上海嘉定化肥厂氨流失量的测定总结

通过对上海市嘉定化肥厂氨流失量的测定及对该工作的总结,不仅准确地了解了小合成氨厂的氨流失情况,还为制定氨流失总量管理办法提供了依据。污染物流失量应以流失总量为统计对象和标准,实测污染物流失量仅作为参考。     

排氨污染的控制和管理

沾益化肥厂通过污染源的调查分析,找出尿素车间是造成总排口氨氮污染增加的主要污染源,占全厂排污量的95％左右。为了控制氨氮的污染,从节能降耗入手,把氨流失和污染作为资源的流失来抓,并把氨氮污染源的管理纳入到企业管理中,形成一套行之有效的科学管理办法,有效地控制了氨氮污染。总排氨氮浓度从1981年的758毫克/升降至1986年的51毫克/升;产品吨尿素氨流失量从1981年的81.34公斤降到1986年的3.47公斤;1984年到1986年基本消除了废水的污染事故;从1985年起企业扭亏为盈,实现了经济、环境、社会效益的同步提高。     

小氮肥厂排水中主要污染物的确定及其流失量控制探讨

清江化肥厂采用等标污染负荷的评价方法,找出厂外排水中主要污染物。氨氮是对外环境影响的主要污染物,占总污染负荷的72.9％,年排放量为115.79吨,占厂外排废水中污染物总量的31.36％。合理的减少氨的流失,是控制氨氮污染的主要途径。通过对氨氮废水源的控制与治理,每年少排含氨废水65万吨,年回收合成氨170吨,消除了产品的流失,并减少软水的消耗,仅后两项就可为企业增加16.7万元/年的经济效益。     

合成氨厂原料气洗涤水的回收利用

1 前言我厂是一个年产12000 t氨的小型合成氨厂。碳化工段原料气的净化,是采用传统的氨回收塔吸收后,再用大量的清水洗涤,洗涤后得到的稀氨水,由于水量大,氨浓度低,难以利用而直接外排,这样不仅造成氨的浪费,而且严重污染了环境。近年来,国内一些合成氨企业对稀氨水进行了回收。为了达到生产用氨的平衡和杜绝外     

钛白粉生产中硫酸的流失去向及衡算

运用物料投入－转型－流失平衡模型，对硫酸法生产钛白粉工艺过程中的主要污染物－－硫酸的流失去向、流失形态、流失量进行了剖析与衡算，针对性地提出了控制污染的方法和管理措施。     

氨回收和稀氨水的治理

成都天然气化工厂合成氨车间投资15万元,采用“计量加入、分段回收、逐级提浓”法进行合成氨生产的氨回收和稀氨水治理。消除了稀氨水的过量和排放,实现了合成氨生产的水平衡;提高了跑氨回收率和氨利用率;大幅度降低了消耗,取得了显著的经济、节能和环境等诸方面的综合社会效益。     

A火电厂氨站喷淋系统改造

液氨在储存和使用过程中存在较大的安全风险,极易燃,且有毒,对人体伤害较大,而且氨一旦产生大量泄漏,会对环境构成严重危害。通过安全评价的手段,查找出A火电厂氨站喷淋装置设置不合理,存在的安全隐患。针对此隐患,A火电厂有关部门按照相关设计标准,提出了对氨站喷淋装置的改、扩建方案,并于改造完成后对氨站喷淋装置试运行,改造后的喷淋装置能够达到要求,但是还存在一些不足,需要进一步改进。     

从四个环节入手搞好车间环保工作

氯化铵车间是天津碱厂的主要用氨车间,也是全厂排放氨、氮污染物最甚的车间。每月我们车间平均要用2000-3000吨合成氨,生产6000-9000吨氯化铵。因此,生产中日常的“合理排放”就使排水中氨、氮大大超过指标(0.5毫克/升),对环境造成很大的污染。     

注碱脱铵技术在污水汽提装置的应用

分析了污水汽提装置净化水氨氯含量偏高的原因，介绍了注碱脱铵技术的机理，讨论了其应用的有关问题。应用结果表明，该技术可使本装置净化水中的氨氯含量明显降低，具有良好的社会和经济效益。     

氨法烟气脱硫技术综述

简述了多种氨法烟气脱硫的原理和技术特点。主要介绍了湿式氨法烟气脱硫技术，为烟气脱硫技术的选择提供参考。     

在中型氮肥厂推行清洁生产

在对合成氨厂污染源调查的基础上,通过对尿素解吸塔的改造、铜洗稀氨水的增浓、氨吸塔含氨废水的循环利用、氨泵密封水的回收,减少了生产过程中污染物－氨氮的产生量,并取得了显著的经济效益。     

氨法在燃煤电厂烟气治理中的应用和发展

燃煤排放的CO2、SO2、NOx等气态污染物会造成酸雨、温室效应、臭氧层破坏等一系列的大气环境问题。减少和抑制燃煤电厂燃烧过程中污染气体的排放,是实现清洁生产和能源可持续发展的基本需要。氨法烟气治理技术作为电厂排放烟气处理的新兴技术,以其污染物脱除效率高、耗能小、二次污染低、脱除副产品可资源化等特点,得到了越来越多的关注,并已在部分燃煤电厂得到成功的应用。对氨法脱除烟气中气态污染物技术进行了分析和总结,并对其应用前景进行了分析和预测,指出了氨法烟气治理技术在燃煤电厂烟气处理方面具有良好的经济、社会和环保效益,并具有广阔的发展前景。     

Life cycle assessment of selective non-catalytic reduction (SNCR) of nitrous oxides in a full-scale municipal solid waste incinerator

Selective non-catalytic reduction (SNCR) of nitrous oxides in a full-scale municipal solid waste incinerator was investigated using LCA. The relationship between NO_x-cleaning and ammonia dosage was measured at the plant. Un-reacted ammonia - the ammonia slip - leaving the flue-gas cleaning system adsorbed to fly-ash or in the effluent of the acidic scrubber was quantified from the stoichiometric reaction of NO_x and ammonia assuming no other reaction products was formed. Of the ammonia slip, 37% was associated with the fly-ash and 63% was in the effluent of the acidic scrubber. Based on NO_x-cleaning efficiency, the fate of the ammonia slip as well as the environmental impact from ammonia production, the potential acidification and nutrient enrichment from NO_x-cleaning was calculated as a function of ammonia dosage. Since the exact fate of the ammonia slip could not be measured directly, a number of scenarios were set up ranging from “best case” with no ammonia from the slip ending up in the environment to “worst case” where all the ammonia slip eventually ended up in the environment and contributed to environmental pollution. In the “best case” scenario the highest ammonia dosage was most beneficial demonstrating that the environmental load associated with ammonia production is of minor importance. In contrast, in a “worst case” scenario” NO_x-cleaning using SNCR is not recommendable at all, since the impacts from the ammonia slip exceed the saved impacts from the NO_x removal. Increased dosage of ammonia for removal of NO_x is recommendable as long as less than 10-20% of the ammonia slip to the effluent of the acidic scrubber ends up in the environment and less than 40% of the slip to the fly-ash ends up in the environment. The study suggests that the actual fate of the ammonia slip is crucial, but since the release of the ammonia may take place during transport and at the facilities that treat the wastewater and treat the fly-ash this factor depends strongly on local conditions and may be hard to determine. Thus, LCA-modeling proved useful in assessing the balance between ammonia dosage and NO_x-removal in flue-gas cleaning from waste incineration.     

石灰石―石膏法与氨法脱硫技术比较

分别介绍了石灰石―石膏法烟气脱硫技术与氨法烟气脱硫技术的特点,并从技术、经济、环保等方面对这两种湿法脱硫技术进行了比较。指出在短期内石灰石―石膏法脱硫技术仍将占据脱硫行业的主导地位,但氨法烟气脱硫技术更适合我国国情,具有广阔的发展前景。     

Mathematical modelling as a tool for environmental evaluation of industrial sectors in Colombia

A general mathematical model has been developed as a tool for environmental evaluation of industrial chemical processes. This model is based on the life cycle assessment (LCA) methodology and includes a modular and cumulative conceptual approximation. Accordingly, the model considers the potential effects on the environment caused by mass, energy and exergy flows. For environmental loads related with mass flows, two main categories are defined: pollution and perturbation environmental effects. Whereas for the environmental effect associated with energy flows, a factor defined as “energy dissipation” is employed, and similarly for exergy flows, a “exergy destruction” parameter is used. The measurement unit employed throughout the model is expressed in terms of “potential environmental impact units/hour”. As an example study case, the integrated production chain (IPC) for nitric acid production in the Colombian context is evaluated. This particular IPC includes the ammonia production plant, energy plants and main process plant. The results demonstrate that for environmental perturbation effects based on mass flows, the main contribution in the IPC corresponds to the energy plants. In the case of pollution environmental loads, the principal contribution relates to ammonia production. Regarding environmental effects associated with energy flows, the highest “energy dissipation” factor corresponds to the main process, followed in order by the ammonia process. Finally, for the effect denominated as “exergy destruction”, it could be established that Colombian energy plants show the highest contribution in the IPC.     

Laboratory evaluation of the pollution potential of land applied dairy manure

Laboratory experiments were performed using 24,900 mm deep soil columns to determine the amounts of nitrogen lost through the processes of leaching and ammonia volatilization from land receiving high applications of dairy cattle manure. The soil columns were conditioned over a period of one year before the start of the experiment and a conscious effort was made to make the physical properties of the columns soil sufficiently reproduced to resemble the undisturbed soil. The effects of three manure and three water application rates on nitrogen losses were monitored over a period of 10 weeks. The concentrations of nitrogen compounds in the leachates obtained from the soil columns were very low. The observed losses of nitrogen caused by leaching and ammonia volatilization were influenced by manure and water application rates. The high concentration of nitrate nitrogen at the beginning of the experiment has the potential of causing groundwater pollution. Also, ammonia volatilization is considered high enough to cause serious odor problems.     

从醇后气中回收淡甲醇

在甲醇分离器后设置淡甲醇回收装置回收醇后收醇后的中甲醇，其回收率达到８７．５％，同时大大降低了排放地沟的稀氨水中的甲醇含量，减轻了稀氨水对环境的污染，有较好的经济效益和环境效益。     

Recovery of zinc and lead from fly ash from ash-melting and gasification-melting processes of MSW--comparison and applicability of chemical leaching methods

Fly ash generated from MSW ash-melting and gasification-melting plants, known as Melting Furnace Fly Ash (MFA), contains considerable amounts of heavy metals such as Pb and Zn. These metals can be recovered using a smelting furnace after "pre-treatment" for removal of unnecessary elements such as Cl, Sn and Si. Chemical methods have been studied for pretreatment in the past. However, they have been discussed only with regard to treatment cost and the concentration of Pb and Zn recovered, but neither applicability to various types of MFA nor the environmental impact have been considered. In this study, acid, alkaline and ammonia/chloride leaching methods were compared from the standpoints of: (1) applicability to MFA, (2) concentration of Pb and Zn recovered, (3) treatment cost, and (4) environmental impact. Twenty-three samples of MFAs were collected and classified into 4 types based on element contents. A Pb and Zn recovery experiment was conducted for the representative MFA of those types. The results showed: (1) MFA from gasification-melting plants cannot be treated by chemical methods; (2) the other MFA can be treated to an acceptable quality by existing smelting furnaces; (3) only MFA from electric resistance ash-melting plants can be treated easily by the water washing method; and (4) alkaline and ammonia/chloride leaching methods were more effective than acid leaching.     

炼油厂厂界恶臭强度分级评估

石油炼制是产生恶臭污染的重点行业之一,恶臭强度是评估恶臭污染程度的重要参数。以炼油厂厂界大气特征污染物为研究对象,综合考虑检出率、嗅阈值和物质浓度3项指标,采用指标评分法筛选出厂界主要恶臭污染物硫化氢、氨、甲苯和二甲苯。基于韦伯-费希纳定律构建了恶臭强度分级评估方法,以某炼油厂为例进行了厂界恶臭强度评估,结果表明,厂界恶臭强度值为0.63,属于Ⅱ级(轻污染),硫化氢是恶臭强度的主要贡献源。应用感官测定法验证了该评估方法的可靠性。从恶臭管理的角度看,炼油厂在厂界达标排放的基础上应进一步实施恶臭污染综合治理措施,以改善周边的环境质量。     

联碱废液的资源化

采用联碱生产过程中的废液与水玻璃反应制取工业白炭黑，并将回收的氨返回生产过程。研究了工艺条件对产品质量的影响，分析了反应原理，此项研究对联碱生产过程中环境污染治理、变废为宝是一种有益的探讨。