海上含油钻屑的热解析除油处理

采用间接加热的热解析技术对海上油田含油钻屑进行处理,考察了热解析处理的效果和影响因素。实验结果表明：在热解析主温度为410.0 ℃下对含油率为14.00%~23.60%（w）的钻屑进行热解析处理,处理后钻屑的石油烃含量低至0.07%;为达到处理后钻屑含油率低于1%的要求,处理速率最高可达2.47 t/h;回收油的主要烃类化合物组成与岩屑油一致,可用于泥浆复配;冷凝回收水的COD及石油类物质超标,处理后可作为循环冷却水的补充水;外排气体的污染物指标达到国家排放标准;该套实验装置处理含油率为14.00%~23.60%的钻屑,柴油消耗量小于15 L/t、电能消耗量小于9 kW·h/t。     

Two-stage thermal gasification of polyolefins

Plastic pellets of polyethylene (PE), polypropylene (PP), and polystyrene (PS) were gasified in a two-stage thermal degradation process. The first stage is the conversion of polyolefins to distilled oils using a melting vessel. In the second stage, the oils from the first stage are gasified using a tubular reactor. The distilled oil yields of PE, PP, and PS in the first stage were 84, 89, 92 wt%, respectively, each at 470°C. The total gas yields of PE, PP, and PS in the second stage were 80, 74, and 6.2 wt%, respectively, each at 800°C. The main components of the product gas for PE and PP were methane and olefins such as ethene and propene. Some aromatic oils, including benzene, toluene, and xylene, were also produced as by-products. The amount of carbonaceous residue, or coke, was very low (less than 1 wt%). By dividing the process into two stages, the coking rate was considerably reduced compared with direct gasification of the polyolefins. Received: July 19, 2000 / Accepted: September 17, 2000     

Remediation of petroleum-contaminated soils by fluidized thermal desorption

A novel type of fluidized bed desorber was developed for the remediation of petroleum-contaminated soils at low temperature with high efficiency. Cahn balance® was utilized to investigate the thermal desorption behavior of soils contaminated by various hydrocarbons. The performance of the fluidized-bed desorber was investigated at different operating modes. Batch operation of the fluidized-bed desorber exhibited 99.9% desorption efficiency at temperatures of ca. 300°C within a half hour. Continuous operation of the fluidized-bed indicated that Q/F (the ratio of the mass flow rate of fluidizing gas to feeding rate of contaminated soils) is less important at higher temperature (>300°C), if proper fluidization is ensured. The periodic operation of the fluidized bed desorber shows the possibility to reduce off-gas volume significantly.     

低温等离子体和催化剂协同作用处理有害气体

低温等离子体和催化剂协同作用技术具有分解效率高、能耗低、副产物少的优点而逐渐成为处理低浓度、大流量有害气体的重要方法。文章对反应机理、反应器的结构和在处理挥发性有机污染物(VOCs)、氮氧化合物等方面的研究进展做了概括,指出了该技术在环境治理方面的应用前景和发展方向。     

Assessment of in situ thermal treatment for chlorinated organic source zones

The East Gate Disposal Yard (EGDY) at Fort Lewis is the source of a large trichloroethene (TCE) plume at this military installation. Source reduction using thermal treatment was applied using electrical resistance heating. A total of about 5,800 kg of TCE‐equivalent volatile organic compounds (VOCs; TCE and dichloroethene) was extracted during thermal treatment of the three zones selected for source reduction. Pretreatment groundwater TCE concentrations were measured up to 100 ppm. Posttreatment groundwater TCE concentrations within the treatment zones averaged less than 100 ppb. Posttreatment soil TCE concentrations decreased by over 96 percent compared to pretreatment soil concentrations. The overall contaminant flux from EGDY was reduced by an estimated 60 to 90 percent by the source reduction effort. The traditional and new techniques for site characterization and remediation performance monitoring applied at EGDY provide insight for installing, operating, monitoring, and assessing thermal treatment. © 2009 Wiley Periodicals, Inc.     

Chemiluminescence in evaluating thermal oxidative stability of acrylonitrile-butadiene-styrene (ABS) copolymers. III. Emulsion-grade products

The thermal oxidative stability of various formulations based on emulsion-grade ABS was studied by the chemiluminescence technique. Emulsion products were found to be essentially less stable than ionic mass polymerization resins. Among the antioxidants studied, Santonox R is clearly more efficient than Irganox 1076 and Irganox 3114, and its superiority is reflected primarily in improved induction period values. The introduction of Tinuvin 770 and Tinuvin 328 UV stabilizers into emulsion resins does not change the durability of the products. In mixtures where both Irganox 1076 and UV stabilizers are present, a certain antagonistic effect was noted at high UV stabilizer concentrations.     

Behavior of bromine on the thermal decomposition of paper-based phenolic laminate wastes

We investigated the thermal properties and behavior of bromine on the thermal decomposition of paper-based phenolic laminate wastes containing polybrominated flame retardants. The thermal properties of the phenolic laminate wastes were measured with a thermogravimeter and a conduction-type scanning calorimeter (TG-CSC). The weight loss of the wastes on thermal decomposition was mainly in three phases between 40°C and 600°C. The enthalpy (ΔH) of the thermal decomposition was 104 cal/g. The material balance of the decomposition components was measured with batch-type thermal decomposition equipment. The ratios of carbon residue, liquid, and gas on decomposition at 800°C in a vacuum were 37 wt. %, 48 wt. %, and 15 wt. %, respectively. The bromine contents in the carbon residue and liquid were less than 0.02 wt. % and 10 wt. %, respectively. These results are useful both in the carbonization process of these wastes and in the application of carbon residue as carbon materials. Received: August 11, 2000 / Accepted: March 7, 2001     

Performance evaluation of material separation from spent fluorescent lamps using the thermal end-cutting method

The recovery of valuable materials such as aluminum, phosphor powder, and glass from spent fluorescent lamps (SFLs) is part of the overall recycling process of lamps. In the end-cutting process, an SFL is separated into a base cap and a glass part using thermal shock caused by the temperature difference between the heating unit and the cooling unit. The separation efficiency of the end-cutting system is estimated by measuring the mass of the parts of the SFL. The optimum condition of the end-cutting process with thermal shock was determined to have a temperature difference of 600 °C and moving speed of 2 cm/s. At optimum conditions, the separation efficiency of glass and the end cap from an SFL using the end-cutting method is estimated to be more than about 97 %. In an air injection system, however, the separation efficiency of phosphor powder from glass is less than 50 %. Separation efficiency in the end-cutting system is increased by decreasing the moving speed of the SFL and increasing the temperature difference between the heating unit and the cooling unit. From the results of experiments, it was found that the end-cutting unit has very high performance because the overall separation efficiency is more than 95 %.     

Treatment of electronic waste to recover metal values using thermal plasma coupled with acid leaching--a response surface modeling approach

The global crisis of the hazardous electronic waste (E-waste) is on the rise due to increasing usage and disposal of electronic devices. A process was developed to treat E-waste in an environmentally benign process. The process consisted of thermal plasma treatment followed by recovery of metal values through mineral acid leaching. In the thermal process, the E-waste was melted to recover the metal values as a metallic mixture. The metallic mixture was subjected to acid leaching in presence of depolarizer. The leached liquor mainly contained copper as the other elements like Al and Fe were mostly in alloy form as per the XRD and phase diagram studies. Response surface model was used to optimize the conditions for leaching. More than 90% leaching efficiency at room temperature was observed for Cu, Ni and Co with HCl as the solvent, whereas Fe and Al showed less than 40% efficiency.     

Effective low-temperature thermal aeration of soils

Low-temperature thermal aeration (LTTA) is a remedial technology developed by Canonie Environmental Services Corp. (Canonie) for use on soils containing nonchlorinated hydrocarbons, chlorinated solvents, volatile organic compounds (VOCs), chlorinated pesticides, and low levels of polynuclear aromatic hydrocarbons (PAHs). The LTTA system separates these hazardous constituents from excavated soils and allows the treated soils to be redeposited on-site without restriction. This article describes the various components and operation of LTTA systems for the remediation of soils contaminated with chlorinated and nonchlorinated constituents. The article also details the results of projects completed to date, principally for soil impacted with chlorinated hydrocarbons, and discusses the general characteristics and results of systems used for soils contaminated with nonchlorinated hydrocarbons (gasoline, etc.).     

污泥热水解技术研究进展

热水解可以改善污泥的生物降解性能和脱水性能,提高后续厌氧消化系统中有机物的去除率。本文阐述了热水解对污泥物理特性主要包括流变特性和脱水行为的影响;分析了热水解对污泥中氨氮浓度及对厌氧消化的作用;同时介绍了热水解技术对整个污泥处理系统能量需求的影响。指出：热水解改善了污泥的厌氧消化性能,提高了沼气等再生资源的产量,且厌氧消化产生的沼气量与热水解技术所需的能量基本平衡。     

Managing petroleum refining wastes by thermal desorption

The U.S. Environmental Protection Agency has developed regulations under the Hazardous and Solid Waste Amendments (HSWA) of 1984 to restrict the land disposal of hazardous wastes. As a result of the regulations, all hazardous wastes to be placed on the land must meet treatment standards based on the performance of the best demonstrated available technology (BDAT) identified for individual waste classifications. The Marathon Oil Company is currently evaluating innovative technologies for managing listed waste materials, with a focus on waste minimization and recycling. Remediation Technologies, Inc. (ReTeC) has conducted testing on wastewater treatment sludges from three Marathon refineries using a proprietary thermal desorption technology. The results from these tests have demonstrated that the technology has the ability to consistently meet BDAT treatment standards, while preferentially separating and condensing residual moisture and oils from the material.     

Perfluoroalkyl and polyfluoroalkyl substances thermal desorption evaluation

Per‐ and polyfluoroalkyl substances (PFAS) are highly resistant to biotic and abiotic degradation and can withstand very high temperatures before breaking down. The storage of PFAS‐impacted water and sediments in a holding pond or stockpiled investigation or remedial action‐derived waste is occurring on an increasing number of sites. The most common PFAS water treatment options include granular‐activated carbon and resins and the most common soil treatment options have been primarily limited to excavation, offsite incineration, and, in some cases, soil stabilization. An increasing number of states across the United States are establishing part per trillion PFAS guidance levels for drinking water. Removing PFAS from soils removes PFAS source impacts to groundwater. In this study, volatilization of PFAS from soil treated using in situ thermal heating is evaluated as a treatment method to achieve a high degree of PFAS removal from soils. The evaluation of temperatures needed to achieve removal is described. To minimize vapor treatment required for PFAS thermal remediation, a scrubber was incorporated into the treatment train to transfer PFAS to the liquid phase in a concentrated, low‐volume solution. Vapor‐liquid equilibrium behavior and the extent of PFAS volatilization from impacted soil over a range of temperatures were evaluated. Results showed that heating soil to 350°C and 400°C reduces PFAS soil concentrations by 99.91% and 99.998%, respectively. It was also confirmed that sulfonate‐based PFAS generally required higher temperatures for volatilization to occur than carboxylate‐based PFAS.     

Continuous in-line gasification/vitrification process for thermal waste treatment: process technology and current status of projects

The Thermoselect High Temperature Recycling process has been developed in order to make available a thermal waste treatment technology avoiding major problems as known from traditional techniques like landfills or ashes, filter dust and emission producing processes. It combines slow degassing with fixed bed oxygen blown gasification and mineral and metal residue melting in a closed loop system. Municipal, industrial and other kinds of waste are compacted to less than one fifth of their original volume by means of an armored hydraulic press, and then periodically pushed into an indirectly heated degasification channel. As the waste plugs are pushed down the channel in an oxygen-free environment, waste humidity is evaporated and the organic components in the refuse are partially degasified and to a certain extent converted into a carbon-like product as the temperature increases. This flaky product and the enclosed inorganic components such as metals and minerals are continuously fed into a high-temperature reactor (HTR). Pure oxygen is added in controlled quantities and reacts with the material following exothermic oxidisation reactions. Due to overall under-stoichiometric conditions, gasification products form a combustible synthesis gas. The heat of reaction leading to temperatures up to about 2000°C in the core of the lower HTR section acts to also smelt the metal and mineral components of the waste. Chlorinated hydrocarbons such as dioxins and furans are reliably destroyed along with other organic compounds in the gaseous and the liquid phase. Material conversion equilibria are assured due to high temperatures and sufficient residence times. The synthesis gas is purified before use as combustible or primary material. After long term operation of the industrial scale demonstration plant in northern Italy, recent orders of differently sized Thermoselect plants can be announced and are illustrated on the basis of three cases out of five [with Herten 225,000 Mg/a and Berlin 300,000 Mg/a] in Germany: (1) Karlsruhe plant, 3 lines, 225,000 Mg/a, under construction; (2) Ansbach plant, 1 line, 75,000 Mg/a, completely purchased in July 1997; (3) Hanau plant, 2 lines, 90,000 Mg/a, partially purchased in October 1997. The technical concepts of these projects are illustrated with special emphasis on the flexibility of tailor-made energy recovery solutions.     

Studies of the thermal degradation of waste rubber

One kind of Chinese waste tire's sample was pyrolyzed under an inert atmosphere by using thermo-gravimetric apparatus (TGA) and differential thermal analysis (DTA). Different pyrolysis temperature ranges were determined according to the reaction transition temperature obtained by TGA and DTA. Then, at each temperature range, the pyrolysis gaseous products were analyzed by gas chromatography (GC). The influence of the temperature range on the relative yields of the major decomposition products is studied, and a mechanism for the formation of the main components was also investigated. The results indicate that pyrolysis of waste rubber follows the radical mechanism, and the major products are not seriously affected by increasing the temperature from room temperature to 420 degrees C and from 421 to 600 degrees C, but the degradation of blend rubber is different for each of the compositional elastomer.     

火电机组热力系统EDTA化学清洗

对火电机组EDTA化学清洗过程中的清洗范围、清洗工艺、控制参数和清洗效果等进行了介绍,并结合工程实际提出了EDTA清洗过程中易出现的问题,为化学清洗工作提供了一定的防范措施.     

火电厂Ovation系统优化升级

介绍了Ovation控制系统的特点及应用情况,阐述了某火电厂1号机组Ovation控制系统优化升级的实施方案,并对系统优化性能进行了总结,为更好的应用ovation系统提供参考。     

Comparative environmental analysis of waste brominated plastic thermal treatments

The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of "fossil fuels" and "climate change". Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste.     

火电厂电缆安全状况调查

通过对30家火电厂92台机组电缆安全状况的调查,研究了火电厂电缆安全技术管理体系的建立和执行情况、电缆设备状况、电缆安全技术措施以及运行管理状况。指出火电厂电缆安全状况在安全管理体系不健全、电缆设备安全隐患较多、安全技术措施不到位且运行管理相对较为松懈等问题,加大了火电厂电缆事故发生机率。针对电缆安全技术现状和管理现状,提出了提高和改善火电厂电缆安全水平的技术和管理措施。