同步脱氮脱硫技术的研究进展

废水同步脱氮脱硫技术因其具有成本低、时间短、二次污染少等优势而成为研究热点;基于废水同步脱氮脱硫的技术,废水脱氮与沼气脱硫同步进行也成为可能;综述了同步脱氮脱硫技术的化学基础、微生物基础,以及其工艺条件等方面的最新研究进展。     

生物化学脱硫在沼气发电中的应用

沼气中含有有害气体硫化氢,其在回收利用过程中,燃烧产生的二氧化硫对机械设备具有腐蚀性,且污染大气。由于啤酒行业污水处理产生的沼气含有有害气体硫化氢,文中介绍了一种利用生物化学脱硫法去除沼气中的硫化氢气体的技术;经过生物化学脱硫后沼气硫化氢含量低于200×10-6,有效保护了燃气内燃发电机组的发动机。     

沼气湿法脱硫新工艺

沼气作为一种生物质能源,已广泛用于内燃机电站发电。但是,沼气中的H2S对内燃机的腐蚀,严重制约了内燃机的可靠使用。文章采用湿法脱硫技术对某养殖场沼气进行处理,并对脱硫前后的内燃机部件损耗进行了比较,证明了该方法的有效性和可行性。脱硫后的沼气中硫化氢浓度低于200 mg/m3,对沼气内燃机的应用具有良好的保护作用。     

湿法脱硫技术在沼气内燃机上的应用

沼气作为生物质能源中的一种,已广泛用于内燃机电站发电.但是沼气中H2S对内燃机的腐蚀,严重制约了内燃机的可靠使用.本文通过湿法脱硫技术对某淀粉厂消化沼气进行处理,并对脱硫前后的内燃机部件消耗进行了比较,证明了该方法的有效性和可行性,脱硫后的沼气中硫化氢浓度低于200mg/Nm3,对沼气内燃机的应用具有良好的保护作用.     

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.     

啤酒厂污水处理所生沼气的综合利用

沼气的综合回收利用实践的结果表明,采用分离式生物脱硫技术进行沼气脱硫,能有效去除沼气中的含硫量,减少大气污染。运行结果表明,沼气锅炉的使用可以使公司天然气总能耗下降9%,取得了良好的节能效果和经济效益。     

氨法烟气脱硫技术的可行性探讨

介绍氨法烟气脱硫原理及工艺流程、经济分析,以及氨法脱硫在国内外的主要应用。氨法工艺脱硫效率高,无废水排放,除化肥硫酸铵外无废渣排放,避免了二次污染,具有循环经济特色,可以生产出硫铵化肥。辽宁地区氨来源广泛,氨法烟气脱硫技术适合在辽宁应用。     

用沼气生产高附加值燃气的技术与市场分析

同沼气发电相比,利用沼气生产管道燃气、车用天然气(CNG)和液化天然气(LNG)具有更好的经济效益.沼气精脱硫、脱氧和脱二氧化碳是生产上述产品的关键技术,在有技术保障的前提下,运营模式也是使大型沼气工程更加盈利的重要因素之一.     

沼气污泥的应用处理

沼气工程在运行过程中将产生污泥，为了保证沼气工程的正常运行和处理效果，应定期或不定期地对沼气工程在运行过程中产生的污泥进行清掏，清除多余的污泥。为了防止对环境造成二次污染，各地应根据周边地区的实际情况，安全、妥善地处置这些污泥。     

中小型工业锅炉干湿法除尘脱硫技术应用

介绍CCTL干湿法除尘脱硫系统设备在某电缆厂5t/h燃煤锅炉上配套应用情况,该设备技术成熟可靠,具有效能高(脱硫效率>95%、除尘效率>98%)、运行稳定、投资少、运行成本低、适用性强、以废治废、无二次污染、副产物回收等优点。     

Techno‐economic assessment for energy generation using bagasse: case study

Bagasse is selected as the biomass source that is studied because of its annual significant rate production in Iran and potential for energy generation. Bagasse has been as an energy source for the production of energy required to run the sugar factory. The energy needed by factories was supplied by burning bagasse directly inside furnaces, which had an exceptionally low output. To this end, today, a secondary use for this waste product is in combined heat and power plants where its use as a fuel source provides both heat and power. In addition, low efficiency of traditional methods was caused to increase the use of modern methods such as anaerobic digestion, gasification and pyrolysis for the production of bio‐fuels. In this paper, the energy conversion technologies are compared and ranked for the first time in Iran. Therefore, the most fundamental innovation of this research is the choice of the best energy conversion technology for the fuel production with a higher efficiency. To assess the feasibility application and economic benefit of biogas CHP plant, a design for a typical biogas unit is programmed. The results show the acceptable payback period; therefore, economically and technically, biogas CHP plant appears to be an attractive proposition in Iran. Copyright © 2012 John Wiley & Sons, Ltd.     

燃煤电厂烟气脱硫脱硝一体化技术发展趋势

火电厂燃煤中排放的硫化物及氮氧化物是造成大气污染的主要成分之一,经济且有效地控制燃煤电厂排放的SO2与NOx对中国这样一个以煤炭为主要资源的国家显得尤为重要。分析了中国现今的脱硫脱硝技术并着重介绍了几种燃煤电厂烟气脱硫脱硝一体化技术,分析它们的特点及存在的问题。指出具有应用前景的脱硫脱硝技术并给出建议。     

Enrichment and cultivation of a sulfide-oxidizing bacteria consortium for its deploying in full-scale biogas desulfurization

Operational experiences and strategies to get suitable chemolithoautotrophic sulfide-oxidizing biomass from activated sludge wastewater treatment plant for its deploying in a full-scale biogas desulfurization plant are described. An economic nutrient source was applied to foster microbial selection and rapid growth. Respirometry was implemented on full-scale installations to monitor the ability of the specialized bacteria consortium to oxidize reduced sulfur i.e. H₂S. During the deployment in the full-scale desulfurization reactor, intermittent sulfide feed from biogas scrubbing was performed to accelerate the startup the desulfurization process.     

Status of biogas technologies and policies in South Korea

To date, there are about 49 biogas plants in South Korea that are generally recognized as economically and technically unsuccessful due to lack of knowhow, deficient technologies and policies. There is a need to analyze the status of biogas technology and policy in South Korea from the point of view of an external biogas expert, since biogas technology in South Korea has not yet been analyzed by foreign biogas experts so far. For analyzing site investigation, literature research and interviews are performed. It was found that there are several lacks of conceptual design of biogas technology, such as plant dimension, energy balance, operation knowhow. Technical and financial support for the development of biogas technology was insufficient so far. There are some policies to support biogas technologies, however financial support from different ministries seemed not to have been used efficiently. Some policies are planned excessively so that they cannot be realized on time. Based on the general policy called “Green Growth”, the Korean government plans to establish a biogas market in South Korea in order to recover energy from organic waste. For this purpose, R&D efforts should be intensified for consulting and education in national and international networks for the transfer of knowhow and technologies. Definition of the existing restrictions on the development of biogas technology is required. By developing a biogas roadmap, the creation of a biogas market could be promoted efficiently in South Korea.     

Study on selective hydrogen sulfide removal over carbon dioxide by catalytic oxidative absorption method with chelated iron as the catalyst

H₂S is a detrimental impurity that must be removed for upgrading biogas to biomethane. H₂S removal selectivity over CO₂ employing catalytic oxidative absorption method and its influence factors were studied in this work. The desulfurization experiments were performed in a laboratory apparatus using EDTA-Fe as the catalyst and metered mixture of 60% (v/v) CH₄, 33% (v/v) CO₂ and 2000–3000 ppmv H₂S balanced by N₂ as the simulated biogas. It was found that for a given catalytic oxidative desulfurization system, it exists a critical pH, at which desulfurization selectivity achieves the highest. It was also observed that desulfurization selectivity increased along with the increase of chelated iron concentration, gas flow rate, and ratio of gas flow rate to liquid flow rate (G/L). This demonstrated that high selectivity and high efficiency for biogas desulfurization could both be achieved through optimizing these parameters. Specific to the desulfurization system of this work, when the gas flow rate was set as 1.1 L/min, after optimizing the above mentioned parameters, i.e. EDTA-Fe concentration of 0.084 mol/L, absorption solution pH of 7.8, and G/L of 55, the desulfurization selectivity factor reached 142.1 with H₂S removal efficiency attained 96.7%.     

Biogas upgrading technologies – Recent advances in membrane-based processes

This study reviews the major biogas upgrading technologies, with specific regard to recent progress in the field of membrane technology. More specifically, the objective of the present work is to provide the state-of-the-art of membrane-based processes for biogas upgrading, focusing primarily on the latest advances in membrane configurations/materials (e.g. for producing novel composite or mixed matrix membranes) and on hybrid technologies which integrate biogas upgrading with established membrane-based processes, such as the membrane bioreactor, membrane electrolysis or gas-liquid absorption. In order to demonstrate the potential of membrane technology for biogas upgrading in real field applications, the review also presents some cutting-edge biogas upgrading plants, located and operated in Europe and USA, and a brief summary of recent research studies (conducted during the last 5 years), which examine the economic feasibility of membrane-based technologies for biogas upgrading. Finally, challenges and future perspectives of applying membrane-based processes for biogas upgrading are discussed.     

Dairy farming and biogas use in Rungwe district, South-west Tanzania: A study of opportunities and constraints

This study examined the opportunities and constraints of biogas use in Rungwe district, South-west Tanzania. Two hundred households with and without biogas facilities were selected randomly from four villages. Structured, semi-structured and open-ended discussion was used to gather information. Findings show a number of opportunities for biogas technology adoption including large numbers of indoor-fed cattle and inadequate firewood in the district, which has increased its cost of such commodity. Households generally spend an average of TShs. 20,656.50 per month or TShs. 247,876.8 per annum for energy. The demand for biogas (90%) among respondents is high and the energy policy as well as donor community favour the promotion of energy efficient technologies such as biogas. Constraints encountered in establishing biogas plants were found to include unaffordability (75%) and water scarcity. Also there is inadequate expertise where some of the biogas plants have been poorly constructed leading to ineffective performance. There is also a small proportion of the respondents who admitted that they had heard nothing about biogas technology. It is being suggested that credit should be available as well as developing affordable biodigestors. Communal biogas should be encouraged to reduce the cost per unit and the government should undertake the improvement of water services.     

牛粪高浓度发酵微氧脱硫过程中的含硫物质研究

针对牛粪沼气发酵进行了微氧法原位脱硫研究。对照组进行严格厌氧发酵,试验组每隔一段时间通入微量空气。试验采用两个容积7 L的发酵罐,各加入纯牛粪4 kg,牛粪的TS为14.96%,发酵温度为40℃,试验组每日通入空气量为18 mL。为分析微氧脱硫法对牛粪高浓度发酵的适用性,重点针对发酵前后发酵液中的含硫物质进行研究。试验结果表明:通入微量空气对纯牛粪发酵进行原位脱硫的平均脱硫率能够达到89.5%。在发酵过程中,含硫物质的转化是硫酸盐还原菌(SRB)和硫化物氧化菌(SOB)的综合作用,当通入空气量与发酵液内的菌群不匹配时,沼气中的硫化氢含量会发生周期性的波动。对发酵前后的发酵物进行硫平衡分析显示,微氧法脱硫后沼液中可计量的含硫物质量明显高于厌氧发酵,说明微氧法脱硫的脱硫效果较好。     

Sustainable biogas energy in Poland: Prospects and challenges

The article investigates prospects and challenges for expanding of sustainable biogas energy in Poland. The number of Polish biogas fuelled power plants and installed electrical power during the 2001-2010 decade is presented. Current economical incentives for biogas energy are discussed. It is emphasized that some revisions to the Polish tradable certificate system are urgently needed in order to encourage energy crop cultivation and the use of best available power technologies. Further, promising, but mostly unexplored feedstocks, such as energy crops, grasses and sorted municipal organic wastes are analyzed. It is also revealed that agrobiogas is characterized by a unique feature of ‘negative net’ CO₂ atmospheric emissions and thus the role of agrobiogas in solving Polish CCS dilemmas is discussed. In regard to biogas energy systems it is stressed, that the cost of electricity from biogas is almost independent on the size of agrobiogas CHP power plants in the range of 0.2-5 MW_e. Therefore agrobiogas energy is well suited for distributed energy systems involving small-scale agrobiogas power plants offering more green jobs and improved local waste management characteristics. Finally, reliable technologies suitable for biogas energy conversion and upgrading of biogas fuel to marketable gaseous fuels are briefly characterized.     

规模养殖污染生态开发处理模式探析

规模养殖粪污经厌氧发酵后产生的沼气和沼液没有充分利用存在严重二污染.针对这一问题,泰华养殖场和南昌大学紧密合作,运用系统工程理论和循环经济等多种理论集成,开发稳定供气工程技术,实现沼气充分利用:创建沼液分流、延迟过滤、自然流好氧、区域内三级储存工程技术,创建五项养种生物链工程技术,实现沼液系统内消化,实现了沼液达标排放.取得了非常好的效果.该开发处理模式结构简单,操作方便,特别适合规模养殖场推广利用,具有重要意义.