The Chinese Journal of Process Engineering

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Chin. J. Process Eng.

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Progress of replacement of hazardous chemicals used in chemical industry with deep eutectic solvents

Hongwei REN Shaohan LIAN Xue WANG You ZHANG Jinfeng ZHANG Erhong DUAN

Chin. J. Process Eng. 2018, 18 (S1): 1-13. DOI: 10.12034/j.issn.1009-606X.20180127

Abstract （774）

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Hazardous chemicals applied in industry suffer great risks and would result in potential danger. As a new type of ionic liquids, deep eutectic solvents (DES) are known for safety, environments friendly, and inexpensive. DES have attracted more and more attentions, and been considered as a promising substitute of hazardous chemicals. This statement was mainly devoted to introduce the definition of principles of green chemistry and GSK solvent selection guide, and apply them to the safety assessment of chemical industry with Deep Eutectic Solvents replacing of hazardous chemicals. In the passage, the harm from hazardous chemicals in chemical industry was firstly reviewed. Based on this, the advantage of DES was illustrated, and it was a promising replacement of hazardous chemicals. The definition, classification, and the properties of DES were descripted. The application progress of DES in preparing metal-catalysts, biomass transformation, gas separation, polymerization, and electrochemical to substitute for hazardous chemicals were reviewed. The behaviors of DESs in replacement of hazardous chemicals were studied according to the Principles of green chemistry and GSK solvent selection guide. As solvent, DES can replace inflammable and highly toxic organic solvents, such as toluene and benzene, which were dangerous to environment. As catalyst, DES can enhance the selectivity and efficiency. As reactant, DES can avoid the usage of toxic reactant. Moreover, the problems and difficulties in research and applications were investigated, and then the prospective application of DES was offered.

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A review of functional separator for improving the flammability of lithium?sulfur batteries

Song CHANG Yongjian HUAI Yanhui ZHI

Chin. J. Process Eng. 2018, 18 (S1): 14-23. DOI: 10.12034/j.issn.1009-606X.20180147

Abstract （731）

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Lithium–sulfur (Li–S) batteries have attracted more and more attention lately because they have very high theoretical specific energy (2500 W?h/kg), five times higher than that of the commercial LiCoO2/graphite batteries. As a result, they are strong contenders for next-generation energy storage in the areas of portable electronics, electric vehicles, and storage systems for renewable energy such as wind power and solar energy. However, poor cycling life, low capacity retention and poor safety are main factors limiting their commercialization. The non-uniform surface of lithium metal tends to form the dendrites during the cycle, causing a short circuit inside and making the battery ignite and burn. Besides, the energy density of lithium?sulfur batteries is about 3~5 times higher. The internal overheating of the battery causes thermal runaway, which can cause fire and explosion. Nevertheless, the use of a functional separator can curb the occurrence of internal short-circuit and thermal runaway of the battery, and improve the safety performance of the lithium?sulfur battery. Meanwhile, the shuttle effect in the cycle can also be weakened to some extent. This article reviews the latest developments and future trends in the functional modification of separators for functional lithium?sulfur batteries.

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Emission and comprehensive utilization of spent sulfuric acid in China

Chong LI Jun ZHOU Yao LIU Zhimao ZHOU

Chin. J. Process Eng. 2018, 18 (S1): 24-34. DOI: 10.12034/j.issn.1009-606X.20180116

Abstract （925）

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Sulfuric acid as the basic hazardous chemicals is applied in various fields of the national economy. But in the meantime, a lot of waste sulfuric acid becomes the inevitable byproduct. According to the incomplete statistics, the annual discharge of used acid in China has exceeded 100 million tons, of which more than 70 million tons were waste sulfuric acid. Along with the increase of industrial acid, the amount of used sulfuric acid will grow in the future. Especially, the frequent accidents of illegal dumping and burying of waste sulfuric acid have become an important cause leading to environmental emergencies. Large amount of spent sulfuric acid not only means the waste of resources but also results in tremendous potential hazard of safety and environment. Nevertheless, China is deficient in sulfur resources and imports a lot of sulfur, so it is of great significance to promote and improve the comprehensive utilization of waste sulfuric acid. This paper summarizes the applied industries of sulfuric acid and the characteristics of waste acid. And it introduces the current treatment situation and regeneration methods of waste sulfuric acid. This paper puts forward some comments on the resources utilization, supervision and future development trend of waste sulfuric acid. It is hoped to play a certain reference value of application, disposal and management of sulfuric acid.

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Comparison and revelation of management category for highly hazardous substances of the United States and China

Yue GAO Fei HUANG Peng LI Jinmei ZHANG Aolin LIU

Chin. J. Process Eng. 2018, 18 (S1): 35-42. DOI: 10.12034/j.issn.1009-606X.20180092

Abstract （645）

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Due to the high inherent risk of the highly hazardous substances, it is very easy to cause heavy casualties and property losses from combusting, explosion, and poisoning accidents if the managements for the highly hazardous substances are not strict or the treatments are improper. Therefore, many laws and regulations relating to the highly hazardous substances have been established by different countries, which formed different supervisory systems of the highly hazardous substances. Accordingly, the management categories of the highly hazardous substances are different in different countries. Among many countries in the world, the United States has established a complete chemical management system with relatively complete laws and regulations. Although the chemical management system has been established in China, the management relating to the highly hazardous substances is still imperfect and has some defects. To study the management category of the highly hazardous substances of China and explore the defects of the management category and propose suggestions to make improvements of the management of the highly hazardous substances, the laws, regulations and standards relating to the highly hazardous substances management of the United States and China have been researched, and the similarities and differences between the management categories of highly hazardous substances of the United States and China have been compared by the statistical analysis. The range, threshold quantities and hierarchical management methods of the highly hazardous substances have been studied. The results showed that the open management category combining the highly hazardous substances list and hazardous characteristics bringed the more comprehensive substances scope of the highly hazardous substances, the threshold quantities of hierarchical management formulated scientifically for different substances and hazardous characteristics provided the more feasible management category of the highly hazardous substances, and the hierarchical management based on hierarchical threshold quantities was more conducive to the rational allocation of safety supervision resources in China.

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Toward green chemistry: integrating life cycle with environmental risk assessment of chemicals

Yiping XU Zijian WANG

Chin. J. Process Eng. 2018, 18 (S1): 43-51. DOI: 10.12034/j.issn.1009-606X.20180152

Abstract （646）

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The principles of green chemistry and the precautionary principle encourage manufacturers and regulators to minimize the generation and use of toxic substances and seek safer alternatives. Environmental risk assessment (ERA) and life cycle assessment (LCA) are considered as major analytic approaches used to support chemical sustainable management and decisions. ERA focuses on predicting the likelihood of a certain effect when dealing with hazard chemicals, by comparing the predicted total exposure of certain receptors to hazard chemicals with corresponding thresholds. LCA is typically invoked to achieve sustainability in green design by comparing the environmental performance of different chemical products, or different life cycle phases of the product. Both ERA and LCA have their specific concept framework and methodology respectively, consequently can supply decision makers with different types of information. However, each method alone has certain limitation during actual application. Integrated framework of two methods can fill the gaps and make strong support for chemical sustainable management. Therefore, different integration approaches, which claimed integration, combination, complementary or hybridization (trade-off) use of ERA and LCA are summarized in the present review. Several scientific issues and challenges on integration framework of ERA and LCA are discussed, i.e. data gap, spatial and temporal characteristics, use of toxicity data and combined effect, as well as coupling model issues and uncertainty. Finally some perspectives are presented on the application of LCA?ERA integrated methods in green chemistry. Communication of risk and hazard information of chemicals is vitally important in promoting hazard chemical reduction and replacement. Therefore the integrated approaches are suggested to identify safer alternatives to a chemical by utilizing an environmental risk assessment over the entire life cycle.

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Research and application of process safety management and evaluation technology for petrochemical device based on decision tree algorithm

Hongxun SHI

Chin. J. Process Eng. 2018, 18 (S1): 52-58. DOI: 10.12034/j.issn.1009-606X.20180070

Abstract （633）

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According to the domestic and international process safety management system standards and performance indicators, the process safety management evaluation index set of petrochemical plant was combed. The correlation degree of the index set was evaluated using the decision tree algorithm based on the correlation degree, thus the process safety management evaluation index system of the petrochemical plant was constructed. The evaluation model was established by multi-level comprehensive fuzzy evaluation method, then the quantitative evaluation grading standard of the plant was proposed. The process safety management evaluation system of the plant was designed and developed. The evaluation and calculation of the process safety management performance of the petrochemical plant were realized. The system was applied in the ethylene plant of an enterprise, which has the practical significance for improving the process safety management level of the plant.

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Utilization of dangerous chemicals and design points for storage facilities on nuclear power plant

Liang DONG Yilin WANG Feng YAN

Chin. J. Process Eng. 2018, 18 (S1): 59-66. DOI: 10.12034/j.issn.1009-606X.20180113

Abstract （735）

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Various chemicals are used during the operation and maintenance process of nuclear power plants, and some of them are identified as hazardous chemicals. In the nuclear power plants, the safety issues of dangerous chemicals are not directly correlated with the safety issues of radioactive materials but their hazards can be added together to enlarge the total hazards, so it’s of great significance to strengthen the design and management of dangerous chemicals. The second-generation modified M310 pressurized water reactor nuclear power plant is taken for instance. More than 14 kinds of chemicals are applied, for example fuming sulfuric acid, liquid ammonia, acetylene and so on. Radioactive materials are also mentioned, such as radioactive sources, radioactive solids, liquid waste and gas waste, but radioactive materials should not be classified as dangerous chemical. Identification of major hazard installations of dangerous chemicals is a management of units that produce, store, use and operate chemicals. The identification in nuclear power plants based on the Identification of major hazard installations for dangerous chemicals, lists of dangerous goods, and the rules for classification and labelling of chemicals—part 18: acute toxicity. The evaluation of major hazard sources is characterized by the ratio of the presence of each identified substance in the identification unit to the critical mass. This ratio is expressed in q/Q(critical value) in the Identification of Major Hazardous Sources of Hazardous Chemicals. If there are many types of dangerous chemicals in the identification unit, the ratios of the identified substances are summed up. If the sum is less than one, it is not a hazard installation of dangerous chemicals, otherwise, it is. The design and management of major hazardous and chemical storage facilities are analyzed and discussed with the experience of design for several nuclear power plants. After identification, dangerous chemicals stored and used by nuclear power plants are not major hazard installations. The design scheme for storage facilities is strictly implemented in accordance with standards and codes, and the measures are completed, which meet the increasingly stringent regulatory requirements for hazardous chemicals, and in the meantime the safety of the hazardous chemicals within nuclear power plants is assured.

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Model analysis of liquid ammonia tank accident consequence and thinking of technical transformation

Dong PAN

Chin. J. Process Eng. 2018, 18 (S1): 67-71. DOI: 10.12034/j.issn.1009-606X.20180131

Abstract （849）

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The safety evaluation method of major hazardous source for hazardous chemicals is adopted. Through quantitative calculation, it is judged and determined that the liquid ammonia tank area belongs to the third-class major hazardous source. According to the typical accident consequences caused by leakage of liquid ammonia storage tank. A vapor cloud explosion model was established to calculate that the death radius of the vapor cloud explosion might be 4.18 m, the serious injury radius was 16.04 m, the minor injury radius was 31.19 m and the safety protection distance was 100.4 m. Then, through the establishment of the leakage diffusion model of toxic and hazardous substances, combining with the weather conditions to simulate the leakage diffusion scene. The quantitative analysis and calculation were conducted. And the conclusion was drawn that the distance from downwind poisoning was 312.01 m, the upwind poisoning was 72.01 m, and the area of the poisoning area was 16291.70 m2. On the other hand, in order to improve the essential safety level of liquid ammonia storage tank, combining with the latest safety standard and standard requirements of major hazardous source storage tank of hazardous chemicals. This paper puts forward the idea of technical transformation of liquid ammonia storage tank. Specific measures about the liquid ammonia storage tank include installation of external liquid level gauge, thermometer and pressure transmitter, adding automatic valve in gas and liquid two-phase pipeline, setting up high and low level liquid level alarm interlock device and toxic gas alarm instrument, adding automatic control start emergency spray absorption system, adding video monitoring to the storage tank area, improving measures such as weather vane, eye washer and electrostatic discharge device on the liquid ammonia storage tank etc. All of the technical transformation about the liquid ammonia storage tank was completed.

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Safety analysis in ethylene oxide production and process designing

Songsong CHEN Li DONG Junping ZHANG Guiyang SHENG Meixiang ZHANG Gaijing CUI

Chin. J. Process Eng. 2018, 18 (S1): 72-81. DOI: 10.12034/j.issn.1009-606X.20180082

Abstract （775）

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Ethylene oxide (EO) is an important intermediate in organic synthesis with a wide range of uses. The special physicochemical properties of ethylene oxide were analyzed for the safety problems of production, storage, transportation and use. EO had a very actively chemical properties, such as the molecule ring was easily opened which would release lots of heat. It is flammable and explosive as that the explosion limit was from 3% to 100% in the air, and the ignition was minimal only 0.06 mJ. The safety operation designs and matters needing attention had been analyzed and discussed along with its special physicochemical properties, reaction characters, easy to self-polymerize, disintegrate and decompose, etc., which was aimed to solve the security problems existing in chemical production processes. The specific suggestions were put forward to improve safety and reliability in it production, transportation and producing, including related device layout design, safety temperature and pressure design, equipment safety and emergency treatment design, etc., and it would lead to reduce the related accidents.

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Quantitative analysis method and index response law of hydrogen sulfide leakage

Baoquan XIN Wei LU Xiangjian ZHANG Lu WAN

Chin. J. Process Eng. 2018, 18 (S1): 82-88. DOI: 10.12034/j.issn.1009-606X.20180084

Abstract （743）

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It is to quantitatively analyze the influence range of hydrogen sulfide leakage under different scenarios and the response law of various parameters, and then provide quantitative data for hydrogen sulfide leakage protection. According to the unified diffusion model and the heavy gas diffusion theory, the diffusion characteristics, concentration distribution and downwind distance of hydrogen sulfide under different leakage conditions were studied by means of Process Hazard Analysis Software Tool (PHAST) of DET NORSKE VERITAS (DNV). The results showed that the immediately dangerous to life or health (IDLH) concentration downwind distance from the 661 m to the 2404 m increased when the leakage persisted for 1 min. The downwind distance and maximum cloud width of IDLH and maximum allowable concentration (MAC) have increased by 3~4 times. Changes in durations of 5 and 30 min were similar. At the same leakage aperture, the IDLH downwind distance was shortened by 31.4%, 23.8%, and 24.7%, respectively, when the mesopore and large holes leaked and ruptured. Correspondingly, the maximum cloud width has increased by 1.4~1.7 times. At a wind speed of 4 m/s, the IDLH and MAC downwind distance of the atmospheric stability E were 2.8 and 3.8 times than that of B, respectively. The IDLH and MAC downwind distances for medium stability D and wind speed 8.5 m/s were 49.2% and 39.3%, respectively, in comparison with that at a wind speed of 1.5 m/s. The downwind distance and the maximum cloud group width showed a logarithmic relationship as the surface roughness increased. The main hazardz that can be caused by hydrogen sulfide leakage were poisoning, followed by jet fire, flash fire and explosion. Quantitative analysis results can be used in leakage protection, considering both individual protection and safety isolation. The influence area of leakage can be used as the boundary of hydrogen sulfide safety isolation.

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Risk of liquid-phase oxidation reaction based on dynamic magnification simulation

Fan ZHANG Mengmeng CHEN Jin ZOU

Chin. J. Process Eng. 2018, 18 (S1): 89-96. DOI: 10.12034/j.issn.1009-606X.20180069

Abstract （611）

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With the popularity of modernization and greening the concept of chemical industry, oxidation process, especially the new oxidation process, occupied an increasing proportion in the current process. However, most of the oxidation reactions were strong exothermic reactions, and the materials involved in the reactions were often unstable. In order to prevent the occurrence of reaction accidents, it was necessary to conduct a systematic study on the safety of reaction. A semi-intermittent dynamic reactor model with control condition was established by using process simulation method for liquid-phase oxidation. The structure, heat transfer setting and process control setting scheme of the reactor model were introduced. The epoxidation of propylene was simulated, the kinetic parameters and reactor parameters were set up. The reactor parameters were calculated by simulating the normal reaction process, demonstrating that the reaction was carried out under normal conditions. Based on the established model, the risk of multi-scene reaction under the conditions of closed insulation, cooling failure and cooling water control valve failure was simulated. The changes of temperature and pressure in the reactor and the composition of the material in the reactor were obtained, which provided data and technical support for making reasonable safety control measures in the follow-up work.

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Molecular simulation on adsorption of methane and toluene by activated carbon

Rifeng ZHOU Jihong SHI Quanzhen LIU Shanjun MOU Chunming JIANG Liang GONG

Chin. J. Process Eng. 2018, 18 (S1): 97-102. DOI: 10.12034/j.issn.1009-606X.20180074

Abstract （842）

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The porous carbon material constructed with graphite slice was used as the structure model of activated carbon. Grand Canonical Monte Carlo (GCMC) and molecular dynamics (MD) methods were used to study the adsorption and diffusion characteristics of methane and toluene in activated carbon at the molecular level. The results showed that the small element size of graphite sheet had certain influence on the adsorption of methane and toluene on porous carbon materials, and the porous carbon material composed of 37 carbon rings was the best adsorption structure. The diffusion rate of methane in the activated carbon material was faster, and the diffusion rate of toluene in the activated carbon was slower. With the increase of carbon atoms in the carbon ring, the self-diffusion coefficient of the gas in porous carbon increased gradually. The group made the optimal density shift to the high density after surface modification. The adsorption capacity was list as the order of hydroxyl>amino>carboxyl>none modified. The introduction of groups to improve the material pore structure helped to increase the adsorption capacity. The adsorption and diffusion characteristics of activated carbon to methane and toluene gases were studied, and the microcosmic mechanism of adsorption and diffusion of activated carbon was analyzed, providing ideas and guidance for the selection and development of excellent adsorption materials.

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CFD simulation of hydrogen sulfide gas absorption process in Venturi scrubber

Shuai YANG Xiangdi ZHAO Yinmou XU Zheng WANG Jiwu YUAN Wanfu SUN

Chin. J. Process Eng. 2018, 18 (S1): 103-110. DOI: 10.12034/j.issn.1009-606X.20180105

Abstract （712）

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Venturi scrubbers are widely applied in gas adsorption and industrial dedusting fields as they have advantages of simple structure, high efficiency and convenient operation. Nowadays, computational fluid dynamics (CFD) method has become a more efficient and useful tool to explore the gas liquid flow characteristics and mass transfer process in Venturi scrubbers as the development of computing ability. Based on the process of hydrogen sulfide gas absorption by sodium hydroxide solution in a self-priming Venturi scrubber, the injection ability, mixing degree as well as scrubbing efficiency at different operation conditions were studied by using the two fluid models, the RNG k?? turbulent model and the species transport model in CFD method. The accuracy of simulated injection flow rates were verified by the experimental data. The simulation results showed that, with increase of gas velocity, the injection flow rate increased, but the homogeneity of radial liquid dispersion in the diffuser became worse. The liquid phase was inclined to flow near the wall, which did not benefit for the hydrogen sulfide absorption process. With the increase of the distance above the throat, the velocities of gas and liquid decreased, resulting in more uniform radial liquid dispersion. In the hydrogen sulfide absorption process, the interphase chemical reaction mainly occurred in one fifth of the diffuser above the throat. In this area, the interphase chemical reaction rate increased and then decreased with the increasing distance above the throat. Therefore, the highest chemical reaction rate did not occur at the throat, but at nearly 5% of the diffuser above the throat. As the gas velocity increased, the interphase chemical reaction rate and scrubbing efficiency became higher, while the hydrogen sulfide concentration and scrubbing time decreased. The research findings provided the basis for the optimization of structure parameters and operation conditions in self-priming Venturi scrubbers.

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Solidification/stabilization of arsenic-bearing gypsum sludge using Portland cement: precalcination effect and arsenic immobilization mechanism

Yong LI Yuan XU Xing ZHU Hua WANG Xianjin QI Kongzhai LI Yonggang WEI

Chin. J. Process Eng. 2018, 18 (S1): 111-121. DOI: 10.12034/j.issn.1009-606X.20180108

Abstract （704）

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Arsenic-bearing gypsum sludge (ABG sludge), designated as one of the most important hazardous waste with high arsenic leaching toxicity in the metallurgical industry of nonferrous heavy metals, was treated by a hybrid technology combined with processes of precalcination and solidification/stabilization (S/S) using Portland cement for the arsenic immobilization. The precalcination effect and mechanism of arsenic immobilization were investigated in the S/S process. ABG sludge had an arsenic content of 8.56%, and its arsenic leaching concentration is high up to 1097.5 mg/L. The solidified fresh sludge had a high arsenic leaching concentration and low compression strength with a poor stability in acid neutralization capacity test. Those result indicated a further intensification of arsenic stablization was needed for the fresh sludge. Precalcination could reduce the arsenic leaching concentrations of sludge to a low level (41.2 and 4.2 mg/L for 600 and 700℃) when temperatures equal to or greater than 600℃ due to the removal of As(III). In subsequent S/S process, encapsulation and adsorption of arsenic in form of Ca2As2O7 and AlAsO4 by C?S?H products were responsible for the immobilization of arsenic in cement-sludge pastes. Precalcination also promoted the interaction between cement and arsenic in pastes, resulting in the intensification of AlAsO4 and dense Ca2As2O7 phase. The solidified pastes of ABG sludge precalcined at 600 and 700℃ possessed arsenic leaching concentrations (0.98 and 0.22 mg/L) lower than that of limit value (5 mg/L in GB5085.3-2007). This technology showed a favorable performance for the immobilization of ABG sludge and the solidified pastes are feasible for landfill disposal.

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Effects of compound microbial agents on high-temperature composting process and harmful gas emissions

Bin LU Xiaoyuan WU

Chin. J. Process Eng. 2018, 18 (S1): 122-128. DOI: 10.12034/j.issn.1009-606X.20180115

Abstract （580）

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High-temperature composting is a common way to treat agricultural solid waste, but its composting process is slow. A large amount of harmful gases pollute the environment during the process. The impact of compound microbial agents applied to high-temperature compost on the process of composting and harmful gas emissions during the period were studied. In this experiment, cattle manure and rice husk were used as raw materials to set up a treatment group inoculated with a composite microbial agent and a control blank group, and to compare the physical, chemical, and biological parameters of the compost, and the emission of harmful gases (methane, N2O). It can be seen that the inoculation of the compound microbial agent can accelerate the temperature rise of the reactor body, prolong the duration of the high temperature of the reactor body, shorten the composting time, and reduce the emission of harmful gases (methane, N2O).

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Efficient conversion of waste cooking oil into biodiesel catalyzed by immobilized ionic liquid

Dongxia YAN Chunyan SHI Xingmei Lü Jiayu XIN Gongying WANG

Chin. J. Process Eng. 2018, 18 (S1): 129-137. DOI: 10.12034/j.issn.1009-606X.20180165

Abstract （657）

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Ionic liquids possess excellent catalytic activities for various chemical reactions including esterification reaction, but the difficulty in phase separation is a major barrier. An immobilized ionic liquid (IL), 1-(4-butylsulfonic)-3-methylimidazolium hydrosulfate [(n-Bu-SO3H)MIm][HSO4], based on sol?gel technique and wetness impregnation method was developed in order to obtain an insoluble IL catalytic system suitable for the esterification of free fatty acids and methanol. The synthesized catalysts were characterized by various techniques and the catalytic properties were fully evaluated. The results demonstrated that the ionic liquid was successfully incorporated into the support. This immobilized Br?nsted ionic liquid catalysts displayed relatively high catalytic activity in esterification of oleic acid and methanol. Under the optimum reaction conditions, the conversion of oleic acid reached to 98.4%. The catalyst was also applied to catalyze the esterification of real waste cooking oil having high free fatty acid and followed by alkyli-catalyzed transesterification, a biodiesel yield of 94.7% was achieved.

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Effect of rust on runaway reaction of ethylene oxide aqueous solution

Jingru LIU Manping JIN Lei ZHAO Fan ZHANG Wei XU Ning SHI

Chin. J. Process Eng. 2018, 18 (S1): 138-145. DOI: 10.12034/j.issn.1009-606X.20180166

Abstract （1169）

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Exothermic reaction of ethylene oxide (EO) contacting with rust is believed to be responsible for explosion accidents of EO distillation tower. In order to systematically study the influence of iron rust/Fe2O3 on the thermodynamic parameters of runaway reaction of EO aqueous solution, the adiabatic calorimetry tests of EO aqueous solution?rust/Fe2O3 system were carried out by adiabatic calorimeter Venting Size Package-2 (VSP-2). The thermodynamic parameters such as the initial exothermic temperature, the maximum exothermic temperature and pressure, time to maximum reaction rate, the adiabatic temperature rise, the variation of temperature and pressure during runaway reaction process were obtained for EO aqueous solution?rust/Fe2O3 system. The results showed that under the experimental conditions the runaway reaction characteristics of EO aqueous solution?rust system were not obvious. There were no distinct temperature and pressure rise during reaction, and the maximum temperature and pressure of the system were lower than 200℃ and 1.0 MPa respectively. For Fe2O3 contacting with EO aqueous solutions, the initial exothermic temperature, the maximum reaction temperature and pressure decreased with increase of EO aqueous solution concentrations, and the time to maximum reaction rate was less than 30 minutes. The initial exothermic temperature of 30wt% EO aqueous solution?Fe2O3 system was close to 100℃. The initial exothermic temperature of pure EO?Fe2O3 system was about 150℃ and the adiabatic temperature rised close to 180℃. The addition of polymer in the Fe2O3?EO aqueous solution system had no obvious effect on the catalytic induction of the runaway reaction, and the severity of the runaway reaction was lower than that of the Fe2O3?EO aqueous solution system. Therefore, the catalytic induction of Fe2O3 solids on the runaway reaction of EO and its aqueous solution was more obvious compared to the on-site rust, and with the increase of EO mass fraction, the consequences of runaway reactions were more serious. The study on runaway reaction behavior of EO with rust would be useful for EO distillation process design and explosion accident prevention.

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Synthesis and photocatalytic degradation performance of 1,3-bis(carboxymethyl)-imidazolium phosphotungstate in treatment of methyl red

Yunzhu LIU Xiaofang FU Lihua GAO Liancai LEI Yibo WANG?

Chin. J. Process Eng. 2018, 18 (S1): 146-152. DOI: 10.12034/j.issn.1009-606X.20180195

Abstract （705）

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As the increase of environmental pollution and awareness of environmental protection, green chemistry is one of important direction of modern science. In recent years, heteropolyacids have been used as an efficient photocatalyst for the removal of organic pollutants. Ionic liquids have been applied in organic synthesis, electrochemistry, separation purification, and materials science because of their unique physical and chemical properties. The polyoxometalate-based ionic liquid hybrid material is a novel green catalyst containing the typical Keggin structure of heteropolyacids and ionic liquid cations, which possesses good water resistance, acidity, and is potential for efficient reaction from separation properties. Based on a model compound, organic dye methyl red (MR), the photocatalytic ability of the solid phase catalyst 1,3-bis(carboxymethyl)-imidazolium phosphotungstate was studied under UV light irradiation. The prepared catalyst was characterized by elemental analysis and IR spectra. The effects of irradiation time of UV light and amount of the catalyst to the degradation efficiency were investigated. The results showed that the synthesis photocatalyst retains both the Keggin structure of phosphotungstic anion and the structure of imidazolium cation. MR can undergo direct photolysis and the time required for complete photolysis was 220 min in the absence of the catalyst. When the amount of the catalyst was 0.02?0.10 g, the degradation efficiency of MR increased significantly with the increasing of the catalyst amount. The total degradation time of MR was 60 min when 0.08 g catalyst was added under UV light irradiation, and its degradation efficiency can reach three times as much as when no catalyst was added. The synthesized solid phase catalyst exhibited higher catalytic activity and good water resistance in the photolysis reactions. In addition, the catalyst was very stable and easily separated from the reaction system for recycling. It overcame the defects of traditional acid catalysts, which provided a promising new idea for high atom economy and green route of photocatalytic reactions.

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High phenol-containing coking wastewater treatment with environmentally benign alkali-enhanced extractant

Dingtian XIAO Latif ULLAH Shan QING Huaqiang XIAO

Chin. J. Process Eng. 2018, 18 (S1): 153-160. DOI: 10.12034/j.issn.1009-606X.20180231

Abstract （652）

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This work hereby reports an eco-friendly efficient extractive wastewater dephenolization process with particular emphasis on cutting secondary organic pollutants. A collection of coking waste water samples containing high phenol concentration was treated by an innovative phenol extraction method. To avoid experimental errors and facilitate water treatment, certain parameters were selected for determining the chemical composition of waste water samples. The distilled ammonia waste water was found to be ideal due to lack of oil film or ammonium sulfate tar precipitation during the dephenolization. In contrast to distilled ammonia waste water, the residual ammoniated water not only was the cause of extreme water pollution, it also consumed large quantity of acid resulting in high cost, thus creating economic issues for this process. For environmental aspects, while determining the phenol removal efficiency other influencing factors, such as determination of cyanides, sulfur ions, ammonia nitrogen content, chloride ions, sulfate ions, total volatile phenols, total salts, sewage oil content, along with total hardness, CODcr, electrical conduction and pH for comparative test and analysis of alkali-enhanced extractant were also determined. The diffusion behavior of organic molecules and reasons which determine changes in parameter before and after the phenol extraction were studied. Repeatedly washing the used BQ complex extractant 5 times with 3wt% sodium hydroxide solution at 23℃, the relatively optimal regenerated extractant can be prepared. The VHC value of the waste water processed by regenerated extractant was 265.45 mg/L. The regenerated BQ complex extractant was found to have a level of CODcr, sewage oil content, pH, dephenolization efficiency values as 3638.34, 188.86, 6.18, 83.76%, respectively, which meaned very little secondary organic pollutants.

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