外文翻譯太陽能增溫丘陵地區(qū)沼氣廠實地考察

1、外 文 翻 譯題 目： 太陽能增溫丘陵地區(qū)沼氣廠實地考察 太陽能增溫丘陵地區(qū)沼氣廠實地考察摘要：目前的研究客觀的表明采用塑料材料代替?zhèn)鹘y(tǒng)的磚材料作為沼氣廠保溫材料效果更好。在裝有太陽能研究及其對沼氣生產(chǎn)的影響的小村莊該領(lǐng)域的研究進(jìn)行了一年（2005年10月，2006年9月）。在夏季（4月-6月）溫度達(dá)到最高21-25c，達(dá)到最低10-13c。在冬季（10月-12月）溫度達(dá)到最高16-21c，最低達(dá)到2c一下。在研究區(qū)的太陽輻射范圍從250-600w/m2。這項研究涉及控制常規(guī)模型（印度的標(biāo)準(zhǔn)模型，在印度的大部分現(xiàn)行僅適用于砌體結(jié)構(gòu)）和實驗類似容量瓶的溫室塑料桶。能源可持續(xù)發(fā)展在實驗室規(guī)模的沼氣

2、池采用塑料材料超過其它材料的試驗結(jié)果給了我們很大的信心，進(jìn)一步開展該試驗的研究。在繼續(xù)的研究里，一年時間使用55天，生產(chǎn)沼氣的目的是用來烹飪和照明。這一年里控制溫度在22.4-26.3c，沼氣池所在環(huán)境溫度為17c。由此可以得出結(jié)論輔助日光溫室塑料廠的沼氣，可以有效地在丘陵地區(qū)的一些小的調(diào)整，開始采用的溫度分布在沼氣生產(chǎn)中扮演了重要作用。關(guān)鍵詞：太陽能溫室；沼氣廠；溫度1.介紹沼氣發(fā)電消耗大約四分之一的糞便，但可用熱氣體比直接燃燒的牛糞全部數(shù)額得到的多20左右。這主要是由于利用率高效率（60）的沼氣與效率低下直接燒牛糞餅（11）的原因。幾千年的沼氣發(fā)電廠已建成在發(fā)展中國家。僅在印度，有估計超過

3、250萬頭牛和糞的三分之一，如果每年從這些生產(chǎn)可用于生產(chǎn)沼氣，可以安裝超過12萬沼氣。除此之外，在現(xiàn)有的設(shè)計和廠房建設(shè)細(xì)看可以導(dǎo)致沼氣的優(yōu)化理論。沼氣廠的設(shè)計，可以優(yōu)化為輕度鋼沼氣的成本，而不是僅僅的整體成本。嘗試用不同的材料的基礎(chǔ)上，安裝成本是高度依賴沼氣廠制造。大多數(shù)金屬沼氣池放在地下，沼氣池進(jìn)度對地面平均氣溫的溫度可以維持溫度較高，但成本，運(yùn)行和維護(hù)，腐蝕問題和傳熱性能使得它不合算。在傳統(tǒng)的水泥設(shè)計，在添加挖裂縫的形成和擴(kuò)展的安裝時間被認(rèn)為是主要的缺點。pvc溫室結(jié)構(gòu)安裝允許從18的地底下太陽能加熱到約37。對這些研究的效率進(jìn)行研究，然而，由于重視不夠，能量增益和損失機(jī)制的意義有限。在冬

4、季的最佳狀態(tài)，需要一個封閉的環(huán)境中。這條件是，取得了抗紫外線的透明塑料蓋，一般被稱為冬季溫室。但紫外線穩(wěn)定聚丙烯是不能耐溫度高于50c，并因此變得脆弱和其隨時間變化透明度降低。傳統(tǒng)的沼氣利用太陽能建議增加保溫材料溫度，避免影響沼氣的輸出。據(jù)觀察，從一個傳統(tǒng)的比較研究和太陽能加上輔助溫室沼氣工程，泥漿溫度可從20c（在傳統(tǒng)的植物）提高到近35，以達(dá)到厭氧發(fā)酵的最佳溫度。在拉瓦爾大學(xué)在冬季寒冷地區(qū)已制定一個新的溫室設(shè)計。已發(fā)現(xiàn)減少30-40的要求相比的一個標(biāo)準(zhǔn)的雙層塑料覆蓋溫室加熱。一般情況下，雖沒有法則，但最佳工藝條件穩(wěn)定，應(yīng)仔細(xì)調(diào)節(jié)工作溫度。作為一項安全措施，它是一種常見的做法，要么埋在地面上

5、的土壤有利的絕緣性能的帳戶中的沼氣池，或使用溫室覆蓋。它已被證明，利用太陽能（溫室效應(yīng)）期間實現(xiàn)沼氣生產(chǎn)的最佳溫度降低。在寒冬季節(jié)，在印度北部丘陵地區(qū)的環(huán)境溫度低于10。由于溫度較低，沼氣有利于生產(chǎn)急劇下降，并可能會停止。由于溫度較低，沼氣有利于生產(chǎn)急劇下降，并可能會停止。因此，為提高沼氣生產(chǎn)，較高的蒸煮溫度比環(huán)境溫度是必需的。此外，期間所需的沼氣產(chǎn)率，實現(xiàn)最適宜的溫度應(yīng)降低。沼氣系統(tǒng)的規(guī)模和成本可以降低。綠色房子的概念應(yīng)納入更大容量的生物氣體工廠。2材料和方法在丘陵地區(qū)進(jìn)行實地考察，它坐落在海拔900-2636以上平面。其緯度和縱向尺寸為130公里（緯度：10-38wp11-49n）其經(jīng)度和

6、橫向尺寸為185公里（東經(jīng)：76.0-77.15e）沼氣廠的安裝費(fèi)用由建設(shè)材料，其中許多參數(shù)是一個重要的影響。編造材料，如錫的導(dǎo)熱性，銅，磚石，水泥混凝土，干土，濕土，塑料，鐵，不銹鋼。實驗的沼氣廠建在地上的塑料水箱分別為高度，直徑和厚度157厘米，135厘米和6毫米。實驗沼氣廠被置于太陽下與印度傳統(tǒng)的水泥標(biāo)準(zhǔn)沼氣廠（迪恩- abandhu模型）作對照。做飯利用沼氣廠產(chǎn)生的氣體（燃燒器）和照明（燈）的目的。一年半連續(xù)研究是從2005年10月-2006年9月，2006年的平均值分別采用皮爾遜積差相關(guān)系數(shù)法統(tǒng)計表。保留時間保持在55天。環(huán)境和泥漿溫度記錄每小時的基礎(chǔ)上，使用所有的實驗和每天的平均年

7、齡校準(zhǔn)的熱電偶（由上午七時至下午6時）。每小時監(jiān)測太陽輻射（上午七時至下午6時），為所有的實驗使用校準(zhǔn)太陽輻射。天然氣產(chǎn)量記錄得每天一個一公升容量（insref氣體的流量計，印度）和甲烷氣體的濕式氣體流量計的研究中使用氣相色譜儀（aimil nucon月兩次系列，印度）。物理化學(xué)分析sis（elico系列-li610，印度），如ph值，總固體，添加到進(jìn)水和作廢的污水沼氣的揮發(fā)性固體在一個月內(nèi)兩次是1992年采用的方法分析。四名成員組成的家庭的沼氣用于做飯和照明的應(yīng)用也被記錄，每月兩次。3.結(jié)果與討論有人企圖利用沼氣廠作為非腐蝕性等物理和化學(xué)性能關(guān)系的一些選擇的原因可以歸結(jié)為制造塑料材具有良好的

8、絕緣體熱，較輕的重量和更大的耐用性。此外，塑料材料具有強(qiáng)大到足以承受的工作溫度及長時間暴露在陽光下。塑料沼氣廠是相對便宜，從這些材料制作，其性能已經(jīng)發(fā)現(xiàn)，要加強(qiáng)。目前的研究進(jìn)行了一場大型沼氣廠2.0m3在不同條件下的能力。協(xié)助溫室和控制沼氣廠，是傳統(tǒng)的模型，并在丘陵地區(qū)作了比較集中的制作材料和溫度的影響塑料桶的沼氣植物。每年的平均值記錄在實驗組和對照沼氣理化參數(shù)下，在黃土丘陵區(qū)的比較研究如表1所示。在實驗組和對照沼氣監(jiān)測年均溫度為下列數(shù)據(jù)，分別為26.3c和22.4c對17.0c和在泥漿溫度記錄相應(yīng)上升的環(huán)境溫度下的環(huán)境條件比高出35.3和24.0。在實驗的沼氣廠地面和環(huán)境條件的溫度變化與太陽

9、輻射方面的代表見圖.1。年均溫室室溫度記錄是29.1c。沼氣植物每年平均產(chǎn)氣率分別為39.1公斤和34.6公斤每1天。在冬季的天然氣產(chǎn)量低于其他月份。在實驗的沼氣廠的平均天然氣產(chǎn)量在冬季季風(fēng)后，夏季季風(fēng)前季節(jié)的分別為1053.3，1193.3，1263.3和1183.3公斤每天。從實驗和控制沼氣的產(chǎn)氣率記錄得最大的天然氣生產(chǎn)在夏季時，周圍只有18c，由31.5c溫室室內(nèi)溫度的熱量轉(zhuǎn)移到水泥砂漿的28.3c。記錄得最大的天然氣生產(chǎn)在夏季環(huán)境溫度在19下時，泥漿溫度在23.6c。在生產(chǎn)沼氣的差異率為33.7。在冬季的幾個月里沼氣生產(chǎn)速率與暑假期間生產(chǎn)的沼氣廠相比削減約77。在環(huán)境溫度變化下影響植物

10、比影響傳統(tǒng)的植物更有效果。表1.物理化學(xué)參數(shù)的實驗和控制沼氣廠（每年）參數(shù)塑料油箱（實驗）沼氣廠（對照組）沼氣廠ts（）初始最后7.60.6vs(%)初始75.461.92.7最后49.16.3ph初始6.66.5最后7.0沼氣的甲烷比例（）64.13.059.94.5平均產(chǎn)氣率（新鮮的輸入每公斤每天）39.13.634.63.1天然氣產(chǎn)量（固體減少每公斤每天）0.7太陽輻射（w/m2）3904539045漿料溫度（）26.31.722.41.1地面溫度（）17.61.317.31.3環(huán)境溫度（）17.01.317.01.3溫室溫度（）2

11、9.11.829.11.8注：值的范圍是“”表示在平原地區(qū)的實驗和控制沼氣植物每年平均甲烷氣體分?jǐn)?shù)值分別為64.1和59.9。甲烷氣體的平均分?jǐn)?shù)在實驗沼氣廠是61.4,61.8，67.3和65.9，在冬季季風(fēng)后，夏季和預(yù)季風(fēng)季節(jié)和相應(yīng)的甲烷沼氣廠控制分?jǐn)?shù)值是56.8，55.8，64.0和63.1。據(jù)觀察，記錄在實驗沼氣廠的甲烷氣體分?jǐn)?shù)為6.5。甲烷氣體方面的實驗和控制沼氣ph值記錄數(shù)據(jù)，在實驗組和對照沼氣廠的進(jìn)水ph值平均為6.6和6.5。在實驗組和對照沼氣純植物每年的平均ph值地區(qū)分別為7.0和7.2。研究結(jié)果還表明，其次是ph值7.0時最佳的天然氣生產(chǎn)速率，ph值4.0出現(xiàn)過生產(chǎn)的天然氣呈

12、酸性。最適ph值介于7.0和7.2，但天然氣產(chǎn)量是6.6和7.6之間相當(dāng)穩(wěn)定。當(dāng)ph值低于6.6時，有發(fā)生甲烷菌顯著的抑制作用，當(dāng)它下降到了6.2的價值，沼氣池內(nèi)容易使這些細(xì)菌產(chǎn)生毒性。圖1.太陽輻射溫度的變化，實驗組和對照沼氣（按季節(jié)）在做飯和照明時，產(chǎn)生沼氣在黃土丘陵區(qū)的比較研究在實驗組和對照植物（按季節(jié)）的時間消耗在表2所示。在這項研究中，做飯沒有在冬季期間，由于可用性低沼氣，并在此期間產(chǎn)生的氣體利用照明應(yīng)用，使沼氣燈照明，也解放了的熱輻射，提高最終用戶的舒適室溫條件下。主要部分產(chǎn)生的沼氣利用，對在本研究中的植物實驗組和對照沼氣做飯照明應(yīng)用。白天和晚上的溫差很大，它會影響細(xì)菌的生長速率。

13、因此，在性能上減少遇到在現(xiàn)有的常規(guī)設(shè)計。但是，使用沼氣廠制造的塑料將克服上述所有問題。一旦安裝傳統(tǒng)設(shè)計，則所有傳統(tǒng)設(shè)計不能遷往其他任何場合。但是，在目前這個研究確定塑料沼氣廠可在任何時候轉(zhuǎn)移到任何方便的地方。表.2實驗和控制沼氣廠（按季節(jié)）用于做飯和照明的時間消耗季節(jié)消耗的時間（小時：分鐘）溫室篷（實驗）沼氣廠沒有溫室篷（對照組）沼氣廠做飯照明做飯照明冬季（2005年10月至12月）-0:28-0:18季風(fēng)（2006年1月至3月）0:250:420:150:28夏季（2006年4月至6月）1:260:470:270:33季前風(fēng)（2006年7月至9月）0:250:330:130:22每年的總時間

14、消耗4:104:502:053:054.結(jié)論在本研究中，作為替代建材沼氣廠在丘陵地區(qū)日光溫室，塑料測試，證明是有效的，在印度的大部分地區(qū)被采納的模型比其他傳統(tǒng)的磚石效果要好的多。在環(huán)境溫度為17時，控制沼氣發(fā)電廠年均泥漿研究期間記錄得的氣溫是26.3和22.4。顯而易見的是，記錄在塑料和常規(guī)控制沼氣漿料溫度分別比環(huán)境條件上升為35.3和24.0，在實驗的沼氣廠年均溫室室內(nèi)溫度記錄是29.1。據(jù)觀察，比對照沼氣廠，記錄在實驗沼氣廠的天然氣產(chǎn)量是11.5。本次調(diào)查的實驗產(chǎn)生的數(shù)據(jù)庫的基礎(chǔ)上，可以得出結(jié)論，有一個良好的范圍，聘請沼氣工程建設(shè)，并進(jìn)一步研究塑料材料證明了這種方法的可行性。由愛思唯爾有限

15、公司主辦2008z3-d0491原文出處：department of bio-energy,school of energy,environment and natural resources,madurai kamaraj university,madurai 625 021,tamil nadu,india received 17 april 2007;received in revised form 1 december 2007;accepted 18 march 2008 available online 14 april 2008solar greenhouse assisted

16、biogas plant in hilly regiona eld studyabstract:the present study was undertaken with the objective of evaluating plastic as an alternative material for biogas plant on a par with conventional brick material material.the eld study was carried out for one year(october,2005september,2006) in a small h

17、amlet at nilgiris incorporating solar energy to study its inuence on biogas production. during summer (apriljune) the temperature reaches to the maximum of 2125and the minimum of 1012.during winter(octoberdecember),the temperature available is maximum of 1621 and minimum of 2.the solar insolation in

18、 the study area ranges from 250 to 600w/m2.in continuation,a semicontinuous study was conducted for one year with the retention time of 55days.the gas generated from the biogas plants was utilized for cooking(burner) and lighting purposes.the yearly average slurry temperatures recorded during the st

19、udy period was 26.3 and 22.4 in experimental and control biogas plants against ambient temperature of 17.0.the yearly average gas yield from the experimental and control biogas plants were 39.1and34.6lkg-1day-1respectively.gas productions in the winter season registered lower than other months.it ca

20、n be concluded that the solar greenhouse assisted plastic biogas plant can be eciently adopted with minor modications in hilly regions since the temperature prole plays a major role in biogas production.keywords:solar;greenhouse;biogas plant;temprature1.introductionbiogas generation consumes about o

21、ne-fourth of the dung, but the available heat of the gas is about 20% more than that obtained by burning the entire amount of dung directly. this is mainly due to the high efficiency(60%) of utilization compared to the poor efficiency(11%) of burning dung cakes directly.several thousand biogas plant

22、s have been constructed in developing countries.in india alone,there are an estimated over 250 million cattle and if one third of the dung produced annually from these is available for production of biogas,more than 12 million biogas plants can be installed.in addition to this,a closer look at the e

23、xisting designs and plant construction can lead to an optimization theory for biogas plants.biogas plant designs could be optimized for the overall costs rather than merely for the cost of the mild-steel biogas oating drum as those were being done earlier.the fabrication of biogas plant is tried wit

24、h different materials based on which the cost of installation is highly dependent.most metal digesters are placed underground,where the temperature of the digester progress towards the average temperature of the ground that could maintain higher temperatures but cost,operation and maintenance,corros

25、ion problem and the heat transfer properties makes it uneconomical.in conventional cement designs,in addition to digging the formation of cracks and the extended installation time are considered to be major drawbacks.installation of pvc greenhouse type structure over a biogas plant allowed solar hea

26、ting of the substrate from18 to about 37.considerable efforts have been devoted in this direction,which resulted in the development of several conceptsviz.constructing greenhouse and shallow solar pond over the dome,use of insulation around the digester. the investigations carried out for studying t

27、he efficiency of these concepts, however,have limited signicance due to inadequate attention to the mechanism of energy gain and loss.this condition is achieved in a greenhouse constructed with uv-resistant transparent plastic cover,generally known as winter greenhouse.but uv-stabilized propylenelm

28、is not resistant to temperatures higher than 50,and it therefore becomes brittle and its transparency decreases with the time.this was most probably due to the increasing opacity of the cover and the increasing number of throne areas.the use of solar canopy over the conventional biogas plants was su

29、ggested for increasing the slurry temperature and hence the output of biogas.it has been observed from a comparative study of the conventional and the solarassisted greenhouse coupled biogas plant that the temperature of the slurry can be raised from 20to nearly 35,the optimal temperature foranaerob

30、ic fermentation.a new design of greenhouse had been developed for colder regions at laval university during winter season.a reduction has been found in the heating requirements of 3040% compared to a standard,double layered plastic covered greenhouse.in general,there is no rule of thumb,but for opti

31、mum process stability, the temperature should be carefully regulated within a narrow range of the operating temperature.as a safety measure,it is a common practice either to burry the digesters in the ground on account of the advantageous insulating properties of the soil,or to use a greenhouse cove

32、ring.due to the lower temperature, biogas production decreases drastically and may stop.thus,for enhancing biogas production,a higher digester temperature than ambient temperature is required.also,for a required production rate of biogas,the period to achieve the optimum temperature should be reduce

33、d. the size and cost of the biogas system can be reduced.the greenhouse concept should be integrated for larger capacity biogas plant.2.materials and methodsthe eld study was carried out in a small hamlet namely kadaladu 9 km from nilgiris.it is situated at an elevation of 9002636m above msl.its lat

34、itudinal and longitudinal dimensions being 130km (latitude:1038wp1149n)by 185km(longitude:76.077.15e).the installation cost of biogas plant is inuenced by many parameters among which construction material is an important one.the experimental biogas plant was constructed from over head plasticwater t

35、ank with height,diameter and thickness of 157cm,135cm and 6mm,respectively.experimental biogas plant was placed above ground covered with greenhouse canopy(experimental biogas plant) which was compared against indian standard conventional cement biogas plant which serves as control.the gas generated

36、 from the biogas plant was utilized for cooking(burner) and lighting purpose.semi-continuous study was conducted for one year from octoberseptember,2006 and the averaged values were tabulated statistically adopting pearsons product moment correlation coefficient method retention time was maintained

37、at 55days.ambient and slurry temperatures were recorded on an hourly basis (from 7a.m. to 6p.m.) using calibrated thermocouples for all the experiments and averaged per day.solar insolation was also monitored on an hourly basis (from 7a.m.to 6p.m.) using calibrated suneters for all the experiments a

38、nd averaged per day.gas production was recorded on a daily basis with wet type gas ow meters of one litre capacity(insref gas ow meter cat.no.iri.06a,india) and methane in the gas was studied twice in a month using gas chromatograph.the application of biogas (family of four members) for cooking and

39、lighting was also recorded twice a month.3.results and discussionan attempt was made earlier by utilizing plastic materials for the fabrication of biogas plant,the reasons for the selection can be attributed to some of their physical and chemical properties such as noncorrosivity,good insulator for

40、heat,light in weight and greater durability.in addition,plastic material is strong enough to withstand operating temperatures and prolonged exposure to sunlight,refabricable and attractive.the plastic biogas plant is relatively cheaper to fabricate from these materials and also its performance has b

41、een found to be enhanced.the present study was carried out in field-scale biogas plants of 2.0m3capacity at different conditions.the experimental biogas plant was made of plastic tank assisted with greenhouse and the control biogas plant was the conventional deenabandhu model and comparison was made

42、 focussing on fabrication material and effect of temperature in hilly region.the averaged values per year recorded for physicochemical parameters in experimental and control biogas plants under the comparative study in hilly region are shown in table1.he yearly average slurry temperatures on itored

43、in experimental and control biogas plants was26.3and 22.4,respectively against ambient temperature of 17.0 and corresponding rise in slurry temperature recorded was 35.3 and 24.0% higher than the ambient condition.the temperature variation in slurry, ground and ambient condition with respect to sola

44、r insolation is represented in fig.1.the yearly average greenhouse chamber temperature recorded was 29.1in the experimental biogas plant.the yearly average gas yield from the experimental and control biogas plants were 39.1 and 34.6lkg-1 day-1.gas production in the winter season was lower than other

45、 months.average gas yidld in experimental biogas plant experimental were1053.3,1193.3,1263.3and1183.3kg-1day-1during winter,postmonsoon,summer and pre-monsoon seasons respectively.the methane content of biogas of both the plants was almost identical,but the moisture in the gas was 43% higher in the

46、rubber-balloon plant than the plant.the changes in ambient temperature affected the rubber-balloon plant more than they affected the conventional plant.table 1physico-chemical parameters for experimental and control biogas plant(annual basis)parametersplastic tank(experimental)deenabandhu(control) b

47、iogas plantts(%) initial12.112.1ts(%) final0.4vs(%) initial74.574.5vs(%) final49.16.361.92.7ph initial6.66.5ph final7.0methane fraction of biogas (%)64.13.059.94.5slurry temperature ()26.31.722.41.1ground temperature ()17.61.317.31.3ambient temperature ()17.01.317.01.3greenhouse ch

48、amber temperature()29.11.829.11.8note:the range of values is indicated by ”the values of yearly average methane fraction of gas for the experimental and control biogas plants in plain region was 64.1 and 59.9%,respectively.the average methane fraction of gas in experimental biogas plant was 61.4,61.

49、8,67.3 and 65.9% during winter,post-monsoon, summer and pre-monsoon seasons and the corresponding methane fraction value in the control biogas plant was 56.8,55.8,64.0 and 63.1%.it is observed that methane fraction of gas recorded in experimental biogas plant was 6.5% higher than the control biogas

50、plant.the average ph value in the inuent in the experimental and control biogas plants was 6.6 and 6.5. the yearly average ph value in the experimental and control biogas plants in plain region were 7.0 and 7.2, respectively.the ph in the post- monsoon season (juneaugust,2006) recorded near neutrali

51、ty than other months.the results also show that optimal gas production occurs at ph of 7.0 followed by 9.0 while ph of 4.0 appears too acidic for meaningful gas production.the optimum ph lies between 7.0 and 7.2,though gas production is fairly stable between 6.6 and 7.6.when ph drops below 6.6,there

52、 occurs a signicant inhibition of methanogenic bacteria and when it drops to a value of 6.2,the digester contents become toxic to these bacteria.fig.1.temperature variations with respect to solar insolation for experimental and control biogas plants (seasonal basis)the time consumption for cooking a

53、nd lighting from generated biogas (seasonal basis) in experimental and con- trol biogas plants under the comparative study in hilly region is shown in table2.during this study,the cooking was not done in winter period due to low availability of biogas and the gas generated during this period was uti

54、lized for lighting application so that the illumination from the biogas lamp also liberated heat radiation to raise the room temperature conditions for comfort of endusers.the major portion of the biogas yielded was utilized for lighting application against cooking both in experimental and control b

55、iogas plants in the present study. the temperature reversal during day and night variationsdiffers far from the ambient conditions;it affects the bacterial growth rate.thus,reduction in the performance is encountered in the existing conventional designs.but,use of plastic in biogas plant fabrication

56、 will overcome all the above problems.all the conventional designs once installed can not be relocated on any other occasions.but,the plastic biogas plant identied in this present study can be shifted to any convenient place at any time (can be placed outdoors in summer season and indoors during win

57、ter season). the sand and sediment depositions in the conventional indian standard design if not removed at regular intervals will bring down the retention time and ultimately the drop in its performance.more over,the gas yield recorded in experimental biogas plant was 11.5% higher than the control

58、biogas plant.table 2time consumption for cooking and lighting from experimental and control biogas plant (seasonal basis)seasonstime consumption(hrs:min)plastic tank with greenhouse canopy (experimental)biogas plantdeenabandhu without greenhouse canopy (control)biogas plantcookinglightingcookinglightingwinter