内电解—Fenton氧化—絮凝沉淀预处理焦化废水

采用内电解—Fenton氧化—絮凝沉淀的化学集成技术预处理焦化废水,优化了各工段的运行参数。实验结果表明：在钢铁铁屑与活性炭的体积比为1∶1的条件下,内电解工段的优化参数为进水pH 2.6~3.1、HRT=1.0 h;Fenton氧化工段的优化参数为Fe2+加入量200 mg/L、H2O2加入量1 000 mg/L、进水pH 3.0左右、反应时间1.0 h;絮凝沉淀工段的设定参数为进水pH 9.5~10.0、聚丙烯酰胺加入量1 mg/L、静置沉降0.5 h。在上述工艺条件下,该集成技术对废水的总COD去除率大于55%,处理后的废水BOD5/COD大于0.28,不添加稀释新水即可进入后续生化处理系统。该工艺占地面积小、系统结构简单、易于工业化,废水预处理成本为4~5元/t。     

一种提高臭氧氧化效率的方法和装置

正该专利涉及一种提高臭氧氧化效率的方法和装置。该装置为一种立式、两段式臭氧氧化废水处理装置。包括预氧化和催化臭氧氧化工段,预氧化工段中装填普通填料,催化臭氧氧化工段中装填专用催化剂,催化剂根据废水中有机物的类型进行选择。臭氧采用多点式投加,根据各工段氧化出水中有机物处理效果调节臭氧投加量。解决了现有臭氧氧化技术中氧化效果不稳定、臭氧消耗量大的问     

ABS废水处理技术

ABS树脂作为性能优良的工程塑料现已广泛应用于制造电视机、冰箱外壳等产品。我厂主生产装置工艺引进韩国 LG化学技术 ,废水处理场由韩国GREEN ENGINEER公司设计并提供设备。废水处理场运行初期因设计及操作等原因 ,处理后出水水质不稳定 ,经过一系列技术改造后 ,现已达到国家一级排放标准。1　废水来源及水质废水主要由 PBL工段废水、ABS工段废水、掺配工段废水和生活污水组成 ,水质情况见表 1。表 1　废水水质项目 PBL 工段废水 ABS工段废水掺配工段废水生活污水混合后废水废水量 / (m3· h- 1 ) 80 15 0 2 30 40 5 0 0p H 6…     

基于计算机流程模拟的氨合成工段节能减排分析

采用过程稳态模拟方法,通过计算机模拟氨合成工段生产流程,以灵敏度分析为手段,对某合成氨厂合成工段制冷系统和换热系统进行节能减排分析。分析结果表明：氨冷温度为-10—0℃时,放空气中氢气排放量呈线性递减;在-7℃时,氨气排放量存在一个极大值;氨冷温度对氢气排放量和制冷量的影响明显,而对氨气排放量影响很小;塔前预热器（热侧）出口气体温度越低,废热锅炉回收热量越多,水冷器损失热量越少;预热器出口气体温度为110℃时,系统回收热量与损失热量相等。最后,提出了节能减排的清洁生产方案。     

苯酐生产中氧化尾气的治理和综合利用

苯酐生产中氧化尾气的治理和综合利用萘法生产苯酐的主反应是，萘与氧气在催化剂（五氧化二矾）的作用及３５５℃左右的温度条件下反应生成苯酐。其生产过程中产生的三废主要是：（１）氧化工段排出的尾气；（２）热处理锅引风和精馏系统排出的气体；（３）加萘系统排出的...     

冷冻机残留氨油的回收

兰化公司化肥厂浓硝车间制冷工段现有98—140万大卡/时冷冻机12台。当工段停车检修或处于事故状态时,系统内部分液氨及油从氨蒸发器及低压氨总管等处向地面直接排     

含腈废水处理过程中污染物的转化规律

对某石化企业含腈废水的处理工艺进行了评估,从污染物的来源、组成、处理效果等方面研究了污染物的转化规律,揭示了现有工艺在含腈废水处理过程中的问题。实验结果表明:该企业污水处理场的废水来源较多,丙烯腈生产废水经四效蒸发系统处理后的出水是其污染物的主要来源,含有相对较多的含氮共轭体系;与其他废水混合后,经氨化作用,有机腈转变为有机胺和铵盐;A/O工段矿化度较高,COD的去除率高达73.0%,但有机胺含量仍较高;在缺氧池—生物流化池—硝化池工段,COD进一步被去除,胺类物质浓度大幅降低,但总氮脱除效果并不理想。     

含铜废催化剂中铜的回收

采用热解—氨浸工艺处理含铜废催化剂（w（Cu）为23.6%）,优化了工艺条件,并通过蒸氨还原法制备出Cu₂O产品。实验结果表明：热解工段中,控制管式热解炉的空气流量为3.0 m³/min,在升温速率20 ℃/min、热解终温600 ℃、终温保持时间90 min的优化条件下,含铜废催化剂中的有机物热解完全;氨浸工段中,以NH₄Cl-NH₃-H₂O溶液为氨浸液,控制氨浸温度为40 ℃,在烧成料研磨时间90 min（粒径29.43 μm）、氨浸液总氨浓度4 mol/L、氨浸时间80 min的优化条件下,铜浸出率达到98%;经蒸氨还原法制得的Cu₂O产品的质量符合HG/T 2961—2010《工业氧化亚铜》中的一等品标准,产率为24%。     

磷铵生产中磷石膏废水和含氟硅酸废水的闭路循环

磷铵生产中磷石膏废水和含氟硅酸废水的闭路循环１前言我国磷矿资源大部分含磷品位低，含铁、铝、镁等有害杂质高，且难于富集。针对这些特点，我厂采用料浆浓缩法建成了年产３万ｔ的磷铵装置。该装置于１９９０年１２月建成并投料试车成功，生产出了合格产品。原磷酸工段...     

结合技术改造 搞好环境保护

江苏省太仓化肥厂是年产3万余吨合成氨、12万吨碳铵的小化肥厂。造气工段每年排出有机废水约150万吨,碳化工段排出稀氨水20余万吨,产生的废气4700余万标准米~3,化工余热59000多万大卡,锅炉炉渣3400多吨,碳化煤渣21600多吨。为根治“三废”,保护环境,该厂依靠技术进步,结合技术改造,开发了“三废”资源综合利用,所做工作如下:     

Two stage fluid bed-plasma gasification process for solid waste valorisation: technical review and preliminary thermodynamic modelling of sulphur emissions

Gasification of solid waste for energy has significant potential given an abundant feed supply and strong policy drivers. Nonetheless, significant ambiguities in the knowledge base are apparent. Consequently this study investigates sulphur mechanisms within a novel two stage fluid bed-plasma gasification process. This paper includes a detailed review of gasification and plasma fundamentals in relation to the specific process, along with insight on MSW based feedstock properties and sulphur pollutant therein. As a first step to understanding sulphur partitioning and speciation within the process, thermodynamic modelling of the fluid bed stage has been performed. Preliminary findings, supported by plant experience, indicate the prominence of solid phase sulphur species (as opposed to H₂S) - Na and K based species in particular. Work is underway to further investigate and validate this.     

Gasification of dried sewage sludge: status of the demonstration and the pilot plant

The disposal of sewage sludge from municipal waste water treatment plants is suffering from raising costs.The gasification is an alternative way of treatment, which can reduce the amount of solid residues that must be disposed from a water treatment plant. The produced gas can be used very flexible to produce electrical energy, to burn it very cleanly or to use it for upgrading.The gasification in the fluidised bed and the gas cleaning with the granular bed filter has shown successful operation. A demonstration plant in Balingen was set up in 2002 and rebuilt to a larger throughput in 2010. As a next step a demonstration plant was built in Mannheim and is now at the end of the commissioning phase. Nowadays the product gas is blended with biogas from sludge fermentation and utilized in a gas engine or combustion chamber to produce heat. In the future the process control for a maximized efficiency and the removal of organic and inorganic impurities in the gas will be further improved.     

Life cycle impact assessment of various waste conversion technologies

Advanced thermal treatment technologies utilizing pyrolysis or gasification, as well as a combined approach, are introduced as sustainable methods to treat wastes in Singapore. Eight different technologies are evaluated: pyrolysis–gasification of MSW; pyrolysis of MSW; thermal cracking gasification of granulated MSW; combined pyrolysis, gasification and oxidation of MSW; steam gasification of wood; circulating fluidized bed (CFB) gasification of organic wastes; gasification of RDF; and the gasification of tyres.Life cycle assessment is carried out to determine the environmental impacts of the various waste conversion systems including global warming potential, acidification potential, terrestrial eutrophication and ozone photochemical formation. The normalization and weighting results, calculated according to Singapore national emission inventories, showed that the two highest impacts are from thermal cracking gasification of granulated MSW and the gasification of RDF; and the least are from the steam gasification of wood and the pyrolysis–gasification of MSW.A simplified life cycle cost comparison showed that the two most costs-effective waste conversion systems are the CFB gasification of organic waste and the combined pyrolysis, gasification and oxidation of MSW. The least favorable – highest environmental impact as well as highest costs – are the thermal cracking gasification of granulated MSW and the gasification of tyres.     

High temperature air-blown woody biomass gasification model for the estimation of an entrained down-flow gasifier

A high temperature air-blown gasification model for woody biomass is developed based on an air-blown gasification experiment. A high temperature air-blown gasification experiment on woody biomass in an entrained down-flow gasifier is carried out, and then the simple gasification model is developed based on the experimental results. In the experiment, air-blown gasification is conducted to demonstrate the behavior of this process. Pulverized wood is used as the gasification fuel, which is injected directly into the entrained down-flow gasifier by the pulverized wood banner. The pulverized wood is sieved through 60 mesh and supplied at rates of 19 and 27kg/h. The oxygen-carbon molar ratio (O/C) is employed as the operational condition instead of the air ratio. The maximum temperature achievable is over 1400K when the O/C is from 1.26 to 1.84. The results show that the gas composition is followed by the CO-shift reaction equilibrium. Therefore, the air-blown gasification model is developed based on the CO-shift reaction equilibrium. The simple gasification model agrees well with the experimental results. From calculations in large-scale units, the cold gas is able to achieve 80% efficiency in the air-blown gasification, when the woody biomass feedrate is over 1000kg/h and input air temperature is 700K.     

污泥热解气化技术的研究进展

通过热解气化等热化学转化方式将污泥转变为液体或气体燃料是极具前景的污泥利用方式之一。从污泥的资源化利用方面着手,阐述了污泥热解气化技术的研究进展,分析了现有污泥热解气化工艺的优缺点和主要影响因素,并对该技术的发展趋势进行了展望。指出:高湿污泥与生物质混合进行共热解可以提高原料的转化率和整个系统的热效率;高效污泥热解气化装置的研发是目前污泥热解气化技术领域亟待解决的问题。     

Energy from gasification of solid wastes

Gasification technology is by no means new: in the 1850s, most of the city of London was illuminated by "town gas" produced from the gasification of coal. Nowadays, gasification is the main technology for biomass conversion to energy and an attractive alternative for the thermal treatment of solid waste. The number of different uses of gas shows the flexibility of gasification and therefore allows it to be integrated with several industrial processes, as well as power generation systems. The use of a waste-biomass energy production system in a rural community is very interesting too. This paper describes the current state of gasification technology, energy recovery systems, pre-treatments and prospective in syngas use with particular attention to the different process cycles and environmental impacts of solid wastes gasification.     

Steam gasification of epoxy circuit board in the presence of carbonates

To recover useful metals from end-of-life electronic devices and to convert plastic components from these devices into clean fuel gas, steam gasification of epoxy board samples was carried out at 600–700?°C and 0.1?MPa pressure in the presence of a ternary eutectic carbonate (lithium carbonate, sodium carbonate, and potassium carbonate). Hydrogen and carbon dioxide were the main products, and methane and carbon monoxide were detected as minor products. The gasification proceeded in two steps: an initial rapid pyrolysis followed by secondary steam gasification of char produced from the pyrolysis. The ternary eutectic carbonate accelerated not only the latter steam gasification but also the initial rapid pyrolysis. The activation energy for the steam gasification of epoxy board samples in the presence of the carbonate was 122?kJ/mol.     

Modeling and comparative assessment of municipal solid waste gasification for energy production

Gasification is the thermochemical conversion of organic feedstocks mainly into combustible syngas (CO and H₂) along with other constituents. It has been widely used to convert coal into gaseous energy carriers but only has been recently looked at as a process for producing energy from biomass. This study explores the potential of gasification for energy production and treatment of municipal solid waste (MSW). It relies on adapting the theory governing the chemistry and kinetics of the gasification process to the use of MSW as a feedstock to the process. It also relies on an equilibrium kinetics and thermodynamics solver tool (Gasify®) in the process of modeling gasification of MSW. The effect of process temperature variation on gasifying MSW was explored and the results were compared to incineration as an alternative to gasification of MSW. Also, the assessment was performed comparatively for gasification of MSW in the United Arab Emirates, USA, and Thailand, presenting a spectrum of socioeconomic settings with varying MSW compositions in order to explore the effect of MSW composition variance on the products of gasification. All in all, this study provides an insight into the potential of gasification for the treatment of MSW and as a waste to energy alternative to incineration.     

Gasification characteristics of MSW and an ANN prediction model

Gasification characteristics make up the important parts of municipal solid waste (MSW) gasification and melting technology. These characteristics are closely related to the composition of MSW, which alters with climates and seasons. It is important to find a practical way to predict gasification characteristics. In this paper, five typical kinds of organic components (wood, paper, kitchen garbage, plastic, and textile) and three representative types of simulated MSW are gasified in a fluidized-bed at 400-800 degrees C with the equivalence ratio (ER) in the range of 0.2-0.6. The lower heating value (LHV) of gas, gasification products, and gas yield are reported. The results indicate that gasification characteristics are different from sample to sample. Based on the experimental data, an artificial neural networks (ANN) model is developed to predict gasification characteristics. The training and validating relative errors are within +/-15% and +/-20%, respectively, and predicting relative errors of an industrial sample are below +/-25%. This indicates that it is acceptable to predict gasification characteristics via ANN model.     

两种煤化工废水的产甲烷抑制性

通过间歇式产甲烷抑制实验,评价了两种煤化工废水#x02014;#x02014;焦化废水和鲁奇煤气化废水的产甲烷抑制性,并初步探讨了废水对产甲烷菌的抑制机理。实验结果表明：两种废水的产甲烷抑制性随废水加入量的增加逐渐增大;当废水加入量为400mL时,焦化废水的产甲烷抑制率达100%,鲁奇煤气化废水的产甲烷抑制率为50%;焦化废水对产甲烷菌的抑制性明显大于鲁奇煤气化废水。