The Chinese Journal of Process Engineering

Cover and Contents

The Chinese Journal of Process Engineering. 2022, 22(4): 0.

Asbtract ( )

PDF (2256KB) ( )

Related Articles | Metrics

Review on progress of 5 V spinel Co-free LiNi_0.5Mn_1.5O₄ cathode material

Jia JIN Jinping WEI Zhen ZHOU

The Chinese Journal of Process Engineering. 2022, 22(4): 421-437. DOI: 10.12034/j.issn.1009-606X.221115

Asbtract ( )

PDF (11182KB) ( )

Related Articles | Metrics

As a candidate cathode material for next-generation Li-ion batteries or solid state batteries, the spinel LiNi0.5Mn1.5O4 is appealing researchers' interest. The 5 V spinel material of LiNi0.5Mn1.5O4 had ordered and disordered phases, and crystal structure, synthetic method and electrochemical reaction mechanism of which were discussed. Also, its electronic conductivity and lithium ion diffusion coefficient were highlighted compared with other cathode materials. The advantages of LiNi0.5Mn1.5O4, such as high discharge plateau, good rate performance, high thermal stability, abundant manganese resources and low cost, were introduced. Then technical obstacles hindering the industrialization of LiNi0.5Mn1.5O4 were discussed, including poor cycle performance at high temperature, low cycling coulombic efficiency, metal dissolution and phase transition, electrolyte decomposition at high voltages, gas generation in full cells. The main reason negatively affected the electrochemical performance of Li-ion batteries was electrochemical oxidation of carbonate esters at the LiNi0.5Mn1.5O4/electrolyte interface which resulted in Ni/Mn dissolution, crystal structural transformation and surface film formation, and eventually led to lower electronic conductivity and Li+ transport kinetics in Li-ion batteries. Some solution ideas were summarized at the material level, such as microscopic morphology control, new binder slurry strategy, doping, coating, high voltage matching electrolytes, synthetic control, and these material solution ideas should be coordinated with full cell design. In addition, this review speculated a few possible application scenarios on basis of its merits, for instance, start-and-stop power supply, low-temperature application, power tools and so on. Commercialization of LiNi0.5Mn1.5O4 relies on elaborate construction design at the battery level beside the materials design. More wide and thorough application research needs to be done to push the industrialization of LiNi0.5Mn1.5O4.

Research progress of enhancement methods of CO₂-CH₄ hydrate displacement in porous media

Xuemin ZHANG Yinhui LI Shanling ZHANG Mengjun ZHANG Jinping LI Yingmei WANG

The Chinese Journal of Process Engineering. 2022, 22(4): 438-447. DOI: 10.12034/j.issn.1009-606X.221122

Asbtract ( )

PDF (992KB) ( )

Related Articles | Metrics

CO2 replacement of CH4 from natural gas hydrate is a very promising method to exploit natural gas hydrate, this method has the dual advantages of energy safe exploitation and greenhouse gas formation storage. Firstly, the research progress of CO2-CH4 hydrate displacement in porous media is reviewed and the key bottleneck problems, such as long reaction cycle, slow rate and low efficiency, which restrict the commercial application of CO2 displacement method to the exploitation of natural gas hydrate, are analyzed. In view of this problem, the research progress of strengthening methods for CO2-CH4 hydrate replacement in porous media is comprehensively reviewed. It includes the enhancement of liquid CO2, the enhancement of small molecules such as N2 and H2, the enhancement of prolongation of reaction time, the enhancement of application of adsorption materials with both CO2 and CH4 gas absorbability and the analysis of new ideas enhanced mass transfer during displacement due to the formation of porous CO2 hydrate. At the same time, the characteristics of various strengthening methods are analyzed. Primarily, different phase states of CO2, small molecules and mixed gases reinforcement replacement and the mechanism of other reinforcement methods are described in detail, and the improvement of various reinforcement methods is discussed. Studies show that, for the overall recovery rate, replacement combined with conventional methods is more effective than introducing small molecule mixture and changing the injected phase state of CO2. Therefore, the combined enhancement of the single method is an effective way to improve the replacement efficiency. Finally, the shortcomings of the current research and the future research direction of the enhancement of CO2-CH4 hydrate displacement process in porous media are proposed.

Study on adsorptive separation property of CaY zeolite for ethylene glycol and 1,2-butanediol

Fan YI Peng HE Junya CAO Yan CAO Liguo WANG Jiaqiang CHEN Huiquan LI

The Chinese Journal of Process Engineering. 2022, 22(4): 448-457. DOI: 10.12034/j.issn.1009-606X.221007

Asbtract ( )

PDF (2418KB) ( )

Related Articles | Metrics

Ethylene glycol is an important petrochemical basic organic raw material, mainly used in the production of polyester, antifreeze, membrane, etc. China has abundant coal resources, which makes coal to ethylene glycol technology increasingly valued. As more and more coal to ethylene glycol plants is successfully running in China, the separation problem of ethylene glycol and 1,2-butanediol is urgently waiting to be solved. Selective adsorption is considered the most promising method because of its environmentally friendly characteristic and low cost. In this work, a fixed-bed column was used to separate ethylene glycol and 1,2-butanediol by using CaY zeolite as an absorbent, n-propanol was selected as the best eluent. In the fixed-bed column experiments, breakthrough curves were obtained and the dynamic adsorption characteristics were analyzed through breakthrough curves. The effect of operational conditions, such as flow rate and operating temperature were examined. The adsorption selectivity of ethylene glycol to 1,2-butanediol reached 1.90 at the temperature of 298 K and the flow rate of 0.8 mL/min. It can be found that the adsorption capacity of EG was much higher than 1,2-butanediol. The experiment results indicated that the breakthrough time and adsorption amount both decreased with increase of the flow rate and operating temperature. Modified Dose-Response models gave satisfactory fits to the experimental data of breakthrough curves in a fixed-bed column. At last, the adsorption sites of ethylene glycol and 1,2-butanediol were determined by Grand Canonical Monte Carlo (GCMC) simulation. It was found that the adsorption sites of ethylene and 1,2-butanediol almost overlapped, which meant ethylene glycol and 1,2-butanediol were competitive adsorptions in CaY zeolite. Moreover, the adsorption capacity of ethylene glycol was greater than 1,2-butanediol, which was consistent with the experiment result. The simulation result provided microscopic theoretical support for the experimental results. From these studies, CaY zeolite had the potential to be used as an effective absorbent for the adsorption and separation of ethylene and 1,2-butanediol.

Catalytic cracking of n?hexane to light olefins by bimetallic modified ZSM-5-USY composite molecular sieves

Kailun ZHANG Nianming JIAO Ying ZHANG Pengbo HAO Guoxia ZHANG Hui WANG Zengxi LI

The Chinese Journal of Process Engineering. 2022, 22(4): 458-468. DOI: 10.12034/j.issn.1009-606X.221037

Asbtract ( )

PDF (1380KB) ( )

Related Articles | Metrics

Compared with steaming cracking, catalytic cracking is more appealing with much lower reaction temperature and adjustable distribution of the product (by changing the catalyst composition). In order to obtain efficient catalysts with high selectivity to light olefins for petroleum catalytic cracking, composite ZSM-5-USY zeolites were modified with single metal (e. g., cerium, yttrium, zirconium, manganese, and copper) or bimetals (e. g., zirconium-cerium, manganese-cerium, yttrium-cerium, and copper-cerium) by incipient impregnation. The physicochemical properties, including crystal structure, acidity, surface area, of the catalysts were characterized by XRD, NH3-TPD and BET. Catalytic activity of the prepared catalysts in cracking were evaluated by using n-hexane as a model compound for petroleum on a fix-bed reactor. The composition of the product was detected online by gas chromatography. The results showed that the composite molecular sieves modified by various metals exhibited quite different catalytic behaviors in n-hexane cracking, and the performance had close relationship with acidity content of the catalyts. Catalysts with higher weak acidity amount exhibited higher conversion of n-hexane and selectivity of C2~C4 olefins. The Ce-Zr co-modified molecular sieve showed excellent catalytic activity and high selectivity of C2~C4 olefins (57%) at 550℃. Steam treatment had significant influence on the acidity of Ce-Zr/ZSM-5-USY and distribution of the cracking products. After steam treatment, stability of the catalyst was significantly improved, and selectivity of C2~C4 olefins increased from 20.02% (when there was no steam treatment) to 57.55% (when the catalyst was steam treated for 4 h), but the n-hexane conversion rate decreased. Kinetics study of cracking of n-hexane over 0.25% Zr-0.5% Ce/ZSM-5-USY showed that this reaction was a first order reaction, and the activation energy was 88.93 kJ/mol.

Enhancement of the thermostability of foot-and-mouth disease vaccine via Al-Pickering emulsion

Qiuting CHEN Nan WU Jie WU Xiaojun WANG Guanghui MA

The Chinese Journal of Process Engineering. 2022, 22(4): 469-477. DOI: 10.12034/j.issn.1009-606X.221134

Asbtract ( )

PDF (2020KB) ( )

Related Articles | Metrics

Foot-and-mouth disease vaccine is a veterinary vaccine, which plays an important role in the development of animal husbandry. However, there are some problems of foot-and-mouth disease vaccines such as poor antigen thermal stability and easy inactivation of antigen. At present, researchers have modified amino acids at the junction of foot-and-mouth disease virus pentamer as one of the strategies to improve the thermal stability of foot-and-mouth disease virus vaccine. This method is complicated to operate and needs to be designed separately for different serotypes of viral capsids. Therefore, this research proposes a strategy that combines antigen stabilization with adjuvant design, combing the oli-in-water emulsion with aluminum hydroxide particles to construct a particle-stabilized emulsion (Pickering emulsion), which would improve the thermal stability of the foot-and-mouth disease vaccine. In this work, spherical, rod-shaped, and flaky aluminum hydroxide particles were prepared by hydrothermal method. The prepared aluminum hydroxide particles had good dispersion, uniform particle size distribution and high crystallinity. Due to the rough surface of Pickering emulsions, antigens were absorbed on the surface and cracks of particles. On this basis, squalene was used as oil phase to prepare Al-Pickering emulsion with uniform size. Subsequently, differential scanning fluorimetry was used to evaluate the thermal stability of inactivated foot-and-mouth disease virus (iFMDV) combined with Al-Pickering emulsion. The results showed that each group of Al-Pickering emulsions improved the thermal stability of iFMDV. The rod-Pickering emulsion had the best promotion effect, and the pyrolysis temperature of iFMDV increased by 1.7?C. The adjuvant effect of Al-Pickering was evaluated by animal experiment. Animal experiment results showed that Al-Pickering emulsion effectively activated the titer of iFMDV specific antibody IgG in serum. In summary, Al-Pickering enhanced the humoral responses and stabilized iFMDV after loading. In addition, they are easily prepared and low-cost. It provides a new idea for the research of adjuvants to improve the thermal stability of vaccines.

Preparation of high-purity trisodium phosphate from the phosphating slag waste liquid after the removal of zinc

Luchan ZENG Yun LI Hongfei GUO Jinfeng ZHANG Jilin CAO

The Chinese Journal of Process Engineering. 2022, 22(4): 478-486. DOI: 10.12034/j.issn.1009-606X.221133

Asbtract ( )

PDF (1976KB) ( )

Related Articles | Metrics

Phosphating slag is the hazardous waste produced during the phosphating process, which has an adverse effect on the quality of phosphating coating and phosphating cost. It is an effective method to utilize phosphating slag by extracting iron and zinc ions from phosphating slag via alkali dissolution; however, the treatment of liquid waste of residual phosphating slag is a challenge topic. In this work, the neutralization and sodium sulfide precipitation methods were used to remove the zinc from the phosphating slag waste liquid. The corresponding process conditions were optimized. And the production processes of highly purified trisodium phosphate from phosphating slag waste liquid after zinc removal were designed respectively. The removal rate of Zn2+ could reach 97.96% via neutralization precipitation method under the pH of the reaction system of 8.85, and the reaction time of 10 min, while the removal rate of Zn2+ could reach 99.80% via the sodium sulfide precipitation method under the pH of the reaction system of 6.85, the molar ratio of sodium sulfide to Zn2+ of 1:1, and the reaction time of 10 min. After adjusting the pH of the treated waste liquid to 12.30±0.03 by using 10 mol/L of NaOH solution, the phosphate anions and sodium ions were recovered by cooling and crystallization at 5℃ to produce the trisodium phosphate. The trisodium phosphate produced from waste liquid after zinc removal by neutralization precipitation method possessed the purity of 97.72% and Zn2+ content of 0.0014%, which is in line with the chemical industry standard of chemical purity. Compared with the production process of trisodium phosphate after zinc removal by using neutralization precipitation method, that using sodium sulfide precipitation method exhibited higher purity of trisodium phosphate with the value of 98.85%, and lower Zn2+ content in trisodium phosphate with the value of 0.0004%, which met the analytical purity standard of the chemical industry. The process is capable of efficiently recovering the PO43- and Na+ ions from the phosphating slag waste liquid, thereby paving a new avenue for the comprehensive utilization of phosphating slag in industry.

Effects of metal oxides on biomass char gasification characteristics and reaction kinetics

Ke LI Xi ZENG Fang WANG Guojun KANG Jianling ZHANG Guangwen XU

The Chinese Journal of Process Engineering. 2022, 22(4): 487-498. DOI: 10.12034/j.issn.1009-606X.220416

Asbtract ( )

PDF (3797KB) ( )

Related Articles | Metrics

To probe the catalytic effect of metal oxides in biomass on char gasification, a thermogravimetric analyzer (TGA) was used to systematically compare the gasification characteristics of deashed char (ALC) and the char loaded metal oxides (ALC-K2O, ALC-Na2O, ALC-CaO, ALC-Fe2O3, ALC-MgO). To improve result accuracy, both of the isothermal and non-isothermal gasification experiments were conducted. And the distributed activation energy model (DAEM) and Flynn-Wall-Ozawa (FWO) method were used to calculate the reaction kinetics. The results showed that the catalytic effects of metal oxides on char gasification were significantly different. Under the isothermal conditions, the gasification activity followed the order of ALC-K2O>ALC-Na2O>ALC-CaO>ALC-Fe2O3>ALC-MgO>ALC. Under the non-isothermal conditions, for the same heating rate, the characteristic reaction temperature of each char gasification (initial temperature, temperature at the maximum rate, finishing temperature) ranged the order of ALC-K2O<ALC-Na2O<ALC-CaO<ALC-Fe2O3<ALC-MgO<ALC. Lower reaction temperature indicated higher reaction activity. Kinetic analysis found that regardless of isothermal and non-isothermal operation, the calculated activation energy followed the order of ALC-K2O<ALC-Na2O<ALC-CaO<ALC-Fe2O3<ALC-MgO<ALC. This was consistent with the tested gasification behavior. Compared to the isothermal gasification, the activation energy from the non-isothermal gasification was a little large, but more stable for the different conversion rates.

Effects of carbonized titanium?bearing blast furnace slag on the compressive strength and electrical resistivity of cement mortar

Chenjun TANG Ming XUAN Xiang DING Yilong JI Huihong LÜ Jianhua ZHU Dong WANG Xiangong DENG Songlin RAN

The Chinese Journal of Process Engineering. 2022, 22(4): 499-505. DOI: 10.12034/j.issn.1009-606X.221095

Asbtract ( )

PDF (2026KB) ( )

Related Articles | Metrics

As a solid waste, titanium-bearing blast furnace slag is discarded in the slag field, which brings the double pressure of waste of titanium resources and environmental pollution to the society. It is of great significance to explore new technology and realize the comprehensive utilization of large amount of titanium-bearing blast furnace slag with full component and high added value. In this work, cement mortar was prepared by replacing standard sand with carbonized high titanium-bearing blast furnace slag (carbonized slag) from Panzhihua steel group as aggregates. The chemical composition, crystallized phase and particle morphology of carbonized slag were characterized by X-ray fluorescence spectrometer (XRF), X-ray diffractometer (XRD) and scanning electron microscope (SEM). The compressive strength and electrical resistivity of cement mortar with different carbonized slag content were tested, and the influence mechanism of carbonized slag on the electrical resistivity was discussed. The results indicated that the compressive strength of cement mortar containing carbonized slag met the requirements of building cement mortar. When the substitution of carbonized slag was 80%, the compressive strength of the obtained cement mortar was 74.7 MPa, which was 26% higher than that of standard cement mortar. With increasing substitution amount of carbonized slag, the electrical resistivity of cement mortar at the age of 3 d and 7 d decreased slowly, while that of cement mortar at the age of 28 d increased first and then decreased. When the cement mortar (28 d age) was wet, the introduction of carbonized slag did not reduce its resistivity. However, when it was dried and the substitution of carbonized slag exceeded 60%, the resistivity was dramatically decreased and lower than that of standard cement mortar. When the stand sand was completely replaced by the carbonized slag, the electrical resistivity of the dried cement mortar was the lowest with a value of 1.7×104 Ω?m, which was 87.5% lower than that of standard cement mortar. Carbonized slag with high titanium content can be used as a candidate material for conductive aggregate to prepare conductive cement-based composites for building heating.

Efficient improvement on activity and stability of lipase via hydrophobic polymer grafting

Zonghao LIU Qinghong SHI

The Chinese Journal of Process Engineering. 2022, 22(4): 506-514. DOI: 10.12034/j.issn.1009-606X.221108

Asbtract ( )

PDF (978KB) ( )

Related Articles | Metrics

The stability and activity of enzymes are the main bottlenecks in enzyme's industrial applications. Therefore, engineering enzymes for improved catalytic performance is an important topic for industrial biocatalysis in the current status. In this work, hydrophobic monomers, isobutyl methacrylate (IBMA) and ethyl methacrylate (EMA) were grafted onto surface of Candida rugosa lipase (CRL) via atom transfer radical polymerization (ATRP), respectively, to synthesize two hydrophobic polymer-grafted lipases, pIBMA-g-CRL and pEMA-g-CRL. Compared with wide-type CRL, the catalytic activity and stability of pIBMA-g-CRL and pEMA-g-CRL improved significantly. After grafting with hydrophobic polymers, Michaelis parameter of CRL decreased from 9.98 mmol/L to 6.91 mmol/L (for pIBMA-g-CRL) and 8.54 mmol/L (for pEMA-g-CRL), whereas turnover number increased from 5.63 to 16.97 (for pIBMA-g-CRL) and 22.36 (for pEMA-g-CRL). As a result, catalytic efficiency of pIBMA-g-CRL and pEMA-g-CRL was 4.39 times and 4.68 times as high as that of wide-type CRL, respectively. Moreover, pEMA-g-CRL retained 92% activity after incubating at 50℃ for 6 h. It reflected that hydrophobic polymer grafting induced the opening of lipase "lid" structure and led to exposure of catalytic active site. Meanwhile, lipase in lid opening conformation had better stability. Spectroscopy experiments further confirmed that the improvement of lipase catalytic performance was closely related to the change in secondary and tertiary structure of lipase. CD results showed a decreased content of α-helix and an increased content of β-sheet in hydrophobic polymer-grafted CRLs. Moreover, as shown by fluorescence emission spectra, a blue shift of hydrophobic polymer-grafted CRLs was observed, which indicated a more compact structure than wild-type lipase. The results in this research demonstrated that IBMA and EMA, as the monomers for grafting CRL, had a significant improvement to the stability and activity of CRL, and the resulting polymer was a potential material for lipase modification.

Application of heterojunctioned materials based on NiIn?LDHs for toluene detection

Linfeng NIE Ning HAN Yunfa CHEN

The Chinese Journal of Process Engineering. 2022, 22(4): 515-522. DOI: 10.12034/j.issn.1009-606X.221136

Asbtract ( )

PDF (2477KB) ( )

Related Articles | Metrics

Nowadays, people have paid more and more attention to air pollution which urging researchers to explore different high-performance gas sensors for air quality monitoring. As a representative of air pollution, volatile organic compounds (VOCs) have been studied a lot. Plenty of work about VOCs gas sensors and how to enhance gas sensing performance has been reported. Constructing a heterojunction structure in gas sensor material was considered to be one of the effective methods to improve the performance of gas sensors. In this work, a series of nickel-indium layered double hydroxides (NiIn-LDHs) precursors with different Ni/In atonic molar ratios were synthesized successfully via chemical precipitation methods. And a series of NiO-In2O3 P-N heterojunctioned materials were fabricated by calcining these NiIn-LDHs precursors in the air at high-temperature. Following with an annealing step at H2 atmosphere at different temperatures, these heterojunctioned materials can be used as gas sensing materials to detect low concentration toluene gas. The influence of Ni/In atomic molar ratios and annealing temperatures on gas sensing performance were studied. The results showed that when Ni/In atomic molar ratio was 3.0 and annealing temperature was 500℃, the obtained material showed the highest response to 0.005‰ toluene. In addition, the material also showed high selectivity to other interfering gases (such as 0.005‰ ammonia, acetone, triethylamine, sulfur dioxide, and high-humidity water vapor), and it had shown good stability in a 12-day-testing. A series of characterizations such as XPS, UPS, etc. confirmed that the material Ni/NiO-In2O3 which formed after annealing at 500℃ owns Schottky barrier and abundant oxygen vacancies. The synergistic effect of P-N junction, Schottky barrier and abundant oxygen vacancies lead to the best sensing performance. This work can provide ideas for the development of high-performance toluene gas sensors.

Preparation of 1,5?pentanediamine using bipolar membrane electrodialysis

Mengying DONG Yuzhu SUN Chen YANG

The Chinese Journal of Process Engineering. 2022, 22(4): 523-532. DOI: 10.12034/j.issn.1009-606X.221102

Asbtract ( )

PDF (1317KB) ( )

Related Articles | Metrics

1,5-Pentanediamine found in prokaryotic and eukaryotic organisms mostly is a natural polyamine with a variety of biological activities. In recent years, 1,5-pentanediamine has been becoming a focus since it can be used as the raw material for the preparation of nylon materials by biological methods and has been produced on an industrial scale. That means nylon materials can be produced at a lower cost by using the 1,5-pentanediamine (C5H14N2) as the raw material instead of 1,6-hexanediamine (C6H16N2) made by petroleum and chemical methods and it makes 1,5-pentanediamine have a wide range of application and business prospects. To extract 1,5-pentanediamine from post-fermentation broth, many methods have been tried. With the development of electrodialysis and ion-exchange membrane, bipolar membrane electrodialysis (BMED) has been widely applicated in an amount of areas since it can decompose salt into acid and base respectively by producing OH- and H+ without adding any other chemicals. In this study three-cell bipolar membrane electrodialysis was used in the main process of separation of bio-based 1,5-pentanediamine from post-fermentation broth. Simulated broths (1,5-pentanediaminium sulfate) were used to determine the optimum duration of EDBM process. The effects of current modes, current density, initial concentration of 1,5-pentanediaminium sulfate and the impurity positive ions in 1,5-pentanediaminium sulfate on BMED were evaluated principally with respect to alkali yield and partially with respect to efficiency and energy consumption. Membrane fouling, which mainly resulted from precipitation was also considered. The result also showed that the more satisfied recovery rate can be obtained at a higher current density. Furthermore, the impurity ions like K+ occurred in 1,5-pentanediaminium sulfate had no effect on base recovery rate, but it had an impact on the speed of recovery. Ultimately, the sulfate ions in the feed solution can be effectively removed and the recovery ratio of 1,5-pentanediamine reached 97.5% with low energy consumption 3.24 kWh/kg C5H14N2 at current density 20 mA/cm2. This process is environmental benignity and sustainable without any waste generated.

Optimization of the technological conditions of phytosterol solid self?microemulsion using response surface methodology

Shuo HUANG Yuxin HU Luping SHA Jianqiao LIU Yongxue GUO

The Chinese Journal of Process Engineering. 2022, 22(4): 533-541. DOI: 10.12034/j.issn.1009-606X.221127

Asbtract ( )

PDF (1278KB) ( )

Related Articles | Metrics

To improve the bioavailability of phytosterols in the body and promote the wide application of phytosterols in medicine, based on the preparation of phytosterol liquid self-microemulsions, the solid self-microemulsion is further prepared by spray drying to improve its transportation and long-term storage stability. First, the type and dosage of the optimal carrier material were selected by analyzing the adsorption capacity, desorption rate, and drug load capacity. Then, with the powder collection rate as an inspection indicator, based on a single factor, the experiment carried out response surface optimization, determined the optimal process parameters of spray drying, and carried out in vitro evaluation. The results showed that the optimal carrier was colloidal SiO2, the ratio of carrier to self-microemulsion was 1:1, the inlet air temperature of spray drying was 120℃, the feeding speed was 10 mL/min, and the inlet air flow was 540 L/h. At this time, the obtained powder collection rate was the largest, the value obtained by the fitting was 49.36%, which wa basically consistent with the theoretical prediction value.There was no significant difference between the predicted value and the actual value, indicating a good fit. The prepared S-SMEDDS was the white powder with an average drug loading of 1.00%. It can be re-dispersed in water to form a light blue clear and transparent emulsion. The re-dispersed particle size was 27.20±1.15 nm and the polydispersity coefficient was 0.137±0.010. According to DSC and SEM, the drug was adsorbed in the pore size of colloidal silica in an amorphous state. Under different pH conditions, the release degree was different, but compared with the bulk drug, the release effect had been greatly improved. It showed that the self-emulsifying drug delivery system can indeed increase the solubility of the drug in water and the permeability in the intestinal tract. In addition, the solid self-microemulsion obtained by spray drying and solidification was uniform in content, easy to store and transport and the application should be considered.

Enhanced removal efficacy of organics from raw water by magnetic ion exchange resin

Yan LI Changjin GUO Lei DING

The Chinese Journal of Process Engineering. 2022, 22(4): 542-551. DOI: 10.12034/j.issn.1009-606X.221074

Asbtract ( )

PDF (1203KB) ( )

Related Articles | Metrics

Water quality of raw water was investigated, and the removal efficacy of dissolved organic matter was analyzed during the traditional drinking water treatment plant. The removal of dissolved organics in raw water was compared and discussed during the different treatment processes enhanced by powder-activated carbon or magnetic ion exchange resin. And the optimal combined process was obtained. The raw water was polluted by seasonal organics, and the hydrophilic components accounted for 80% of total organic matters approximately. The 20%~30% of dissolved organic matters were removed by the traditional drinking water treatment process. Compared with other treatment processes, the process of resin pre-adsorption coupled with coagulation had the best efficacy for the removal of dissolved organic matters, and the removal efficiency of DOC and UV254 was 41.48% and 80.0%, respectively. Compared with the enhanced coagulation, the removal efficiency of DOC and UV254 was improved by 17.7 and 35.49 percent by the process mentioned above, and the dosage of coagulant was reduced by 86.67%. Langmuir isotherm model and pseudo second-order kinetic equation could describe the equilibrium and kinetics of dissolved organic matters adsorbed on resin. Magnetic ion exchange resin pre-adsorption can be used as a reliable technology to enhance the traditional drinking water treatment process for the removal of dissolved organic matter from raw water.

Evaluation of safety performance and thermal stability of hard carbon anode for sodium?ion battery

Xinrong YANG Haiying CHE Ke YANG Chaoliang PAN Xiaozhen LIAO Zifeng MA

The Chinese Journal of Process Engineering. 2022, 22(4): 552-560. DOI: 10.12034/j.issn.1009-606X.220420

Asbtract ( )

PDF (2636KB) ( )

Related Articles | Metrics

As a promising energy storage system, the sodium-ion battery has attracted wide attention due to its rich sodium resources and cost advantages in energy storage and low-speed electronic vehicle application. With the development of the sodium-ion battery industry, battery safety is one of the key issues which is often caused by the heat loss of battery cells. In this work, the safety factors of sodium-ion batteries were studied, including thermal stability of hard carbon materials, over-discharge test, safety test (extrusion and acupuncture, etc.), and thermal runaway test. According to the first cycle discharge curve of a hard carbon coin cell, the solid electrolyte interphase (SEI) of hard carbon in different discharge potentials with differential scanning calorimetry (DSC) at 0.9, 0.5, 0.15 and 0.01 V, respectively were studied. The results showed that with the increase of sodium embedded in the hard carbon, the position of the exothermic peak appeared earlier and became more obvious and the presence of electrolytes reduces the stability of hard carbon embedded with sodium. The safety performance of full sodium-ion batteries can be evaluated by calorimetric analysis of the thermal runaway process of batteries. 1 Ah soft package batteries were prepared to study the over-discharge test and safety test. Compared with the non-over-discharge cells, cells over-discharge to 0 V had little difference in cycle performance after 500 cycles. The current density (0.1 or 1 C) had no significant influence on capacity recovery and cycle performance of the battery. The extrusion and acupuncture tests showed that the sodium-ion battery had good safety performance as the batteries were no fire and no explode. In addition, the thermal runaway test as calorimetric analysis was generally carried out by an accelerating rate calorimeter (ARC). The ARC test showed that the onset temperature of detectable self-heating were 136.6, 131.6, 136.3, 128.2, 166.6 and 138.6℃ at 80% state of charge (SOC), 60% SOC, 50% SOC, 40% SOC, 30% SOC and 0% SOC, respectively. Moreover, the thermal runaway occurred at 240.9℃ only at 80% SOC. It proved that the safety performance of the sodium-ion battery was good and the sodium-ion battery had the best safety performance at 30% SOC.

Table of Content