二氯乙烷生产与市场

2 0 0 1年全球二氯乙烷 (EDC)消费量近 3 433万t,产能约 4 50 0万t/a ,产量约 3 433万t。经氯乙烯单体 (VCM)生产聚氯乙烯 (PVC)是EDC最主要的最终用途 ,估计约占全球EDC消费量的 95 %。预计 2 0 0 1～ 2 0 0 6年全球对EDC需求的年均增长率为 3 .4 % ,到 2 0 0 4年亚洲 (不包括日本 )EDC仍具有每年 9%的最高增长潜能。未来消费增长将取决于对VCM和PVC的需求。     

Analysis for vinyl chloride in PVC powders by head-space gas chromatography

At a temperature above the glass transition point of poly(vinyl chloride) (PVC), the solubility of vinyl chloride monomer (VCM) in PVC accurately follows Henry's law behavior for VCM contents up to 4000 ppm. This observation has lead to a rapid, simple gas-chromatographic method for the determination of VCM in PVC from the analysis of the vapor phase (head-space) over PVC powder samples in a sealed container. The basic experimental techniques, calculations, and examples of experimental data are given. The method can be used with any commercial gas chromatograph equipped with a flame ionization detector without instrument modification.     

含氯废弃物无公害焚烧技术的研讨

介绍含氯废弃物无公害焚烧处理的新技术，能使焚烧产生的极毒氯气变成稀盐酸。该新技术已应用于ＰＶＣ和ＶＣＭ生产中；研讨了对该新技术的推广应用，特别是用于无公害处理“白色”污染—ＰＶＣ塑料废弃物的可能性。     

Use of a gas chromatograph for measurement of the rate of monomer desorption from poly (vinyl chloride) resins

Previous studies by a gravimetric technique have established that the sorption and desorption of small quantities of vinyl chloride monomer (VCM) by poly (vinyl chloride) (PVC) resin powders obeys Fickian diffusion kinetics. Consequently, the rate of sorption or desorption is very sensitive to the size and structure distribution of the resin particles and is a useful measure of these properties. To facilitate the measurement of desorption rates, an “inverse GC” technique has been developed, with the PVC powder taking the place of the usual gas Chromatograph column. The detector and electronics of the GC are used to follow the VCM content of a carrier gas stream passing through a PVC resin sample initially equilibrated to a uniform VCM content. This method yields results consistent with the gravimetric data and provides a convenient means of characterizing PVC particle structure.     

Vinyl chloride formation from the thermal degradation of poly(vinyl chloride)

The volatile products from the thermal degradation of poly(vinyl chloride) (PVC) resins and compounds are shown to contain trace amounts of vinyl chloride. Data presented show the effect of temperature and resin type on the amount of vinyl chloride formed. At the maximum temperatures involved in PVC processing which may reach 210°C., vinyl chloride monomer (VCM) evolution amounts to less than 1 ppm (resin basis). A technique employing a thermogravimetric balance and charcoal adsorption of volatiles is described for studying thermal degradation of PVC. The volatiles are analyzed for vinyl chloride by gas chromatography. Peak identity was confirmed by mass spectrometry.     

Vinyl chloride formation from the thermal degradation of poly(vinyl chloride)

The volatile products from the thermal degradation of poly(vinyl chloride) (PVC) resins and compounds are shown to contain trace amounts of vinyl chloride. Data presented show the effect of temperature and resin type on the amount of vinyl chloride formed. At the maximum temperatures involved in PVC processing which may reach 210°C, vinyl chloride monomer (VCM) evolution amounts to less than 1 ppm (resin basis). A technique employing a thermogravimetric balance and charcoal adsorption of volatiles is described for studying thermal degradation of PVC. The volatiles are analyzed for vinyl chloride by gas chromatography. Peak identity was confirmed by mass spectrometry.     

聚氯乙烯生产过程全流程调度

研究了电石法制聚氯乙烯(PVC)全流程生产调度问题, 包括从电石生产、盐水电解到氯乙烯(VCM)聚合产品出厂各环节, 其中电石生产和VCM聚合是间歇过程, 其他生产环节是连续过程, 是一个混杂系统调度问题。本文针对过程特性对该问题进行了合理假设, 以包括电耗、库存、产品型号切换、交货延迟等的成本最小为目标, 建立了基于离散时间表示的混合整数线性规划(MILP)调度优化模型, 并针对一个案例进行了调度优化求解和分析, 验证了模型的可行性。     

Prediction of vinyl chloride monomer migration from rigid PVC pipe

Data on the solubility and diffusion of vinyl chloride monomer (VCM) in PVC resin powders have been combined with published solutions of Fick's diffusion equation to yield predictions of the amount and rate of loss of residual VCM (RVCM) from rigid PVC pipe under storage and service conditions. The principal factors controlling VCM migration are the initial VCM content, thickness of the PVC section, temperature and the age of the PVC product. Analysis Solutions are presented for RVCM loss from freshly exturded pipe (uniform VCM concentration) into either the storage environment or the pipe contents. From these solutions, estimates are made for the real-world situation of closed-system service following variable storage periods. The validity of this approach for rigid PVC pipe in water-service is supported by reasonable agreement between its predictions and experimental laboratory data on the VCM content of water stored in PVC pipes. Both the predictive model and experimental data indicate that PVC pipe containing ≤ mg/kg (1 part per million) residual VCM will result in VCM concentrations in water of less than 0.002 mg/kg - under any expected service conditions.     

液氯液化尾气合成氯化氢生产氯乙烯

对液化尾氯的应用进行了可行性探索,通过对液化尾氯的生产数据分析,并从理论计算上求证,证明氯气液化尾氯合成氯化氢直供电石法PVC生产是安全可行的。     

聚合釜冷凝器自聚原因分析及改进措施

对PVC生产过程中聚合釜釜顶冷凝器列管内出现氯乙烯(VCM)自聚的问题进行分析,并从工艺参数和设备改型等方面提出技术改造措施,从而延长PVC聚合釜的清釜周期和提高聚合釜的生产利用率。     

The migration of vinyl chloride monomer from PVC pipe into water

A study was undertaken to determine the extent of residual vinyl chloride monomer (VCM) migration from PVC pipe into water. Methods were developed to analyze VCM in water at low levels. Test samples of PVC pipe were exposed to water under static and flowing conditions for varying time intervals. The results indicate that the level of VCM extracted into water is directly proportional to the level of residual monomer in the pipe. Pipe containing <1.0 mg/kg(<1.0 ppm) residual VCM showed no VCM extracted into water with a test sensitive to 0.002 mg/kg (2 ppb).     

新国标下的氯乙烯尾气净化难点及解决方法

介绍了我国烧碱、聚氯乙烯行业大气污染物排放标准的变化,剖析了执行新国家标准(GB 15581—2016)后氯乙烯尾气净化的难点及解决方法,并列举了氯乙烯尾气净化装置改造实例。新建或改造的氯乙烯尾气净化装置,既要选择合适的工艺技术方案,又要严格遵守各项分析标准的规定,才能达到新国家标准对排放气的要求。     

Solubility of vinyl chloride in poly (vinyl chloride) in a water slurry

The solubility of vinyl chloride (VCM) vapor in poly (vinyl chloride) (PVC) in a water slurry has been measured between 55 and 65°C. The heat and entropy of sorption were shown to be very close to those of condensation. The solubilities measured in this study were higher than those obtained in other studies on dry PVC and PVC latex. The interaction parameter (x) in the Flory-Huggins equation has been shown to vary between 0.34 and 0.61 over the composition range studied. The effect of ageing the slurry in the presence of VCM is also discussed.     

变压吸附回收氯乙烯精馏尾气中的氯乙烯和乙炔

介绍了采用变压吸附回收氯乙烯精馏尾气中氯乙烯和乙炔的工艺流程,并对变压吸附装置运行过程中出现的问题提出了解决方案。以中盐湖南株洲化工集团有限公司10万t/a PVC生产装置计,每年可回收乙炔气132 664 m3,回收氯乙烯单体246.48 t,产生的经济效益约200万元。     

氯碱企业建设氧氯化锆及白炭黑项目的可行性

针对烧碱配套聚氯乙烯装置盈利空间减弱的形势,提出氯碱企业建设氧氯化锆和白炭黑项目的方案：采用锆英砂沸腾氯化法工艺生产氧氯化锆,同时将其副产的四氯化硅采用气相法工艺生产白炭黑.这样可以充分利用氯碱企业的过剩资源——氯气和氢气,并将生产白炭黑过程中副产盐酸解吸的氯化氢用于氯乙烯的合成,达到降低聚氯乙烯生产成本的目的.     

煤制氢解决PVC生产企业氯平衡实现循环经济

分析了目前我国PVC、烧碱生产企业状况。提出了通过配套固定床煤气发生炉产生氢气和煤气的建议:将氢气用于消化电石法PVC生产过程中的多余氯气(生产氯化氢),而剩余煤气则在固碱生产中作为燃料使用。详细叙述了煤气发生炉配套变压吸附装置生产氢气的工艺流程,并阐述了综合利用过程。     

Influences of diallyl phthalate as chain extender on the properties of high molecular weight poly(vinyl chloride) resin

A higher porosity with better thermostability is desirable for poly(vinyl chloride) (PVC) resin. In this study, high molecular weight PVC resins are prepared by vinyl chloride monomer (VCM)‐diallyl phthalate (DAP) suspension copolymerization in a 20‐L reactor at 50 °C using DAP as chain extender. SEM, BET, and analyses of plasticizer absorption results show the high molecular weight poly(vinyl chloride) (HPVC) by DAP‐VCM copolymerization is loose and porous. With increasing DAP content when the mass ratio of DAP/VCM (ω) is below the gel point, the porosity and the degree of polymerization increase. Nevertheless, the bulk density and particle size decrease. When more than the gel point, these relationships are reversed. Thermogravimetric analysis revealed that the HPVC had better thermostability than that of commercial PVC, and its thermostability increases with increasing ω before it reaches the gel point. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45093.     

An investigation of precipitation polymerization in liquid vinyl chloride by photon correlation spectroscopy

Simultaneous photon correlation spectroscopy and light transmittance measurements were used to follow changes in the particle size and particle number density of poly(vinyl chloride) (PVC) particles which phase separated in liquid vinyl chloride (VCM) during the early stages of bulk polymerization. The scope and limitations of these techniques for studying dynamic systems are discussed. The nature and extent of interaction forces are deduced from experimental data together with a proposed mechanism for the colloidal stability of PVC gel particles in liquid VCM.     

PVC生产过程中节能降耗的有效途径

介绍了河北宝硕集团股份有限公司在PVC生产过程中节能降耗的有效途径 ,采用聚合釜密闭入料 [可降低消耗VCM 1 0kg/(t·PVC) ]、汽提浆料 [回收单体 94 1t(按 4万t/aPVC计算 ) ]以及其它的新技术、新工艺等 ,节约资金达 1 385万元 /a。     

Technical progresses for PVC production

This review covers recent development of PVC production technologies of the suspension polymerization process, the bulk (mass) polymerization process and the emulsion polymerization process with some historical background. The development of process for the vinyl chloride monomer (VCM) production is also explained briefly. Since the suspension process is regarded to be the most important process with its 80% share of the world total production, this review follows mainly the technology development of the suspension polymerization process. Because of the importance of hygienic problems caused by VCM, the technology development in the field of emission control is also covered.