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Nitrous oxide (N2O) is a greenhouse gas produced in the manufacture of 6,6‐nylon and nitric acid. While an attractive oxidant that releases only N2 as a by‐product, the kinetic stability of N2O typically requires high temperatures and pressures for activation. This work describes initial kinetics of oxygen transfer in the epoxidation of cholesteryl acetate with N2O catalysed by D4‐Ru(VI)(por)(O)2 complexes in efforts to provide a better mechanistic understanding of this chemistry. Insights include a need for low concentrations of the alkene to avoid competitive binding to the metal, possible saturation behavior at high N2O pressures, transfer of only one oxygen of RuVI(O)2 to substrate and a possible catalyst turnover involving disproportionation of RuIV(O) and RuIV(O)(N2O) to active RuVI(O)2, RuIV(O) and N2. These insights will be used in future designs of improved catalysts and reaction protocols that may operate efficiently at low pressures of N2O and ambident temperature. [ABSTRACT FROM AUTHOR]

Plastic pollution is a generational problem, and stakeholders are turning to chemical recycling as a potential solution. However, decision‐makers necessitate quick and reliable capital investment estimations to evaluate innovative technologies, especially in the early project stage, when limited historical data are available. To address this need, we built a database of 160+ chemical recycling plants, querying for nominal capacity, year and place of construction, total capital investment (TCI), number of long‐term jobs and opportunity of subsidies. Then, we compared conventional association of the advancement of cost engineering AACE class 5 estimation methods, with literature estimates, and commercial capital expenditure confidence intervals for pyrolysis, gasification, solvolysis, and selective dissolution. We demonstrate the unreliability of classic methods, and we propose ballpark correlations based on the plant capacity, or the energy loss. Chemical recycling plants suffer from poor economy of scale (with current technologies), and capacity is not always the best indicator for TCI estimation. Pyrolysis and gasification are energy‐driven technologies, and their TCI correlates very well (R2=0.91–0.92) with the total energy losses. Solvolysis and selective dissolution, instead, are at an earlier development stage, so cost engineers or researchers will have to accept less certain TCI vs capacity (R2=0.60). [ABSTRACT FROM AUTHOR]

Torrefaction is a thermal procedure used to convert biomass into a substance resembling coal that possesses superior fuel properties compared to the original biomass. Torrefied biomass is hydrophobic and has a greater energy density, making it more advantageous for handling and storage. The purpose of this investigation is to establish a simulation model of the torrefaction process utilizing Malaysian biomass and optimize it for mass yield and energy consumption. Additionally, the objective is to integrate the optimized torrefaction process into an existing biomass power plant. By retrofitting a biomass‐based power generation facility with torrefaction technology, the existing feedstock can be upgraded before sending it to the power plant. Essentially, torrefaction technology represents an enhancement of biomass utilization technology, ultimately allowing for the maximum application of biomass energy. [ABSTRACT FROM AUTHOR]

Biomass fast pyrolysis is a promising technology to produce available char and high‐value gas due to its green and sustainable ability. In the current work, the biomass fast pyrolysis in draft tube spouted bed has been numerically investigated via the multiphase particle‐in‐cell model. In this model, gas turbulence is calculated via large eddy simulation and particles are individually tracked in the Lagrangian manner. This model is successfully validated against experimental data. The particle‐scale information of sand and biomass feedstock has been discussed, and the influence of draft tube configuration on the pyrolysis performance has been studied. The results show that the equipment of draft tube prevents gas leakage from spout to annulus, leading to large axial gas flux in the spout. Biomass particles in the spout and freeboard have high temperature and heat‐transfer coefficient. Some biomass particles move along the outer wall of draft tube, indicating that the equipment of draft tube can avoid back‐mixing by preventing direct contact of particles in the spout and annulus. Increasing the height of draft tube results in larger axial gas flux and higher sand heat‐transfer coefficient, while decreases biomass temperature in the spout. The simulation results can offer valuable insights into comprehending intricate reactive gas–solid characteristics and conducting operation and design optimization of spouting apparatus. [ABSTRACT FROM AUTHOR]

The environmental impacts of the manufacture of chitosan (CS) and polymeric poly(1‐trimethylsilyl‐1‐propyne) (PTMSP) mixed‐matrix membranes (MMMs) for CO2 separation by life cycle assessment (LCA) are compared. An ionic liquid of non‐reported toxicity is used in CS membranes to enhance the mechanical strength, and different fillers are used to increase mechanical and functional properties: ETS‐10, ZIF‐8, HKUST‐1, and Zeolite A. Results with the same CO2 permeation flux indicate that ETS‐10/IL‐CS is the membrane manufacture with highest impacts due to its lower permeability. When comparing impacts with same permeation areas, the polymeric one is the membrane with highest impacts. Biopolymer and polymer manufacture are the components with highest contribution to the total environmental impacts of each membrane. To decrease all their impacts below fossil polymer membrane for the same CO2 permeation flux, CS membranes permeabilities should be improved by a numerical factor of 1000, 100, and 2 for the ETS‐10, ZIF‐8, and HKUST‐1/IL‐CS MMMs, respectively. [ABSTRACT FROM AUTHOR]

Valencene is a natural sesquiterpene with desirable bioactivity and aroma, making it a valuable ingredient in the food and cosmetics industries. Traditionally, valencene was extracted from the citrus fruits, and its applications were restricted by the low concentrations in natural sources and high costs for extraction. Photosynthetic biomanufacturing represents a promising route for efficient and stable production of valencene, while cyanobacteria have been considered one of the most promising platforms regarding biotechnological routes for the direct conversion of CO2. In this work, we engineered Synechocystis sp. PCC 6803 to synthesize valencene. By introducing a heterologous valencene synthase and modifying the native MEP pathway, we obtained an efficient cyanobacterial cell factory that produced 154 mg/L valencene during a semi‐continual cultivation, with an average productivity of 4.3 mg/L/day, and the cell factory exhibited robust growth and production in non‐sterilized conditions. We also achieved the production of other sesquiterpenes including bisabolene, amorpha‐4,11‐diene, farnesene, and nerolidol by engineered cyanobacteria with enhanced MEP pathway flux, showing promising potentials as a universal chassis. [ABSTRACT FROM AUTHOR]

A novel fungal pathogen, Rhytisma arcticum, is described, causing tar spot disease on Salix arctica in Ellesmere Island, Canada. Stromata, asci and ascospores—distinctly smaller than other Rhytisma species found on Salix—are its distinctive morphological features. rDNA internal transcribed spacer (ITS) and large‐subunit (LSU) sequence analyses revealed a close relation of this species to R. polare previously reported on Spitsbergen Island. This study describes a novel plant pathogen species in one of the northernmost locations of the world. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ginkgo biloba leaves contain beneficial flavonoids, bilobalide (BB), and ginkgolides. However, the toxic ginkgolic acid (GA) limit its application. In this study, various traditional processing methods were used to prepare G. biloba leaf tea (GBLT), including white tea, black tea, dark tea, green tea, and freeze‐dried as control, followed by investigations of their effects on quality, antioxidant capacity, bioactive components, and cytotoxicity of the tea products. RESULTS: Results showed that different processing methods significantly impact the tea products' quality indexes and the principal component analysis (PCA) and hierarchical cluster analysis (HCA) corroborated it. White tea had the highest total sugar (TS) and GA content and the most potent cytotoxicity on HepG2 cells. However, TS and GA content and the cytotoxicity of GBLT markedly decreased during fermentation and fixation. Moreover, white tea possessed higher total phenolic content (TPC), total flavonoid content (TFC), and more vigorous antioxidant activities than green tea, black tea, and dark tea. Terpene trilactones value was stable, but different catechins contents fluctuated according to the manufacturing process of different GBLTs. Among the four GBLTs, dark tea combining fixation and fermentation had the lowest GA content and cytotoxicity, less bioactive components reduction, appropriate quality, and stronger flavor. CONCLUSION: These findings demonstrate that fixation and fermentation help reduce GAs during the manufacturing of GBLT. However, their ability to retain bioactive substances needs further optimization in future studies. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Kraft pulp production generates residues and by‐products of significant importance to the mill. Solid residues from forestry activities are commonly used to generate steam in power boilers. In the recovery cycle, black liquor generates steam (and subsequently energy) by burning in the Tomlinson boiler, while white liquor is regenerated. Well‐developed alternative technologies can use these residues and by‐products to generate different types of biofuels. This review addresses the use of such technologies integrated with Kraft mills, in the concept of biorefineries, showing advantages, disadvantages, and successful examples. Solid residues from forestry can be used to produce bio‐oil through processes such as fast pyrolysis and hydrothermal liquefaction. Bio‐oils are currently used for heating through combustion in commercial/industrial boilers, but greater appreciation occurs if used as biofuels, which is done through catalytic upgrading processes. Black liquor gasification generates synthesis gas, which can be burned for energy co‐generation, used to produce synthetic fuels, or as a hydrogenating agent for bio‐oil or crude tall oil catalytic upgrading. Kraft biorefineries are gradually being implemented, justifying efforts to improve existing and new biomass conversion technologies. [ABSTRACT FROM AUTHOR]

A novel resistance internal is proposed to optimize the flow field and improve the gas–liquid contact in a co‐hydrogenation reactor of coal and vacuum residuum. Local gas holdup, local liquid velocity, and characteristics of the bubble were investigated in a scaled‐down laboratory model. The quantitative results showed that the resistance internals could reduce the thickness of the liquid reflux layer by a percentage up to 32% and reduce the difference in the local gas holdup at cross‐sections of up to 44%. The Sauter mean diameter of the bubble decreased from 20.30 to 16.00 mm, which aroused the increase in bubble surface area by a percentage of up to 71.9%. The resistance internal promoted the breakup of the bubble with multiple mechanisms and provided diversion to fluid. In this work, improvement at multiple scales was realized, and the technical support for industrial application was provided. [ABSTRACT FROM AUTHOR]

The rate of conversion during gasification of char particles depends on the type of reagents, the concentration of reactants, and reactor temperature, among many other parameters; however, the overall conversion depends on the residence time distribution (RTD) of the particles in the reactor. The objective of the present work is to investigate the influence of gasifying agents, their concentration, and reactor wall temperature on the RTD of the char particles. The aim also includes studying the effect of mean residence time on the overall char conversion during gasification of Victorian brown coal in an entrained flow reactor. Two gasifying reagents, namely, CO2 and H2O, are selected in the present study. A discrete particle model (DPM) is coupled with computational fluid dynamics (CFD) to simulate the solid phase dynamics. Gasification is modelled using a lumped approach. The mean residence time of the solid char particles, determined using three different methods, is observed to increase with the CO2 concentration and wall temperature but decrease in the H2O environment. The longer residence time leads to higher overall char conversion in a CO2 environment despite the higher reactivity of H2O compared to CO2 as a gasifying reagent. [ABSTRACT FROM AUTHOR]

The polytetrafluoroethylene (PTFE) serves as a dielectric layer for surface dielectric barrier discharge (SDBD) and the prepared plasma‐activated saline (PAS) exhibited strong bactericidal effects, however, the fluorides are inevitably generated and bring about side effects in biological application. In this study, the SDBD devices with the dielectric layers of quartz or ceramic compared with that with PTFE were utilized to explore the effective and fluoride‐free PAS using different working gases. The Quartz‐PAS prepared with air exhibited a relatively strong bactericidal effect without inducing the DNA‐protein crosslinks (DPCs) in Escherichia coli cells, while the Ceramic‐PAS exhibited a weak bactericidal effect and induced the DPCs formation. This study supplies guidance in the preparation and regulation of PAS for biomedical applications. [ABSTRACT FROM AUTHOR]

Nowadays, the utilization of non‐conventional oil resources has become an increasingly attractive solution for producing valuable chemicals and materials due to the depletion of conventional oil resources. Plasma technology, powered by renewable energy sources, provides a potential way to convert low‐grade residual oil into lighter hydrocarbons in an environmentally friendly fashion. This study has developed a laboratory‐scale plasma pyrolysis system to investigate the impacts of residual oil characteristics and operating variables such as residual oil‐specific enthalpy, arc gas flow rate, arc gas composition, quenching, and plasma configuration. The results show that the higher specific enthalpy of the residual oil leads to higher yields of C1, C2, and H2, particularly C2H2. An increment in the arc gas flow rate improves the pyrolysis impact; however, an excessively high arc gas flow rate lowers the thermal plasma jet's temperature, causing a limited pyrolysis effect. In the composition of arc gas, the increasing concentration of H2 can enhance the specific enthalpy and improve carbon conversion from residual oil to gas products, both of which result in a higher yield of light gases. Furthermore, ethane gas has been used as a quenching medium after plasma pyrolysis. The results reveal that ethane can be cracked into ethylene and other products by taking full use of the heat energy of the gas. Meanwhile, the sharp decrease in the gas temperature inhibits the further pyrolysis of the main valuable products. [ABSTRACT FROM AUTHOR]

Radiant syngas cooler (RSC) is an important piece of equipment for heat recovery and steam generation in the gasification plant. In this work, the industrial RSC model of an opposed multi‐burner coal‐water‐slurry gasification device is established, and the heat recovery performance of RSC is studied by numerical simulation method. The simulation result of the total heat transfer rate is compared with the industrial operation data. The effect of different operating parameters on RSC is further studied, including the operating load, inlet syngas temperature, and ash deposition thickness. The results show that there is a spindle‐shaped high‐temperature zone on the circumferential membrane wall surface with a distance of 6.5 m from the top under the basic operating conditions. There is also an obvious high‐temperature zone in the mid‐upper section of the fire side for the radiation screen. When the operating load decreases from 100% to 60%, the outlet syngas temperature decreases by 167 K, and the steam output decreases by 22%. The influence of inlet syngas temperature on outlet syngas temperature and steam output is approximately linear. For every 10 K drop of inlet syngas temperature, the outlet syngas temperature decreases by 10 K, and the steam output decreases by 0.91 × 103 kg/h. With the increase of the ash deposition thickness, the surface temperature and heat flux of the water wall rise and the outlet syngas temperature increases, while the steam output decreases. The research provides guidance for the design and stable operation of RSC in the radiation‐quenching gasification process. [ABSTRACT FROM AUTHOR]

Galvanized steel scrap flow and injection into the HIsarna reactor are investigated using discrete element method (DEM). The scrap particle is fed into the reactor through an inclined chute and hits the slag surface where the zinc content is evaporated and solid particles melt. A DEM model is setup and validated using experimental data obtained from the exact plant‐scale chute geometry and scrap particles. Using the DEM model, the effect of chute inclination, injection elevation, injection mode (batch and continuous), batch size, and flowrate on particle distribution and exerted pressure on the slag surface are investigated. It is found that continuous mode of injection is the most suitable method to increase the spread of particles and also to reduce the exerted pressure on the slag surface. Placing dent‐like obstacles at the tip of the chute significantly increases the impact area, especially for batchwise injection, thus reducing force and pressure on the slag surface that minimizes the risk of liquid splash. Larger particle impact area is also beneficial to obtain higher zinc evaporation rate from particle surface and also to minimize the slag surface temperature disturbance. [ABSTRACT FROM AUTHOR]

This manuscript reports a CO2 hydrogenation process in a catalytic laboratory‐scale packed‐bed reactor using an Fe/BZY15 (BaZr0.85Y0.15O3‐δ) catalyst to form hydrocarbons (e. g., CH4, C2+) at elevated pressure of 30 bar and temperatures in the range 270≤T≤375 °C. The effects of temperature, feed composition (i. e., CO2/H2 ratio, and residence time (i. e., Weight Hourly Space Velocity (WHSV) are studied to understand the relationship between CO2 conversion and carbon selectivity. Catalyst characterization elucidates the relationships between the catalyst structure, surface adsorbates, and reaction pathways. Thermodynamic analyses guide the experimental conditions and assist in interpreting results. While the feed composition and temperature influence the product distribution, the results suggest that the higher‐carbon (C2+) selectivity and yield depend strongly on residence time. The results suggest that the CO2 hydrogenation reaction pathway is similar to Fischer–Tropsch (FT) synthesis. The reaction begins with CO2 activation to form CO, followed by chain‐growth reactions similar to the FT process. The CO2 activation depends on the redox activity of the catalyst. However, the carbon chain growth depends primarily on the residence time. as is the case for the FT synthesis, high residence time (on the orders of hours) is required to achieve high C2+ yield. [ABSTRACT FROM AUTHOR]

The development of new materials and their production processes along with the environmental constraints demand new data of high quality, especially thermodynamic and physical property data. As slags play a crucial role in metallurgical processes and recycling, the need of better understanding of the reaction mechanisms between slag and metal is also increasingly felt. High precision data and better understanding of the reaction mechanism require efficient collaboration between the researchers in the laboratory and in the industries. Unfortunately, in some cases, the reported data are not obtained in well‐controlled experimental conditions. Without the knowledge of the experimental conditions, the use of the data in industrial practice would possibly lead to unintended results. In other cases, the measurements themselves, even their principles, are questionable. This review article addresses how to make the laboratory investigation more relevant to the industrial reality. Some existing uncertainties in the laboratory studies are also discussed. To help a sensible discussion, some specially designed experiments are conducted to support the argument. The review is focused on slag properties (namely, sulfide capacity, phosphate capacity, apparent viscosity, and apparent interfacial tension) and studies of interfacial slag phenomena. [ABSTRACT FROM AUTHOR]

There are some problems in gas–liquid stirred tank reactor (STR), such as low mass transfer efficiency, high exhaust gas oxygen concentration, and low product conversion rate, due to limitations of stirring speed and input power. This article summarizes the effect of adding circulating jet internals on bubble size distribution, overall gas holdup, gas–liquid volumetric mass transfer coefficient, and power per unit volume of the STR. When circulating jet is added, the average bubble Sauter mean diameter in the STR is reduced to 1.26 mm, and the overall gas holdup is increased to 8.23%, which is an increase of 3.62 times of the original STR. The gas–liquid volumetric mass transfer coefficient is increased to 0.05556 s−1, which is 4.84 times of the original STR. The power per unit volume is increased by only 1.4 times. These data provide references for the design and scale‐up of new jet STRs. [ABSTRACT FROM AUTHOR]

We investigate syngas production from polyolefins commonly found in solid waste in a semi‐batch reactor system via gasification and catalytic reforming. We find that the gasification behavior of polymer waste is correlated to the energy of the weakest CH bond in the polymer structure. Furthermore, we show that the syngas yield can be enhanced by the use of adsorbents and reforming catalysts, which promote gasification and reforming over pyrolysis reactions. Adsorbents are required for the achievement of high syngas yields when the polymer feed is comprised of polymers that pyrolyze at lower temperatures, such as PS, PP, and LDPE, resulting in carbon loss as light hydrocarbons. Adsorbents trap these light gases and release them at a higher temperature, where reforming over a Ni/Al2O3 catalyst can take place. This behavior also results in synergistic effects when blends of polymers are gasified. The Ni/Al2O3 catalyst is stable over multiple recycle reactor runs. [ABSTRACT FROM AUTHOR]

Optimization of maintenance services of a company working in the gas metering sector is investigated. In particular, daily tasks of operators are optimized by exploiting the paradigm of vehicle routing problems with a set of predefined time windows that overlap one with the others and four competing objectives to take into account. First, an exact integer formulation is presented that can be solved only for a reduced number of customer sites to visit. Then, a heuristic approach is proposed to find approximate solutions with huge savings on the computational effort, also for high‐dimensional instances. Numerical results on both real and synthetic scenarios showcase the effectiveness of the approach. [ABSTRACT FROM AUTHOR]

Homogeneous nucleation and heterogeneous condensation of salt vapors near the wall of superheater or reheater tubes greatly improve the sticky propensity of deposited surfaces or impacting particles and then lead to a fast‐growing rate of initial layer. Based on the deposition experiment of mechanically mixed KCl + SiO2 particles in an entrained flow reactor, a numerical model with considering the salt particle vaporization, salt vapor condensation, and its effect on SiO2 deposition is proposed for simulating impaction and adhesion behavior of molten and solid particles. The results show that deposits are mainly from the impaction of solid and molten particles and the condensation of salt vapors. The condensation rate of salt vapors in the stagnation zone at the windward side of metal probe is maximal. In comparison with the overall deposition rate, although the amount of salt vapors condensed on the probe surface can be negligible, it significantly affects the deposition rate of SiO2 particles. The coupled CFD model over a link between particle sticking and salt vapor condensation could well simulate the deposition behavior of mechanically mixed ash particles under rich‐salt‐vapor atmosphere. [ABSTRACT FROM AUTHOR]

It is important to prevent vapor explosion for steel mill industries for the reason that explosions can produce overpressure which cause buildings and facilities to rupture. The spontaneous vapor explosion occurs when a molten slag contacts with coolant. In this research, the molten slag which includes more than 10 chemical compositions produced in actual steel mill industries is employed. Three types of coolant were employed which can be used in real industries such as tap water, freshwater, and yard coolant. Spontaneous vapor explosion occurred when the yard coolant, which has a higher concentration of salt than either tap water or freshwater, was used as coolant. When the vapor explosion occurred, the temperature of the yard coolant was exclusively investigated in the range of 40°C to 55°C. The vapor explosion was independent of the molten slag temperatures employed. The vapor explosion in this work was attributed to the high salt concentration of the yard coolant, which improved the heat transfer to the vapor film around the molten slag droplet. The heat transfer promoted the vapor film to collapse and triggered the spontaneous vapor explosion. [ABSTRACT FROM AUTHOR]

A plasma's working gas is a significant factor affecting their discharge characteristics and the induced chemistries during plasma–water interactions. However, the effects on the discharge mode and discharge stability have not been fully investigated. This study focuses on the discharge mode transition and stability with nitrogen and oxygen gases. Compared with the oxygen discharge, the nitrogen discharge remained stable over a larger voltage range and long duration time. A diffuse mode discharge had better stability and lower plasma activity for both nitrogen and oxygen gases, whereas a transient spark mode in nitrogen and filament mode in oxygen had lower stability but a higher plasma activity. This study improves the understanding of the physicochemical processes of plasma–water interactions. [ABSTRACT FROM AUTHOR]

Rationale: Measurement of greenhouse gas (GHG) concentrations and isotopic compositions in the atmosphere is a valuable tool for predicting their sources and sinks, and ultimately how they affect Earth's climate. Easy access to unmanned aerial vehicles (UAVs) has opened up new opportunities for remote gas sampling and provides logistical and economic opportunities to improve GHG measurements. Methods: This study presents synchronized gas chromatography/isotope ratio mass spectrometry (GC/IRMS) methods for the analysis of atmospheric gas samples (20-mL glass vessels) to determine the stable isotope ratios and concentrations of CO2, CH4 and N2O. To our knowledge there is no comprehensive GC/IRMS setup for successive measurement of CO2, CH4 and N2O analysis meshed with a UAV-based sampling system. The systems were built using off-the-shelf instruments augmented with minor modifications. Results: The precision of working gas standards achieved for d13C and d18O values of CO2 was 0.2? and 0.3?, respectively. The mid-term precision for d13C and d15N values of CH4 and N2O working gas standards was 0.4? and 0.3?, respectively. Injection quantities of working gas standards indicated a relative standard deviation of 1%, 5% and 5% for CO2, CH4 and N2O, respectively. Measurements of atmospheric air samples demonstrated a standard deviation of 0.3? and 0.4? for the d13C and d18O values, respectively, of CO2, 0.5? for the d13C value of CH4 and 0.3?for the d15N value of N2O. Conclusions: Results from internal calibration and field sample analysis, as well as comparisons with similar measurement techniques, suggest that the method is applicable for the stable isotope analysis of these three important GHGs. In contrast to previously reported findings, the presented method enables successive analysis of all three GHGs from a single ambient atmospheric gas sample. [ABSTRACT FROM AUTHOR]

Rationale: The stable HCNOS isotope compositions can be reported as (a) the isotope ratio of two stable isotopes (R); (b) the isotope delta value (δ); and (c) the atom fraction of the isotopes (x). Recalculations between these different expressions are needed frequently and require the use of the absolute isotope ratio for the zero points of the stable isotope delta scales (Rstd). The inconsistent use of Rstd values may lead to a discrepancy in recalculated results. Methods: We summarised the recalculation procedures between different expressions of the stable isotope compositions and introduced a user-friendly EasyIsoCalculator that allows the recalculation between the main expressions of isotope compositions. We mathematically and empirically evaluated the possible inconsistencies in reporting of the stable isotope data due to the use of different Rstd and different normalisation methods. Results: The recalculation between δ-values and other expressions of the stable isotope compositions always involves the use of Rstd. The choice of Rstd will have a significant influence on the recalculated values. The use of different Rstd values has a significant influence also on the normalisation of raw values but only when the normalisation is conducted versus the working standard gas value, causing discrepancy, e.g. for δ( 13C/12C) up to ~ 0.3 ‰. Conclusions: Differences in the selection of Rstd value may lead to significant differences among different laboratories. The uncertainty in the calculations originates primarily from the uncertainty in the Rstd determination; however, it is lower than the discrepancy arising from the inconsistent use of Rstd. Consistent use of the same Rstd values is required to eliminate the unnecessary discrepancy if different data sets are recalculated from delta value to other expressions. [ABSTRACT FROM AUTHOR]

Rationale: The isotope delta is calculated from the isotope ratio of a sample and the absolute isotope ratio of the zero reference point defining each stable isotope international scale (Rstd). Therefore, Rstd requires accurate determination. However, the literature contains a large number of Rstd values, and selection of different Rstd may lead to inconsistency in reporting and recalculating stable isotope results. Methods: We reviewed Rstd used in the proprietary software provided by the manufacturers of stable isotope instruments commonly employed for analyses of stable HCNOS compositions. We compared the Rstd values and assessed the potential implications of using different Rstd and the normalization versus tank working gas standard for consistency in reporting stable isotope results. Results: Different Rstd values are used by different manufacturers of stable isotope analytical instruments. For R(2H/1H)VSMOW two different but very similar values are used, 0.00015575 and 0.00015576; for R(13C/12C)VPDB three different values are used, 0.0111802, 0.0112372 and 0.01118028; and for R(15N/14N)Air‐N2 two values, 0.0036782 and 0.0036765, are used. All manufacturers are using the same value for R(18O/16O)VSMOW, 0.00200520, but three different values for R(18O/16O)VPDB, 0.002067200, 0.00208835 and 0.002088349. For R(34S/32S)VCDT four different Rstd are used, 0.0441509, 0.0441626, 0.044162589 and 0.0441520597. Conclusions: The use of different Rstd values may lead to differences in the isotope delta values obtained if the normalization versus working standard gas is applied. For the range of Rstd used in proprietary software, the potential differences are lowest for oxygen (< 0.002 ‰) and nitrogen (< 0.001 ‰), and highest for carbon (0.107 to 0.112 ‰) and sulfur (0.023 ‰). Evaluation of the existing Rstd values and recommendations for the best estimates are highly desirable to ensure worldwide consistency in stable isotope data reporting. [ABSTRACT FROM AUTHOR]

Rationale: Oxygen isotopic ratios of silicates are excellent tools to reconstruct paleotemperature and isotopic composition of the precipitating fluid. However, the measurement of 17O/16O is difficult due to the low abundance of 17O. The present study reports a simplified high‐precision analytical technique for measuring the two oxygen isotope ratios, 17O/16O and 18O/16O, in silicates. Methods: Silicate samples were ablated by a CO2 laser in a BrF5 environment. The released oxygen (O2) was then cryogenically trapped in a molecular sieve zeolite (MSZ). Associated contaminants such as BrF5, F2, NF3 etc. were cleaned by passing the gas through a NaCl trap followed by a cooled (−25°C) MSZ‐packed U‐tube trap. The purified O2 was analysed in a MAT 253 isotope ratio mass spectrometer for oxygen isotope ratios. Results: The δδ17O and δ18O values of the working gas were calibrated by NBS‐28 and crosschecked by inter‐laboratory references UWG‐2, SCO and IMAU‐O2. The average analytical precisions (using aliquots of NBS‐28, UWG‐2, SCO, and laboratory internal standards IIT‐KGP‐SQ quartz and IIT‐KGP‐NQ quartz) of the δ17O, δ18O and ∆′17O values were 0.04‰, 0.08‰ and 4 per meg, respectively. Conclusions: A new cryogenic cleaning technique was developed that does not require GC but efficiently removes NF3‐contaminants from oxygen gas produced by laser fluorination of silicates. The technique is simple, quick and cost‐effective and provides highly precise and accurate δ17O, δ18O and ∆′17O values. [ABSTRACT FROM AUTHOR]

In physics‐based liquid simulation for graphics applications, pressure projection consumes a significant amount of computational time and is frequently the bottleneck of the computational efficiency. How to rapidly apply the pressure projection and at the same time how to accurately capture the liquid geometry are always among the most popular topics in the current research trend in liquid simulations. In this paper, we incorporate an artificial neural network into the simulation pipeline for handling the tricky projection step for liquid animation. Compared with the previous neural‐network‐based works for gas flows, this paper advocates new advances in the composition of representative features as well as the loss functions in order to facilitate fluid simulation with free‐surface boundary. Specifically, we choose both the velocity and the level‐set function as the additional representation of the fluid states, which allows not only the motion but also the boundary position to be considered in the neural network solver. Meanwhile, we use the divergence error in the loss function to further emulate the lifelike behaviours of liquid. With these arrangements, our method could greatly accelerate the pressure projection step in liquid simulation, while maintaining fairly convincing visual results. Additionally, our neutral network performs well when being applied to new scene synthesis even with varied boundaries or scales. [ABSTRACT FROM AUTHOR]

Atomic energy commission of syria (AECS) PF‐1, 2 devices were operated in N2 and Ar gases at pressures varied between 0.1–1 mbar and applied voltage of 15 kV on the capacitors bank with capacitance of 25 μF. The voltage, current, and current derivative curves were digitally recorded by Ohmic voltage divider and two Rogowskii coils; one with a big number of turns for current and the other one with a low number of turns for the current derivative. Also, the current curve for the discharge as LCR circuit was recorded to calibrate the current measurement. By integrating the current derivative in time and using the curve of calibrated current, the current curve free of noise has been established. By inserting the geometrical and electrical parameters of two AECS PF‐1, 2 devices, the working gas pressure and the kind of the gas into six phase model which describes the instability in the plasma, and adding the anomalous resistance as a term in the current and voltage equations in the model; the computed curves for voltage and current were found and compared with the obtained experimental curves at the same conditions taking into account the readjustment of model parameters fm, fc, fmr, and fcr until getting a good fitting between the measured and computed currents. This fitting has proved the validity of six phase Lee model and its ability to give a description of plasma focus in the radial phase stage (which consists now of four subradial phases: radial inward shock, radial reflected shock, the pinch phase, and after that the instability phase), which is followed by the expanded phase of plasma focus. In parallel to our work, similar efforts were made on the INTI PF device in Ne; the validity of six phase Lee model was proved by getting a proper fitting between the measured and computed currents under the operational conditions. Moreover, the equivalent resistances and time scales of the anomalous resistance phases were obtained by this method; also, the ratios for PF device classification into two types according to the static inductance of the PF system were determined for N2 and Ar as working gases in AECS‐PF1, 2. [ABSTRACT FROM AUTHOR]

The permeability damage of high‐rank coal reservoirs is the main factor affecting the development of coalbed methane (CBM) in the late production stage. Coal core samples from southern Qinshui Basin were saturated with actual formation water, 1/2 salinity formation water, and distilled water to study the swelling of clay minerals. Then, the mechanism of permeability change caused by water sensitivity and its effect on gas production was discussed. The results show that the permeability decrease caused by flow velocity sensitivity did not occur during the water sensitivity experiments. The permeability damage caused by water sensitivity is mainly the static damage from swelling of clay minerals, especially illite/smectite mixed clays and chlorite. During the process of CBM development, the water sensitivity of coal reservoirs will lead to the sharp increase of Na+ concentration and a decrease of Mg2+ concentration in the produced water. Meanwhile, the clay minerals swell due to the adsorption of more Mg2+ and Ca2+, decreasing the reservoir permeability and gas production rate. Water sensitivity experiments on coals collected from Southern Qinshui Basin were conducted and its impact on the productivity of CBM wells was evaluated. Source of CBM well output water and change of water IC were discussed. Mechanism of coal permeability change caused by the water sensitivity was revealed. [ABSTRACT FROM AUTHOR]

Abstract: Rh‐based materials have emerged as potential candidates for hydrogen revolution from electrolyzing water or ammonia borane (AB) hydrolysis. Nevertheless, most of the catalysts still suffer from the complex synthetic procedures combined with limited catalytic activity. Additionally, the facile syntheses of Rh catalysts with high efficiencies for both electrochemical water splitting and AB hydrolysis are still challenging. Herein, we develop a simple, green, and mass‐producible ion‐adsorption strategy to produce a Rh/C pre‐catalyst (pre‐Rh/C). The ultrafine and clean Rh nanoclusters immobilized on carbon are achieved via the in situ reduction of the pre‐Rh/C during the hydrogen‐evolution process. The resulting in situ Rh/C catalyst presents an outstanding electrocatalytic performance with low overpotentials of 8 and 30 mV at 10 mA cm−2 in 1.0  m KOH and 0.5  m H2SO4, respectively, outperforming the state‐of‐the‐art Pt catalysts. Furthermore, the in situ Rh/C is also highly active for AB hydrolysis to produce hydrogen with a high turnover frequency of 1246 mol H 2  molRh−1 min−1 at 25 °C. The in situ‐formed ultrafine Rh nanoclusters are responsible for the observed superior catalytic performance. This facile in situ strategy to realize a highly active catalyst shows promise for practical applications. [ABSTRACT FROM AUTHOR]

DEM/CFD allows to track individual particles and their interactions with other particles, surrounding walls, and the gas phase in-between the particles. The contributions do not claim to cover all relevant aspects needed for DEM/CFD simulations of reactive particle-gas systems but can be seen as a first overview and starting point for interested readers. Thermal and chemical treatment of bulk solids and particle systems is a basic unit operation in many industrial sectors. [Extracted from the article]

As the demand for and production of biodiesel increase exponentially, the utilization of the biodiesel byproducts will be of increasing commercial significance. The autothermal reforming (ATR) of biodiesel byproducts into synthesis gas (syngas) was experimentally studied by using the BASF Pt and Rh/Pt (rhodium/platinum) dual-layer monolith catalyst. A total gaseous carbon yield as high as 98 % was obtained with near-equilibrium concentrations of H2, CO, CO2, and CH4. The optimum operating conditions to produce high yields of syngas with minimal coke formation were also determined to be at atmospheric pressure, a temperature of 750 °C, a steam/carbon (S/C) molar ratio of 3, and an O2/C molar ratio of 0.1. The Aspen simulation software package was used to calculate the equilibrium product composition for autothermal reforming of biodiesel byproducts on molecular basis. A comparison between the equilibrium and experimental data was made, and the agreement was generally good, indicating that close-to-equilibrium conditions were attained for the selected reaction conditions. [ABSTRACT FROM AUTHOR]

The viscosities of 45 coal ash slag samples at high temperature have been measured under different temperatures and shear rates. The computer thermodynamic software package FactSage has been used to predict liquidus temperatures, volume fractions of crystallized solid particles (ϕ), and the compositions of remaining liquid phase for 45 coal ash slag samples. The flow properties of completely liquid and partly crystallized coal ash slag samples have been predicted by three viscosity models. The Urbain formalism has been modified to describe the viscosities of fully liquid slag and homogeneous remaining liquid phase in coal ash slag samples. The modified Einstein equation and Einstein-Roscoe equation have been used to describe the viscosities of heterogeneous coal ash slag samples of ϕ < 10.00 vol % and ϕ ≥ 10.00 vol %, respectively. These three models provided a good description of the experimental data of fully liquid and heterogeneous coal ash slag samples. The new models also predicted flow properties of mixtures of coal ash slags with CaO, FeO, MgO, SiO, and AlO. © 2010 American Institute of Chemical Engineers AIChE J, 2011 [ABSTRACT FROM AUTHOR]

Discusses the operation of a novel hybrid scrubber for particulate control efficiency. Design of the experimental setup; Effect of inlet fly-ash loading and gas flow rate; Effect of liquid to gas flow rate ratio.

Focuses on the impact of liquefied natural gas imports on gasoline prices in North America. Effects of the insertion of incremental regasification facility on natural gas prices; Factors that will determine the difference of price depression at various terminal locations around the region; Determination of resulting natural gas prices at the point of importation.

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]

This study was designed to assess the availability of polycyclic aromatic hydrocarbons (PAHs) present at a gasworks site to different soil remediation techniques. The study examined the effect on PAH availability of using different organic solvents, the degree of pretreatment, and the extraction time. In total, 25 PAHs (with two to six fused rings) and five carbonyl derivatives were measured. The results indicated that the PAHs and their derivatives were bound loosely to the surface of the studied soil and that there were no significant kinetic boundaries associated with the extraction of the PAHs. Furthermore, it was concluded that the studied soil was not suitable for bioremediation, as the concentration of PAHs with low molecular weight were limited. However, pressurized liquid extraction (PLE) with methanol as the solvent extracted 97% of all PAHs and PAH-derivatives, indicating that extraction may be effective as part of a soil remediation technique for old gasworks soils. [ABSTRACT FROM AUTHOR]

Investigates a basic purge model that is applicable over a wide range of vessel purge or gas sweep operations for batch and continuous chemical processes. Significance of the model in accessing the environmental impact for chemical manufacturing processes; Modeling guidelines for the purge or gas sweep operations; Solvent mixtures and components used in estimating the saturation level for each volatile component.

This paper investigates the long‐term behavior of porous media contaminated by nonvolatile organic compounds (NVOC) in terms of specific interfacial surface area. Specifically, a natural sand, Moffett sand (MS), was contaminated with naphthalene and the surface area was measured repeatedly over time using nitrogen adsorption–desorption techniques. A field‐contaminated sand affected by lampblack material (LB) from former manufactured gas plant operations was also studied. Lampblack is a carbonaceous skeleton containing polycyclic aromatic hydrocarbons (PAHs) and other hydrocarbons. It is hypothesized that soils contaminated by these types of chemicals will exhibit significantly less surface area than their clean counterparts. The surface areas for the contaminated MS samples increased toward their clean‐MS values during the 700‐h aging period, but achieved the clean values only after pentane extraction or heating at 60°C. Heating at 50°C failed to achieve a similar recovery of the clean‐MS surface area value. Nonspecific mass loss tracked the increase in surface area as indirect evidence that naphthalene loss was the cause of the surface area increase. For the LB samples, aging at 100°C produced a slight decrease in surface area and mass while aging at 250°C caused the surface area to increase roughly threefold while the mass decreased by approximately 1%. These results suggest that, under moderate heating and over the time scale of this investigation, there is a redistribution of the complex contaminant mixture on the solid matrix. Greater temperatures remove mass more efficiently and therefore exhibited the surface area increase expected in this experiment. [ABSTRACT FROM AUTHOR]

The article reports on an increasing demand for coal gasification. There have been a series of announcements from Asia, North America and Europe on coal-to-liquid (CTL) schemes but China is considered as the most ardent about the potential of CTL. According to British Petroleum, there are enough coal reserves in the world to last for 164 years compared to 40.5 years for oil and 68 years for natural gas. Such advantage that coal gasification can deliver is that it will lessen the dependence on oil and gas for electricity and liquid fuels.

The article discusses the supply of African gas to Europe via pipelines from Algeria and Libya. The creation of a global gas market through the development of the liquefied natural gas (LNG) technology and shipping in the past 15 years has opened up the possibility of north American and Asian countries getting gas from Nigeria, Egypt and Algeria. It is the author's view that the price of gas being imported from Africa will increase as a result of the tightening demand from the international gas markets to be used for power generation and industrial raw materials in emerging market soars.