Wet Residue Research Articles

Phase equilibria for the pseudo-ternary system (NaCl + Na 2 SO 4 + H 2 O) of coal gasification wastewater at T = (268.15 to 373.15) K

Abstract The pseudo-ternary system (NaCl + Na2SO4 + H2O) of coal gasification wastewater was studied at T = (268.15 to 373.15) K. The solubility and density of the equilibrium liquid phase were determined by the isothermal solution saturation method. The equilibrium solids were also investigated by the Schreinemaker's method of wet residues and X-ray powder diffraction (XRD). According to the experimental data, the phase diagrams were determined. It was found that there was no significant solubility difference on the NaCl-rich side between the ternary system (NaCl + Na2SO4 + H2O) in coal gasification wastewater and in pure water. However, the solubility on the Na2SO4-rich side of coal gasification wastewater was apparently higher than that of pure water. The increase in the solubility of Na2SO4 was most likely caused by the effects of other impurities apart from NaCl and Na2SO4 in coal gasification wastewater. The measured data and phase equilibrium diagrams can provide fundamental basis for salt recovery in coal gasification wastewater.

Measurements of temperature and gas composition within the burning bed of wet woody residues in a 4 MW moving grate boiler

Moving grate firing systems are widely used for biomass combustion. The characteristics of the fuel bed combustion in moving grate boilers are of practical interest as they are directly related to the release of pollutants and affect the furnace efficiency. Measurements of temperature and gas species concentrations inside the fuel bed are necessary to improve our understanding of the highly complex processes involved in biomass combustion. There have been few experimental studies of the fuel bed of industrial scale grate furnaces. The present study measured temperature and gas species concentrations within a thick burning bed of wet woody biomass, in a 4MW reciprocating grate boiler. Measurements were carried out under three different operating conditions through ports located in the wall of the furnace using a stainless steel probe incorporating a thermocouple. Temperatures of about 1000°C were measured close to the grate, indicating intense combustion at the bottom of the fuel bed. The temperature distribution along the bed height showed that different stages of the combustion process take place in horizontally adjacent layers along the grate. Higher flow rates of the primary air resulted in relatively higher CO and lower CO2 and NO concentrations in the fuel bed.

A Sodium Chloride–Zinc Chloride–Water System: Solubility of Solids and Density of Liquid in Wide Range of Temperatures

The equilibrium phase diagrams of NaCl–ZnCl2–H2O system at 260.35 and 250.15 K were studied by method of isothermal solution saturation, wet residues, and thermogravimetric analysis. Water content in precipitate at these temperatures for hydrate 2NaCl·ZnCl2·nH2O was determined, n = 3. Densities of ternary NaCl–ZnCl2–H2O solutions were measured at 288.15–321.35 K and compared with values predicting by the Laliberte model. It was shown that the model provides mainly underestimated density values.

Determination and modeling of binary and ternary solid-liquid phase equilibrium for the systems formed by 1,8-dinitronaphthalene and 1,5-dinitronaphthalene and N-methyl-2-pyrrolidone

The solubility of 1,8-dinitronaphthalene and 1,5-dinitronaphthalene in N-methyl-2-pyrrolidone at (293.15–343.15)K and the mutual solubility of the ternary 1,5-dinitronaphthalene+1,8-dinitronaphthalene+N-methyl-2-pyrrolidone mixture at (313.15, 328.15 and 343.15)K were determined experimentally using the isothermal saturation method under atmospheric pressure (101.2kPa). The solubility of 1,8-dinitronaphthalene in N-methyl-2-pyrrolidone is larger than that of 1,5-dinitronaphthalene. Three isothermal ternary phase diagrams were built according to the measured mutual solubility data. In each ternary phase diagram, there were one co-saturated point, two boundary curves, and three crystalline regions. Two pure solids (pure 1,8-dinitronaphthalene and pure 1,5-dinitronaphthalene) were formed in the ternary system at a given temperature, which were identified by Schreinemaker’s method of wet residue and powder X-ray diffraction (PXRD) pattern. The crystallization region of 1,8-dinitronaphthalene was smaller than that of 1,5-dinitronaphthalene at each temperature. The modified Apelblat equation, λh equation, NRTL model and Wilson model were used to correlate the solubility of 1,8-dinitronaphthalene and 1,5-dinitronaphthalene in N-methyl-2-pyrrolidone; and the NRTL and Wilson models were employed to correlate and calculate the mutual solubility for the ternary 1,5-dinitronaphthalene+1,8-dinitronaphthalene+N-methyl-2-pyrrolidone system. The largest value of root-mean-square deviation (RMSD) was 20.34×10−4 for the binary systems; and 7.38×10−3 for ternary system. The calculated results via these models are all acceptable for the binary and ternary solid-liquid phase equilibrium.

Solid-liquid equilibrium and phase diagram for the ternary (2-naphthaldehyde + o-phthalic anhydride + 1,4-dioxane) system

In this research, solid-liquid equilibrium for the ternary system (2-naphthaldehyde+o-phthalic anhydride+1,4-dioxane) was measured at 283.15K, 293.15K and 303.15K, respectively. Three isothermal phase diagrams of the system were plotted using the values of the experimental solubility. Pure 2-naphthaldehyde and o-phthalic anhydride were formed at (283.15, 293.15 and 303.15)K, and were determined by Schreinemaker’s wet residue method. The crystallization region of o-phthalic anhydride was found to be much larger than that of 2-naphthaldehyde at a certain temperature. The experimental solubility at multiple temperatures was correlated by the NRTL and Wilson models. The NRTL model was more accurate than the Wilson model in this system. The diagram of density versus component was also constructed.

Phase Equilibrium for the Ternary Systems (KCl + K2SO4 + H2O) and (KH2PO4 + K2SO4 + H2O) at 288.15 K and Atmospheric Pressure

The phase equilibrium of (KCl + K2SO4 + H2O) and (KH2PO4 + K2SO4 + H2O) at 288.15 K is studied by isothermal solution saturation method and wet residues. The equilibrium solid phases are analyzed by the Schreinemaker’s method of wet residues and verified by X-ray diffraction (XRD). On the basis of the experimental data, the diagram of density versus composition and the phase diagram are plotted. The crystallization regions are determined. In the two systems, KCl and KH2PO4 have a strong salting-out effect on K2SO4, and the salting-out effect of KCl on K2SO4 is stronger than that of KH2PO4 on K2SO4. There are in all two crystalline regions, two univariant curves, and one invariant point. The crystalline region of K2SO4 is the largest, whereas that of KCl is the smallest. All results can offer fundamental data support for optimizing processes and further theoretical studies.

Determination and Correlation of Solid–Liquid Phase Equilibrium and Phase Diagram for a Multicomponent System of Mixed Dibasic Acids. Ternary System of Succinic Acid + Adipic Acid + Ethanol

The solid–liquid phase equilibrium for the ternary succinic acid + adipic acid + ethanol system was determined at 283.15, 303.15, and 313.15 K, respectively, under about 101.3 kPa. The mutual solubility for the ternary system were obtained. At each temperature, there existed two pure solid phases in the ternary system, which were pure succinic acid and pure adipic acid, and identified by the Schreinemaker’s wet residue method and X-ray diffraction (XRD) pattern. The crystallization region of adipic acid was a little smaller than that of succinic acid at a certain temperature. The solid–liquid phase equilibrium for the ternary system was correlated and calculated by using the Wilson and NRTL models, and the corresponding binary interaction parameters were acquired. Results showed that calculated solubility values with NRTL model agreed better than those with the Wilson model. In addition, the densities of the equilibrium liquor were obtained and correlated with an empirical equation. The mutual solubility and the phase diagram for the ternary system are helpful in separating of succinic acid and adipic acid mixtures.

Determination and thermodynamic modeling of solid–liquid phase equilibrium for 3,5-dichloroaniline in pure solvents and ternary 3,5-dichloroaniline + 1,3,5-trichlorobenzene + toluene system

The solid–liquid phase equilibrium data for 3,5-dichloroaniline in n-propanol, isopropanol, n-butanol, isobutanol, toluene, ethyl acetate and acetone at (283.15 to 308.15)K were determined experimentally by gas chromatography under 101.3kPa. The solubility of 3,5-dichloroaniline in these solvents decreased according to the following order: ethyl acetate>(acetone, toluene) for the solvents of ethyl acetate, acetone, and toluene; and for the other solvents, (isopropanol, n-butanol)>n-propanol>isobutanol. According to the solubility of 3,5-dichloroaniline in pure solvents, the solid–liquid phase equilibrium for the ternary mixture of 3,5-dichloroaniline+1,3,5-trichlorobenzene+toluene were measured by using an isothermal saturation method at three temperatures of 283.15, 293.15, and 303.15K under 101.3kPa, and the corresponding isothermal phase diagrams were constructed. Two pure solids were formed in the ternary system at a fixed temperature, which were pure 3,5-dichloroaniline and pure 1,3,5-trichlorobenzene and were identified by Schreinemakers’ method of wet residue. The temperature dependence of 3,5-dichloroaniline solubility in pure solvents was correlated by the modified Apelblat equation, λh equation, Wilson model and NRTL model; and the ternary solid–liquid phase equilibrium of 3,5-dichloroaniline+1,3,5-trichlorobenzene+toluene were described by the Wilson model and NRTL model. Results showed that calculated solubility values with these models agreed well with the experimental ones for the studied binary and ternary systems. The solid–liquid equilibrium and the thermodynamic models for the binary and ternary systems can offer the foundation for purification of 3,5-dichloroaniline from its mixture.

Measurement and calculation of solid–liquid equilibrium for ternary systems of 3,4-dichloronitrobenzene + 2,3-dichloronitrobenzene + ethanol/n-propanol

The stable (solid+liquid) phase equilibrium in ternary systems of 3,4-dichloronitrobenzene+2,3-dichloronitrobenzene+ethanol and 3,4-dichloronitrobenzene+2,3-dichloronitrobenzene+n-propanol at three temperatures was determined by means of an isothermal solution saturation method under pressure p=101.2kPa. The isothermal phase diagrams of the two ternary systems were plotted on the basis of the experimental mutual solubility data. The equilibrium solids formed in the two systems were identified by Schreinemakers’ method of wet residues. It was found that each phase diagram included one co-saturated point, two co-saturated curves and three crystallization zones in the ternary systems of 3,4-dichloronitrobenzene+2,3-dichloronitrobenzene+ethanol and 3,4-dichloronitrobenzene+2,3-dichloronitrobenzene+n-propanol. Two pure solid phases were formed in the studied systems, which were pure 2,3-dichloronitrobenzene and pure 3,4-dichloronitrobenzene. The crystallization zone of 3,4-dichloronitrobenzene was smaller than that of 2,3-dichloronitrobenzene at a given temperature, which showed that 2,3-dichloronitrobenzene could be easily separated from the solution. Furthermore, the solid–liquid phase diagrams were calculated by using NRTL model. The calculated phase diagrams agreed well with the experimental ones. Knowledge of (solid+liquid) phase equilibrium and ternary phase diagrams would be very valuable to design and optimize the solvent crystallization process of 2,3-dichloronitrobenzene and other crystallization processes involving the two ternary systems.

The effect of eight common herbicides on the predatory activity of the agrobiont spider Pardosa agrestis

The impact of eight herbicides in different residual stages on the predatory activity of a potential biological control agent, the wolf spider Pardosa agrestis, was studied in the laboratory. We found that fresh wet residues of all tested herbicides negatively affected the total and cumulative predatory activity of this species. Moreover, treatment with 48-h-old residues of the glufosinate ammonium herbicide Basta induced a significant increase in predatory activity in P. agrestis, presumably as a consequence of hormesis. These results imply that the natural pest control provided by the agrobiont spider P. agrestis can be weakened by the application of the studied herbicides. On the basis of our results, we suggest that sublethal effects on beneficial organisms should be considered in the planning of weed management of agroecosystems and should not be omitted from the herbicide registration process.

Determination and modeling for solid–liquid phase equilibrium of ternary caprolactam + cyclohexanone oxime + methyl tert-butyl ether system

The solid–liquid equilibrium (SLE) for ternary system of caprolactam + cyclohexanone oxime + methyl tert-butyl ether were determined at three temperatures of (278.15, 293.15 and 308.15) K under pressure of 101.2 kPa. Three isothermal phase diagrams of the system were constructed based on the measured mutual solubility data. There were two pure solids formed in the ternary phase diagram, including pure caprolactam and pure cyclohexanone oxime, which were identified by the method of Schreinemakers' wet residue. At each temperature, the phase diagram contained three crystallization regions (which corresponded to caprolactam, cyclohexanone oxime, and a mixture of caprolactam and cyclohexanone oxime), two crystallization curves, and one co-saturated point. The crystallization field of caprolactam was larger than that of cyclohexanone oxime. The NRTL model was employed to correlate and calculate the ternary phase diagram. The calculated ternary phase diagram with the NRTL model agreed well with the experimental ones. The solid–liquid phase equilibrium and phase diagram for the ternary system of caprolactam + cyclohexanone oxime + methyl tert-butyl ether could provide basis for the purification process of caprolactam.

ChemInform Abstract: Clean Solid Biofuel Production from High Moisture Content Waste Biomass Employing Hydrothermal Treatment

AbstractReview: 268 refs.

Profile biochemical sheep fed levels of inclusion of wet brewery residue

O objetivo deste trabalho foi avaliar os parâmetros bioquímicos de ovinos alimentados com níveis de inclusão do resíduo úmido de cervejaria na dieta. Foram utilizados 20 animais machos inteiros, mestiços da raça Santa Inês com aproximadamente oito meses de idade, pesando 18±2,5 kg de peso vivo (PV). Os tratamentos foram constituídos por níveis de inclusão do resíduo úmido de cervejaria em dietas para ovinos nas proporções de 0, 10, 20 e 30%. As amostragens sanguíneas foram coletadas no final do experimento em 4 tempos, sendo a primeira coleta realizada antes do fornecimento da dieta aos animais, a segunda foi pós-prandial (duas horas após a primeira), a terceira cinco horas após a primeira e a quarta com oito horas de intervalo da primeira, através de venopunção da jugular. Foram determinadas as atividades séricas das seguintes concentrações: Glicose, Proteínas totais, Albumina, Aspartatoaminotransferase-AST, Gamaglutamiltransferase-GGT, FosfataseAlcalina-ALP, Colesterol, Ureia e Creatinina. Na avaliação do perfil enzimático da AST, ALP e GGT não houve diferença estatística significativa (P>0,05) entre os tratamentos estudados. Na avaliação do perfil proteico, a atividade sérica da ureia (mg/dL) foi relativamente elevada quando comparado aos valores de referência. Os parâmetros séricos das proteínas totais não diferiram significativamente (p > 0,05). Na avaliação do perfil energético, os valores de colesterol obtidos neste experimento apresentaram diferenças significativas estatisticamente (p <0,05), porém para níveis de glicose não houve diferença significativa. O resíduo úmido de cervejaria na dieta de ovinos, considerando os parâmetros bioquímicos, pode ser usado como coproduto, pois não prejudica a fisiologia do animal.

Determination and modeling of binary and ternary solid–liquid phase equilibrium for the systems formed by adipic acid, urea and diethylene glycol

Solid–liquid phase equilibrium data for binary (adipic acid + diethylene glycol) and (urea + diethylene glycol) systems at temperatures from (298.15–333.15) K and ternary (adipic acid + urea + diethylene glycol) system at temperatures of 298.15 K, 313.15 K and 333.15 K were determined herein under pressure of 101.3 kPa. The corresponding solids formed in the ternary system were confirmed by Schreinemakers' method of wet residue. Three isothermal phase diagrams were constructed in terms of the measured mutual solubility data. Two pure solids were formed at each temperature, which corresponded to pure adipic acid and pure urea. The crystallization region of urea was smaller than that of adipic acid at each temperature. NRTL model and Wilson model were used to correlate the obtained solubility data, and the interaction parameters' values of adipic acid-urea were acquired. The calculated solubility with the two models agreed well with the experimental values.

Determination and modeling of solid–liquid equilibrium for ternary system of 3,4-dichloronitrobenzene + 2,3-dichloronitrobenzene + methanol

The solid–liquid phase equilibrium for ternary system of 3,4-dichloronitrobenzene + 2,3-dichloronitrobenzene + methanol were determined experimentally by the method of isothermal solution saturation at temperatures of 283.15 K, 293.15 K and 303.15 K under pressure of 101.3 kPa. According to the obtained solubility data, the isothermal phase diagrams of the system were constructed. At each temperature, there were two pure solid phases formed, which were confirmed by Schreinemakers' wet residue method and corresponded to pure 3,4-dichloronitrobenzene and pure 2,3-dichloronitrobenzene. The crystallization regions of pure 3,4-dichloronitrobenzene and pure 2,3-dichloronitrobenzene increased with decreasing in temperature. The crystalline region of 2,3-dichloronitrobenzene was larger than that of 3,4-dichloronitrobenzene at the same temperature, and increased rapidly as the temperature increase. The data of solid–liquid phase equilibrium were correlated with NRTL model and Wilson model. The calculated solubility data with NRTL model agreed well with the experimental values. The mutual solubility data and ternary phase diagrams for the system were of great significance for optimizing the purification procedure of 3,4-dichloronitrobenzene and 2,3-dichloronitrobenzene.

Phase Equilibrium in the Ternary System NaH2PO4 + Na2SO4 + H2O at 323.15 K and 343.15 K

The ternary system of NaH2PO4 + Na2SO4 + H2O at 323.15 K and 343.15 K is studied by the method of isothermal solution saturation. The equilibrium solid phases are investigated by the Schreinemaker’s method of wet residues and verified by X-ray diffraction. The solubility of the system is determined. On the basis of the experimental data, the phase diagrams are plotted and the crystallization regions are determined. The phase equilibrium at different temperatures are compared and discussed. This comparison further illustrates that the temperature can influence the equilibrium of the ternary system. The research can offer meaningful data support for separation processes and further theoretical studies.

High Reliability No-Clean Solder Paste for Designs where Flux Cannot be Dried

The miniaturization trend is driving industry to adopting low standoff components or components in cavity. The cost reduction pressure is pushing telecommunication industry to combine assembly of components and electromagnetic shield in one single reflow process. As a result, the flux outgassing/drying is getting very difficult for devices due to poor venting channel. This resulted in insufficiently dried/burnt-off flux residue. For a properly formulated flux, the remaining flux activity posed no issue in a dried flux residue for no-clean process. However, when venting channel is blocked, not only solvents remain, but also activators could not be burnt off. The presence of solvents allows mobility of active ingredients and the associated corrosion, thus poses a major threat to the reliability. In this work, a new halogen-free no-clean SnAgCu solder paste, 33-76-1, has been developed. This solder paste exhibited SIR value above the IPC spec 100 MΩ without any dendrite formation, even with a wet flux residue on the comb pattern. The wet flux residue was caused by covering the comb pattern with 10 mm × 10 mm glass slide during reflow and SIR testing in order to mimic the poorly vented low standoff components. Paste 33-76-1 also showed very good SMT assembly performance, including voiding of QFN and HIP resistance. The wetting ability of paste 33-76-1 was very good under nitrogen. For air reflow, 33-76-1 still matched paste C which is widely accepted by industry for air reflow process. The above good performance on both non-corrosion with wet flux residue and robust SMT process can only be accomplished through a breakthrough in flux technology.

Determination and correlation of solid–liquid phase equilibrium and phase diagram for multicomponent system of mixed dibasic acids. (I) Ternary system of adipic acid + glutaric acid + ethanol system

In this work, the solid–liquid phase equilibrium data for ternary system of adipic acid + glutaric acid + ethanol were measured using an isothermal saturation method at the three temperatures of 283.15, 303.15, and 313.15 K under 101.3 kPa. Three isothermal phase diagrams were built according to the measured solubility data. There were two pure solids formed in the ternary system at a given temperature, which corresponded to pure adipic acid and pure glutaric acid, and were confirmed by Schreinemaker's method of wet residue. The crystallization region of glutaric acid was smaller than that of adipic acid at each temperature. Two thermodynamic models, NRTL and Wilson were employed to correlate and calculate the mutual solubility data for the ternary adipic acid + glutaric acid + ethanol system. Results indicated that calculated results with NRTL model agreed well than those with Wilson model. Furthermore, the densities of the equilibrium liquid phase were obtained and correlated with an empirical equation.

Measurement and correlation of ternary solid–liquid equilibrium of 2-methyl-1,4-naphthoquinone + phthalic anhydride + acetone system

The solid–liquid equilibrium or the ternary system of 2-methyl-1,4-naphthoquinone + phthalic anhydride + acetone were determined at three temperatures of (283.15, 293.15 and 303.15) K, respectively. Three isothermal phase diagrams of the system were constructed on the basis of the measured solubility. Two pure solid phases were formed at (283.15, 293.15 and 303.15) K, including pure PA and pure 2-MNQ, which were confirmed and determined by the method of Schreine makers' wet residue. The densities of equilibrium liquid phase were determined experimentally at the corresponding temperatures versus mass fraction of component. The phase diagram at 283.15 K is similar to those at (293.15 and 303.15) K and the crystalline fields of 2-MNQ and PA decrease with an increase in temperature. The ternary diagram can provide the fundamental basis for separation of 2-MNQ and PA.

(Solid + liquid) equilibria for the ternary system (CsBr + LnBr3 + H2O) (Ln = Pr, Nd, Sm) at T = 298.2 K and atmospheric pressure, thermal and fluorescent properties of Cs2LnBr5·10H2O

The (solid+liquid) phase equilibria of the ternary systems (CsBr+LnBr3+H2O) (Ln=Pr, Nd, Sm) at T=298.2K were studied by the isothermal solubility method. The solid phases formed in the systems were determined by the Schreinemakers wet residues technique, and the corresponding phase diagrams were constructed based on the measured data. Each of the phase diagrams, with two invariant points, three univariant curves, and three crystallization regions corresponding to CsBr, Cs2LnBr5·10H2O and LnBr3·nH2O (n=6, 7), respectively, belongs to the same category. The new solid phase compounds Cs2LnBr5·10H2O are incongruently soluble in water, and they were characterized by chemical analysis, XRD and TG-DTG techniques. The standard molar enthalpies of solution of Cs2PrBr5·10H2O, Cs2NdBr5·10H2O and Cs2SmBr5·10H2O in water were measured to be (52.49±0.48)kJ·mol−1, (49.64±0.49)kJ·mol−1 and (50.17±0.48)kJ·mol−1 by microcalorimetry under the condition of infinite dilution, respectively, and their standard molar enthalpies of formation were determined as being −(4739.7±1.4)kJ·mol−1, −(4728.4±1.4)kJ·mol−1 and −(4724.4±1.4)kJ·mol−1, respectively. The fluorescence excitation and emission spectra of Cs2PrBr5·10H2O, Cs2NdBr5·10H2O and Cs2SmBr5·10H2O were measured. The results show that the upconversion spectra of the three new solid phase compounds all exhibit a peak at 524nm when excited at 785nm.