共查询到20条相似文献,搜索用时 31 毫秒
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Ayhan Demirbas 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2013,35(5):413-422
This article deals with slow pyrolysis of oak wood and agricultural residues such as hazelnut shell and wheat straw at high temperature (950–1250 K) in a cylindrical reactor. The aim of this work is to study the effect of the treatment conditions such as temperature, particle size, and lignin and inorganic matter contents on bio-char yield and reactivity. When the pyrolysis temperature increased, the bio-char yield decreased. A high temperature and smaller particles increase the heating rate resulting in a decreased bio-char yield. The higher lignin content in hazelnut shell results in a higher bio-char yield in comparison with oak wood and wheat straw. Bio-chars from hazelnut shell and wheat straw are more reactive in gasification than bio-chars from oak wood because of the higher ash content. The bio-char obtained are carbon rich, with high heating value and relatively pollution-free potential solid biofuel. 相似文献
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苇沟大型猪场猪粪沼渣在黄瓜栽培上的应用 总被引:2,自引:0,他引:2
用絮凝后的猪粪沼渣和沼水在黄瓜栽培上应用试验结果表明,用沼渣作基肥效稍优于等量N,P,K化肥,用沼水作追肥肥效明显低于等N化肥。沼渣中所含的Ca,Fe,Cu,Mg,Mn,Zn,Mo等元素与黄瓜植株中所含的元素种类基本一致,长期应用沼渣可保持土壤肥力平衡,应用絮凝沼渣与化肥混合配成的复肥作基肥后,瓜中许多元素的含量低于其他处理,此现象可能与沼渣絮凝剂和加工工艺有关。 相似文献
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生活垃圾综合处理厂在堆肥过程中产生堆肥剩余物,占总垃圾量的10%~20%,热值较高适于焚烧处理.文章对城市生活垃圾堆肥剩余物的组成、工业分析及元素分析进行分析研究,表明该类堆肥剩余物具有热能回收利用价值.采用TGA方法研究垃圾堆肥剩余物的燃烧特性,结果表明,垃圾的燃烧过程包括水分析出、挥发分燃烧和焦炭燃烧三段进行.挥发分在320℃左右剧烈燃烧,焦炭在420~450℃左右开始强烈燃烧,燃尽温度达750℃左右.在实际流化床焚烧炉上焚烧结果表明,垃圾堆肥剩余物能够在800~950℃内稳定燃烧,并且NOx、SO2、CO、HCl以及重金属等污染物的排放浓度达到国家环保排放标准.为了减少焚烧飞灰量,建议采用炉排炉焚烧此类垃圾,以降低飞灰的处置成本. 相似文献
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Deti Xie 《国际能源研究杂志》2015,39(8):1068-1082
China, one of the countries in the world abundant in agricultural wastes, has a great potential for rural biogas production. As a strategy for building a new socialist countryside and sustainable agriculture in rural China, the development of biogas is an important means to convert agricultural wastes to clean and safe energy, thereby reducing the need for fossil fuel and alleviating environmental pollution. This study presents an assessment of the biogas production potential, its current development state, and perspectives of agricultural wastes in rural China. Estimated data show that annual biogas potential from agricultural wastes is approximately (3350.58 ± 669.28) × 108 m3 (equal to 239.22 ± 47.78 million tons of equivalent standard coal); such potential has been underutilized in the past. By analyzing and summarizing the direction for future development and various benefits of rural biogas in China, we present burning questions and countermeasures for biogas development and recommend that the future development of rural biogas in China should focus on both household‐scale and large‐scale development, giving priority to the establishment of large‐scale biogas engineering and biogas plants, improvement of biogas comprehensive utilization level, and construction of a reticular model of systemized green agricultural engineering linked with biogas to solve completely the problem of agricultural waste accumulation and improve the living conditions in rural China. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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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%。 相似文献
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论述了年产万吨酒精厂用红薯干为主要生产原料,采用生物厌氧,兼氧消化,好氧,物化处理等技术,综合治理酒精糟液的先进工艺,实现了日处理浓度有机污水400-500t,COD,BOD,SS降解净化率均在99%以上,出水达到GB8978-1996规定的第二类污染物二级排放标准。全年生产沼气255万-270万m^3,可获直接经济效益260余万元人民币。 相似文献
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醋糟厌氧发酵特性的研究 总被引:3,自引:0,他引:3
以醋糟为厌氧发酵原料,分别进行了连续进料试验和全进全出料试验。连续进料试验结果表明,在每天进料量保持不变的情况下,日产气量稳定,平均产气率为0.918 m3/(m3.d),最高产气率可达1.111 m3/(m3.d)。经过计算可知,8.52 kg醋糟可产1 m3沼气。全进全出料发酵试验结果表明,醋糟厌氧发酵的体积上浮和膨胀非常明显。当进料浓度为4%时,料液最大膨胀体积为322.68 cm3,为发酵料液体积的28.8%。醋糟厌氧发酵具有降解速率快,滞留期短等特点。 相似文献
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试验研究了梨渣和猪粪在分批厌氧发酵和连续厌氧发酵工艺中的产气性能.分批厌氧发酵考察不同接种量、渣粪比以及发酵温度对梨渣产气量和甲烷含量的影响,结果表明,接种量为30%和40%时发酵可以正常启动;梨渣中加入猪粪后产气性能提高,渣粪比为1:∶1时,甲烷含量在60%以上;高温条件下的总产气量比中温条件下高32%,但所产沼气中甲烷含量偏低.连续厌氧发酵试验表明,梨渣的添加比例从15%提高到50%时,干物质产气率从207 L/kg降低到109 L/kg,甲烷含量从81.2%降低到57.0%. 相似文献
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玉米秸秆沼渣热裂解及热动力学研究 总被引:1,自引:0,他引:1
采用热重法(TG)-微分热重法(DTG)-差热分析法(DTA)研究玉米秸秆沼渣热解过程及热裂解反应动力学特征和机理。研究结果表明玉米秸秆沼渣的失重过程分为吸附水蒸发阶段和秸秆裂解、挥发性物质蒸发阶段。热解过程中,加热速率对玉米秸秆沼渣热解有显著作用。使用FWO、KAS和Popescu方法计算出其热解活化能分别为233、359、358 kJ/mol。对41种常用热裂解动力学机理函数分析确定其热裂解动力学机理为三级方程g(α)=(1-α)-2。扫描时电子显微镜(SEM)分析表明,热裂解可破坏玉米秸秆沼渣的木质纤维束状结构,降低木质纤维中的木质素和半纤维素的质量分数,但效果随升温速度的增大而变差。 相似文献
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Ayhan Demirbaş 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2013,35(10):933-940
In this study, the fuel properties of mosses and algae, and the effect of pyrolysis temperature on the yield of bio-oil from moss and alga samples, were investigated. The yield of bio-oil from pyrolysis of the samples increased with temperature. The yields were increased up to 750 K in order to reach the plateau values at 775 K. The maximum yields were 39.1, 34.3, 33.6, 37.0, 35.4, 48.2 and 55.3% of the sample for Polytrichum commune, Dicranum scoparium, Thuidium tamarascinum, Sphagnum palustre, Drepanocladus revolvens, Cladophora fracta and Chlorella protothecoides, respectively. The bio-oil yield for Chlorella protothecoides (a microalga sample) rose from 5.7 to 55.3% as the temperature rose from 525 to 775 K, and then gradually decreased to 51.8% and was obtained at 875 K with a heating rate of 10 K/s. Formulas can be developed to calculate higher heating value (HHV) of different moss and alga samples. The calculated HHV using these new correlations showed mean differences ranging from ?2.3% to +0.06%. The equation developed in this study showed good agreement with experimental results on moss and algae samples. The HHVs for bio-oils from mosses 21.5–24.8 MJ/kg and the HHVs for bio-oils from algae and microalga 32.5 and 39.7 MJ/kg, respectively, were obtained at temperature ranging from 775 to 825 K. In general, algae bio-oils are of higher quality than bio-oils from mosses. In general, microalgae bio-oils are higher quality than bio-oil from wood. 相似文献
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采用热重分析(TG)分析沼渣的热解特性,研究沼渣的热解动力学并计算指前因子A、焓变ΔH、吉布斯自由能ΔG、熵变ΔS等热力学参数。进一步考察温度对沼渣热解产物分布与性质的影响。其热解过程可分为3个失重阶段,其中第2阶段为主要失重阶段,采用Flynn-Wall-Ozawa(FWO)法、Friedman法和Kissinger-Akahira-Sunose(KAS)法计算的平均活化能分别为410.00、471.32和420.01 kJ/mol,热力学参数计算结果表明沼渣热解过程具有稳定的能量输出。沼渣热解油的产率随温度上升先增加后降低。气体产物的高位热值(HHV)从400 ℃时的6.82 MJ/Nm3增加到700 ℃时的8.54 MJ/Nm3。红外光谱(FTIR)、拉曼(Raman)光谱表明热解温度升高生物炭结构的有序性增加。 相似文献
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Selçuk Bilgen 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(9):1286-1292
The purpose of this study is to evaluate the chemical exergy (ECH) of liquid products obtained from fast pyrolysis of biomass. I have calculated the chemical exergy values from a formula in literature and have developed a formula for estimating the chemical exergy of biomass from the higher heating value and their ultimate analysis values. The mean differences between these values range from –0.391% to 0.460%. The formula developed for estimating the chemical exergy of biomass from the higher heating value and their ultimate analyses had a correlation coefficient (R2 = 0.9999), and the prediction of this formula is good. The goal is to identify desirable attributes that may serve as the basis for decision-making for future biofuel options. Studies on the pyrolytic oils showed that the oils obtained from chestnut cupulae and maple fruit can be used as a renewable fuel and chemical feedstock. 相似文献
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《能源学会志》2020,93(1):210-223
By introducing exogenous nitrogen during biomass pyrolysis under nitrogen-rich conditions, high-value nitrogen-containing products, i.e., nitrogen-rich char and oil may be produced. Based on the cogeneration of high-value nitrogen products from biomass, biomass nitrogen-enriched pyrolysis was performed in a fixed bed with different sources and contents of ammonia. The yields, composition and characteristics of the products were investigated. Moreover, the formation mechanism of N-containing species was explored in depth for the pyrolysis and catalytic pyrolysis with HZSM-5 and Zn/HZSM-5 catalysts via elemental analysis, XPS, FTIR and BET. The results showed that ammonia impregnation could promote a Maillard reaction, reduce the content of small aldehydes and ketones, and produce a nitrogen-enriched bio-oil. The contents of N-containing species and phenolic substances in the pyrolysis oil of biomass impregnated with 10% urea reached 15.66% and 56.69%, respectively. Moreover, the nitrogen on the coke surface after pretreatment was mainly composed of CN, CN and NCOO functional groups. The bio-char generated abundant pyridinic-N, pyrrolic-N, quaternary-N, and pyridone-N oxides. The presence of urea introduced many alkaline N-containing functional groups on the surface of the bio-char and promoted the transformation of nitrogen from amides and imides to heterocyclic nitrogen with higher thermal stability. Furthermore, Zn was an excellent catalyst for the Maillard reaction, and the Zn/HZSM-5 catalyst had a higher selectivity for aromatic hydrocarbons (96.98% for biomass and 86.48% for urea/biomass) and N-containing heterocyclic compounds, such as indoles (6.16% for biomass and 13.51% for urea/biomass). Additionally, the coke content decreased, and the catalyst deactivation decreased. 相似文献
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《Energy Policy》2013
In recent years, Italy has witnessed a proliferation of agricultural biogas plants. This article argues that institutional factors have played an important role in their diffusion. It describes the state and evolution of agricultural biogas in Italy, and then investigates the extent to which institutional pressures have been influential in shaping organizational models of biogas production. It finds that the dominance of one particular organizational model is the result of an isomorphic process in which a monopolistic market, legal structures, and subsidies play a role. The prevalence of this organizational model, however, does not lead to the effective use of biogas production, and furthermore it results in low environmental efficiency. For a more sustainable development of bioenergy, Italian policy-makers should reform the existing institutional framework by reorganizing subsidies, liberalizing the management of gas grids, and involving farmers in local projects. 相似文献
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A. Demirbas 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2013,35(1):38-44
Abstract This article reports on physico-chemical properties of olive cakes to evaluate them as a raw material in energy production through thermo-chemical pyrolysis conversion process. The present study focuses on the actions related to the possibilities to utilize in particularly olive cake as an agricultural residue. Olive cake is a very promising material for the production of bio-oil. Liquid, solid, and gaseous products were obtained from olive cake by pyrolysis. If the purpose were to maximize the yield of liquid products resulting from biomass pyrolysis, a low temperature, high heating rate, and short gas residence time process would be required. Flash pyrolysis gives high oil yields. The heating was carried out from 298 K to 1,050 K in the absence of oxygen. The yields of liquid products were obtained from the olive cake by pyrolysis for the runs of different heating rates: 10 K/s, 20 K/s, and 40 K/s. The highest bio-oil yields from the olive cakes were 31.0% at 700 K, 36.0% at 700 K, and 41.0% at 700 K obtained from 10 K/s, 20 K/s, and 40 K/s heating rate runs, respectively. The highest bio-oil yields olive stone shells were 27.0% at 700 K, 31.0% at 700 K, and 34.5% at 750 K obtained from 10 K/s, 20 K/s, and 40 K/s heating rate runs, respectively. 相似文献