提高污泥焚烧处理中热能的回收利用

本文就可调节控制的操作工序对污泥焚烧的热能回收利用与费用的影响等问题进行了探讨。并以实例介绍了焚烧污泥的脱水技术、烟气脱臭温度的确定以及如何提高蒸汽的再利用率等问题.     

炭黑尾气和废水的综合治理技术

采用综合治理技术,同时处理炭黑生产尾气和废水,即利用焚烧尾气时产生的高温来焚解废水,使废水中的油和酚等物质分解为二氧化碳和水,并用余热锅炉对烟气的热量加以回收利用,达到以废治废和节能的目的。综合治理设施的总投资160万元人民币,运转一年左右即可收回。该技术可在化工、石油、冶金等工业生产中推广应用。     

内循环曝气生物滤池深度处理含油废水

将内循环曝气生物滤池(IRBAF)用于石化企业含油废水的深度处理.运行试验结果表明,IRBAF进出水中COD、ρ(氨氮)和ρ(石油类)平均值分别由153.2,8.8,8.5 mg/L降至82.3,1.4,5.1 mg/L,去除率分别为46.3％、84.1％和40.0％.处理1t水运行成本仅为0.30元.装置运行后,每年向环境中排放的COD、氨氮和石油类分别减少124.04,12.96,5.95 t,每年可节水1 680 kt,节水效益336万元.     

超临界水氧化法处理污水处理场的污泥

美国得克萨斯洲Harlingen市建成第一套超临界水污泥处理装置,现正进行试运行,待第二套装置建成后,污泥总处理能力约为35000加仑/d(污泥固体质量分数为7%～8%),可处理掉2座城市污水处理场和1座工业废水处理场产生的全部污泥. 这是超临界水氧化法首次工业化用于处理污水场污泥.在1100、3400磅/英寸2及有氧存在的条件下,有机物被氧化成二氧化碳和水,重金属被氧化成不能被滤出的状态. 该装置的投资为300万美元,污泥(干泥)处理费约为180美元/t,而土地施用法和土地填埋法对污泥的处置费用为275美元/t .该装置处理1 t干泥产生的废热及CO2产品可销售120美元,从而使处理费用降至60美元/ t. (以上由陈殿英供稿)     

聚氯乙烯生产中的废水综合利用

介绍了新疆天业化工园区聚氯乙烯生产中废水的处理技术和综合利用情况,包括乙炔上清液的回收、含汞废液处理及聚合母液水的处理回收利用。利用节水技术,每年可回用水近580万t,氯化氢气体5万t,产生经济效益5380万元。     

锅炉“三废”的治理

1.概述我厂有燃煤锅炉4台,每年约产炉渣1.4万吨、飞灰2.8万吨、烟气9.0×10~8标米~3。为阻止飞灰随烟气排入大气,使用水膜除尘器进行烟气除尘。1982年我厂锅炉废气污染源得到了治理。但是,水膜除尘器产生了含煤灰(即飞灰)的废水,成为新的水污染源。为治理该污染源和回收利用这部分煤灰(含     

聚氯乙烯生产中的废水综台利用

介绍了新疆天业化工园区聚氯乙烯生产中废水的处理技术和综合利用情况，包括乙炔上清液的回收、含汞废液处理及聚合母液水的处理回收利用。利用节水技术，每年可回用水近580万t，氯化氢气体5万t，产生经济效益5380万元。     

从富氢干气中回收氢气技术

依据清洁生产审核、评估的结果，提出了从富氢干气中回收氢气的高费方案，并加以实施。富氢干气先用化学吸收法进行脱硫处理，再用高压吸附、低压抽真空解吸，从含粗氢的干气中提纯出99．9％(体积分数)的氢气。该装置负荷为35％的情况下，可回收氢气2500t/a，减排二氧化硫约100t／a，创经济效益约426．6万元／a。     

炼油厂IGCC电站NOx排放控制技术比较与工程实践

针对IGCC电站烟气排放ρ（NO_x）不达标的问题,分别采用燃气轮机注氮脱硝和余热锅炉（余热蒸汽发生器,HRSG ）SCR脱硝技术降低烟气的NO_x排放量。介绍了两种技术的原理,比较了两种技术的脱硝效果、运行成本及技术特点。实际运行结果表明：安装了注氮设备的燃气轮机可以控制排气的ρ（NO_x）小于90 mg/m³,但每年的运行成本较高（达2 250万元）;在余热锅炉中安装SCR脱硝设备,性能测试数据符合设计要求,SCR出口ρ（NO_x）小于50 mg/m³,且每年的运行成本较低,仅为422万元。     

密闭电石炉气经废热锅炉燃烧后的尾气净化

浙江巨化电石有限公司45kt/a的电石炉是国内第一套引进挪威埃肯型密闭电石生产技术的国产化电石生产装置,1993年建成投产。在密闭电石炉内,焦炭与生石灰经高温熔炼生产电石,随之产生约2300-2400m3/h炉气。该炉气的主要成分为CO、N2、H2、CO2、CH4及氰化物,其中CO占85%左右。由于炉气中含有一定的焦油及大量的粉尘(质量浓度为50-100g/m3),处理难度较大。另外,因炉气中含有极少量的氰化物,直接排放会对大气环境造成严重污染。1998年,电石公司建起1台10t/a、工作压力为1.27MPa、蒸汽温度为250-280℃的废热锅炉,500-600℃的电石炉气可以直…     

活性污泥焚烧过程中镍的迁移分布特性

采用管式炉对污水厂活性污泥焚烧过程中Ni的迁移分布特性进行研究。实验结果表明：当污泥掺烧量（污泥质量与煤和污泥总质量的比）为25%时，Ni的挥发率（飞灰与气体中Ni质量的总和与污泥中Ni质量的比）几乎为零，且污泥与煤混合试样的综合燃烧效果最好；当污泥焚烧加入硫化物时，各种硫化物对Ni的残留率（炉渣中Ni的质量与污泥中Ni质量的比）提高能力大小顺序为Na₂S>S>Na₂SO₃>Na₂SO₄；当污泥焚烧加入氯化物时，促使Ni向烟气中迁移，且加入无机氯更易使Ni向烟气中迁移。     

Integrated drying and incineration of wet sewage sludge in combined bubbling and circulating fluidized bed units

An original integrated drying and incineration technique is proposed to dispose of sewage sludge with moisture content of about 80% in a circulating fluidized bed. This system combines a bubbling fluidized bed dryer with a circulating fluidized bed incinerator. After drying, sewage sludge with moisture less than 20% is transported directly and continuously from the fluidized bed dryer into a circulating fluidized bed incinerator. Pilot plant results showed that integrated drying and incineration is feasible in a unique single system. A 100 t/d Sewage Sludge Incineration Demonstration Project was constructed at the Qige sewage treatment plant in Hangzhou City in China. The operational performance showed that the main operation results conformed to the design values, from which it can be concluded that the scale-up of this technique is deemed both feasible and successful.     

Element associations in ash from waste combustion in fluidized bed

The incineration of MSW in fluidized beds is a commonly applied waste management practice. The composition of the ashes produced in a fluidized bed boiler has important environmental implications as potentially toxic trace elements may be associated with ash particles and it is therefore essential to determine the mechanisms controlling the association of trace elements to ash particles, including the role of major element composition. The research presented here uses micro-analytical techniques to study the distribution of major and trace elements and determine the importance of affinity-based binding mechanisms in separate cyclone ash particles from MSW combustion. Particle size and the occurrence of Ca and Fe were found to be important factors for the binding of trace elements to ash particles, but the binding largely depends on random associations based on the presence of a particle when trace elements condensate in the flue gas.     

Adsorption removal of pollutants by active cokes produced from sludge in the energy recycle process of wastes

This study proposes a recycling system of sludge into active cokes and the fundamental examinations for the application were carried out. In the system, active cokes were produced by carbonizing pellets of sludge in a steam stream. Pyrolysis gas yielded by carbonization can be available to a fuel for a steam generation boiler. The exhaust heat from the boiler is used sequentially for drying of sludge. The active cokes are applied to the adsorbent for dioxin removal in exhaust gas from incinerators of wastes, or for purification of gas obtained in a gasification process of wastes, particularly removal of H2S. The used adsorbent is not recycled, but incinerated in the furnace without a desorption process to decompose adsorbed dioxin or to oxidize H2S for a sequential desulfurization process of SO2. Dry pellets of sludge were carbonized in a quartz tube reactor under various atmospheres. The micro pore structure and the adsorption performance of the cokes produced without activation process were examined. The micro pore structure was influenced by the temperature, the sort of flow gas (N2, CO2 and steam) and carbonization time, and the active cokes produced under the condition of the temperature 823 K for 60 min in the steam atmosphere had a largest specific surface area in the diameter less than 5 nm. The amount of benzene adsorption as an alternative substance of dioxin into the active cokes had a similar quality to a commercial active char produced from coal if it was evaluated by adsorption per a unit specific surface area. This fundamental knowledge must be reflected to an optimum design for development of a simple continuous process to produce the active cokes by a fluidized bed type of the carbonization furnace.     

燃煤电站SNCR脱硝系统喷射还原剂介质对锅炉效率的影响

以燃煤电厂1台600MW机组配套SNCR脱硝系统为例,分别介绍了采用尿素、液氨为SNCR脱硝还原剂时,各还原剂的喷入量对锅炉效率和燃煤成本的影响。结果发现,以设计煤种Qnet,ar=11766.7kJ/kg计,当浓度5%的尿素溶液喷入时,有1.67%的燃煤发热量被水蒸发所吸收,导致排烟损失增加0.6659%。假设其他损失不变,不计固体尿素的升温、分解热反应等的影响,尿素溶液的喷入对锅炉热效率的影响在0.6659%左右,燃煤成本约增加900多万元/a;在喷入氨空混合气情况下,约0.2%的燃煤发热量被混合气所吸收,导致排烟损失增加0.02%。假设其他损失都不变,不计分解热反应等的影响,混合气的喷入对锅炉的热效率的影响亦即在0.02%左右,燃煤成本约增加30万元/a。从节能的角度看,液氨为还原剂应作为优选。     

旋转填充床分离沼气中的CO_2

以水为吸收液,采用旋转填充床分离微生物厌氧发酵沼气中的CO_2,考察了工艺条件对CO_2吸收效果的影响。实验结果表明:进液量越大、气液比越小、进口CO_2体积分数越小、操作压力越大、进液温度越低则CO_2的吸收效果越好,而床转速以适中为宜;在进液量60 L/h、气液比3.3、床转速1 000 r/min、进口CO_2体积分数40%、操作压力1.2 MPa、进液温度5℃的条件下,CO_2吸收率为57.4%,提纯后气体的CO_2体积分数为17%。     

垃圾焚烧中抑制二恶英二次生成的方法探讨

根据生活垃圾焚烧技术中二恶英的生成机理，余热锅炉的烟气在低温区急冷可以避免二恶英在低温区的再次合成，但目前在余热锅炉烟气低温区急冷是不可行的。提出一种从垃圾焚烧系统设计上进行烟气的急冷，从而抑制二恶英低温区二次生成的新方法。     

Elutriation characteristics of fine particles from bubbling fluidized bed incineration for sludge cake treatment

In this study, measurements of elutriation rate were carried out in a bench scale bubbling fluidized bed incinerator, which was used to combust sludge cake. The particle size distribution and ignition loss were analyzed to study the elutriation characteristics of bubbling fluidized bed incineration. Drawn from the experimental data, the elutriation rate constant K(i)* for fine particles were obtained and correlated with parameters. It was found that most of the solid particles (about 95%) elutriated came from the fluidized medium (inorganic matters), but few came from unburned carbon particles or soot (about 5%). Finally, this paper lists a comparison of K(i)* between this study and the published prediction equations derived or studied in non-incineration modes of fluidized bed. A new and modified correlation is proposed here to estimate the elutriation rate of fine particles emitted from a bubbling fluidized bed incinerator. Primary operation variables (superficial gas velocity and incineration temperature) affecting the elutriation rate are also discussed in the paper.     

变压吸附技术分离模拟油田火驱尾气中的CO_2

采用变压吸附技术分离模拟油田火驱尾气(CO_2-N_2-CH_4混合体系)中的CO_2。考察了吸附压力、吸附温度和气体流量对吸附效果的影响。实验结果表明:在吸附温度为25℃、吸附压力为0.6 MPa、气体流量为2 000m L/min、初始CO_2体积分数为13.01%的条件下,CO_2的穿透吸附量为60.34 m L/g,CO_2吸附率为78.92%,碳分子筛对CO_2的分离因子为8.233;在床层利用率为0.523的条件下进行降压解吸,当吸附压力降至0.1 MPa时,出口CO_2体积分数约为80%,CO_2的回收率可达96.38%。