Institutional Repository of Institute of Process Engineering, CAS (IPE-IR）
Not a member yet
40778 research outputs found
Sort by
<p>Enhancing dimethyldichlorosilane production in Rochow-Muller reaction by adding ZnO-Sn-P co-promoter in CuO/SiO2</p>
No full textCommercial nonsupported Cu-based catalysts have to be mixed with various promoters to enhance their catalytic performance in the Rochow-Muller reaction. However, considerable debates still exist at a fundamental level on how these promoters function. Herein, we systematically investigated the effects of ZnO, Sn, and P promoters on the catalytic property of the CuO/SiO2 catalyst for synthesizing dimethyldichlorosilane (M2) via the Rochow-Muller reaction. A series of CuO/SiO2 catalysts containing these promoters were prepared by the ball-milling method. The CuO/SiO2 catalyst with the coexistence of ZnO, P, and Sn promoters showed the highest catalytic activity, even superior to the commercial non supported Cu-based catalysts. Detailed characterizations showed the increased capability for oxygen adsorption on the CuO surface and dissociative chemisorption of methyl chloride led to the improved catalytic performance. This work deciphers the promoter mechanism and demonstrates a promising strategy for the efficient synthesis of M2.(C) 2022 Elsevier Inc. All rights reserved
Transformation and migration mechanism of fluorine-containing pollutants in the pyrolysis process of spent lithium-ion battery
No full textPyrolysis is an effective method to remove organics (e.g. electrolytes and binders) from spent lithium-ion battery (LIB). In this study, the co-pyrolysis characteristics of fluorine-containing substances and active materials from LIB were investigated using thermogravimetric-differential scanning calorimetry (TG-DSC), infrared spectroscopy (IR), and mass spectrometry (MS) analysis. Associated with the pyrolysis, active materials adsorb the residues of electrolyte on the surface and into the pores (20-200 degrees C), while polyvinylidene fluoride (PVDF) forms a liquid film to cover the local surface of active materials (400-500 degrees C). These interactions prevent deep removal of organics, leaving fluorine-containing contaminants in active materials. The barrier effect of PVDF liquid mesophase on the removal of organics with secondary liquidous phase formation during pyrolysis was confirmed by in situ optical observation. The migration behavior of fluorine element during the pyrolysis of black mass (BM) from spent LIB was also investigated. With pyrolysis temperature increasing from 100 degrees C to 600 degrees C, the dissociable fluorine content in pyrolyzed BM increased from 1.4 wt% to 3.7 wt%. The fluorine-containing contaminants in BM cannot be removed completely by simply increasing pyrolysis temperature. This study provides a better understanding on the transformation of fluorine-containing pollutants during the pyrolysis of BM
Fast and high-resolution fractionation of positional isomers of a PEGylated protein using membrane chromatography
No full textThe fractionation of positional isomers of a PEGylated protein is quite challenging as these have similar mo-lecular weight, and only very slightly different surface charge. In this study, cation exchange z2 laterally-fed membrane chromatography (z2LFMC), which has been shown to be suitable for high-speed, high-resolution protein purification, was used to fractionate positional isomers of mono-PEGylated lysozyme. The performance of the z2LFMC device was compared with a commercial preparative cation exchange column having the same volume and ligand. PEGylated lysozyme purification experiments showed that while the positional isomers of mono-PEGylated lysozyme could not be satisfactorily resolved using the preparative commercial cation exchange column, almost baseline resolution of these could be achieved using the z2LFMC device. Moreover, the z2LFMC device-based process was faster by an order of magnitude. The results discussed in this paper demonstrate that z2LFMC is a superior alternative to column-based chromatography for challenging protein separations, such as the one discussed here, both in terms of speed and resolution
Increasing the greenness of an organic acid through deep eutectic solvation and further polymerisation
No full textAcrylic acid (AA) is an important and widely used industrial chemical, but its high toxicity renders its use incompatible with the concept of green development. By leveraging its terminal carboxyl group and unsaturated bond, we designed and explored a new strategy to increase the greenness of AA via its eutectic melting using a quaternary ammonium salt (choline chloride) to form a deep eutectic solvent (DES), followed by polymerisation of the DES to form a polymer (poly(DES)). The greenness of AA, DES, and poly(DES) was evaluated via an in vitro test using MGC80-3 cells and an in vivo test using Kunming mice. The toxicity improved from Grade 2 (moderately toxic) for AA to Grade 1 (slightly toxic) for DESs and Grade 0 (non-toxic) for poly(DES) in the in vitro test. Moreover, the poly(DES)s showed a lower toxicity in mice than the DESs in the in vivo test. Thus, greenness enhancement was successfully achieved, with the greenness following the order AA < DES < poly(DES). Furthermore, the mechanisms underlying the change in toxicity were explored through microscopy and flow cytometry, which revealed that the DES can permeate the MGC80-3 cell membrane during the G(0)/G(1) phase to adversely affect DNA synthesis in the S phase, but the poly(DES) cannot. Finally, the green poly(DES), which showed good adsorption properties and flexible functionality, was successfully applied as a carrier or excipient of drugs. Through the novel strategy reported herein, greenness enhancement and the broadening of the application scope of a toxic organic acid were achieved, making such acids applicable for green development. (C) 2021 Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd
Numerical Simulation of Flow Field Optimizing the Rotating Segregation Purification of Silicon for SoG-Si
No full textIn order to improve the preparation efficiency of high-purity silicon, a new method of rotary segregation purification has been developed to prepare polysilicon. Numerical simulation based on ANSYS19.0 software and water model experiments were used to study the distribution of flow field and optimize the impurity removal process. A numerical simulation model suitable for rotating interface is established. The simulation result is in good agreement with the water model experiment. A vortex flow is found in the middle of the mold when the mold insertion depth is 90 mm. The vortex is conducive to the thinning of the impurity enrichment layer at the solid-liquid interface. With the mold insertion depth increases from 90 to 170 mm, two vortex flows appear in the middle and bottom of the mold, respectively. Moreover, setting the mold rotation rate at 100 rpm can contribute to a more stable flow field and a higher melt flow velocity. When the diffusion layer thickness is less than 0.1 mm, the impurity segregation coefficient can approach close to its equilibrium segregation coefficient, indicating that impurity segregation be effectively enhanced by increasing the rotation rate of mold, strengthening the effect of solidification rate and increasing the rotational speed. Industrial tests were carried out at the 100 kg level. The result shows that the rotary segregation method and equipment can achieve the removal of very low impurity in silicon (99.999 pct), and SoG-Si (99.9999 pct) was obtained. This method provides a new way for silicon purification, and it is believed that better results can be obtained through continuous improvement
A new sustainable concept for silicon recovery from diamond wire saw silicon powder waste: Source control and comprehensive conservation
No full textMetal impurities and SiO2 shell are two key components that must be eliminated for 6 N silicon remanufacturing from diamond wire saw silicon powder waste. Previous research on 6 N silicon recovery has focused more on metal impurity removal without paying sufficient attention to the relationship between metal impurities and the SiO2 shell, even though the surface oxidation of silicon particles is an important factor restricting metal removal. In this study, a novel investigation into the source of metal impurities and the SiO2 shell growth was conducted, combined with acid leaching and linear regression analysis to determine the relationship between the metal impurities and the SiO2 shell. The results indicated that both raw materials displayed strong negative correlations of -0.952 and -0.996 between the removal efficiency and the thickness of the SiO2 shell. And the Al, Fe, Ni, and Mg are more likely to be enriched in the SiO2 shell due to the improper management of metal contaminants and an increase in the O content in the waste stream. Furthermore, source control and comprehensive conservation are recommended for the efficient remanufacture of 6 N silicon. This study provides a new sustainable concept for silicon recovery from diamond wire saw silicon powder waste