter, graphite and platinum electrodes, heating plate, stirrer, temperature sensors, cathode and anode plates, concentrating lens and potentiostat. The overall aim is to optimize the efficiencies by generating higher currents and eventually hydrogen as light enhances the separation of water process. The results obtained in this study are promising for photoelectrochemical hydrogen production under the solar simulator and concentrated light irradiation conditions. Furthermore, an electrolysis setup using the coated metals and graphite rod is built to investigate the amount of photocurrent production. The characterization is also conducted under light and no-light conditions, where the amount of produced current and hydrogen increased in light compared to no-light condition. At the applied voltage of −0.6 V and −0.4 V vs. Ag/AgCl, the photocurrent densities of 0.8 mA/cm2 and 0.27 mA/cm2 are obtained with a solar conversion efficiency of 0.86% and 0.24%, respectively. [ABSTRACT FROM AUTHOR]

Gasification is a clean technology which converts the liquid or solid fuels into a high caloric value syngas for power generation. In this research work, we developed a computational fluid dynamic model of crude oil gasification for hydrogen production; the accuracy of the model was approved in our previous work. Effects of some important factors such as residence time, steam/fuel ratio and equivalence ratio on hydrogen yield, and char conversion were explored. Results showed that the residence time and steam/fuel ratio play a major role in the process. It was also found that the equivalence ratio has a negative effect on the hydrogen yield and a positive effect on the char conversion. [ABSTRACT FROM PUBLISHER]

The present study demonstrates the possibility of generating hydrogen by methanol steam reforming at temperatures of 235–260 °C inside a non-concentrating solar collector, ideally for stationary fuel cell systems. In contrast to the current state-of-the-art, the solar collector provides all heat required for heating and evaporation of the reactants, endothermic reaction, and compensation of heat losses, without any external heat supply (such as from combustion of fuel or electric heating) and without the need for concentration of sunlight (as in conventional parabolic trough systems). Without the need for solar concentration, the system is simpler and more compact than conventional systems, and it can utilize all direct and indirect incident sunlight. The solar collector-reactor achieves hydrogen generation up to 6.62 L STP min −1 per m 2 collector area (equivalent to 1088 W m −2 LHV) under 1 sun, with solar-to-hydrogen efficiencies up to 78% and total energetic efficiencies (considering solar and fuel input) up to 43%. [ABSTRACT FROM AUTHOR]

Hydrothermal gasification of tomato processing plant waste was examined in batch autoclaves at temperatures of 300–600 °C and pressures of 20.0–42.5 MPa. The catalytic effects of KOH and K 2 CO 3 at the aforementioned temperatures and pressures were also investigated. While increasing the pressure enhanced methane yield, alkali addition improved both hydrogen and methane yields. The highest yields for H 2 and CH 4 were recorded as 27.4 and 21.8 moles kg−1 C at 600 °C and with KOH. In addition, carbon gasification efficiency (CGE) obtained was up to 86% while carbon liquefaction efficiency (CLE) was reduced to 3.5% with KOH at 600 °C and 20 MPa. A product gas with a calorific value of 24.9 MJ/Nm3 was obtained during hydrothermal gasification at 500 °C and 42.5 MPa, in the presence of KOH. [Display omitted] • Tomato plant waste was converted to product gas with a calorific value of 24.9 MJ/Nm3. • The increase in the pressure promoted CH 4 production at constant temperature. • The highest yield of CH 4 was obtained at 600 °C and 42.5 MPa as 21.8 mol/kg C. • H 2 yields reached to 33.8 mol/kg C at 600 °C and 20.0 MPa. [ABSTRACT FROM AUTHOR]

In this study, we presented an unexpected environmentally benign and easy-to-implement reaction for producing highly pure hydrogen (99.8%) and value-added carboxylate from primary alcohols under basic conditions. No catalyst was required, and no environmentally harmful gas, such as CO and CO 2 , was produced. The reaction conditions, different reactants and the water tolerance of the reaction were examined. It was found that as long as the temperature is higher than 500 K, no matter what the pressure is, hydrogen and carboxylate can be produced from primary alcohols. Strong alkalinity and high solubility of the base is necessary for the reaction. It was confirmed that ethanol-water mixtures, which could be produced from biomass fermentation, can be used as feedstock in this process, making it more meaningful in terms of sustainability. The mechanism of the reaction was also investigated in detail. [ABSTRACT FROM AUTHOR]

Hydrogen production via steam reforming of methanol has been studied over a series of CuO/ZnO/Al 2 O 3 catalysts synthesized by the combustion method using urea as fuel. Furthermore, the effect of alumina loading on the properties of the catalyst has been investigated. XRD analysis illustrated the crystallinity of the Cu and Zn oxides decreases by enhancing alumina loading. BET showed the surface area improvement and FESEM images revealed lower size distribution by increasing the amount of alumina. EDX results gave approximately the same metal oxide compositions of primary gel for the surface of the nanocatalysts. Catalytic performance tests showed the well practicability of catalysts synthesized by the combustion method for steam reforming of methanol process. Alumina addition to the CuO/ZnO catalyst caused the higher methanol conversion and the lower CO generation. Among different compositions the sample with molar component of CuO/ZnO/Al 2 O 3 = 4/4/2.5 showed the best performance which without CO generation at 240 °C its methanol conversion decreased from 90 to 60% after 90 h. [ABSTRACT FROM AUTHOR]

In order to improve the production of environmental friendly hydrogen, new advanced alkaline electrolyzers must be designed to optimize their combination with renewable energies. In pursuing this goal, modeling of alkaline electrolyzers becomes a powerful design tool. In this paper is presented a mathematical model that describes the behavior of an alkaline electrolysis cell. Unlike most of the existing models in literature, the proposed model simulates the influence of both electrode/diaphragm distance and electrolyte concentration in regular operation. The role of these aspects is crucial when designing alkaline electrolyzers since the process efficiency is found to be very sensitive to them. The computations done with the model presented here were validated with in situ experimental data, reporting a great accuracy: the maximum error was around 1% from all polarization curves studied. Combination with renewable energies was also studied by introducing a solar PV profile and the error reported never exceeds 3%. The influence of the considered variables (temperature, electrode/diaphragm distance and electrolyte concentration) was quantified using sensitivity analysis. [ABSTRACT FROM AUTHOR]

The safety of hydrogen generation facilities is the main concern in their process operation. This study was conducted to identify the hazards and evaluate the risks of a hydrogen generation plant. For this purpose, PrHA (Process Hazard Analysis) was applied for hazard identification while LOPA (Layer of Protection Analysis) was used for risk assessment. The study was conducted in the hydrogen production unit of Behshahr Industrial Complex, Iran in 2011 and 2012. In the process of risk assessment, the records of the accidents and plant flow diagrams were studied. Then, the knowledge of the experts and operators were used through brainstorming prior to the application of LOPA technique. LOPA standard template was applied using PHA-Pro6 software. The initiating events, consequences, independent protection layers and probability of failure were determined for 16 scenarios in 7 nodes. The results showed that without the application of IPLs, the risks of 2 scenarios needed immediate action, 9 scenarios required action at next opportunity and 5 scenarios were operational. The application of IPLs would significantly decrease the risks. The study concluded that LOPA has sufficient credibility for semi quantitative risk assessment of high potentially hazardous plants. [ABSTRACT FROM AUTHOR]

Abstract: In this note, we report two different experimental confirmations of the new chemical species of MagneHydrogen (MH discovered by R. M. Santilli in 2003 [1]) with 99% Hydrogen content, but also having a multiple of the specific weight of conventional molecular Hydrogen. A number of features of the new species MH are pointed out, such as the increased energy content and the lack of seepage through the walls of a container. These features appear to be relevant for the Hydrogen industry. Samples of the new species of MH are made available at no cost to qualified chemists for independent verifications. [Copyright &y& Elsevier]

The effect of steam/biomass ratio, oxygen/carbon ratio on gas composition, gas heating value, gas yield, tar yield, carbon conversion, cold gas thermal, and overall thermal efficiency on a circulating fluidized bed biomass (coir pith) gasifier has been presented. The presence of steam altered the composition of product gas. A hydrogen yield of 43% has been observed for a steam/biomass of 4.5 and a temperature of 1,008°C due to the presence of potassium oxide in larger quantities in coir pith ash. As the steam/biomass increased, gas heating value decreased, the gas yield decreased, tar yield increased, and carbon conversion decreased. [ABSTRACT FROM PUBLISHER]

Abstract: Thermodynamic features of hydrogen production by sorption enhanced steam reforming (SESR) of propane have been studied with the method of Gibbs free energy minimization and contrasted with propane steam reforming (SR). The effects of pressure (1–5 atm), temperature (700–1100 K) and water to propane ratio (WPR, 1–18) on equilibrium compositions and carbon formation are investigated. The results suggest that atmospheric pressure and a WPR of 12 are suitable for hydrogen production from both SR and SESR of propane. High WPR is favourable to inhibit carbon formation. The minimum WPR required to eliminate carbon production is 6 in both SR and SESR. The most favourable temperature for propane SR is approximately 950 K at which 1 mol of propane has the capacity to produce 9.1 mol of hydrogen. The optimum temperature for SESR is approximately 825 K, which is over 100 K lower than that for SR. Other key benefits include enhanced hydrogen production of nearly 10 mol (stoichiometric value) of hydrogen per mole of propane at 700 K, increased hydrogen purity (99% compared with 74% in SR) and no CO2 or CO production with the only impurity being CH4, all indicating a great potential of SESR of propane for hydrogen production. [Copyright &y& Elsevier]

Abstract: This paper describes a study regarding the effect of Ni addition to NixMg1−xO solid solutions on the catalytic performances of ethanol steam reforming for hydrogen production. Nickel nanoparticles supported on NixMg1−xO demonstrated higher conversion of ethanol and yields of hydrogen than the bare support. We correlated the improved performances of Ni-based catalysts with the reducibility of nickel species. The addition of Ni to the solid solution support produced more easily reducible surface nickel species. Higher content of bulk nickel species in the support could inhibit the surface nickel species from diffusing into the bulk, leading to more surface nickel species that is easily reducible to its active form. [Copyright &y& Elsevier]

To obtain reliable estimates of the quantities and rates of the gas production in L/ILW a series of measurements was carried in the last 7 years in Hungary. The typical gas production rates were 0.05-0.2 STP litre gas/day for CO and CH generation, and less for H. No explosive gas mixture was indicated in the L/ILW drums during the investigated storage period. Compositions of headspace gases in closed L/ILW vaults were in agreement with gas generation processes observed in L/ILW drums. The stable carbon isotope measurements show that the main source of the CO gas is the degradation of organic matter and indicates microbial degradation processes as the main sources of CH. Typical tritium activity concentrations were <10 Bq/l gas in the drums and <1,000 Bq/l gas in the vaults. Typical C activity values of the headspace gases were <2.0 Bq/l gas in the drums and <1,000 Bq/l gas in the vaults. [ABSTRACT FROM AUTHOR]

The results of research of the Pt-, Ru- and Pt–Ru/2% Ce/(θ + α)-Al2O3 catalysts with various ratio of Pt to Ru for selective catalytic oxidations of CH4 into synthesis-gas at short contact times are presented. Optimum conditions for preparation of catalysts were found. It was established that the CH4 conversion at 1,173 K changes from 96 to 100%, selectivity by H2—100%, and CO—95–100% at contact times 3.0–4.0 ms. [ABSTRACT FROM AUTHOR]

Abstract: The gasification characteristics of coir pith are studied in a circulating fluidized bed gasifier using air as the gasifying medium. The effect of various parameters such as temperature, Equivalence Ratio (ER), and Oxygen/Carbon ratio (O/C) on gas yield, gas composition, gas heating value, carbon conversion, cold gas and overall thermal efficiency is studied. The ERs employed in the study are 0.18, 0.21, 0.24 and 0.31. It has been found that temperature has an influence on the cracking reactions, as indicated by the increased yield of hydrogen. The maximum yield of hydrogen is obtained at a temperature of 1028.6 °C, and as the Equivalence Ratio (ER) increased, hydrogen yield decreased. The gas yield also increased with increase in temperature and ER. Also it has been observed that the gas heating value increases with increase in temperature and decrease in ER. Carbon conversion is found to increase with increase in temperature and increase in ER. It is found that the increase in temperature favours both the cold gas thermal and overall thermal efficiencies. Also the cold gas and overall thermal gasification efficiencies decrease with increase in Equivalence Ratio. [Copyright &y& Elsevier]

Abstract: The current study examines the effect of downstream synthesis gas feeding on Fischer–Tropsch product distributions in two series plug flow reactors over a precipitated iron catalyst. Synthesis gas at a constant H2:CO ratio of 2.5 was fed into the entrance of a first reactor, and the resulting products were fed into a second reactor along with fresh synthesis gas of varying H2:CO ratios (3, 2, 1, and 0.5). The selectivity of C5+ hydrocarbons in the downstream feeding cases was over two times lower than the corresponding “top feeding” cases, in which an equivalent amount of synthesis gas was fed through both series reactors without the addition of downstream synthesis gas. These observations were attributed to the effects of bed residence time and H2:CO ratios as influenced by the simultaneous water–gas shift reaction. [Copyright &y& Elsevier]

The present paper illustrates an innovative steel processing route developed by employing hydrogen direct reduced pellets and an open slag bath furnace. The paper illustrates the direct reduction reactor employing hydrogen as reductant on an industrial scale. The solution allows for the production of steel from blast furnace pellets transformed in the direct reduction reactor. The reduced pellets are then melted in open slag bath furnaces, allowing carburization for further refining. The proposed solution is clean for the decarbonization of the steel industry. The kinetic, chemical and thermodynamic issues are detailed with particular attention paid to the slag conditions. The proposed solution is also supported by the economic evaluation compared to traditional routes. [ABSTRACT FROM AUTHOR]

Reforming characteristics and optimal operating condition for the syngas (synthesis gas) production were studied by using gliding arc plasma with catalytic reactor. Parametric screening studies were carried out for the variations of vapor flow ratio, CO2 flow ratio, input electric power, and reactant flow rate. When the vapor flow ratio, CO2 flow ratio, reactant flow rate, and input electric power were 0.65, 0.14, 14 L/min, and 1.37 kW respectively, the production of hydrogen and propane conversion rate showed the optimal levels as 62.6%. Under these optimal conditions, the concentrations of the syngas were as follows: H2 44.4%, CO 18.2%, CH4 11.2%, C2 H2 2.7%, C3 H6 1.9%, C2 H4 0.6%, and C3 H4 0.4%. Also, the conversion rate of carbon dioxide was 29.2% and H2/CO ratio was 2.4. [ABSTRACT FROM AUTHOR]

Abstract: The performance of the Texaco gasifier in hydrogen production was studied numerically. To estimate the accurate carbon conversion, a two-stage equilibrium model was proposed. In the proposed model, the two reactions which determined the carbon conversion were separated from other vapor–vapor reactions. The governing equations of the proposed model were derived and a self-consistent method was developed to solve the governing equations. The %AAD of the calculated carbon conversions from the measured values was 2.89 and that of the calculated gas production rate was 0.64. Calculated gas compositions showed a fairly good agreement with the experimental ones for commercial scale plants. It was found that the chemical reactions that occurred in the Texaco gasifier possess a mechanism for keeping the carbon conversion close to unity against a wide variation in the H2O to coal ratios. [Copyright &y& Elsevier]

Gasification technology has matured to the point that previously-held hesitations regarding performance and availability have given way to acceptance of the technology for energy generation. Indeed, the past few years have seen a significant increase in the number of gasifiers installed for generation of power and heat, and the number of installations is expected to increase dramatically over the next several decades as demand for efficient and environmentally sound energy generation increases. It is valuable to consider the environmental impact of this new generation of energy production systems, specifically release of gaseous emissions from combustion of the synthesis gas produced by gasification. Emissions from syngas combustion in turbines, engines and boilers are discussed in this review. The types of emissions considered include the unburned fuel components and partially oxidized species, nitrogen and sulfur-containing gases, volatile organic compounds, and other trace elements. Combustion of synthesis gas, in general, produces lower emissions for heat and power generation than conventional liquid and solid fuels. The composition of the syngas strongly influences the level of emissions. Hydrogen and carbon monoxide in synthesis gases results in elevated combustion temperature that facilitates the thermal formation of NO and NO2. In contrast, higher temperatures promote complete combustion and reduce the emission of organic volatiles, which are formed mainly from minor fractions of hydrocarbons in synthesis gases. Particulate matter, metallic compounds and other undesired pollutants are usually removed before firing synthesis gases for heat and power production. Therefore, integrated gasification and combined cycle systems are more environmentally friendly than conventional power generation systems. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates the technical aspects of innovative hydrogen production concepts based on coal gasification with capture. More specifically, it focuses on the technical evaluation and the assessment of performance of a number of plant configurations based on standard entrained-flow gasification processes (dry feed and slurry feed types) producing hydrogen at pipeline pressure, which incorporate improvements for increasing hydrogen purity and pressure. The dry feed type of entrained-flow gasifier is currently considered to be the most efficient means of producing hydrogen from coal. The main shortcomings are relatively low hydrogen purity due to the need of using nitrogen as a transport gas for the coal and a pressure limitation of this type of design. The purity issue can be solved by using captured to transport the coal in the gasifier. The pressure limitation can be overcome by using in-plant compression of the raw syngas. Simulations, made using commercial process flow modelling packages (ChemCAD), show that these changes can be made without compromising plant efficiency; on the contrary, the efficiency slightly increases because of the better thermal integration of the plant. [Copyright &y& Elsevier]

Abstract: The paper explores the reliability of using an underground coal gasification (UCG) technique for hydrogen manufacturing. Methods for increasing the temperature in underground gasifier are analyzed with the aim of improving the hydrogen-manufacturing process. In this paper, the rationales behind hydrogen manufacturing in UCG is explained. The experimental conditions and process of the underground gasification in Woniushan Mine, Xuzhou, Jiangsu Province are introduced, and the experimental results are analyzed. By adopting the new method of two-stage UCG with long channel and big section, the daily water gas production reaches about 16,000m3, with a maximum output of 46,000m3, with content between 40% and 73%, and both CO and contents over 6%. The daily average output of is . Experimental results show that the two-stage underground gasification with multi-point air (steam) feed cannot only improve the average temperature of the gasifier effectively, but also shorten the cyclical time of the two stages by a wide margin, which increases the time when water gas with a high content of is produced by 0.95–1.24 times and 1.2–1.7 times respectively, as opposed to that of the conventional mode of pumping air (seam) with fixed points for field and model tests. Furthermore, the experimental data indicate that the backward gasification can form new temperature conditions and increase the gasification efficiency of coal seams and the productivity of hydrogen, which proves the feasibility of UCG for large-scale production. [Copyright &y& Elsevier]

Abstract: Poland has significant reserves of energy in the form of coal. However, the exploitation of these reserves could lead to significant carbon emissions. Hydrogen technologies present a potentially sustainable option for the Polish energy system. This paper reviews the existing Polish energy system, resources, policies and measures from the perspective of planning a transition to a hydrogen-based economy. The key challenges and opportunities gathered by systematic consultation of senior stakeholders are presented. Coke oven gas and coal gasification are the major short and medium term sources of hydrogen. Underground conversion of coal deposits with integrated carbon capture and storage (CCS) is most important in the long term. Other opportunities include development of renewables, by-product hydrogen and nuclear power. Current lack of infrastructure, particularly for CCS, hydrogen pipelines and clean coal is seen as a significant barrier. Regional and central government should cooperate with industry to develop a portfolio of demonstration projects to provide experience and stimulate demand for hydrogen. [Copyright &y& Elsevier]

Abstract: The gasification of coal to produce hydrogen for use either in power generation or/and for synthesis applications and transport is attracting considerable interest worldwide. Three types of generic gasifiers (entrained flow, fluidised bed and fixed bed gasifiers) presently in use in commercial gasification plants or under development worldwide are described. Their suitability for processing all types of coals is discussed. This includes an assessment of the impact of some of the major properties of coal on the design, performance and maintenance of gasification processes. [Copyright &y& Elsevier]

Abstract: Internationally there is considerable interest in utilizing hydrogen as an energy carrier. The use of hydrogen offers considerable potential benefits such as reducing greenhouse emissions, reducing urban pollution, increased energy security and increased efficiencies from the use of advanced energy conversion technologies. One of the most important questions when considering the development of a hydrogen economy is “where will the hydrogen come from?” Possible answers include electrolysis of water, steam reforming of methane and the gasification of coal. Given the high costs associated with electrolysis of water, and the increase in the cost of methane predicted over time, the gasification of coal is viewed by many as being the cheapest method of hydrogen production in the foreseeable future. These considerations are particularly relevant to New Zealand where gas supplies are dwindling but where there is sufficient coal to last for many centuries at present utilization rates. This, along with the current high international interest in hydrogen energy, has been recognized by the New Zealand Government in the form of a six-year [2002–2008] research project “Hydrogen Energy for the Future of New Zealand”. One important coal property that, in particular, determines the suitability of a particular coal for use in a fluidised bed gasifier is its reactivity towards the gasification reaction. It was found that a high percentage of New Zealand''s coal resource is particularly well-suited towards fluidised bed gasification, reacting at anywhere between 0.9 to 1.75 times the rate of Australian brown coals. It was found the New Zealand lignites contained significant levels of organically bound calcium, which was shown to be responsible for not only the high reactivity of the New Zealand lignites, but also a product gas composition with higher than expected hydrogen concentrations. These findings are discussed along with their implications for the gasifier and gas clean-up design. [Copyright &y& Elsevier]

Abstract: The CO2 reforming catalyst and process have been developed. The commercial size CO2 reforming catalyst has been demonstrating its activity and stability in the gas to liquid (GTL) pilot plant tests for around 6000h, and the first GTL oil from natural gas in Japan has been being produced from November 2002 to October 2004. In these tests, synthesis gas was generated by CO2 and H2O reforming with low CO2/carbon and low H2O/carbon ratios in feed gas composition. The proprietary catalyst which has high resistance against carbon deposition could allow the stable operation under CO2 and H2O reforming conditions. The CO2 reforming simulator could well represent the results of the pilot plant tests. The proposed process showed superior economics on the feasibility studies of applications to GTL processes. [Copyright &y& Elsevier]

The production of hydrogen and synthesis gas (syngas) from methane is a key technology for the twenty-first century. It is currently performed predominantly by steam reforming of methane. An alternative reaction route is the direct catalytic partial oxidation of methane (CPOM) at high-temperature, short contact time conditions, which proceeds autothermally over noble metal catalysts. However, syngas yields are limited at autothermal operation by a complex interplay of total and partial oxidation reactions. We demonstrate that these limitations can be overcome through dynamic heat integration in a catalytic reverse-flow reactor. The efficient heat integration in this reactor type leads to strongly increased syngas yields; that is, it effectively converts sensible heat into chemical energy. Furthermore, even shorter contact times can be achieved without yield losses, allowing for even more compact reactors or further increased reactor throughput. The combination of short contact time catalysis with dynamic heat integration therefore appears ideally suited for small-scale and decentralized syngas and hydrogen production. [ABSTRACT FROM AUTHOR]

The mixed tris-cyclopentadienyl tetrahydrofuranato samarium complex bis-(cyclopentadienyl) methylcyclopentadienyl tetrahydrofuranato samarium (I) was synthesized by reaction of (C5H5)2SmCl with methyl cyclopentadienyl sodium in THF. [(C5H5)2(C5H4CH3)(C4H8O)Sm] (I) was characterized by elemental analyses—IR spectra and MS spectra. The structure of [(C5H5)2(C5H4CH3)(C4H8O)Sm] (I), which has two slightly different independent molecules per asymmetric unit, has been elucidated through complete X-ray analysis. The crystals are monoclinic, with a = 12.791(3) Å, b = 10.467(2) Å, c = 26.108(5) Å, β = 98.22(2)°, and space group Cc, R = 0.0381 for 2103 observed reflection with I ≥ 3 σ(I). [ABSTRACT FROM AUTHOR]

This article focuses on a study related to ultrastable gold nanocatalyst supported on surface-modified TiO2 nanocrystals. Supported gold nanocatalysts have very high activities in some important industrial reactions, including oxidation of CO and hydrocarbons, water-gas-shift reaction, H2O2 production from H2 and O2, removal of CO from hydrogen steams, and selective epoxidation. One of the strategies in developing ultrastable supported gold nanocatalysts is to find a suitable substrate capable of efficiently stabilizing supported gold nanoparticles.

Abstract: CHRISGAS is the acronym for Clean Hydrogen-rich Synthesis Gas), a 5½-year “Flagship” project funded within the EC’s 6th Framework Programme and by the Swedish Energy Agency. 20 partners representing industry and research from 7 EU member states have been involved in the project which commenced in September 2004 and ended in February 2010. Research on the whole value chain from biomass resources, drying, pressurised gasification and other thermo-chemical processing to final synthesis (syngas) gas, as well as plant cost studies including synthesis of vehicle fuels for three full scale production capacities has been covered in the integrated CHRISGAS project (http://www.chrisgas.com). From a hydrogen-rich synthesis gas renewable transportation fuels, such as DME (dimethyl ether), FT-diesel and hydrogen can be produced. At the project onset one of the primary aims was to demonstrate the manufacture of a suitable syngas based on biomass gasification at the Värnamo large scale pilot plant. Unfortunately due to insufficient additional funding this aim could not be fulfilled within the timeframe of the project. This paper describes the history and the evolution of the project; it also presents the other papers included in this edition within the context of the work areas of the CHRISGAS project. [Copyright &y& Elsevier]

Abstract: The rebuild of the Växjö Värnamo Biomass Gasification Center (VVBGC) integrated gasification combined cycle (IGCC) plant into a plant for production of a clean hydrogen rich synthesis gas requires an extensive adaptation of conventional techniques to the special chemical and physical needs found in a gasified biomass environment. The CHRISGAS project has, in a multitude of areas, been responsible for the research and development activities associated with the rebuild. In this paper the present status and some of the issues concerning the upgrading of the product gas from gasified biomass into synthesis gas are addressed. The purpose is to serve as an introduction to the scientific papers written by the partners in the consortium concerning the unit operations of the process. [Copyright &y& Elsevier]