沼液浓度对生菜种子发芽的影响

用不同浓度的沼液浸泡生菜种子对其发芽有不同的影响。实验结果表明，沼液浓度达到或超过50％时，对生菜种子的发芽有抑制作用；沼液浓度不超过30％时，对生菜种子的发芽则有促进作用，最佳沼液浓度为10％～20％。     

沼液浓度对番茄种子发芽的影响研究

用不同浓度的沼液浸泡番茄种子对其发芽有不同的影响。实验结果表明,沼液浓度达到或超过７０％时,对发芽有抑制作用;沼液浓度不超过５０％时,对发芽有促进作用,最佳沼液浓度为５％～３０％。     

沼液浓度对韭菜种子发芽的影响研究

实验表明,韭菜种子在不同浓度的沼液中发芽结果差异较大.沼液浓度大于50%时,抑制了韭菜种子的发芽和芽的生长;沼液浓度为100%时,种子完全不能发芽;沼液浓度低于20%时,可以促进种子的发芽与芽的生长;最佳沼液浓度为1%～20%.     

油菜种子在沼液中发芽的研究

实验表明,油菜种子在不同浓度的沼液中发芽结果不同。沼液浓度大于５０％时,对油苛种子发芽和生长有抑制作用;沼液浓度低于３０％时,对种子发芽和生长有促进作用;适宜浓度为１％～３０％,最佳浓度为１０％。     

小桐子油及其生物柴油雾化特性实验研究

采用雾化喷吹实验,研究不同雾化压力条件对小桐子油及其生物柴油雾化特性的影响.首先对小桐子油及其生物柴油在不同温度下的运动黏度进行测定,并进行数据拟合.喷吹对比实验结果表明,随着雾化压力的升高,雾化贯穿距增大,雾化锥角变大.相同压力条件下,小桐子生物柴油的贯穿距和雾化锥角比小桐子油大,雾化效果好.小桐子油及其生物柴油雾化...     

沼气发酵液及其处理液对乌塌菜种子发芽的影响

低浓度沼液能促进乌塌菜种子的发芽,高浓度的沼液抑制乌塌菜种子的发芽。沼液经过不同的处理后抑制作用有一定程度的消除,经较高浓度的高温灭菌沼液和pH值为6.3的沼液处理过的乌塌菜种子的发芽率均比相应浓度的原沼液高。将沼液分离成水溶性、中性脂溶性、酸性脂溶性三部分,通过发芽实验结果表明,抑制种子发芽的因素主要存在于沼液的水溶性部分,脂溶性部分能提高种子的发芽率。     

小桐子油脂肪酸在超临界甲醇中酯化反应动力学的研究

以小桐子油完全水解制取的脂肪酸为原料,对亚临界-超临界两步法制备生物柴油的第二步脂肪酸在超临界甲醇中酯化反应的影响因素进行了研究。试验结果表明:在脂肪酸与甲醇体积比为1:2,反应温度290℃,反应时间20min时,小桐子油脂肪酸酯化反应较为合适,转化率为98.49%。由试验数据采用数学规划求解进行动力学分析,得到小桐子油脂肪酸在超临界甲醇中酯化反应的平均反应级数为1.4467,活化能为66.79kJ/mol,动力学模型为-(dc_A)/(dt))=5.65×10~5e~(-(66.79)/(RT))c_A~(1.4467)。     

小桐子油枯厌氧消化产气潜力研究

在23±1℃条件下,采取批量发酵工艺,研究了小桐子油枯发酵产沼气的潜力.试验结果表明:小桐子油枯TS,VS产沼气的潜力分别为404.23,435.12 ml/g,原料的TS,VS利用率分别为19.90%,34.30%;通过稀碱溶液调节发酵料液的pH值,有利于厌氧发酵产气的进行,TS,VS产沼气潜力分别升至478.79,515.38 ml/g,原料的TS,VS利用率分别升至25.89%,48.02%.     

城市有机废弃物厌氧发酵沼液絮凝处理及其肥效研究

文章利用聚合氯化铝(PAC)和聚丙烯酰胺(PAM)对厌氧发酵沼液进行絮凝处理,以絮凝率和COD去除率为评价指标,在单因素试验基础上,采用Box-Behnken响应面法,研究PAC投放量、PAM投放量和沼液pH值对絮凝率和COD去除率的影响,并建立数学模型,获得沼液处理的最优条件,最后开展沼液肥效的研究。研究结果表明:当沼液的pH值为6.92,PAC的投放量为912 mg/L,PAM的投放量为21.36 mg/L时,沼液絮凝率和COD去除率达到最大,分别为47.96%和45.1%,总氮去除率为51.1%,总磷去除率为44.3%,氨氮去除率为60.3%;处理后的沼液在低浓度下可促进辣椒幼苗的生长,而未处理的沼液对辣椒幼苗的生长有很强的抑制作用。     

小桐子油在亚临界水中水解反应的试验研究

以小桐子油为原料,对油脂在亚临界水-超临界甲醇两步法制备生物柴油的第一步水解反应中水解的影响因素和反应动力学进行了研究。试验结果表明,在小桐子油与水体积比为1:3,反应温度290℃,反应时间40min时,小桐子油水解反应最为合适,转化率为98.9%。对此水解反应进行了动力学分析,得到小桐子油在亚临界水中水解反应的平均反应级数为0.78,活化能为55.34kJ/mol,动力学模型为-(dc_A/dt)=7254.96e~(-55.34/RT)c_A~(0.78)。     

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。     

沼气发酵液开发生产高效有机花卉液肥

沼气发酵液虽是一种优质有机肥，但直接应用存在两大问题：其一，沼气发酵液本身具有抑制和促进两方面作用，不仅表现为促进农作物和牲畜生长，防治病虫害的作用，同时也具有抑制作用；其二，虽然沼气发酵液内营养物质丰富，但含量总体偏低。根据花卉生长、发育和繁殖所需的营养，以沼气发酵液为基础，补充适量的营养物质，通过pH值的调整消除抑制因素，从而开发出具有商品价值的高效有机花卉液肥。     

The effect of total solids concentration and temperature on biogas production by anaerobic digestion

This paper analyzed the effect of total solids (TS) concentration and temperature on biogas production from anaerobic digestion with dairy manure. Batch experiments were carried out for TS concentrations of 6%, 8%, and 10%, respectively, at five different temperatures (31, 34, 37, 40, and 43°C). Results showed that two factors both had significant effect on biogas production. The optimal condition for anaerobic digestion was 8% TS concentration at the temperature of 40°C. Under such condition, the biogas production is much better than the others and the yield peaked higher. Daily biogas production of 8% was more than those test groups which are 6% and 10% under the same temperature. When TS concentration was 8%, the rank of total biogas production of different digestion temperature test was 40 ＞ 37 ＞ 34 ＞ 43 ＞ 31°C, the biogas production of the 31, 34, 37, 40, and 43°C was 0.123, 0.159, 0.171, 0.205, and 0.153 L/g, respectively.     

沼渣底施对黄瓜生长及土壤微生物数量的影响

采用盆栽试验,研究了沼渣肥用量对黄瓜不同生育时期生长情况和土壤中细菌、真菌两种微生物数量的影响。结果表明,不同添加量的沼渣肥都能够显著促进黄瓜生长,其中以5.0%沼渣的综合应用效果最好,该处理对黄瓜收获期的根重、地上部重、植株干重、株高、叶数和茎粗分别比未施肥对照组高130.51%,141.87%,72.88%,26.70%,39.32%和35.11%。沼渣肥的施用也显著改变了土壤中微生物的数量,使土壤中细菌数量增加、真菌数量降低,对生育前期土壤微生物的数量影响很大,随着生育期的延长而逐渐降低。土壤中微生物含量与黄瓜生物量相关性分析表明,土壤细菌数与黄瓜生物量成正相关,土壤真菌数量与黄瓜生物量成负相关。田间试验表明,施用沼渣比常规处理产量增加8.3%,比空白对照增产19.2%。     

Propagation by stem cuttings and root system structure of Jatropha curcas

Scarce knowledge about the propagation of Jatropha curcas is one of the limitations for the growth of cultivated area with this oilseed crop. The effect of stem cuttings length, basal area, and position on the branch on sprouting and early growth of jatropha plants were evaluated, and the effect of the propagation method on the structure of root system of adult plants was studied. The growth and development of Jatropha curcas plants were influenced by length and basal area of stem cuttings. Short cuttings favor early sprouting, but long and thick cuttings promote more shoot and root growth. Plants originated from stem cuttings obtained from the base of the branch grew more shoot structures (buds, stems, and leaves) than stem cutting from middle and apex of the branch. Leaf area at 75 days after planting was not influenced by the dimensions of stem cutting. The most vigorous root system was observed in the plants that originate from direct seeding, without any transplanting. Propagation using bag or root plug interferes with the formation of a deep tap root. Propagation through stem cuttings resulted in a very different root system structure, with predominance of superficial and thin roots. When the cap of a tap root is lost, the plant was able to regenerate a new root.     

Experimental study of flame zones variations of biogas enriched with hydrogen

Enriching biogas with hydrogen could enable conventional natural gas systems to be used for clean energy. This technique has generally been evaluated using laboratory devices, so this study addresses a conventional combustion system, consisting of a 100 kW burner fed with biogas-hydrogen mixtures instead of natural gas. Flame behavior and ignition behavior were investigated. The flame structure was analyzed by infrared thermography. The tests were performed with three different mixtures of CH₄–CO₂ recreating an energetically rich biogas, 30% CO₂ (BG70), standard biogas 40% CO₂ (BG60) and poor biogas 50% CO₂ (BG60). Then, each biogas type was enriched with hydrogen up to 20%. Major improvements were obtained between 5% and 10% hydrogen composition since the flame stability increases considerably. Flame structure closest to natural gas flame was achieved for BG60 and BG70 at 10% H₂. However, the flame temperature remained lower than that of natural gas in all cases.     

Investigation of Combustion of Emulated Biogas in a Gas Turbine Test Rig

Combustion of biogas in gas turbines is an interesting option for provision of renewable combined heat and power from biomass. Due to an increasing share of fluctuating renewable energies in the power grid(especially from wind and solar power), flexible power generation is of increasing importance. Additionally, with an increasing share of agricultural and municipal waste in biogas production, biogas composition is expected to be within a broader range. In this paper, the combustion of synthetic biogas(carbon dioxide and methane) in a combustion test rig with a swirl burner and a high pressure optical chamber is researched at different conditions. Results are compared to a CHEMKIN-PRO simulation using a detailed reaction mechanism. The results show that within the researched experimental matrix, stable biogas combustion for gas turbines can be achieved even with significantly changing gas composition and nominal power. Carbon dioxide concentration is varied from 0 to 60%. CO concentrations(normalized to 15% O_2) in the flue gas do not change significantly with increasing carbon dioxide in the fuel gas and, for the researched conditions, stayed below 10 ppm. NO_x concentration is below 10 ppm(normalized to 15% O_2) for pure methane, and is further decreasing with increasing carbon dioxide share in the fuel gas, which is mainly due to changing reaction paths as reaction analysis showed. Thermal load of the combustor is varied from 100% to 20% for the reference gas composition. With decreasing thermal load, normalized carbon monoxide flue gas concentration is further reduced, while NOx concentrations are remaining at a similar level around 5 ppm(normalized to 15% O_2).     

Experimental investigation on biogas enrichment with hydrogen for improving the combustion in diesel engine operating under dual fuel mode

Biogas valorization as fuel for internal combustion engines is one of the alternative fuels, which could be an interesting way to cope the fossil fuel depletion and the current environmental degradation. In this circumstance, an experimental investigation is achieved on a single cylinder DI diesel engine running under dual fuel mode with a focus on the improvement of biogas/diesel fuel combustion by hydrogen enrichment. In the present investigation, the mixture of biogas, containing 70% CH₄ and 30% CO₂, is blended with the desired amount of H₂ (up to 10, 15 and 20% by volume) by using MTI 200 analytical instrument gas chromatograph, which flow thereafter towards the engine intake manifold and mix with the intake air. Depending on engine load conditions, the volumetric composition of the inducted gaseous fraction is 20–50% biogas, 2–10% H₂ and 45–78% air. Near the end of the compression stroke, a small amount of diesel pilot fuel is injected to initiate the combustion of the gas–air mixture. Firstly, the engine was tested on conventional diesel mode (baseline case) and then under dual fuel mode using the biogas. Consequently, hydrogen has partially enriched the biogas. Combustion characteristics, performance parameters and pollutant emissions were investigated in-depth and compared. The results have shown that biogas enriched with 20% H₂ leads to 20% decrease of methane content in the overall exhaust emissions, associated with an improvement in engine performance. The emission levels of unburned hydrocarbon (UHC) and carbon monoxide (CO) are decreased up to 25% and 30% respectively. When the equivalence ratio is increased, a supplement decrease in UHC and CO emissions is achieved up to 28% and 30% respectively when loading the engine at 60%.     

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。     

城市有机垃圾厌氧干发酵研究

在２０－５０％ ＴＳ浓度下，采用厌氧消化污泥作接种物，ＴＳ量与接种物量之比为１０：１，可保证有机垃圾厌氧消化过程正常进行。这时垃圾的生物降解量、产沼气量和产甲烷量均随ＴＳ浓度的增高而降低，ＴＳ浓度为５０％时降低幅度最大。产甲烷过程，挥发酸量和每克ＴＳ和ＶＳ的产气量均与ＴＳ浓度有关。