沼气发酵猪粪管理系统对温室气体排放的影响

基于生命周期清单分析以及清洁发展机制,引入"碳足迹"概念,对我国散养猪以及规模化养猪场引入沼气发酵系统后猪粪管理系统温室气体排放及减排进行了估算。农户散养猪粪处理系统中,12 m3沼气池厌氧发酵过程碳足迹为223.40 kg CO2e/a,沼气代替原煤燃烧减少444.33 kg CO2e/a温室气体,沼气发酵净减少220.93 kg CO2e/a温室气体,我国散养生猪产生的猪粪以此沼气池发酵可减少温室气体20 984.62 Gg CO2e/a;分析运行规模约1 000 m3大型沼气工程的碳足迹,保守估计为2 835.32 t CO2e/a,运行沼气工程替代煤炭以及减少猪粪排放的温室气体共约2 914.23 t CO2e/a,故沼气工程年减少温室气体78.91 t CO2e,该项目共可减排1 578.20 t CO2e。在猪粪管理系统中采用沼气发酵系统可以更好地促进温室气体减排的进行。     

基于变频和温控技术的医院空调系统节能改造

医院是公共建筑中能耗最大的建筑之一,这也意味着其空调系统存在着巨大的节能改造空间。针对辽宁省某儿童医院现有空调系统的运行现状和特点,以变频技术和温控技术为改造核心手段,提出了切实有效的节能改造方案。经过分析计算表明,该方案可节约用电量71.9万k W·h/a,间接减少标准煤用量240t/a,取得了良好的经济效益和社会环境效益。     

北京燕山石化公司烟机运行分析及改进措施

分别介绍了中国石化北京燕山分公司炼油厂2000kt/a重油催化裂化装置和800kt/a催化裂化装置配套的烟机发电机组更新改造及运行分析情况,提出了优化装置反再系统的工艺控制、严格控制烟气催化剂浓度等措施以保证烟机发电机组长周期运行。     

太阳能集热系统在印染行业的应用

印染是高耗能企业,每年消耗大量蒸汽生产热水。为了减少企业能耗,以某印染厂为例利用太阳能替代部分蒸汽生产热水。结果表明:4 320 m2的太阳能集热系统可生产热水60 000t/a,节约蒸汽3 900 t/a,节约运行成本40.9万元/a,回收期4.6年。同时,对主要的纺织印染城市的太阳能资源研究分析发现:在浙江、江苏、山东等区域,太阳能集热系统的最长回收期不超过6.5年,具有较好的经济和环境效益。     

新型双面辐射阶梯炉在延迟焦化装置的工业应用

中国石化济南分公司延迟焦化装置原设计为一炉两塔型式,处理量为500kt/a,所用加热炉(F-101)为双面辐射方箱加热炉。2009年对该装置进行了扩能改造,改为两炉四塔型式,新增处理量为700kt/a的一炉两塔,装置处理量扩大到1.20Mt/a。新增加热炉(F-102)为新型双面辐射阶梯炉,开工后一直运行平稳,F-102加热炉火焰燃烧状况好,不存在舔炉管现象。从应用情况来看,F-102单炉新鲜进料处理量可以达到962.6kt/a;应用加热炉F-102,装置的产品液体收率(汽油、柴油和蜡油)比应用加热炉F-101增加1.90个百分点;在两炉同时运行情况下,对两炉进行操作弹性和生焦率对比标定。结果表明,F-102的操作弹性明显大于F-101,生焦率比F-101低0.52个百分点,新鲜原料燃料消耗量比F-101低0.48kg/t,热效率比F-101高2.6个百分点。从增加产品液体收率、节约燃料方面计算,应用新型双面辐射阶梯炉F-102,可增加效益2505.36万元/a。     

垃圾填埋气产量的估算与测试

针对某垃圾填埋场,采用IPCC模型和Gardner-Probert模型理论对填埋气总产量和年产气量进行了计算,结果表明,以600m3/h的抽气量进行利用可使用10a以上,具有很好的利用前景。利用开发出的填埋气测试装置,进行了单井抽气能力的测试,通过长达半年的连续抽气运行实验,单井抽气流量可以稳定在40m3/h,为工程设计提供     

催化裂化装置长周期运行的经验探讨

催化裂化装置是目前我国原油二次加工的主要装置,随着加工原油重质化和劣质化程度加剧,催化裂化装置长周期运行难度加大。目前,国内催化裂化装置平均运行周期接近3a,与国外同类装置相比差距较大(如美国埃克森公司炼油厂、Phibro公司休斯顿炼油厂的催化裂化装置一般可连续运转4～5a),种种因素引发的非计划停工时有发生。据2008年中国石化对催化装置非计划停工的原因统计,静、动设备故障导致的非计划停工次数位列第一,腐蚀导致的非计划停工次数位列第二,结焦、结垢和误操作导致的非计划停工位列第三,其余是公用工程、仪表电气故障等原因导致的非计划停工。中国石化荆门分公司拥有两套催化裂化装置,长周期运行工作取得了较大进步,其中0.8Mt/aDCC催化裂化装置最近两个生产周期的运行时间分别为1118d和1339d,1.2Mt/a RFCC催化裂化装置最近两个生产周期的运行时间分别为970d和1072d。总结近年来长周期运行的经验认为,牢靠的设备保障,严格的工艺管理,良好的机电仪维护,稳定的公用系统,扎实的职工培训,坚持本质安全的理念和卓有成效的技术攻关,是确保催化裂化装置长周期运行的基础和保障。     

阿坝州以水电和地矿资源为优势的电化学工业综合利用发展规划

四川阿坝州地区地处高原山区,拥有水电和地矿资源优势,以该优势为基础,规划了资源综合利用循环经济型发展项目。利用阿坝州山区水电资源发展高效电化学化工产业,以45×104t/a氯酸钠和30×104t/a电石为基础,将氯酸钠电解尾气(H2)和电石炉(采用密闭式电石炉)尾气(CO、CO2)回收充分利用合成甲醇,再以甲醇为原料生产高附加值下游产品——二甲醚、甲醇蛋白、甲醛、脲醛树脂、中(高)密度纤维板。形成了40×104～50×104t/a氯酸钾,30×104t/a电石,15×104t/a甲醇,5.0×104t/a二甲醚,2.0×104t/a甲醇蛋白,8.0×104t/a甲醛,12×104t/a脲醛树脂,30×104m3中、高密度纤维板的生产规模。项目总投资21.71亿元,年销售收入为45.59亿元,年利税达到10.29亿元。回收尾气可增产15×104t/a甲醇,所用甲醇合成工艺比常规工艺能耗降低1/3,除了可观的经济效益外,每年还可减排CO223.3×104t,实现了保护生态、振兴地方经济的科学发展。     

太阳能逆变器

<正>太阳能逆变器是将直流电转换成交流电的设备。逆变器按运行方式可分为独立运行逆变器和并网逆变器。a)独立运行逆变器用于独立运行的太阳能电池发电系统,为独立负载供电;b)并网逆变器用于并网运行的太阳能电池发电系统。逆变器按输出波型可分为方波逆变器和正弦波逆     

轻烃内氧部分氧化替代外燃蒸汽转化制取合成气的先进技术

我国轻烃资源丰富,是制氨、尿素与甲醇的主要原料。我国现年产合成氨和甲醇近3000×104t,耗用轻烃(折CH4计)近300×108m3/a,大都采用外燃蒸汽转化,其中包括用干燃料的轻烃约100×108m3/a,并燃烧排放出CO2达2000×104t/a。采用我国成功开发的纯氧自热转化替代外燃蒸汽转化,用2m3O2可替代出燃料1m3CH4,免除产生CO2排放2kg/m3CH4,同时将节省下来的轻烃燃料作原料用可增产30%。与外燃蒸汽转化相比,新工艺原料消耗可降低20%～30%,甲醇合成能力可提高20%～100%,减排CO220%～80%,而且新工艺的转化炉体积小、造价低、省去了耐高温贵镍合金材料、使用寿命长。我国近3000×104t/a轻烃制氨、甲醇生产厂,如果应用此新工艺替代传统外燃蒸汽转化工艺,每年可节省轻烃燃料约100×108m3,可用于增产氨、甲醇125×104t/a,减排CO22000×104t/a。我国若在四川苍溪,采用纯氧自然转化、无CO2排放的等压合成甲醇转化制乙烯工艺,建设2×50×104t/a乙、丙烯基地,仅耗用天然气20×108m3/a。     

Particulate Fouling and On-Line Cleaning of Ferric Oxide Particles in Internally Enhanced Tubes

This paper describes the results of accelerated particulate fouling tests performed on three enhanced tubes and a plain tube. The tests were performed using ferric oxide as the foulant material. Three enhanced tubes included 25 start, 10 start helically ribbed tube and a ripple tube. Effect of the water velocity (1.2–1.7 m/s) on fouling resistance was investigated. The maximum fouling resistance occurred in the 25 start helically ribbed tube (about 8.0 × 10^?5 m²K/W after 100 hours). For the 10 start helically ribbed tube, the fouling resistance was relatively small (less than 1.8 × 10^?5 m²K/W). The rippled and plain tubes show almost negligible fouling resistance. High velocity flushing was effective for all the tubes except for the 25 start helically ribbed tube. On-line brush cleaning maintained the fouling resistance below 1.8 × 10^?5 m²K/W for all tubes. The fouling concentrations used in the tests were significantly higher than would be expected in commercial heat exchangers. Also, the velocity range investigated was lower than would be expected in heat exchanger operation.     

高浓度乙二醇气田废水厌氧生化处理试验研究

天然气输送过程中,通常注入乙二醇,以抑制水合物产生。由于回收时分离不完全,部分乙二醇与产出水混合,形成高浓度乙二醇气田废水。对于这类废水的处理,现有方法实际应用效果均不理想,在文献调研和分析的基础上,提出采用厌氧生化法处理。试验采用自行设计的厌氧生化反应器,整个试验过程依次为厌氧微生物适应阶段、提高负荷阶段、稳定运行阶段。试验结果显示:厌氧活性污泥对乙二醇气田废水的适应期为3d,经过20d的连续提高负荷,使最终负荷达到约12kg COD/(m3·d),稳定运行阶段进水COD浓度为13000mg/L,HRT控制在24h,稳定运行后出水COD在1000mg/L以下;进水COD浓度高于10000mg/L时,提高其p H值到7.4~7.5,可以保证厌氧效果不受影响。这表明,厌氧生化法处理含高浓度乙二醇气田废水是可行的。     

Study on water transport in hydrophilic gas diffusion layers for improving the flooding performance of polymer electrolyte fuel cells

For hydrogen-based polymer electrolyte fuel cells (PEFCs), water transport control in gas diffusion layers (GDLs) by wettability distribution is useful to suppress the flooding problem. In this study, the water transport of a novel GDL with hydrophilic-hydrophobic patterns was investigated. First, we clarified that the water motion in the hydrophilic GDL with microstructures could be reproduced by the enlarged scale model. The scale model experiment also showed that the same water behavior in hydrophilic GDL can be obtained from Capillary numbers (Ca) in a range of Ca ~ 10^?5 to 10^?3. As the computational load is inversely proportional to Ca, the computational load could be reduced by 1/100th by using Ca ~ 10^?3, which is 100 times higher than PEFC operation (Ca ~ 10^?5). Finally, the simulation with Ca ~ 10^?3 was performed, and we showed that the GDL with straight region of contact angle 50° minimized the water accumulation.     

Experimental study of acrylamide monomer polymer gel for water plugging in low temperature and high salinity reservoir

Water plugging agent has been widely applied on oilfield EOR processes for decades. Conventional plugging agents used on reservoirs with low temperature (50°C) and high salinity (28.6 × 10⁴ mg/L) encounters with some limitations, such as slow gelling, weak gel strength, and poor instability. To overcome these problems, a novel acrylamide monomer polymer gel with strong gel strength, controllable gelling time and good stability was developed. The gelation processes of the plugging agent system at low temperature and high salinity is studied. The cross-linking reaction process of plugging agent is found to be in three stages: induction stage, rapid cross-linking, and stable stage. The composition of this plugging agent system is optimized: 5~7.5 wt% acrylamide + 0.5~0.75 wt% cross-linking agent + 0.005 ~0.12 wt% retarder + 0.5 wt% initiator. The plugging rate is over 96.5% in high permeability sandpack. It also displays good shear resistance. With the continuous flooding by water after the gel is formed, the polymer gel shows good flooding resistance. It can block the water effectively until 10 PV of injected water.     

陡坡溢洪道掺气坎空腔长度及掺气坎角度试验

以苏家河口水电工程为例,针对其陡坡溢洪道掺气坎对流量大小适应性较差的问题进行了试验,对#2掺气坎3种体型(1∶4、1∶10、1∶15)进行了挑角的优化设计。结果表明,在陡坡溢洪道设置掺气坎时应保证挑角和坎高与单宽流量相互匹配,即挑角在3°～5°之间的空腔长度能满足各种工况,否则可能出现掺气坎适应性很差的问题,不利于工程泄洪时的正常和安全运行;空腔长度与挑角在小流量情况下呈指数关系,在大流量情况下呈对数关系,这为实际工程设计提供了依据。     

Results from an industrial size biogas-fed SOFC plant (the DEMOSOFC project)

The EU-funded DEMOSOFC project aims to demonstrate the technical and economic feasibility of operating a 174 kW_e Solid Oxide Fuel Cell (SOFC) in a wastewater treatment plant. The fuel for the three SOFC modules (3 × 58 kW_e) is biogas, which is available on-site from the anaerobic digestion of sludge collected from treated wastewater. The integrated biogas-SOFC plant includes three main units: 1) the biogas cleaning and compression section, 2) the three SOFC power modules, and 3) the heat recovery loop. Main advantages of the proposed layout are the net electric efficiency of the SOFC, which is in the range 50–55%, and the near-zero emissions. A specific focus of the demonstration project is the deep and reliable removal of harmful biogas contaminants. The presented work is related to the design of the SOFC system integrated into the wastewater treatment plant, followed by the analysis of the first results from the plant operation. We analyzed the biogas yearly profile to determine the optimal SOFC capacity to install that is 3 SOFC modules. The rational is to maintain high the capacity factor while minimizing the number of shutdown per year (due to biogas unavailability). First results from plant operation are also presented. The first SOFC module was activated in October 2017 and the second in October 2018. The measured SOFC efficiency from compressed biogas to AC power has always been higher than 50–52%, with peaks of 56%. Dedicated emissions measurements have been performed onsite during December 2017. Results on real biogas operation show NO_x < 20 mg/m³, SO₂ < 8 mg/m³ (detection limits for the instrument) and PM lower than ambient air values.     

Lighting controls: Survey of market potential

This study describes the impact of lighting management systems that dynamically control lights in accordance with the needs of occupants. Various control strategies are described: scheduling, tuning, lumen depreciation, and daylighting. From initial experimental results, the energy savings provided by each of the above strategies are estimated to be 26, 12, 14, and 15%, respectively.Based upon a cost of $0.05–0.10 per kWh for electric energy and a 2-, 3-, or 4-yr payback, target costs for a simple and a sophisticated lighting management system are found to be $0.24 and 1.89 per ft², respectively, for a cost-effective investment.A growth model, based upon an extrapolation of the increase in building stock since 1975, indicates that the commercial and industrial (C & I) building stock will grow from 40 × 10⁹ ft² in 1980 to about 67 × 10⁹ ft² by the year 2000. Even with the use of more efficient lighting components, the energy required for this additional C & I stock will be 307 × 10⁹ kWh compared to the 230 × 10⁹ kWh used today. Adopting controls would reduce this requirement to 243 × 10⁹ kWh, an increase of only 13 × 10⁹ kWh above current use.The specified information is used to analyze the economic impacts that using these systems will have on the lighting industry, end users, utility companies, and the nation's economy. A $1–4 × 10⁹ annual lighting control industry can be generated, creating many jobs. The estimated return on investment (ROI) for controls for end users would be between 19 and 38%. Utilities will be able to make smaller additions to capacity and invest less captial at 7–10% ROI. Finally, the annual energy savings, up to $3.4 × 10⁹ for end users and about $5 × 10⁹ for utilities, representing unneeded generating capacity, will be available to capitalize other areas of our economy.     

商洛市水资源现状浅析

采用商洛市10个水文站1956--2005年的实测水文资料进行统计分析,分析了商洛市地表水资源总量为501亿m^3,地下水资源总量为19．6亿m^3,为合理开发利用水资源提供科学依据。     

Anaerobic hydrogen and methane production from low-strength beverage wastewater

In this study, the low-strength effluent from an equalization tank of the wastewater treatment plant in a beverage factory was used for the production of hydrogen and methane. The COD concentration of this low-strength wastewater was 2.9 ± 2.0 g COD/L. In a two-phase anaerobic fermentation system, the hydrogen-producing bioreactor was operated at HRT 8 h, while the methane-producing reactor operated at HRT 24 h. The maximum MPR, methane yield (MY), methane content and COD removal were 72 ± 31 mL/L-d, 58 ± 12 mL/g COD, 92 ± 2% and 78%, respectively. Energy efficiency in this study was calculated as follows, the maximum heating value was 2.2 × 10⁸ kcal/y. The annual carbon-emission reduction was 8.8 × 10⁴ kg CO₂/y, 5.2 × 10⁴ kg CO₂/y, 7.2 × 10⁴ kg CO₂/y when energy-equivalent coal, natural gas or fuel was used, respectively.     

Photo-oxidation of liquid sulphur by iron (iii) salt

One of the applications of solar energy is the photo-thermochemical production of fuel, particularly hydrogen. In this regard photo-oxidations/reductions are important processes and may provide a route to harnessing solar energy. Liquid sulphur absorbs in the visible region (400–500 nm). The absorption of light in this region will produce excited sulphur and hence can take part in the photo-oxidation/reduction process. The photo-oxidation of liquid sulphur by Fe(III) salt (anhydrous ferric chloride) at 150 ± 5°C was studied in both the presence and absence of visible light. It was found that liquid sulphur was photo-oxidized by Fe³⁺ which itself was reduced to Fe²⁺. The overall rate constants for photo-thermochemical and pure thermochemical reactions were found to be 5–3 × 10^?6 M^?1 s^?1 and 2–8 × 10^?6 M^?1 s^?1, respectively. A mechanism for the photo-thermochemical reaction is proposed.