BIOGAS PRODUCTION POTENTIAL FROM AGRICULTURAL RESIDUES IN LATVIA

Transcription

1 ENGINEERING FOR RURAL DEVELOPMENT Jeava, BIOGAS PRODUCTION POTENTIAL FROM AGRICULTURAL RESIDUES IN LATVIA Viis Dubrovskis, Vadimirs Koteenecs, Eduards Zabarovskis, Arvids Cems, Imants Pume Latvia University of Aricuture Abstract. It is needed to evauate the bioas and enery potentia from different biomass, incudin manure, wastewater sude, enery pants, and food and biofue processin waste in Latvia. Bioas output from different biomass was investiated in aboratory scae diesters operated at 38 ºC. Biomass mixed with inocuums (fermented cow manure) was investiated for bioas production in fifteen diesters, operated in batch mode at temperature 38 ± 1.0 ºC. Averae methane yied per unit of dry oranic matter ed (dom) from ryerass siae was 316 k dom and averae methane (CH 4 ) content was Averae methane yied from oat middins was 244 k dom and averae methane content was Averae methane yied from jam was 728 k dom and averae methane content was A investiated biomass can be successfuy cutivated for enery production in Latvia. Keywords: aricutura waste, anaerobic diestion, bioas, enery crops, methane. Introduction Latvia cannot provide the country with own produced enery and fossi enery resources are imported from other countries. There are ha of unused aricuture and in Latvia. Effective use of this and coud hep to obtain a sinificant amount of enery. One of the most advanced methods of enery production from biomass is anaerobic diestion [3]. Bioas is a product of reat vaue and its production technooy does not increase carbon dioxide emission and is environmentay friendy. In recent years the bioas production is boomin aso in Latvia. There is a need to use different raw materias in bioas pants. Bioas potentia investiation resuts from aricutura waste are very important for cacuatin the riht oadin rate and maintainin a stabe anaerobic diestion process at any pant [1]. 1. Ryerass siae (GPS) Materias and methods Investiations on aboratory equipment with different raw materias were carried out usin one method. The ryerass siae was used for the first investiations. The averae substrate was taken and the Latvia University of Aricuture, the Bioenery Laboratory determined the composition of the substrate usin ISO 6496:1999. The substrates from each type of raw materias were anaysed for dry matter, oranic matter, ash content and chemica composition. The anaysis was measured by usin standardized methods [2]. A diesters were connected to the as storae faciities and taps; the diesters were operatin in continuous mode at temperature from 38 ± 0.5 ºC. The data of the as voume and composition were reistered every day. Aso the diestate was weihed and the ph vaue, dry matter, ash content and oranic matter composition were determined. Fermented cow manure was used as inocuum in a 15 reactors. Ony inocuum was fied in reactor R inocuum (contro), which was different for each raw materia. Bioas or methane voumes obtainabe from inocuum in reactor R inocuum were used for evauation of net bioas or methane obtainabe from the ed biomass. The bioas voume produced from the ed biomass cacuates as foows: where V BA bioas produced from dry oranic matter (dom) of ed biomass, k dom ; V BS bioas produced from dom of substrate in anaerobic fermentation process, ; V BIN bioas voume produced from dom of inocuum in the anaerobic fermentation process, ; (1) 446

2 ENGINEERING FOR RURAL DEVELOPMENT Jeava, M doma mass of voatie soids in ed biomass, k dom. The methane voume produced from the ed biomass cacuates as foows: (2) where V CH4A methane produced from dry oranic matter (dom) of ed biomass, k dom ; V CH4S methane produced from dom of substrate in anaerobic fermentation process, ; V CH4IN methane produced from dom of inocuum in the anaerobic fermentation process,. A 15 bioreactors were positioned in a heated camera havin automatic temperature contro at 38 ± 1 ºC. Fermentation was provided in a period up to 30 days or unti no bioas was reeased from the reactors. The dry matter, ashes content and ph eve were measured before and after the anaerobic fermentation process. Biomass weiht was measured on the scaes Kern16KO2 FKB havin accuracy ± 0.2. Measurement of ph eve was provided by hep of the equipment PP-50. By hep of a speciaized unit Shimadzu the biomass sampes were dried for moisture and tota soid content at temperature 120 ºC with mass weihtin accuracy ± Ashes for voatie soid content evauation were measured by hep of the oven Nabertherm at temperature 550 ºC. Bioas from every reactor was uided into externa storae bas for as voume measurement and anaysis of as composition. The as composition, e.., methane, carbon dioxide, oxyen and hydroen suphide content, was measured with the as anayser GA Standard error was estimated by hep of standardized data processin toos for each roup of diesters. Resuts and discussion The resuts of the anaysis of raw materias are shown in Tabe 1, diestate in Tabe 2. The bioas and methane yieds are shown in Tabe 3 and Fi. 1. The resuts of diestate anaysis are shown in Tabe 2. Tabe 1 Raw materia anayses Raw/diester ph TS, TS, Ash, Dom, Dom, Weiht, Dom substr. Tot, Siae GPS R Inocuum Averae resuts of diestate anayses Raw/diester ph TS, TS, Ash, Dom, Dom, Weiht, substr. R ± ± 4.7 Inocuum Raw materia Bioas and methane yied k dom METHAN E, k dom Inocuum Averae R Tabe 2 Tabe 3 Averae methane yied was ± k dom. In this study, the resuts of individua bioreactors were itte chane vaues, so it was abe to fi the reactor with very simiar materias and eavenin. Athouh the weiht of the raw materias is the same, the bacteria composition and the composition of equity cannot aways be achieved. 447

3 ENGINEERING FOR RURAL DEVELOPMENT Jeava, kdom dom kdom dom Siae GPS R1 Siae GPS R2 Siae GPS R3 Siae GPS R4 Fi. 1. Bioas and methane k dom from ryerass siae Concusions 1. The methane yied k dom from GPS siae shows that it is we used for the production of bioas in Latvia. 2. In comparison with the iterature data (Faustzahen bioas KTBL, FNR 2007) the resuts are averae. 2. Oat middins Materias and methods Oat middins, sieved rains were used for the investiations. The methods and work pace are the same as described in the investiation diesters were fied with 20 oat middins and 0.5 inocuum. Resuts and discussion The resuts of the anayses of raw materias are shown in Tabe 4, diestate in Tabe 5. The bioas and methane yieds are shown in Tabe 6 and Fi. 2. Tabe 4 Anayses of raw materias Raw/diester ph substr. TS, TS, Ash, Dom, Dom, Weiht, Tota, dom Oat middins R Inocuum Diestate anayses resuts Raw/diester ph TS, TS, Ash, Dom, Dom, Weiht, substr. R ± 3.4 Inocuum Raw materia k dom Bioas and methane yied METHANE, k dom Inocuum Averae Averae methane yied was ± 0.01 k dom. Tabe 5 Tabe 6 448

4 ENGINEERING FOR RURAL DEVELOPMENT Jeava, kdom kdom Oats middins R1 Oats middins R2 Oats middins R3 Oats middins R4 Fi. 2. Bioas and methane k dom from oat middins Concusions 1. Oat sharps ot k dom methane, which is a ood averae resut. 2. Oat middins, if they are we enouh no condition rain, is a ood raw materia for bioas production. 3. Jam Materias and methods Jam, which was not usabe for food, was investiated. The methods and work pace are the same as described in the investiation diesters were fied with 20 jam and 0.5 inocuum. Resuts and discussion The resuts of the anayses of raw materias are shown in Tabe 7, diestate in Tabe 8. The bioas and methane yieds are shown in Tabe 9 and Fi. 3. Tabe 7 Anayses of raw materias Raw/diester ph TS, TS, Ash, Dom, Dom, Weiht, Tota, substr. dom Jam R Inocuum Diestate anayses resuts Raw/diester ph TS, TS, Ash, Dom, Dom, Weiht, substr. Jam R ± 2.4 Inocuum Raw materia Bioas and methane yied k dom k dom Inocuum Averae Averae methane yied was ± k dom. Tabe 8 Tabe 9 449

5 ENGINEERING FOR RURAL DEVELOPMENT Jeava, kdom kdom Jam R7 Jam R8 Jam R9 Jam R10 Fi. 3. Bioas and methane k dom from jam Concusions 1. Damaed jam produced a ot of methane, k dom. 2. The study shows that unfit for human consumption jam can be very we used for production of bioas. References 1. Faustzahen Bioas 2007 KTBL Darmstadt. 2. Methodenbuch Eneretische biomassenutzun DBFZ version P Dubrovskis V., Pūme I., Koteļeņecs V., Zabarovskis Z. Bioas production and bioas potentia from aricutura biomass and oranic residues in Latvia. Proceedins of Internationa Conference Bioas in Proress Part 2. pp ISBN: