超临界水氧化在难处理废水领域中的工程应用进展

系统总结了超临界水的溶液性质、超临界水氧化反应机理以及工业化过程中的基础工艺流程,指出了超临界水氧化技术具有处理彻底、反应迅速、无二次污染的特点,虽然在处理难处理废水上具有广泛的应用前景,但在工程化过程中不可避免地面临设备腐蚀、盐沉积堵塞、基础数据缺失、结焦堵塞、催化剂二次污染等问题。将超临界水氧化工艺装置撬装在可移动运载工具上,用于适应国内污染点分散的特点,具有巨大的市场价值。     

超临界水氧化技术及其应用

超临界水氧化技术(SCWO)是一种新型的有机废水处理技术,具有反应速率快、处理效果好、不形成二次污染和去除效率高等优点。介绍了超临界水的特性和氧化反应机理,综述了SCWO在处理火炸药生产废水中的应用,并针对其存在的设备腐蚀、反应器堵塞等问题提出了解决方法和研究方向。     

超临界水氧化技术在废水处理中的应用

综述了超临界水氧化技术在废水处理中应用的国内外背景,主要介绍了目前国内超临界水氧化技术废水处理的研究和应用情况。阐述了超临界水氧化技术的原理,和统的废水处理方法相比,超临界水氧化技术废水处理有反应快、彻底、污染小、容易分离、高效节能等优点,也存在易腐蚀、易堵塞、一次投资高等问题。     

超临界水及其氧化反应的研究及应用

超临界水(SCW)具有与常态下的水截然不同的性质,由此导致了超临界水的多种用处。超临界水氧化(SCWO)作为一种以超临界水为介质的新的废物处理技术以其完全快速等优点而日渐成为研究的热点。本文介绍了超临界水的特性和超临界水氧化的基本原理,反应器的装置,综述了超临界水氧化的动力学、应用、工艺改进、工程问题等方面的研究进展情况。     

PTA残渣的超临界水氧化处理与资源化利用

介绍了精对苯二甲酸(PTA)残渣的国内外处理情况,提出了利用超临界水氧化技术对PTA残渣进行无害化处理,同时可以回收利用超临界水氧化处理PTA残渣过程中放出的热能,实现PTA残渣的资源化利用,并分析了超临界水氧化技术存在的腐蚀和盐沉积问题。     

超临界水氧化技术工业化的瓶颈问题及解决方法

超临界水氧化技术作为一种绿色环保技术,在处理有毒、难降解和高浓度有害物质上有众多优势,且目前其应用基础已经形成,国外也有实际的工业应用之例。但是超临界水氧化反应器的腐蚀和结垢问题,以及超临界水氧化的高能耗、高费用的问题严重阻碍了该技术在工业生产中的推广和发展,成为制约其工业化的瓶颈问题。本文综述超临界水氧化过程中的反应器的腐蚀和结垢问题、反应热问题,同时指出当前解决这些问题的方法。此外还列举了目前采用超临界水氧化技术的单位以及其所采用的反应器类型。     

超临界水氧化技术

超临界水氧化（SCWO）技术是一种新兴的，很有前景的处理有机污染物的环保技术，具有很多特色和优势，然而，SCWO主要问题是反应器的腐蚀和盐的沉积，阻碍了SCWO的推广和工业应用。阐明了不同的反应器和工艺的改进观念。论述了SCWO存在的问题，讨论了可能的解决措施。并对SCWO系统中未来的发展提出了建议。     

超临界水氧化法处理有机废水的研究进展

超临界水氧化技术是一种能彻底破坏有机污染物结构的新型氧化技术,它在废水处理方面有着独特的优势。作者对超临界水氧化技术的工艺流程、反应器类型及研究现状进行了综述,并对其应用前景进行了展望。     

超临界水氧化技术

超临界水氧化技术是一种很有前途的,以超临界水为反应介质,彻底破坏有机毒害物质的新型环保技术。文章全面综述了超临界水的特征,超临界水氧化的基本原理,工艺流程。着重对超临界水氧化技术存在的问题,如材料的腐蚀和无机盐的沉积进行了讨论,并分析了解决的方法,最后对其应用前景进行了展望。     

超临界水氧化技术研究及进展

介绍了超临界水的特性 ,并对超临界水氧化技术的研究及应用进行了综述 ,提出了超临界水氧化技术的工程应用开发中存在的问题     

A novel concept reactor design for preventing salt deposition in supercritical water

Reactor plugging and corrosion are the key problems which hinder commercial applications of supercritical water oxidation and gasification, and can be efficiently overcome by preventing salt deposition on internal surface of reactor. In this work the problems caused by salt deposition and the correspondingly main solutions are further reviewed objectively. A novel reactor is designed and manufactured with a feed rate of about 100 L/h for sewage sludge treatment. The reactor combines the characteristics of Modar reactor and transpiring wall reactor for the first time, which is expected to prevent reactor plugging and corrosion as well as to decrease catalyst deactivation rate. The reactor is the core equipment of the first pilot-scale plant for supercritical water oxidation in China. Further optimizations of reactor configuration and operational parameters need plenty of experiments and/or a long-time test with sewage sludge in the subsequent work.     

Effects of structural parameters on water film properties of transpiring wall reactor

Corrosion and salt deposition problems severely restrict the industrialization of supercritical water oxidation. Transpiring wall reactor can effectively weaken these two problems by a protective water film. In this work, methanol was selected as organic matter, and the influences of vital structural parameters on water film properties and organic matter removal were studied via numerical simulation. The results indicate that higher than 99% of methanol conversion could be obtained and hardly affected by transpiration water layer, transpiring wall porosity and inner diameter. Increasing layer and porosity reduced reactor center temperature, but inner diameter's influence was lower relatively. Water film temperature reduced but coverage rate raised as layer, porosity, and inner diameter increased. Notably, the whole reactor was in supercritical state and coverage rate was only approximately 85% in the case of one layer. Increasing reactor length affected slightly the volume of the upper supercritical zone but enlarged the subcritical zone.     

亚临界水中盐的析出规律研究

在亚临界条件下,研究氯化钠和硫酸钠在亚临界水中的析出规律,主要考察了温度、压力对盐的去除率的影响。结果表明:氯化钠在350℃,5 MPa的条件下去除率达到最大;硫酸钠在350℃,4 MPa的条件下去除率达到最大。通过研究两种盐的析出规律,可以为超临界水氧化装置的预热反应器中预先去除废水中的无机盐(主要是氯盐和硫酸盐)提供科学依据,从而减缓和降低高盐对超临界设备的腐蚀和阻塞问题。     

Near and supercritical water. Part II: Oxidative processes

This paper is a review of applications of near and supercritical water with a focus on supercritical water oxidation (SCWO). Hydrolytic and hydrothermal reactions have been reviewed in Part I [G. Brunner, Near critical and supercritical water. Part I. Hydrolytic and hydrothermal processes, J. Supercrit. Fluids, this issue]. The potential lies in the complete destruction of persistent, anthropogenic waste material. The obstacles in the technical application are due to the highly corrosive reaction medium and the precipitation of salts. Reactor construction is the decisive feature for a commercial process. First, tank type reactors had been favored. Corrosion was kept low by ceramic material and salt deposition was avoided by a stream of cold and clean water at the reactor vessel walls. Later, tubular reactor design was preferred, and several means to prevent corrosion and salt deposits have been applied.     

Transpiring wall reactor in supercritical water oxidation

Reactor corrosion and plugging problems have hindered the commercialization of supercritical water oxidation (SCWO) for wastewater purification. The use of transpiring wall reactor (TWR) is an effective means to overcome the above two problems by forming a protective water film on the internal surface of the reactor to aviod contacting corrosive species and precipitated organic salts. This work mainly aims to objectively review experimental investigations and numerical simulation results concerning TWR. Subsequent investigations for parameters optimizations of TWR are also proposed in order to ultimately build effective regulation methods of obtaining excellent water film properties. All this information is very important in guiding the structure design and operation parameters optimization of TWR.     

国外超临界水氧化技术的研究现状

超临界水氧化是水处理技术发展的新方向,但该技术对设备的要求比较高,工业化应用仍有一定的难度。为了克服这一难题,目前的研究工作主要集中在催化剂的选择以及设备防腐蚀等方面。介绍了贵金属类催化剂、过渡金属类催化剂、碱金属盐类催化剂、杂聚酸类催化剂以及碳基类催化剂,在降解不同污染物时的催化效率。在反应器材质和反应器形式的研究中,分别对铁、镊、铬等纯金属以及不同材料的合金在各种条件下的防腐蚀性能作了比较;两种最新的反应器形式:可蒸发壁式反应器和流动式反应器。它们在超临界水氧化中表现出了良好的防腐能力。     

Research progress of supercritical water oxidation based on transpiring wall reactor

超临界水氧化技术的发展面临着腐蚀和盐沉积两大技术难题,采用蒸发壁反应器是解决这两大技术难题最为有效的方法。本文综述了国内外蒸发壁反应器的结构特点和性能,分析了基于蒸发壁反应器的超临界水氧化技术应用过程中仍然存在的问题,如多孔管的性能、物料的预热、系统能量利用及经济性,并提出了相应的解决办法。     

CFD simulation of a transpiring‐wall SCWO reactor: Formation and optimization of the water film

A two‐dimensional axisymmetric computational fluid dynamics model of a transpiring wall reactor for supercritical water oxidation was developed using the commercial software Fluent 6.3. Numerical model was validated by comparisons with experimental temperature profiles and product properties (total organic carbon and CO). Compared with the transpiration intensity, the transpiring water temperature was found to have a more significant influence on the reaction zone. An assumption that an ideal corrosion and salt deposition inhibitive water film can be formed when the temperature of the inner surface of the porous tube is less than 374°C was made. It was observed that lowering transpiring water temperature is conducive to the formation of the water film at the expense of feed degradation. The appropriate mass flux ratio between the total transpiring flow and the core flow was determined at 0.05 based on the formation of the water film and feed degradation. © 2015 American Institute of Chemical Engineers AIChE J, 62: 195–206, 2016     

超临界水氧化技术处理化工废水的研究

介绍了超临界水的特性、超临界水氧化法的基本原理、工艺流程及其优点,着重阐述了国内外超临界水氧化技术处理废水的研究现状,并指出超临界水氧化技术工业化存在的一系列问题.