我国最大鸡粪沼气发电厂正式发电

GE能源集团近日宣布其在中国最大的鸡粪发电厂——山东民和股份沼气发电清洁机制项目开始正式运营。项目利用3台GE颜巴赫JMS3201兆瓦燃气内燃机发电,总装机容量3兆瓦。利用厌氧发酵系统对鸡粪进行发酵,日可消耗300吨鸡粪及500吨废水。产生的沼气被输送到颜巴赫燃气内燃机中,发出的电力被输入当地电网,发酵剩余的沼渣还可制成肥料。     

大型沼气工程运行分析

以北京德青源沼气工程和山东民和沼气工程为实例介绍采用CSTR工艺对鸡粪进行厌氧发酵,其pH为6.88～8.49、氨氮为5 000 mg/L、VFA 80 mmol/l,运行稳定良好;采用新型生物脱硫技术对沼气进行脱硫净化,H2S去除率能够达到97%以上,为大型沼气工程的调试与运行提供参考.     

实例分析大中型沼气工程能源效益

以扬州某畜禽养殖场大中型沼气工程为例,从各种能源替代类别差异的视角,利用等效能量替代的方法对大中型沼气工程产生沼气的能源替代效益进行分析,同时计算沼气发电余热回收利用所节约的能源量,为分析计算畜禽养殖场大中型沼气工程能源效益和经济效益提供了方法和案例.     

3MW集中式热电肥联产沼气工程设计与建设

山东民和牧业股份有限公司利用所属23家养殖场的鸡粪和污水作为沼气发酵原料,投资建设大型畜禽养殖场集中式沼气发电工程.原料经水解除砂工艺将鸡粪中的砂砾除去,保证发酵效率;采用中温(38 ℃)发酵工艺,产沼气30 000 m3/d;采用高效率低运行成本的生物脱硫工艺,将沼气中的H2S含量降至200×10-6以下;经净化的沼气在双膜干式贮气柜中贮存,供给热电联产的发电机组使用.发电量60 000 kWh/d,机组余热用于冬季发酵系统自身增温;发酵后的沼液用作周围葡萄、苹果及玉米地的有机肥料.项目实现了温室气体减排84882tCO2当量.文章介绍了该沼气发电工程的工艺特点和技术要点,为同类型沼气发电工程设计和建设提供参考.     

唐山市畜禽粪便产沼气发电生命周期评价

为探究唐山市某畜禽粪便厌氧发酵沼气项目的减排潜力,通过项目案例的实际生产数据,运用生命周期评价方法分析唐山市某畜禽粪便产沼气发电项目和传统火力发电项目不同阶段的环境影响表现。结果表明：火力发电各阶段的污染物排放差异较大,主要集中在燃煤发电阶段;沼气发电各阶段污染物排放量除SO2、CO2、CH4外无明显差异。沼气发电全生命周期过程的环境表现均优于火力发电,具有更高的减排能力,其中沼气发电加权后的环境酸化潜势比火力发电低96.64%,其次分别是人体毒性潜势（77.32%）、全球变暖潜势（67.78%）和富营养化潜势（5.71%）。     

CSTR和HCPF工艺在沼气工程的应用对比分析

在国家相关政策的支持和鼓励下,以产沼气为主的厌氧发酵大型沼气工程是畜禽粪污处置的发展趋势。中温湿式厌氧发酵工艺是国内外主流工艺,并发展出众多的反应器类型。其中,CSTR反应器和HCPF反应器可处置含固率较高的畜禽粪污,单位容积产气量大,因而得到较广泛的关注。结合实际工程案例,详细对比分析了2种反应器的结构、工艺特点、产气率和初投资等,为大型沼气工程项目的工艺选择和方案制定提供参考和依据。     

解决牛粪厌氧发酵中浮渣结壳的几种方法

在畜禽养殖场沼气发电工程中,牛粪具有固体及纤维物质含量高的特点.在厌氧发酵过程中极易在厌氧反应器内部形成浮渣层并硬化结壳,如不及时解决,将导致沼气无法顺利进入气室,严重影响厌氧反应器的正常运行.针对这个问题,文章介绍几种在实际工程中经常用到的防止浮渣结壳的方法(高位出料、机械搅拌、反冲回流等),供工程设计人员参考.     

德国典型沼气发电技术及其借鉴

以5处沼气发电工程为例,介绍了德国典型的沼气发电技术,其普遍采用"混合厌氧发酵、沼气发电上网、余热回收利用、沼渣沼液施肥、全程自动化控制"的技术模式,通过该模式的实施,最终实现发酵原料的全方位综合利用;并通过电、热以及沼渣沼液的外售给工程运行带来收益,最终实现市场化运行。通过对此次考察相关情况的介绍与总结,以期为我国大中型沼气工程的发展提供一些借鉴。     

NaOH与H_2O_2综合预处理水稻秸秆及其厌氧发酵产沼气效果研究

为实现沼气工程中农作物秸秆的有效利用、解决沼气工程对畜禽养殖厂过度依赖的问题提供有效途径,以水稻秸秆作为厌氧发酵原料,采用NaOH和H_2O_2方法对水稻秸秆进行预处理。采用自制的批次厌氧发酵装置进行沼气厌氧发酵试验,探讨不同浓度的NaOH、H_2O_2及预处理时间对水稻秸秆沼气发酵的影响。采用响应面优化方法对预处理工艺条件进行优化,得到最优预处理条件为:NaOH浓度5.71%,H_2O_2浓度1.48%,处理时间12 h。验证实验中甲烷含量最高可达61.2%,沼气产量为15866 mL,与预测值16061 mL的相对误差为1.21%,小于5%,由验证实验可知模型是有效的。     

畜禽粪便厌氧消化沼气发电行业的现状分析

介绍了大型养殖场畜禽粪便处理的必要性,分析了沼气发电的技术现状以及我国发展沼气发电所面临的困难,预测了我国畜禽粪便厌氧消化沼气发电的前景。     

Green biohydrogen production in a Co-digestion process from mixture of high carbohydrate food waste and cattle/chicken manure digestate

This study was investigated biohydrogen production on the effects of different ratio of food waste to seed digestate and pH value from co-digestion process in anaerobic reactor. The seed digestate was mixture of cattle manure 45%, corn silage 25%, chicken manure 15%, and olive pomace 15% which was collected from the biogas plant in central Italy. It was found that the peaks of total biogas and the biohydrogen productions were 1355 ± 26 and 436 ± 10 mL whereas the biohydrogen yield was 50.4 mL/g-VS (45.8 mL/g-COD) with 43.33% COD removal rate, the bacteria to substrate volatile solids (VS) ratio was 2:1 where seed digestate to food waste was 6:4 under pH 6.5. As a consequence, food waste with a high COD concentration can be adapted C/N ratio by the cattle manure and chicken manure in the seed digestate which resulted in a high biohydrogen production. The food waste co-digestion system mixed with biogas plant digestate is one of approach to increase total biogas production.     

鸡粪与NaOH预处理麦秸联合厌氧发酵产气性能与协同效果研究

试验研究了不同负荷下不同混合比例的鸡粪与NaOH预处理麦秸的厌氧发酵产气性能和协同作用效果。以鸡粪和2%NaOH预处理后的麦秸作为发酵原料,研究了混合物料在3种负荷和9种混合比例条件下的厌氧发酵产气情况。结果表明:在3种负荷(50,65,80 g/L)中,均是鸡粪和麦秸比例为1∶2时产气效果最佳,其累计产气量分别达到32 000,43 030 mL和50 370 mL;其TS产气率分别达到328.2,356.9,352.8 mL/g,比纯鸡粪相应负荷分别提高了27%,29%,23%。不同比例下,3种负荷中,均是65 g/L时产气效果最好,鸡粪与麦秸的协同作用使累计产气量提高了7%～17.7%。     

添加酒糟、草木灰对猪粪厌氧发酵的影响

以猪粪为发酵原料,研究在25℃条件下分别添加不同量的酒糟、草木灰对厌氧发酵产沼气的影响,分析了厌氧发酵过程中产气速率、累积产气量、pH值、氨态氮质量浓度及甲烷含量的变化。结果表明,在猪粪中添加草木灰1 g,累积产气量大且甲烷含量高;添加酒糟5 g,累积产气量大且甲烷含量高。添加1,3,5 g草木灰,pH值呈现降低—升高—稳定的趋势,氨态氮呈现升高—降低—稳定的趋势;添加1,3,5 g酒糟后,发酵过程中的pH值和氨态氮变化规律相似,均呈现升高—降低—升高—稳定的趋势。因此,合理的酒糟、草木灰添加量是提高猪粪厌氧发酵产气量及甲烷含量的前提。     

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%。     

Optimization of biogas from chicken droppings with Cymbopogon citratus

Optimization of biogas production and quality from chicken droppings by anaerobic co-digestion with Cymbopogon citratus was investigated. The anaerobic digestions of chicken droppings, chicken droppings with C. citratus as well as C. citratus alone were carried out for a period of 30 days at an average ambient temperature of 33.1 ± 2 °C using identical reactors (A–C) respectively. Results obtained indicate that chicken droppings produced on the average 1.8 L/kg/day of biogas, co-digestion of chicken droppings and C. citratus produced 1.3 L/kg/day of biogas while C. citratus alone produced 1.0 L/kg/day with estimated average methane content of 41.71%, 66.20% and 71.95% for reactors A–C respectively. The water boiling rates of biogas from chicken droppings, chicken droppings with C. citratus, and C. citratus alone were 0.079 L/min, 0.091 L/min and 0.12 L/min respectively, after the gases were scrubbed with water and slaked lime. It was observed that notwithstanding the higher biogas volumetric yield from chicken droppings digested alone, the co-digestion of chicken droppings with C. citratus had better gas quality with respect to the methane content present and cooking rate. This study has shown that the methane content of biogas from animal manure substrates could be improved by co-digestion with energy plants.     

Process simulation and modeling: Anaerobic digestion of complex organic matter

This work is focused on evaluating kinetic models of complex organic matters hydrolysis and volatile fatty acids degradation in anaerobic digestion process, simulated using SuperPro design software. Kinetic model evaluation was also carried for simulated integrated system of liquid anaerobic digestion (LAD) of dairy manure and solid state anaerobic digestion (SS-AD) of corn stover. Already developed hydrolysis and volatile fatty acid (VFA) degradation kinetic constants were used to simulate anaerobic digestion processes of dairy manure and corn stover separately and in the integrated process as well. Hydrolysis of complex soluble organic matters such as protein, carbohydrate and fat was modelled using first-order kinetics. Monod model was tested for the VFAs such as acetic, propionic and butyric acid degradation and biogas production. Comparative study has been done between the experimental data published already and results obtained from SuperPro simulated processes. The simulated results were well comparable with the experimental results.     

Prospective application of farm cattle manure for bioenergy production in Portugal

Biogas is a promising renewable fuel, which can be produced from a variety of organic raw materials and used for various energetic purposes, such as heat, combined heat and power or as a vehicle fuel. Biogas systems implementation are, therefore, subjected to several support measures but also to several constraints, related with policy measures on energy, waste treatment and agriculture. In this work, different policies and policy instruments, as well as other factors, which influence a potential expansion of Portuguese biogas systems are identified and evaluated. The result of this analysis shows that the use of the cattle manure for biogas production is still far from its potential. The main reason is the reduced dimension of the Portuguese farms, which makes biogas production unfeasible. Various options are suggested to increase or improve biogas production such as co-digestion, centralized plants and modular plants. Horizontal digesters are the most suitable for the typical Portuguese plant size and have the advantage of being also suitable for co-digestion due to the very good mixing conditions. Mesophilic anaerobic digestion due to a more robustness, stability and lower energy consumption should be the choice. The recent increase in the feed-in tariffs for the electricity production based on anaerobic digestion biogas is seen as a political push to this sector.     

多元原料混合发酵制备沼气技术研究进展

目前,我国沼气的发酵原料主要是禽畜粪便和农作物秸秆,随着厌氧发酵技术的发展,更多种类废弃物也逐步受到人们的关注。有机废弃物沼气化利用在我国生态文明建设中有着重大意义。论文综述了我国生物质资源,如禽畜粪便、农作物秸秆、农产品加工废弃物、市政有机废弃物和能源作物的特性和作为沼气发酵原料的优缺点,比较了这些原料的沼气生产潜力,探讨了混合原料发酵技术及重要的几种沼气发酵外源添加剂。     

沼肥对保护地番茄生长发育及其产量的影响

采用二裂式区组设计的方法,以番茄为供试作物,以沼肥（沼液、沼渣）、猪粪和化肥为肥料,研究了不同施肥措施对番茄生长发育及其产量的影响。结果表明：与施用化肥相比,施用沼液的番茄植株平均株高及根系体积有所增加,番茄产量略有降低;与施用猪粪相比,施用沼渣可促进植株茎秆的健壮生长及根系发育,番茄产量提高20．8％;与沼渣和化肥配合施用相比,沼渣与沼液配合施用促进了番茄植株的生长发育,其植株生长稳健,根系发达,而且番茄产量增加;与猪粪和化肥配合施用相比,猪粪与沼液配合施用促进了番茄植株的生长发育,其株高较高、茎秆粗壮、根系发达,但番茄产量下降。