Solid-phase Products Research Articles

Theoretical and experimental studies on the thermal decomposition of 1-butyl-3-methylimidazolium dibutyl phosphate

Ionic liquid, an organic molten salt, has efficient flame-retardant performance. Few researchers have attempted to study its flame-retardant mechanism. Moreover, thermal stability and pyrolysis products have a great impact on the flame retardancy. Therefore, this paper focused on the phosphate ionic liquid of 1-butyl-3-methylimidazolium dibutyl phosphate ([Bmim][DBP]) and analyzed its thermal decomposition products and characteristics. The major bond energies of [Bmim][DBP] were calculated using B3LYP/6–311++G(d,p)//M06–2X/6–311++G(d,p) level. The experimental results show that the pyrolysis products were as followed: alkane or alkene with a carbon chain length of 1–4; imidazole and its derivatives; esters. Furthermore, Gas chromatography-mass spectrometer and Fourier transform infrared spectrometer were utilized to measure the gaseous products and solid phase products of [Bmim][DBP], which were obtained during thermogravimetric analysis. The results of theoretical and experimental analysis were highly consistent. Finally, the possible flame-retardant mechanism of [Bmim][DBP] was proposed.

Influence of parameters of delayed asphalt coking process on yield and quality of liquid and solid-phase products

Paper studies the effect of excess pressure during delayed coking of asphalt, obtained by propane deasphaltization of tar, on yield and physical and chemical properties of hydrocarbon fuels' components and solid-phase product – petroleum coke. Asphalt was coked at a temperature of 500 °C and excess pressure of 0.15-0.35 MPa in a laboratory unit for delayed coking of periodic action. Physical and chemical properties of raw materials and components of light (gasoline), medium (light gasoil), and heavy (heavy gasoil) distillates obtained during experimental study were determined: density, viscosity, coking ability, sulfur content, iodine number, pour points, flash points, fluidity loss and fractional composition. Quantitative group hydrocarbon and microelement compositions and properties of obtained samples of petroleum coke (humidity, ash content, volatiles' yield, sulfur content, etc.) were also studied. Comparative assessment of their quality is given in accordance with requirements of GOST 22898-78 “Low-sulfur petroleum coke. Specifications”. In addition, patterns of changes in excess coking pressure on yield and quality indicators of distillate products and petroleum coke were revealed. With an increase in excess pressure of coking process from 0.15 to 0.35 MPa, content of paraffin-naphthenic hydrocarbons in light and heavy gasoils of delayed coking decreases. Common pattern in asphalt coking is an increase in yield of coke and hydrocarbon gas with an increase in excess pressure from 0.15 to 0.35 MPa.

Modeling and Optimization of Antibody-drug Conjugate Production Using Process Intensified Solid-phase Method

Conventional solution-phase method currently employed for the production of Antibody-drug Conjugates (ADC) has certain drawbacks, which makes production inefficient and cost extensive process. In this study, we developed a rigorous cost model for an intensified solid-phase production method utilizing a packed bed resin column to carry out all the steps involved in the production of ADC, at an industrial scale. The aim of this study was to find a suitable operating region (column length and feed velocity) to minimize the cost of ADC production. Simulation results showed that productivity was maximum when the process was operated at a linear velocity ranging between 120-140 cm/hr and unit cost of ADC production was minimum when column length was 60 cm and operated at 100 cm/hr. We found that production cost is highly dependent on monoclonal antibody (mAb) cost, followed by cytotoxic drug as being the second-highest contributor to the overall production cost.

Investigation of obtaining low-sulfur coke from heavy oil residues in the presence of a recycling agent

The current state of the oil refining industry requires obtaining high-quality products that meet environmental requirements. An important issue is the deep processing of oil, as well as the use of oil waste as a raw material. The paper is devoted to study of the influence of various technological parameters during delayed coking of tar on the yield and physicochemical properties of hydrocarbon fuel components and solid-phase product - petroleum coke. As raw materials tar obtained from the Kumkol deposit (Kazakhstan) was applied. Heavy oil residues were coked at a temperature of 510 °C and an overpressure of 0.5 MPa in a laboratory coking unit. It was found that the group hydrocarbon composition of gasoline fraction is consisting mainly from isoparaffin (22.04%) and naphtenic compounds (22.15%), kerosene fraction from paraffin (19.42%) and isoparaffin (25.79%) and diesel fraction composition comprise paraffin (26.04). Raman scattering at 1165 cm−1 belong to CC aromatic and C = C region and indicates a high crystallinity of the coke structure. Coke is obtained with more developed specific surface 6.76 m2/g. The volume of the liquid product is 12.06 g (60.3%) and gas evolution amounted 5%.

Kinetics of Co-Mingled 99Tc and Cr Removal during Mineral Transformation of Ferrous Hydroxide

Four simulated waste streams relevant to the vitrification of Hanford nuclear waste were studied to evaluate the removal kinetics of technetium-99 (Tc) and co-mingled Cr(VI) during treatment with solid ferrous hydroxide (Fe(OH)2(s)). Simulants treated with Fe(OH)2(s) were reacted for 24 h and sub-sampled periodically to monitor Tc and Cr removal. Solution sample analysis during the reaction was coupled with solid phase characterization, for example, X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD), to establish influence of the solid phase product on Tc and Cr removal rates. Based on these results, the majority of Tc and Cr removal occurs within the first 5 min of simulant contact with Fe(OH)2(s). However, the order in which Tc and Cr are completely removed from each simulant depends on the simulant chemistry, the preferred reduction pathway, and the solid phase product, for example, magnetite (Fe3O4) versus goethite (α-FeOOH). Low pH and low Cr concentrations favor rapid Tc removal, with XRD and XAS confirming that Fe3O4 readily incorporates reduced Tc(IV) into its structure. High pH, high Cr concentrations, and the presence of other co-mingled constituents favor heterogeneous removal of Tc early in the reaction (<1 h) with removal rates often faster than those determined for Cr. At reaction times of >1 h, Tc removal slows as homogeneous removal of Cr begins to dominate, concurrent with an increase in the formation of FeOOH as the solid phase reaction product. These results suggest that for complex, high pH waste streams, Tc removal within the first hour after Fe(OH)2(s) treatment is necessary for complete Tc reduction and improved mineral immobilization.

Transformation of Meloxicam Containing Nanosuspension into Surfactant-Free Solid Compositions to Increase the Product Stability and Drug Bioavailability for Rapid Analgesia.

PurposeThe aim of this work was to study the influence of solidification of meloxicam (Mel) containing nanosuspension (nanoMel) on the physical stability and drug bioavailability of the products. The nanoMel sample had poly(vinyl alcohol) (PVA) as a protective polymer, but no surfactant as a further stabilizing agent because the final aim was to produce surfactant-free solid phase products as well.MethodsThe solidified samples produced by fluidization and lyophilization (fluidMel, lyoMel) were examined for particle size, crystallinity, and in vitro release of Mel compared to similar parameters of nanoMel. The products were subjected to an animal experiment using per oral administration to verify their bioavailability.ResultsMel containing (1%) nanoMel sample was produced by wet milling process using an optimized amount of PVA (0.5%) which resulted in 130 nm as mean particle size and a significant reduction in the degree of crystallinity (13.43%) of Mel. The fluidization technique using microcrystalline cellulose (MCC) as carrier resulted in a quick conversion and no significant change in the critical product parameters. The process of lyophilization required a longer operation time, which resulted in the amorphization of the crystalline carrier (trehalose) and the recrystallization of Mel increased its particle size and crystallinity. The fluidMel and lyoMel samples had nearly five-fold higher relative bioavailability than nanoMel application by oral administration. The correlation between in vitro and in vivo studies showed that the fixed Mel nanoparticles on the surface of solid carriers (MCC, trehalose) in both the artificial gastric juice and the stomach of the animals rapidly reached saturation concentration leading to faster dissolution and rapid absorption.ConclusionThe solidification of the nanosuspension not only increased the stability of the Mel nanoparticles but also allowed the preparation of surfactant-free compositions with excellent bioavailability which may be an important consideration for certain groups of patients to achieve rapid analgesia.

Hydrogen production in acoustoplasma discharge in a liquid-phase medium flow

In the paper, plasma discharge in a liquid flow at high pressure for use in producing hydrogen gas has been carried out. Methods and equipment for plasma discharge excitation in a liquid medium flow have been developed by the authors. The liquid flow has been directed at excess pressure to the hydrodynamic radiator located at the reactor inlet where an ultrasonic two-phase vapor-liquid flow has occurred at lower pressure due to the pressure difference and decrease in the flow enthalpy. Electric field which intensity exceeds the breakdown threshold of this two-phase medium is generated between electrodes located in the reactor by an external power supply, thus resulting in excitation of the low-temperature quasi-steady plasma glow discharge. Theoretical estimation of the parameters of such discharge has been carried out by the authors. It is shown in the paper that low temperature plasma initiated under the conditions of a liquid-phase medium flow in the discharge gap between electrodes could effectively split hydrogen-containing molecules of organic compounds in a liquid with formation of gaseous products having hydrogen content of more than 90%. In addition, theoretical calculations of the discharge voltage and current which are in good agreement with the experimental results have been carried out in the process simulation. With a mixture of oxygen-containing organic compounds as a raw material, the output capacity of the 50 mL reaction system used in experiments has been around 1.5 l of hydrogen per minute. Decomposition of those compounds in plasma may also result in formation of some solid-phase products, such as carbon nanoparticles and nanoparticles of the discharge electrode oxide materials.

Study of the Conversion of Carbon-containing and Organochlorine Impurities in the Process of Hydrogen Reduction of Silicon Tetrachloride by RF (40.68 MHz) Arc Discharge.

A contracted RF (40.68 MHz) arc discharge of atmospheric pressure, stabilized between two rod electrodes, was used to obtain trichlorosilane by the reaction of hydrogen reduction of silicon tetrachloride (SiCl4). In model mixtures of macro-composition in the ratio H2/SiCl4/CCl4=10/1/1, it was shown that C and SiC are the main solid-phase product which are deposited on the surface of electrodes in the form of dendrides. The temperature of the ends of the electrodes determined using emission thermometry is 1600 K. The thermodynamic analysis of H2+SiCl4+CCl4 system confirms that the formation of C and SiC occurs in the temperature range of 1600 K. The deposition of solid-phase products occurs on the electrodes in the zone of high electric field strength.

Conjugated Thermolysis of Metal-Containing Monomers: Toward Core–Shell Nanostructured Advanced Materials

A detailed analysis of recent advances in the use of metal-containing monomers as precursors for the preparation of core–shell nanostructured advanced materials by the method of conjugated thermolysis was carried out. This method consists in the simultaneous course of the processes of thermal polymerization of monomers and the formation of metal-containing nanoparticles during thermal transformation. The general scheme of conjugated thermolysis includes three successive stages: dehydration (desolvation), polymerization and thermolysis of the resulting metallopolymers. Particular attention was paid to the composition of solid-phase products of conjugated thermolysis. Kinetic schemes and reactions of thermal transformation of metal-containing monomers were analyzed. The use of the obtained nanocomposites as magnetic materials, sensors, catalysts and tribological materials was generalized. Problems and prospects of using conjugated thermolysis for the production of advanced nanomaterials were outlined.

Red gypsum utilization and acidic wastewater treatment based on metal self-enrichment process.

The massive accumulation of red gypsum has brought great harm to human and environment. In order to achieve low-cost and high-benefit resource utilization of red gypsum, a method of metal self-enrichment during the cycle and transformation of red gypsum was proposed. The carbon dioxide and ammonia water react with red gypsum to manufacture ammonium sulfate and solid phase products. And solid phase products neutralize pickling wastewater to produce metal-enriched red gypsum for the next cycle. After the cycle, solid phase product with one circulation (containing 39.45% Fe and 7.37% Ca) and two circulation (containing 45.79% Fe, 4.75% Ca) could be obtained, which can be used as the proportioning of metallurgical sinter. The self-enrichment process not only realizes the comprehensive utilization of red gypsum, but also solves the treatment of acidic wastewater.

Observation of diffusion behavior between Cr2O3 and calcium ferrite based on diffusion couple method at 1373 K

The existence of Cr2O3 has an effect on the quality of high-chromium vanadium-titanium magnetite sinter. In order to investigate the influence of Cr2O3 on the quality of sinter in the solid-phase reaction stage of sintering process, the solid-phase reactions of Cr2O3-calcium ferrite (CF) system at 1373 K in air at different times were studied by diffusion couple method. The change of diffusion interface and the migration of Ca, Cr and Fe were observed by emission scanning electron microscopy. The results show that in the process of diffusion, the diffusion thickness of Ca2+ in CF layer was 10.22 μm, and that of Ca2+ in Cr2O3-CF diffusion couple was 57.65 μm at 1373 K for 8 h. The relationship between the thickness of the product layer and time at 1373 K for 0 h–20 h was obtained. The diffusion of Ca2+ to the Cr2O3 layer is the driving force of the solid phase reaction, and the diffusion of Ca2+ in the ferrite layer is the limiting link of the solid phase reaction, the order of magnitude of diffusion coefficient of Cr2O3-CF diffusion couple was 10−11 cm2 s−1. Ca2+ in calcium ferrite is likely to combine with Cr3+ to form CaCr2O4. The production of calcium ferrite will be reduced when Cr2O3 is present in sintering material. Meanwhile, the solid phase product CaCr2O4 in the diffusion process has the properties of high melting point and difficult reduction. The shortage of liquid phase due to high melting point and the difficulty in reduction may affect the quality of sinter.

Chemical looping gasification of lignocellulosic biomass with iron-based oxygen carrier: Products distribution and kinetic analysis on gaseous products from cellulose

Product distribution and kinetics analysis of chemical looping gasification (CLG) of cellulose with Fe2O3 were investigated. Based on the thermodynamic simulation, the optimum vaporization temperature of the product H2 was 850 °C. The influence of reaction temperatures and oxygen carrier mixing ratios on product distribution were explored via tube furnace reactor combined with on-line mass spectrometry. When the Fe2O3 mixing ratio was 10%, the gas phase product content was the highest, which may be caused by the incomplete oxidation transition to complete oxidation. Kinetic parameters such as the activation energy of the gas phase product were obtained by an isoconversion method. The CLG process could reduce the activation energy of gaseous products of CO2, CH4, and H2, and the activation energy of CO2 (79.21 kJ/mol) was the highest. Characterization of solid phase products analyzes using SEM. The solid phase product content decreases slightly with increasing temperature because of the higher carbon conversion at elevated temperatures. As the Fe2O3 blending ratio increased, the surface morphology of CE changed from bulk to relatively loose structure, and the particles also aggregate, which may be beneficial to the reaction. This paper provides a reference for clarifying the thermodynamics and kinetics of chemical looping gasification of biomass organic components.

The Titan haze simulation experiment: Investigating Titan’s low-temperature atmospheric chemistry in a pulsed plasma jet expansion

AbstractThe Titan Haze Simulation (THS) experiment is a unique experimental platform that allows to simulate Titan’s complex atmospheric chemistry at low Titan-like temperature by generating a plasma discharge in the stream of a plasma jet expansion. Both gas and solid phase products are generated and can be analyzed using different in-situ and ex-situ diagnostics. Here, we present an overall description of the work accomplished with the THS in the last 10 years, our current research efforts, and the important implications for the analysis of Cassini’s returned data and preparation for future Titan missions.

SYNTHESIS OF HYDROGEN IN ACOUSTOPLASMA DISCHARGE IN A LIQUID-PHASE STREAM

In this paper, the plasma discharge in a high-pressure fluid stream in order to produce gaseous hydrogen was studied. Methods and equipment have been developed for the excitation of a plasma discharge in a stream of liquid medium. The fluid flow under excessive pressure is directed to a hydrodynamic emitter located at the reactor inlet where a supersonic two-phase vapor-liquid flow under reduced pressure is formed in the liquid due to the pressure drop and decrease in the flow enthalpy. Electrodes are located in the reactor where an electric field is created using an external power source (the strength of the field exceeds the breakdown threshold of this two-phase medium) leading to theinitiation of a low-temperature glow quasi-stationary plasma discharge.A theoretical estimation of the parameters of this type of discharge has been carried out. It is shown that the lowtemperature plasma initiated under the flow conditions of a liquid-phase medium in the discharge gap between the electrodes can effectively decompose the hydrogen-containing molecules of organic compounds in a liquid with the formation of gaseous products where the content of hydrogen is more than 90%. In the process simulation, theoretical calculations of the voltage and discharge current were also made which are in good agreement with the experimental data. The reaction unit used in the experiments was of a volume of 50 ml and reaction capacity appeared to be about 1.5 liters of hydrogen per minute when using a mixture of oxygen-containing organic compounds as a raw material. During their decomposition in plasma, solid-phase products are also formed in insignificant amounts: carbon nanoparticles and oxide nanoparticles of discharge electrode materials.

An automated platform for the enzyme-mediated assembly of complex oligosaccharides.

An automated platform that can synthesize a wide range of complex carbohydrates will greatly increase their accessibility and should facilitate progress in glycoscience. Here we report a fully automated process for enzyme-mediated oligosaccharide synthesis that can give easy access to different classes of complex glycans including poly-N-acetyllactosamine derivatives, human milk oligosaccharides, gangliosides and N-glycans. Our automated platform uses a catch and release approach in which glycosyltransferase-catalyzed reactions are performed in solution and product purification is accomplished by solid phase extraction. We developed a sulfonate tag that can easily be installed and enables highly efficient solid phase extraction and product release using a single set of washing conditions regardless of the complexity of the glycan. Using this custom-built synthesizer, as many as 15 reaction cycles can be performed in an automated fashion without a need for lyophilization or buffer exchange steps.

Functionalising lignin in crude glycerol to prepare polyols and polyurethane

In this work, crude glycerol liquefaction of lignins produced in the pulp and paper industry, as well as an organosolv lignin (sugarcane bagasse), was studied with the ultimate aim of preparing bio-based polyols for polyurethane (PU) preparation. This is a proposed strategy to valorise the by-products of biodiesel and lignocellulose biorefineries. Size-exclusion chromatography revealed that the lignins behave differently during liquefaction based on a ranging product molecular weight (MW). The MW of the liquefaction products was concluded to be related to the phenolic and aliphatic hydroxyl group content of the respective lignins, as well as the removal of glycerol and monoacylglycerol during liquefaction. Lignin was modified to yield mostly a solid-phase product. Fourier transform infrared spectroscopy suggests that crude glycerol constituents like glycerol and fatty acid esters are bound to lignin during liquefaction through formation of ether and ester bonds. Liquefaction yield further also varied with lignin type. The liquefaction products were effectively employed as bio-based polyols to prepare PU.

Moving Brick Receiver–Reactor: A Solar Thermochemical Reactor and Process Design With a Solid–Solid Heat Exchanger and On-Demand Production of Hydrogen and/or Carbon Monoxide

Three crucial aspects still to be overcome to achieve commercial competitiveness of the solar thermochemical production of hydrogen and carbon monoxide are recuperating the heat from the solid phase, achieving continuous or on-demand production beyond the hours of sunshine, and scaling to commercial plant sizes. To tackle all three aspects, we propose a moving brick receiver–reactor (MBR2) design with a solid–solid heat exchanger. The MBR2 consists of porous bricks that are reversibly mounted on a high temperature transport mechanism, a receiver–reactor where the bricks are reduced by passing through the concentrated solar radiation, a solid–solid heat exchanger under partial vacuum in which the reduced bricks transfer heat to the oxidized bricks, a first storage for the reduced bricks, an oxidation reactor, and a second storage for the oxidized bricks. The bricks may be made of any nonvolatile redox material suitable for a thermochemical two-step (TS) water splitting (WS) or carbon dioxide splitting (CDS) cycle. A first thermodynamic analysis shows that the MBR2 may be able to achieve solar-to-chemical conversion efficiencies of approximately 0.25. Additionally, we identify the desired operating conditions and show that the heat exchanger efficiency has to be higher than the fraction of recombination in order to increase the conversion efficiency.

From the Notion of Elementary Soil Particle to the Particle-Size and Microaggregate-Size Distribution Analyses: A Review

A review of approaches to particle-size and microaggregate-size distribution analyses applied in soil science is given. The concepts of the structural organization of soils, primary soil particles, elementary soil particles, and soil microaggregates are considered. Methodological problems, such as the preparation of soil samples for the analyses and interpretation and comparison of the results obtained by different methods, are discussed. The authors suggest the theoretical substantiation of differences between the notions of primary soil particles (soil building units) and elementary soil particles. Primary soil particles are individual mineral particles. Elementary soil particles are solid-phase products of pedogenesis represented by fragments of rocks and minerals and by organomineral and organic particles, all the components of which participate in chemical and physicochemical interactions. Special attention is paid to the existing classifications of soils according to their textures. It is suggested that the upper boundary of the clay fraction in the Russian classification should be shifted from 1 to 2 µm.

Influence of Polyepoxysuccinic Acid on Solid Phase Products in Portland Cement Pastes

The influence of polyepoxysuccinic acid(PESA) on the solid phase products in hydrated Portland cement pastes was investigated by isothermal calorimetry, X-ray diffraction(XRD), 29Si and 27Al nuclear magnetic resonance(NMR). The results indicated that PESA bonds Ca2+ ions in pore solution to prevent portlandite formation, and also combines with Ca2+ ions on the surface of silicate minerals to prolong the control time of phase boundary reaction process, leading to the retardation of silicate mineral hydration. Meanwhile, the interlayer Ca2+ ions in Jennite-like structure bridging PESA and C-S-H gels prevent silicate tetrahedron and aluminum tetrahedron from occupying the sites of bridging silicate tetrahedron, which causes the main existence of dimer in C-S-H structure, deceases the degree of Al3+ substituting for Si4+ and promotes the transformation from 4-coordination aluminum to 6-coordination aluminum. Furthermore, the -Ca+ chelating group from reacting PESA with Ca2+ ions combines easily with SO42- ions, resulting in transformation from ettringite, AFm to TAH(Third aluminum hydrate). However, with the higher addition of PESA, it will bridge the excess PESA by Ca2+ ions to form a new chelate with ladder-shaped double chains structure, which not only reduces the amount of PESA bonding Ca2+ ions, but also decreases its solidifying capability for SO42- ions, leading to the transformation from TAH to AFm or ettringite. Meanwhile, at later hydration, the inhibition effect of PESA on cement hydration is weakened, and the transformation degree from TAH to AFm is higher than that to AFt with the addition of PESA.

Adsorption-pyrolysis technology for recovering heavy metals in solution using contaminated biomass phytoremediation

Feasibility of adsorption-pyrolysis technology to recover metals from solution using contaminated biomass phytoremediation was discussed. The technology can meet three objectives: the disposal of metals-contaminated biomass from phytoremediation, the adsorption of metals from wastewater and the reuse of metals-saturated biomass. In this study, the recovery of Cd and Cu in metals-containing solution from contaminated biomass of phytoremediation was achieved through adsorption and pyrolysis technology. The results showed that pH value of the metals-containing solution and the pyrolysis temperature for metals concentration are the key factors of the novel technology. When the pH of the metals-containing solution was 6, the content of Cd and Cu in the saturated biomass after approximately 30min adsorption was 2.7wt% and 1.25wt%. Next, the saturated biomass is pyrolyzed at 450°C, and the final content of Cd and Cu in the solid phase product was 7.13wt% and 6.58wt%, respectively. The concentration of metals from the adsorption-pyrolysis process for bio-ore was primarily due to the redox reaction of Cd and Cu salts and the volatilizing properties of elements. The results suggested that the adsorption-pyrolysis technology is feasible for recovery of Cd and Cu in solution.