Energy conversion study on cumbu napier CO -4

Transcription

1 Intenational Jounal of Agicultue, Envionment and Biotechnology Citation: IJAEB: 8(3): Septembe 2015 DOI Numbe: / X New Delhi Publishes. All ights eseved AGRICULTURE ENGINEERING Enegy convesion study on cumbu napie CO -4 R. Divyabhaathi* 1 and P.Venkatachalam 2 1 Depatment of Bioenegy, Agicultual Engineeing College and Reseach Ins tute, Tamil Nadu Agicultual Univesity, Coimbatoe , India. 2 Depatment of Agicultual Engineeing, Agicultual College and Reseach Ins tute, Tamil Nadu Agicultual Univesity, Maduai , India. *Coesponding autho: divya92.tnau@gmail.com Pape No. 365 Received: 4 Febuay 2014 Accepted: 19 August 2015 Abstact Agicultue has fo seveal yeas fomed the backbone of Indian economy, contibuting appoximating 30.2% of the goss domestic poduct employing ove 77% of the population above 10 yeas of age (Suajit, 2012). Developing counties like India poduce lage quantities of ago-esidues such as ice husks, bagasse, goundnut shells, co on stalks etc. in lage quantities but they ae used inefficiently causing extensive degadation to the envionment. The study was to analyze the enegy potential of the cop Cumbu Napie CO -4 by bique ing and biogas poduction. The study had been oiginated keeping in view the vast potential of Cumbu Napie CO -4 hybid and is utilized fo the poduction of bio methane (biogas) and bique es athe than using only as fodde cop so that enegy, economic as well as envionmental benefits, can be ealized. The use of Cumbu Napie CO -4 bique es educes the usage of wood as a fuel fo combustion and the biogas poduced fom anaeobic digestion of the cop would be a suitable way of its utilization fo enegy geneation which minimizes fossil fuel consumption and significantly educe the Geen House Gas emissions. Futhe, sludge obtained fom bio digestion is eniched oganic manue, which would be vey useful fo enhancing agicultue poductivity in faming. Highlights Chaacteistics analysis and Bique ing of Cumbu Napie CO -4. Biogas poduction potential of Cumbu Napie CO -4. Keywods: Cumbu napie CO -4, bique ing, anaeobic digestion, biogas TNCN014, a high yielding intespecific hybid between fodde Cumbu CO -8 and Napie gass FD 461 was developed at the depatment of Foage Cops, Cente fo Plant Beeding and Genetics, Tamil Nadu Agicultual Univesity (TNAU), Coimbatoe and eleased as CO (CN) 4. The tiploid hybid displays luxuious vegetative gowth. Cumbu Napie CO -4 is well adapted to the soil and climatic conditions of Tamil Nadu. This hybid is highly palatable fo milch animals like goat and sheep. The incease in yield of this hybid ove the vaiety CO -3 was 33% which ecoded a mean yield of 382t/ha/ yea (Vij ayakuma et al. 2009). An enegy study makes an a empt to citically evaluate the studies to make a beakthough in agicultual secto (Muugan, 2011). The poblems caused by agicultual solid wastes can be significantly mitigated though the adoption of envionmentally waste to enegy technologies such as biomethanation

2 Divyabhaathi and Venkatachalam (anaeobic digestion), combustion, pyolysis etc. (Sabjeet et al. 2013). In this study Cumbu Napie CO -4 involves in two pocesses of bique ing and anaeobic digestion. The fist pocess, bique ing is a mechanical compaction pocess fo inceasing the density of bulky mateial. Using bique ing machines the poduct bique e is fomed and is a block of flammable ma e which can be used as fuel. Geneally bique es ae a good substitute to fiewood and chacoal fo domestic cooking and ago-industial opeations, theeby educing the high demand fo both. Besides, bique es have advantages ove fuel wood in tems of geate heat intensity, cleanliness, convenience in use and elatively smalle space equiement fo stoage (Singh et al. 1992) (Olounnisola 2004). In Cumbu Napie CO -4 the natual lignin in the mateial binds the paticles togethe to fom a solid (bique e) theefoe thee is no need of bindes to be involved in bique ing pocess. Second pocess is the poduction of biogas which is the gas geneated when bacteia degade biological mateial in the absence of oxygen, in a pocess known as anaeobic digestion. It is an ecofiendly substitute fo enegy. Biogas is about 20% lighte than ai has an ignition tempeatue in ange of 650 C to 750 C. It is an odoless and cololess gas that buns with blue flame simila to LPG gas. Its caloic value is 20 Mega Joules (MJ)/m 3 and it usually buns with 60 % efficiency in a conventional biogas stove (Suyog Vij, 2011). By adding cow dung and Cumbu Napie CO -4 to anaeobic high ated digestes fo a etention time of 90 days biogas (methane) is fomed and the fully digested sluy can be used as bio-fetilize. Mateials and Methods Cumbu Napie hybid gass CO -4 was collected fom the Depatment of foage cops, TNAU. The aw mateial was sun died fo 7 days, shedded to pass though a 2-5 mm sieve and stoed at oom tempeatue. The substate was chaacteized as it gives significant infomation on suitability of the substate fo bique ing and biogas poduction. Poximate Analysis Poximate analysis as defined by ASTM (Ameican Society fo Testing Mateials), is the detemination of biomass constituents like moistue content, volatile ma e, fixed cabon and ash content Volatile Ma e (VM) Volatile Ma e was detemined using muffle funace (ASTM, E-872) by keeping the died sample in a cucible at 650 C fo 6 minutes and then 750 C fo anothe 6 minutes. The diffeence in weight due to the loss of volatiles was taken as the total volatile ma e pesent in the substate. Moistue Content (MC) Moistue content plays an impotant ole in contolling enegy eleased duing buning and biogas poduction. By oven method (ASTM, E-871), the moistue content was detemined by dying weighed amount of sample in an open peti dish in an electical oven at C fo 1 hou and weighed again till constant weight was obseved. The diffeence in weight, befoe and a e dying indicates the moistue content of sample. The moistue content (wet basis) was detemined by the fomula, MC (%) = Ash Content (AC) wet weight-dy weight wet weight x 100 The ash content was found out (ASTM, E-830) by taking the substate in a silica cucible and heating in a muffle funace to 750 C fo 2 hous o moe till constant weight was ecoded. The weight of the esidue epesents the ash content. Fixed Cabon (FC) Fixed cabon of died mateial is obtained by subtacting volatile content and ash content fom 100. It is given by the fomula, FC (%) = 100 [(VM (%) + AC (%))] 728

3 Enegy Convesion Study on Cumbu Napie Co-4 Caloific Value (CV) Caloific value is the heat poduced by combustion of a unit quantity of substance unde specific conditions. It is expessed as enegy/mole of fuel (kj/ mol), enegy/mass of fuel, enegy/volume of fuel. It is conventionally measued with a bomb caloimete (ASTM D5865). The caloific value of the fuel (cal/g) was calculated by, T2 T1 * wate equivalent CV = weight of the sample taken whee, T 2 - Final tempeatue, C T 1 - Initial tempeatue, C Wate equivalent kcal/kg C Stength Stength can be calculated using hadness test and wate stability test. In hadness test the bique ed mateial was thown fom a height of 1.5 m fo nealy 15 times and the stength can be found out using the amount lost. In wate stability test, the bique e is kept inside wate fo nealy 5 minutes. With the amount of bique e disintegated the quality can be found out. Bique e Poduction The steps involved in bique ing pocess ae Collection of aw mateial Pepaation of aw mateial (cushing) Compaction (bique ing) Cooling and stoage The samples wee died in sola tunnel dye fo 2 days to a moistue content of 8% and cushed to a paticle size between micons. The piston pess type model was used fo bique ing. In this technology the optimum moistue content is about 10-15% and the powe consumption is about 50 kwh/ton and density of the bique e is about g/cm 3 and it is opeated in stokes. The poduction capacity of the machine is about 100 kg bique es/ hou. Hydaulic pessue exeted on the piston is 100 pascal. Size of the bique e poduced is 50 mm diamete, a e which it was tansfeed to the oven and died at 105ºC to constant weight Anaeobic Digestion Anaeobic digestion is a pocess that takes place in the pesence of biodegadable biomass (substate), anaeobic micooganism and a milieu (digeste) which is fee of molecula oxygen. The pocess convets the biomass into enegy in a gaseous mixtue known as biogas. The complex pocess of anaeobic digestion can be divided into fou phases such as hydolysis, acidogenesis, acetogenesis and methanogenesis Hydolysis Hydolysis is fist step in which un-dissolved compounds like cellulose, potein, fats ae degaded into monomes (wate soluble fagments) such as amino acids, glucose, fa y acids, and glyceol by consotia of anaeobic bacteia which excete extacellula enzymes like cellulases, poteases and lipases. The monomes (amino acids, glucose, fa y acids, and glyceol) ae diectly available to next goup of bacteia. Hydolysis is a compaatively slow and can be the ate limiting stage in anaeobic digestion especially when the oganic ma e contains high concentation of lignin and cellulose. Lipids hydolysis takes place at a much faste ate in compaison with poteins and cabohydates. Acidogenesis The micooganisms engaged in hydolysis ae geneally the same which caies out acidogenesis. Usually hydolysis and acidogenesis ae togethe efeed to as fementation eactions. Species of genea bacteiods, eubacteium, clostidium, bifidobacteium, lactobacillus, butyivibio ae consideed to dominate the fementation eactions. The poducts of hydolysis ae conveted into oganic acids by micooganisms. These oganic acids ae usually temed as volatile fa y acids. Acidic 729

4 Divyabhaathi and Venkatachalam acid, fomic acid, lactic acid, popionic acid, succinic acid and butyic acid ae majoly fomed duing this pocess. Only glyceol, amino acids and sugas undego acidogenesis. On the othe hand glyceol poduces acetate, lactate, 1,3 popanol. The poducts of this stage ae geneally conveted into acetate, hydogen and cabon dioxide which ae consideed as potential methanogenic substates. Acetogenesis The poducts fom the acidogenic phase seve as substate fo othe bacteia, those of acetogenic phase. This stage involves the action of acetogenic bacteia that convet the volatile fa y acids and alcohols fomed duing acidogenesis into acetate, hydogen and cabon dioxide. Two goups of acetogenic bacteia have been isolated which ae known as hydogen and acetate poduces. Both acetogens and methanogens ae sensitive to highe hydogen concentations (ph acidic), theefoe it is essential to stictly monito the concentations of hydogen duing the anaeobic digestion pocess. When the hydogen patial pessue is low, H 2, CO 2 and acetate ae pedominantly fomed. The highe hydogen patial pessue educed the acetate fomation wheeas the fomation of popionic acid, butyic acid and ethanol was inceased. The fomation of acetate indicates good potential fo methane fomation, the poduction of butyate and popionate ae deemed as distubances. The hydogen poducing goups have the potential of beaking down popionate and othe oganic acids into acetate and hydogen. This beak down of popionate helps to pevent the accumulation of popionate that othewise would have antimicobial influences on vital micooganisms (methanogens). Methanogenesis Methanogenesis is the final phase of the anaeobic digestion pocess. In this stage, methane and cabon dioxide (biogas) ae poduced by vaious methane poducing micooganisms temed as methanogens. The most impotant substates fo these oganisms ae hydogen gas, cabon dioxide, and acetate, which ae fomed duing anaeobic oxidation. The methane-poducing goup that usually dominates in the biogas pocess is acetotophic methanogens, which use acetate as substate. In thei metabolism, acetate is boken into two pats in which one of the cabons is used to fom methane and the othe to fom cabon dioxide. Hence, acetotophic methane poduces ae sometimes also named as acetatespli ing methanogens. Nomally, Acetate is the souce of about 70% of the biogas poduced in a digeste. Hydogentophs ae the methanogens which used cabon and hydogen gas as pimay souce fo the fomation of methane. Pesently thee ae only two well ecognized goups of methanogens that beak down acetate. They ae Methanosaeta and Methanosacina, though thee ae also othe goups of methanogens which use hydogen gas such as Methanococcus, Methanobacteium, Methanobevibacte and Methanogenium. Methanosacina and Methanosaeta have diffeent gowth ates and also they diffe egading thei capability to use acetate. Geneation time, i.e. the time equied fo a micooganism to divide itself into two, is between 1 and 12 days fo methane poduces. CO 2 + 4H 2 CH 4 + 2H 2 O On the othe hand, acetotophic methanogens convet acetate into methane and cabon dioxide. CH 3 COOH CH 4 + CO 2 Lab Scale Studies fo Biogas Poduction. Batch digestion studies wee caied out to study the biogas chaacteistics of Cumbu Napie. Anaeobic digestion of Cumbu Napie was caied out using 2.5 lite ambe coloed glass bo les with a ubbe stoppe. Two thid of the bo le cap was coveed using ubbe cok so that it would be ai tight. One glass tube is taken though the stoppe and it acts as an outlet fo the biogas. To this glass, bent tube of 40 cm long ubbe tube with a pinch cok was connected. The gas poduction was estimated by wate displacement. The following teatments wee used fo the study 730

5 Enegy Convesion Study on Cumbu Napie Co-4 100% Cow dung Final tempeatue = C T1 : 1kg Cow dung ml of wate 100% Cumbu Napie gass Caloific value = ( ) * 2240 = kcal/kg T2 : 1kg of Cumbu Napie ml of wate 50:50 (Cow dung : Cumbu Napie) T3 : 500g of Cumbu Napie + 500g of Cow dung ml of wate 75:25 (Cumbu Napie : Cow dung) T4 : 750g of Cumbu Napie + 250g of Cow dung ml of wate 25:75 ( Cumbu Napie : Cow dung) T5 : 250g of Cumbu Napie g of Cow dung ml of wate 25:25 ( Cumbu Napie : Cow dung) T6 : 250g of Cumbu Napie g of Cow dung g of wate Results and Discussion Chaacteization of substate Table 1. Poximate analysis of Cumbu Napie CO-4 S.No Constituents % 1. Moistue content 8 2. Volatile matte Ash 8 4. Fixed cabon 14 Caloific Value Sample 1 : (Powde) Initial tempeatue Final tempeatue = C = C Caloific value = ( ) * 2240 = 3920 kcal/kg Sample 2 : (Bique e) Initial tempeatue = C Since the Caloific value of Cumbu Napie bique es is nealy equal to the caloific value of wood of about kcal/kg, it is a good substitute of fuel fo buning Hadness test Bique e Sample 1: Initial weight: 120g Final weight: 65g Bique e Sample 2: Initial weight: 117g Final weight: 66g Since nealy half the weight of bique e is etained a e these many tails, the bique e is consideed to be a good one Wate Stability test Bique e Sample 1: 5 10 minutes Bique e Sample 2: 11 minutes It is infeed that both the bique es ae consideed to be an excellent one since they etain its stability up to 10 minutes unde wate Batch Digestion Studies (Biogas) The biogas poduction stated a e 24 h of the bo ling and eached maximum a e the second week. The batch digestion was continued up to fou weeks a e which the gas poduction stated declining. The digestion peiod fo all the teatments was found to be 20 days, when the gas poduction stated declining. The gas poduction behavio was entiely diffeent in all the teatments and study. Aveage Biogas Poduction (in 4 days inteval) The aveage gas poduction vaied fom 0.03 lit/ day to lit/day. The maximum gas poduction 731

6 Divyabhaathi and Venkatachalam was lit/day in the 9 th day. The aveage biogas poduction was found to be highe in the 12 th day a e which the poduction of the biogas stats deteioating. 2. The methane content was found to be highe in teatment T6 with a methane content of about 0.2 lit/day. 3. The amount of biogas poduced pe day is 0.1 m 3. Conclusion Fig. 1. Aveage biogas poduction/fou days Maximum Biogas Poduction The maximum biogas poduced was in teatment T6 followed by T2 and T5 with the biogas poduction of about 0.21 lit/day, 0.19 lit/day and 0.13 lit/day espectively with the TS of about 10% Fig. 2. Maximum biogas poduction of teatments in batch study 1. The gas poduction is found to be the maximum fo the teatment in which 10% TS is maintained and the gas poduction was 0.1 lit/day on an aveage. The bique ing of Cumbu Napie CO -4 poduced a caloific value almost equal to that of bique es made of wood and the futhe esults obtained though hadness and wate stability test poved that Cumbu Napie CO -4 is a viable souce of bique e and hence can be used as a souce of fuel. Fom the study on biogas it was evident fom the esult that the Cumbu Napie CO -4 samples used in the investigation ae good fo biogas poduction. Consideing the batch system, among the six teatments, the teatment T6: 250g Cumbu Napie g of Cow dung ml of wate was found to be best fo ecommendation. The bique es of the cop would educe the usage of wood fo buning and the biogas poduced can supplement fossil fuel theeby paving way fo a sustainable futue. Thus this study established a poof of concept fo the use of the fodde cop Cumbu Napie CO -4 hybid as an enegy substitute. In this eseach the biogas equied fo the efficient fying of chips has been calculated and the stove has been designed based on the equiement. Also the gasification potential of the cashew nut shell has been studied and found that the can be significantly utilized fo gasification pocess as it contains lage volatile content and low ash content. Acknowledgment: We would like to solicit ou eanest gatitude to the Agicultual Engineeing College and Reseach Institute, Tamil Nadu Agicultual Univesity, Coimbatoe fo giving us the oppotunity to undego the study in the field of ou inteest and also fo poviding us the latest technological facilities to cay out the study. Refeences Muugan, D Studies on enegy consumption in agicultual poduction in India: A citical Evaluation. Intenational Jounal of Agicultue, Envionment and Biotechnology 4(1):

7 Enegy Convesion Study on Cumbu Napie Co-4 Olounnisola, A.O Bique ing of Ra an funitue waste. Jounal of Bamboo and Ra an 3(2): doi: / Sabjeet, S.S. and Anand, G Pesent Status of Renewable Enegy Souces in Punjab. Intenational Jounal of Agicultue, Envionment and Biotechnology 6(2): Singh, A. and Singh, Y Bique ing of Paddy Staw. Agicultual Mechanization in Asia, Afica and Latin Ameica Suajit, Biquet Ting Machine. h p:// com/doc/ /biquet-ting-machine Accessed 24 Novembe Suyog Vij, Biogas Poduction fom Kitchen Waste. Semina epot submi ed to National Institute of Technology, Roukela. Vijayakuma, G., Babu, C., Velayudham, K. and Raveendan, T.S A High Yeilding Cumbu Napie Gass CO (CN) 4. Madas Agicultual Jounal. 96(7-12):

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