三氯乙酸生产工艺的研究和工业化生产

在催化剂作用下,对氯乙酸生产过程中产生的母液进行通氯氯化,生产出了三氯乙酸。     

硫酸生产新工艺

介绍了一项以纯氧[（？）（O_2）99.5%或更高]作为氧化剂的硫酸生产新工艺,该工艺采用三转三吸以获得更高的SO_2转化率,超过85%的尾气循环进入转化器以大幅度减少尾气的排放量。重点介绍了焚硫工序、SO_2转化工序和SO_3吸收工序的工艺流程及关键设备焚硫炉、转化器结构。与采用同样参数的常规工艺相比,新工艺吨酸中压蒸汽产量更高、硫磺和电能消耗更低,排放气体中SO_2、SO_3和NO_x含量及数量均低得多。     

A novel cyclic process for synthesis gas production

This paper reports a novel cyclic partial oxidation process for the production of synthesis gas with the in situ separation of oxygen from air. A perovskite-type oxide, La_0.8Sr_0.2Co_0.5Fe_0.5O_3−δ, is employed in the experimental study of the process as an oxygen retaining material. Air and methane are periodically brought into contact with the oxide packed in a fixed-bed reactor. The oxide, during the air step, exclusively retains oxygen while partial oxidation reaction occurs during the methane step utilizing the retained oxygen. Although combustion and cracking reactions occur in addition to the partial oxidation reaction during the methane step, high methane conversion is achieved and hydrogen and CO are produced with high selectivity.     

工业磷酸一铵生产工艺的优化

云天化国际云峰分公司工业磷酸一铵(MAP)装置通过湿法磷酸净化剂脱硫改湿法磷酸矿浆脱硫、顺流加料蒸发流程改逆流加料蒸发流程、母液再脱硫循环、滤渣和废水综合利用等一系列技术改造,优化了工艺,产量稳步提升,原料和能耗大大降低,提高了磷酸一铵生产的综合效益。     

NMPC of an industrial crystallization process using model-based observers

This paper illustrates the benefits of a nonlinear model-based predictive control (NMPC) approach applied to an industrial crystallization process. This relevant approach proposes a setpoint tracking of the crystal mass. The controlled variable, unavailable, is obtained using an extended Luenberger observer. A neural network model is used as internal model to predict process outputs. An optimization problem is solved to compute future control actions taking into account real-time control objectives. The performances of this strategy are demonstrated via simulation in cases of setpoint tracking and disturbance rejection. The results reveal a significant improvement in terms of robustness and energy efficiency.     

氟硅酸法制备氟硼酸新工艺

介绍了用氟硅酸制备氟硼酸的试验研究、工艺流程、设备投资情况。本工艺反应温度 70～95℃ ,反应时间 1～ 4h ,硼酸用量比 ( 0 .9～ 1 .2 )∶1 ,氟硅酸浓度要求≥ 1 6%。产品氟硼酸浓度≥ 40 %。     

A novel method for continuous production of cyclodextrins using an immobilized enzyme system

Selected specific α-amylase and glucoamylase enzymes were immobilized and combined with immobilized cyclodextrin glycosyltransferase to continuously produce cyclodextrin (CD). The liquefied starch was cyclized to CD by ICGTase and then treated by immobilized α-amylase and glucoamylase to contain CD and glucose only. β-CD and soluble CD (α- and γ-CD) in the final CD solution could be easily separated. The pH-activity curve, temperature-activity curve, batch re-usability and continuous operation stability of immobilized enzymes were discussed. The continuous production of CD by an immobilized enzyme system was also reported. The optimal conditions for using immobilized α-amylase and glucoamylase simultaneously were 40°C and pH 4.5 adjusted by 1 mol dm^?3 HCl/NaOH. A 70% yield of CD could be obtained from 1% (w/v) of liquefied starch under continuous operation at 0.055 h^?1 space velocity, and almost all the oligosaccharides (β 98%) were converted to glucose. In this study, the separation of α-CD, γ-CD and glucose, using organic solvent from the final product after precipitating β-CD, was also investigated.     

湿法磷酸净化生产工业磷酸新工艺的研究

采用湿法磷酸与盐酸法磷酸按体积比(1~6)∶1混合,除去Ca2+、SO42-、Fe3+等杂质,澄清过滤后的磷酸再用磷酸三丁酯进行6~12级萃取提纯浓缩以生产工业磷酸。该法利用盐酸萃取磷酸可大大提高中低品位磷矿的利用率,与湿法磷酸混配省去了传统脱硫、除铁工序,可节约成本,所得产品纯度高于工业磷酸行业标准。     

A novel electrochemical process for the production of ammonium perchlorate

Perchloric acid, HCLO₄, and ammonium perchlorate, NH₄ClO₄, of high purity have been produced by electrolysis of chloric acid and subsequent reaction with high purity ammonium hydroxide to produce ammonium perchlorate. The process involves no alkali metals, chlorides or transition metals such as chromates, and thus produces propellant and explosive grade ammonium perchlorate of high purity and with no associated instability or pollution problems. The products can be recovered by solution crystallization-drying or direct spray-drying, respectively.     

A novel electrolytic process using a Cu cathode for the production of Mg metal from MgO

Journal of Applied Electrochemistry - An environmentally friendly and effective molten salt electrolysis process using a copper (Cu) cathode was developed for producing magnesium (Mg) metal from...     

用湿法磷酸制工业磷酸二氢铵工艺综述

综述用湿法磷酸制工业磷酸二氢铵的几种工艺,包括传统化学法工艺、改进化学法工艺、化学净化与溶剂萃取联合除杂质工艺、湿法磷酸净化工艺、化学净化与溶剂萃取相结合工艺、萃取盐酸法工艺,介绍各工艺的生产流程,分析各工艺优缺点。建议厂家根据实际情况选择合适的工艺。     

分子蒸馏方法提纯十二烷二酸（英文）

A novel purification process is involved to obtain the high purity [N 99%(by mass)] dodecanedioic acid (DC12). It involves a re-crystal ization followed by molecular distil ation from the crude product. The objective of this study is to investigate general conditions, feed rate, distil ing temperature and vacuum, necessary for centrifugal distil-lation of DC12. Under the optimum conditions, distilling temperature 180 °C, pressure 30 Pa and feed flow rate 700 ml·h?1, the purity of DC12 in the residence reached 97.55%with a yield of 53.18%by the analysis of gas chromatography. Multiple-pass distillation made a considerable contribution by improving the purity to 99.22%. Additionally, the effect of pretreatment (re-crystallization) on distillation process was revealed through a series of comparative experiments.     

利用ADC副产盐酸生产PVC的工艺

介绍了ADC发泡剂副产盐酸的综合利用途径。将深解吸得到的氯化氢用于PVC生产,该工艺技术成熟,并可提高ADC产品品质。     

New process for catalyst-free biodiesel production using subcritical acetic acid and supercritical methanol

The production of glycerol as a by-product is unavoidable in the current conventional biodiesel manufacturing processes. Since biodiesel production is expected to increase in the near future, effective utilization of glycerol will become an issue of interest. In this study, therefore, a process consisting of subcritical acetic acid treatment to convert rapeseed oil to fatty acids and triacetin followed by conversion of the obtained fatty acids to their fatty acid methyl esters in supercritical methanol treatment was investigated. The obtained results clearly revealed that this two-step reaction could proceed effectively at a high reaction rate, and that fatty acid methyl esters and triacetin could be obtained under milder reaction condition than the one-step process utilizing supercritical methyl acetate and supercritical methanol.     

A novel process for preparing pure chenodeoxycholic acid from poultry bile

Macroporous adsorption by column chromatography was introduced into chenodeoxycholic acid (CDCA) separation from duck bile in this study. After bile saponification in 2.5 M NaOH for 6 h and conversion of CDCA calcium salt with Na₂CO₃, CDCA was purified by the hydrophobic chromatography with macroporous resin HZ-802. With 40% ethanol as loading solvent and 50% and 60% ethanol as stage elution solvents, high purity of CDCA was obtained, and its melting point could be achieved 160–170 °C (99% purity) after crystallization by 65–70 °C water bath cultivation. The novel process was environmentally friendly and economical compared to conventional method, and it has been successfully scaled up in industry.     

工业生产氟硅酸镁工艺探究

为了寻求工业生产氟硅酸镁的最佳工艺条件,降低能耗并提高产品质量,系统研究并优化了利用磷肥工业副产氟硅酸和氧化镁粉生产氟硅酸镁晶体颗粒产品的工艺参数。列举了氟硅酸镁产品的粒径以及粒度分布等物化性能指标,得到了氟硅酸镁产品最大产率的最佳工艺参数：直接将氧化镁粉计量加入合成槽,并确定其加入的顺序,氟硅酸质量分数为16%,m（氧化镁）/m（氟硅酸）为0.244~0.260,合成温度控制在40~50 ℃,得到浓度较高的产品溶液;蒸发温度为35~45 ℃,蒸发浓缩的晶浆进入MSMPR冷却结晶槽;冷却结晶温度控制在30 ℃,结晶槽搅拌器的转动频率控制在20~40 Hz,产品粒径可以控制在0.16~0.37 mm,该研究可为相关生产企业提供工艺技术方面的借鉴。     

湿法磷酸净化生产工业磷酸一铵研究

磷酸一铵用作灭火剂、阻燃剂等工业领域需要有较高的纯度.传统的湿法磷酸氨化法生产的磷酸一铵杂质含量高,主要用作农业肥料,无法作为工业品使用.工业用磷酸一铵一般采用热法磷酸来生产,成本高,污染重.研究了将湿法磷酸净化来生产工业用磷酸一铵的方法,同时副产肥料级磷酸一铵.研究结果表明,该方法可以生产磷(以五氧化二磷计)质量分数在59%以上的工业用磷酸一铵,磷(以五氧化二磷计)收率在70%以上,副产的肥料级磷酸一铵有效磷(以五氧化二磷计)质量分数在30%～40%,有效磷收率为15%～20%.     

A novel polymerization process using rotating disk atomizer

Macroporous highly crosslinked styrene(St)-divinylbenzene(DVB) copolymers were prepared by solution and suspension polymerization techniques. The obtained materials allowed the grafting of poly(N-vinyl-tert-butylcarbamate) (PVCa) either by addition of VCa macroradicals to the solid bound double bonds or by termination involving the reaction of VCa macroradicals with radicals present on the carrier. Poly(vinylamine) (PVAm) grafted on St-DVB carriers was obtained after the hydrolysis of grafted PVCa with HCl and the subsequent removal of the aminebonded HCl by means of NaOH. Heterogeneous bifunctional catalysts were obtained by attachment of cobalt(II) 4,4′,4″,4?-tetracarboxyphthalocyanine (CoPc(COOH)₄) to the grafted PVAm. The prepared catalysts were applied to the autoxidation of thiols to disulfides, both in predominantly apolar media and in aqueous media. It was demonstrated, that important prerequisites for the applicability of macroporous St-DVB copolymers as carriers for the PVAm-CoPc(COOH)₄ catalyst include a high surface area, a sufficiently large average pore diameter and accessibility of the pendent double bonds.