生物反应器填埋场处理渗滤液的效能及产能特性研究

选用新型生物反应器填埋场(由卫生填埋场和产甲烷反应器组成),进行了渗滤液处理效能及产能特性研究。结果表明:新型生物反应器填埋场有助于渗滤液中有机物进行分相降解,在渗滤液的净化和填埋场垃圾的稳定化上优于渗滤液直接循环的填埋场。产甲烷反应器处理垃圾渗滤液时,在进水的VFA浓度大于3000mg/L条件下,CODCr去除率76%～94%;容积CODCr去除率0 88～4 85g/(L·d);容积沼气产率0 5～2 85L/(L·d)。     

规模化养牛场沼气工程启动运行研究与实践

主要研究了大型沼气工程的启动运行过程。采用有效体积为1 000 m3的USR厌氧沼气发酵罐,接种来自稳定产气的沼液,在温度为(35±1)℃,pH为7.0～8.0和HRT为15 d的条件下连续运行55 d,先后经历了水力负荷提高期、有机负荷提高期及稳定运行期,成功启动运行了沼气发酵罐。启动运行完成后,COD去除率达到80%,容积产气率为1.43 m3/(m3.d),甲烷含量大于65%,VS降解率大于40%。     

填埋场项目地下水环境影响评价

填埋场分为垃圾填埋和安全填埋两种,而这两种填埋都会产生渗滤液对地下水造成影响。主要研究安全填埋项目,以样品检测与模拟为方法研究影响机制识别、不确定性分析等方面。     

新型抗结壳沼气反应器产气特性研究

针对沼气发酵过程中的结壳问题,研制了一种具有抗结壳性能的新型沼气反应器,并以马铃薯皮为原料在沼液温度为27(±3)℃时进行了有、无抗结壳装置的反应器产气性能对照实验,结果发现抗结壳反应器的沼液面悬浮固体物质量仅为后者的1/22,而总产气量和COD去除率分别提高17.5%和27.1%。此外,实验研究了抗结壳反应器中固体物浓度对沼气发酵性能的影响,并在固体物浓度为4%时得到最大日产气量为11.2L,COD去除率为69.7%,产气中甲烷浓度长期维持在约62%,反应器具有较强的沼液pH值调节能力。研究表明新型抗结壳反应器具有较好的抗结壳性能和较高的产气率及原料利用率。     

CSTR反应器鸡粪厌氧消化中试启动研究

在中温(37℃)条件下,利用全混式厌氧(CSTR)反应器进行鸡粪废水厌氧消化启动的实验室模拟,将试验分为4个阶段(Ⅰ,Ⅱ,Ⅲ,Ⅳ),逐级增加进料负荷量,研究分析各阶段影响因素。结果表明:CSTR反应器能够正常启动鸡粪废水厌氧消化,当试验各阶段(Ⅰ∶Ⅱ∶Ⅲ∶Ⅳ)进料比为1∶2∶2.67∶3.33时,相应的最高产气速率之比约为1∶1.76∶2.04∶2.46;在进料COD为25 496 mg/L,HRT为31 d时,氨氮最高浓度为2 122 mg/L左右,COD去除率为(57.5±1.93)%,每日甲烷产量(单位质量VS)为(301±6)mL/g。试验4 d后,CSTR反应器产生的沼气中CH4含量稳定在61.8%～70.1%。     

有机垃圾高温厌氧消化中试验研究

采用高温厌氧消化处理方法对城市生活有机垃圾进行了中试试验研究.其有机垃圾产气量73.4m3/t,产气速率0.52m3/m3.d,COD去除率48.8%.结果表明,高温厌氧消化处理是城市生活有机垃圾较好的处理方式之一.有机垃圾不仅可以得到处理,最大限度地减少其污染环境;同时,还可以产生一定的经济效益和巨大的环境效益.这种垃圾处理方式值得应用和推广.     

TS对城市有机垃圾和剩余污泥联合厌氧消化的影响

在中温(35℃)条件下,以城市有机垃圾和污水处理厂剩余污泥为发酵原料,其中生活垃圾∶污泥=4∶1(w/w,干重),研究了固形物含量分别为3%,4%,6%,8%,10%对厌氧发酵过程及发酵效率的影响。结果表明:当发酵液TS为4%时厌氧发酵效率最高,发酵过程中pH适宜产甲烷菌生长,产气时间长,累积产气量最大,为11 967 mL,且甲烷含量较高;同时发酵过程中氨氮浓度升高缓慢,不会对甲烷菌造成氨抑制,对原料中有机质的降解效果明显,COD去除率为61.7%,TS去除率为47.19%,VS去除率为55.93%。     

南通某垃圾填埋场产气量及发电效益估算

文章以南通市某垃圾填埋场为研究对象,利用USEPA开发的Land GEM模型进行填埋场产气量估算,并基于模型估算产气量进行发电成本效益分析。根据填埋场垃圾组分及填埋量等条件确定模型参数(甲烷产气率为0.106 a-1,产甲烷潜力为68 m3/t),将模型参数输入Land GEM模型估算出40 a的填埋气理论产气量。填埋场产气量在封场后一年(即2028年)达到最大,为4 957.45 m3/h,填埋气可收集量(收集率为30%)为1 487.23 m3/h。根据填埋气可收集量选择2台1 MW燃气内燃机进行发电,并进行成本效益分析,结果发现,一次性投资成本约为1 815万元,第一年收入能达到820.885万元,项目运行两年2个月就能完成成本的回收。     

超声波预处理对秸秆发酵的影响

以秸秆为研究对象,在37℃条件下对不同的超声波强度和工作时间预处理的秸秆进行为期50 d的厌氧发酵试验,分析发酵过程中产气效率、累计产气量、pH值、CH4浓度等参数变化,并对秸秆微观结构进行电镜扫描,研究超声波预处理对秸秆微观结构的破坏以及厌氧发酵产气特性影响。试验结果表明:超声波预处理能提高秸秆发酵累计产气量和产气效率,平均单位日产气量由未经预处理的4.54 ml/(g.d)提高到经超声波处理后的6.86 ml/(g.d),提高了51.10%;超声波预处理对秸秆发酵pH无显著影响;沼气中平均甲烷浓度由未经预处理的43.83%提高到处理后的47.86%;最佳超声波预处理功率为225 W,处理时间为30 min。     

北京市餐厨垃圾产生状况及厌氧发酵产气潜力分析

随着餐饮行业的发展,越来越多的餐厨垃圾造成的污染成为我们亟待解决的问题.文章通过对北京市城区的餐馆进行实地调查,针对不同规模的餐馆,分别对其餐厨垃圾产生的数量、成分、性质及其收集处理方式、处理费用和最终用途进行了深入的调查分析;并对中国目前的管理政策进行了探讨.文章还通过批式厌氧消化实验对学校食堂的餐厨垃圾进行了产气潜力分析,结果显示在20g/L的容积污染负荷下,经过35 d的中温(35℃)消化,总产气量达到7 380 mL,总甲烷量达到4 023 mL,甲烷含量平均为54.51%,VS去除率为50%,产气率和产甲烷率分别达到369ml/g和201 ml/g,实验表明餐厨垃圾具有很好的产气性能,为进一步研究提供了理论基础.     

龙岩市垃圾卫生填埋场填埋气体产量预测研究

对填埋气的回收利用,既能减排温室气体,又能回收能源。根据龙岩市的垃圾组成、填埋场处理量等条件,系统地分析了各种产气模型的计算方法、优缺点及适用条件,合理地选择了产气模型和参数。根据该模型计算出龙岩市垃圾填埋场气体产量和气发电机装机容量。     

Technical/economic/environmental analysis of biogas utilisation

Biogas may be utilised for Combined Heat and Power (CHP) production or for transport fuel production (CH₄-enriched biogas). When used to produce transport fuel either electricity is imported to power the plant or some of the biogas is used in a small CHP unit to meet electricity demand on site. The potential revenue from CH₄-enriched biogas when replacing petrol is higher than that for replacing diesel (Irish prices). Transport fuel production when replacing petrol requires the least gate fee. The production of greenhouse-gas is generated with cognisance of greenhouse-gas production with the scheme not in place; landfill of the Organic Fraction of Municipal Solid Waste (OFMSW) (20% of biomass) with and without combustion of landfill gas is investigated. The transport scenario with importation of brown electricity generates more greenhouse-gas than petrol or diesel, when the ‘do-nothing’ case involves combustion of landfill gas. The preferred solution involves transport fuel production with the production of CHP to meet electricity demand on site. A shortfall of this solution is that only 53% of biogas is available for export.     

Trace compounds of biogas from different biogas production plants

Biogas composition and variation in three different biogas production plants were studied to provide information pertaining to its potential use as biofuel. Methane, carbon dioxide, oxygen, nitrogen, volatile organic compounds (VOCs) and sulphur compounds were measured in samples of biogases from a landfill, sewage treatment plant sludge digester and farm biogas plant. Methane content ranged from 48% to 65%, carbon dioxide from 36% to 41% and nitrogen from <1% to 17%. Oxygen content in all three gases was <1%. The highest methane content occurred in the gas from the sewage digester while the lowest methane and highest nitrogen contents were found in the landfill gas during winter. The amount of total volatile organic compounds (TVOCs) varied from 5 to 268 mg m⁻³, and was lowest in the biogas from the farm biogas plant. Hydrogen sulphide and other sulphur compounds occurred in landfill gas and farm biogas and in smaller amounts in the sewage digester gas. Organic silicon compounds were also found in the landfill and sewage digester gases. To conclude, the biogases in the different production plants varied, especially in trace compound content. This should be taken into account when planning uses for biogas.     

垃圾填埋气在发电方面的应用--某13.8MW电厂的运行经验

根据欧盟能源政策有关促进可再生能源和热电联产的计划，距雅典市7km远的Ano Liosia垃圾填埋场兴建了一座热电厂。结合填埋场的具体情况，对热电厂的建设和运行进行了一系列调整。填埋场产生的填埋气用来进行热电联产。由竖井和水平管网组成的集气系统将填埋气引入热电厂，产生的电足够供应15000人的城镇。热电厂2001年投入运行，包括11个热电机组，总装机容量达13．8MW，年发电量约为110GWh，全部并入电网。烟气余热回收的热量用来生产蒸汽和热水。年产热约16．5MW。文章介绍了Ano Liosia热电厂的运行经验。     

Biogas purification for MCFC application

Biogas from landfills is a powerful renewable fuel that can be used as a feedstock for fuel cell systems. However, it has to be purified of sulphur compounds and halogenated species, which are poisonous for both fuel cells and reforming catalysts. This work presents a benchmarking study on the removal of sulphur and halogenated compounds from a model landfill biogas through adsorption. Six commercial adsorbents have been tested to compare their selectivity and their uptake capacity towards nine different sulphur compounds. A multi-step adsorption process, characterised by a high adsorptive-capacity and rather low costs has been proposed. Two specific activated carbons for the removal of halogenated species have also been tested for the purification of nine chlorinated hydrocarbons that are present in the model biogas. One single system that could completely eliminate the halogenated molecules contained in the biogas could not be found, which indicates the necessity of specific developments.     

欧盟沼气产业的新资源——能源作物

近十年来,欧盟国家的沼气产业已经成形。作为传统原料的活性污泥、填埋垃圾和畜禽粪便资源已经远远不能满足沼气的发展,沼气产业的发展对原料提出了更高的要求,沼气专用能源作物应运而生。文章介绍了德国、奥地利和丹麦等国的学者对沼气专用能源作物的筛选、发酵产气技术和工艺、替代石化燃油的潜力、CO2的减排效应以及合理地插入轮作制度等方面的研究进展。     

Life cycle assessment (LCA) of waste management strategies: Landfilling,sorting plant and incineration

This paper focuses on a Life Cycle Assessment (LCA) of four waste management strategies: landfill without biogas utilization; landfill with biogas combustion to generate electricity; sorting plant which splits the inorganic waste fraction (used to produce electricity via Refuse Derived Fuels, RDF) from the organic waste fraction (used to produce biogas via anaerobic digestion); direct incineration of waste. These scenarios are applied to the waste amount and composition of the Municipality of Roma (Italy) and are evaluated under different points of view: global and local emissions, total material demands, total energy requirements and ecological footprints. Results, reliable for most of the European big cities, show landfill systems as the worst waste management options and significant environmental savings at global scale are achieved from undertaking energy recycling. Furthermore, waste treatments finalized to energy recovery provide an energy output that, in the best case, is able to meet the 15% of Roma electricity consumption.     

欧盟国家新兴的生物天然气产业

欧盟国家在近几十年发展沼气的过程中,经历了从以处理生活污水无害化产生的污泥为主,到以获取优质可再生能源为主、能源和环保兼顾的战略性转折,原料范围显著扩大,规模迅速向产业化方向发展。欧盟2007年沼气总量达到约100×108m3,其中50%来自垃圾填埋气,30%来自农业废弃物和能源作物,20%来自下水道处理产生的污泥。瑞典在全球率先开发车用生物天然气;德国的沼气厂由2000年的1000家发展到2010年的约5000家,发电产能为2700MW;瑞士则非常重视可持续的原料供应及沼气发酵技术的研究创新和开发;英国现有38座沼气厌氧工程,垃圾填埋气占全部沼气产量的约90%,主要用于燃气轮机发电和供热;法国议会于2010年7月通过新环保法案,强制性收购生物天然气并给予并入天然气管网的优惠性补贴。减排温室气体和提高天然气自给率是欧盟产业沼气大发展的最大推动力,而立法和扶持政策在其产业沼气的成长阶段发挥了决定性作用。随着传统原料资源量的日渐匮乏,沼气专用能源作物应运而生,其潜力远大于其他资源。能源作物青贮后可以长期不霉变、不腐烂,这对于大型沼气企业全年稳定生产具有决定性意义。另外,沼气的单位土地能量产出率是最高的。我国天然气资源短缺,大力发展产业沼气将对提高我国天然气自给率和实现应对全球气候变化中长期规划目标起到不可忽视的作用。     

MSW landfill biogas desulfurization

Biogas utilization in MCFC systems requires a high level of gas purification in order to meet the stringent sulfur tolerance limits of both the fuel cells and the reformer catalysts. In this study, two commercial activated carbons (ACs) have been tested for H₂S removal from the biogas produced at the Montescarpino Municipal Solid Waste landfill in Genoa, Italy. The performed analyses show a low selectivity of activated carbon towards the adsorption of only sulfur species. This represents a drawback for the use of this type of system, however, the use of mixed beds of different ACs has demonstrated to be advantageous in improving the removal efficiency of H₂S. Thus, the adsorption treatments with AC can ensure the high level of gas desulfurization required for fuel cell application. Nevertheless, the low adsorption capacity observed using landfill biogas would lead to high operative costs that suggest the application of a preliminary gas-scrubbing stage.     

尿素预处理对玉米秸秆厌氧发酵产沼气特性影响及动力学分析

针对玉米秸秆厌氧发酵产沼气过程中难降解问题,选用尿素对玉米秸秆进行预处理,并进行批次厌氧发酵产沼气试验研究。结果表明:经过45 d厌氧发酵,累积产气量最高为757.83 mL/g VS,最低为588.64 mL/g VS,厌氧发酵进行到25 d时达到45 d累积产气量的85%。分析联合预处理对累积沼气产气量影响得出,尿素质量浓度、预处理时间和玉米秸秆粒径3个因素对累积沼气产气量的影响程度是:玉米秸秆粒径>尿素质量浓度>预处理时间。通过2种动力学模型分析产气规律,对比模型的检验参数,得出Cone模型拟合预处理玉米秸秆厌氧发酵产气规律的适合度较高。