ORGANİK ATIKLARIN FERMANTASYONU SONUCU ELDE EDİLEN BİYOGAZLARIN YANMA KARAKTERİSTİKLERİNİN İNCELENMESİ

Bu çalışmada, tasarlanıp imal edilmiş bir biyogaz reaktöründen elde edilen biyogazın yanma karakteristikleri hakkında sayısal çalışmalar yürütülmüştür. Biyogaz reaktöründen elde edilen gaz, sisteme uyumlu yakma sisteminde yakılarak, yanma sonu emisyon değerleri ve sıcaklık dağılımları sayısal olarak araştırılmıştır. Yapılan araştırmalarda elde edilen deneysel sonuçlar, sayısal sonuçlarla karşılaştırılmış olup sıcaklık dağılımı bakımından önemli derecede uyum olduğu tespit edilmiştir. Sayısal modellemelerde k-Ɛ standard türbülans modeli, P-1 radyasyon modeli ve PDF/Mixture Fraction yanma modeli kullanılmıştır. Modellemelerde, hacimce % 55 CH4 - % 45 CO2 ve % 45 CH4 - % 55 CO2 karışımlı biyogazlar modellenmiş, sıcaklık ve emisyon dağılımları Ansys Fluent ticari kodu ile tahmin edilmiştir. Elde edilen tahmin sonuçları, % 45 CH4 - % 55 CO2 karışımlı biyogazın sıcaklık seviyelerinin yanma odası giriş bölgelerinde daha düşük, yanma odası çıkışına doğru daha yüksek olduğunu göstermiştir. CO2 ve H2O tahminlerinde ise, bünyesinde daha fazla miktarda CO2 bulunduran biyogaz için CO2 seviyeleri ve H2O seviyeleri daha yüksek olarak belirlenmiştir.

Anahtar Kelimeler:

Biyogaz, Yanma, Emisyon

INVESTIGATION OF COMBUSTION CHARACTERISTICS OF BIOGASES OBTAINED FROM FERMENTATION OF ORGANIC WASTES

In this study, numerical studies have been carried out on the combustion characteristics of the biogas obtained from a designed and manufactured biogas reactor. Gaseous fuel mixtures obtained from the biogas reactor have been burned in the system integrated a combustion system. Emission and temperature distributions have been investigated throughout the combustion chamber. Experimental results obtained from the experimental study have been compared with numerical results and it has been determined that the predicted results are in agreement with the experimental results considerably in terms of temperature distributions. In the numerical modelling, k-Ɛ standard turbulence model, P-1 radiation model and PDF / Mixture Fraction combustion model have been used. In the modelling, biogases mixed with 55% CH4 - 45% CO2 and 45% CH4 - 55% CO2 by volume have been modelled and the temperature and emission distributions have been predicted by Ansys Fluent commercial code. The predicted results show that the temperature levels of 45% CH4 - 55% CO2 biogas mixture are lower in the combustion chamber inlet regions and higher towards the combustion chamber outlet. In CO2 and H2O predictions, CO2 levels and H2O levels are higher for the biogas with more CO2.

Keywords:

Biogas, Combustion, Emission,

PDF

___

[1] HOSSEINI, S.E., BAGHERI, G., WAHID, M.A., “Numerical investigation of biogas flameless combustion”, Energy Conversion and Management, 81, 41-50, 2014.
[2] LEUNG, T., WIERZBA, I., “The effect of hydrogen addition on biogas non-premixed jet flame stability in a coflowing air stream”, International Journal of Hydrogen Energy, 33, 856–3862, 2008.
[3] SOMEHSARAEI, H.N., MAJOUMERDA, M.M., BREUHAUSB, P., ASSADIA, M., “Performance analysis of a biogas-fueled micro gas turbine using a validated thermodynamic model”, Applied Thermal Engineering, 66, 181-190, 2014.
[4] CHEN, S., ZHENG, C., “Counterflow diffusion flame of hydrogen-enriched biogas under MILD oxy-fuel condition”, International Journal of Hydrogen Energy, 36, 15403-15413, 2011.
[5] NIKPEY, H., ASSADI, M., BREUHAUS, P., MØRKVED, P.T., “Experimental evaluation and ANN modeling of a recuperative micro gas turbine burning mixtures of natural gas and biogas”, Applied Energy, 117, 30- 41, 2014.
[6] LAFAY, Y., TAUPIN, B., MARTINS, G., CABOT, G., RENOU, B., BOUKHALFA, A., “Experimental study of biogas combustion using a gas turbine configuration”, Experimental in Fluids, 43, 395-410, 2007.
[7] JAHANGIRIAN, S., ENGEDA, A., WICHMAN, I.S., “Thermal and Chemical Structure of Biogas Counterflow Diffusion Flames”, Energy&Fuels, 23, 5312-5321, 2009.
[8] ILBAS, M., SAHIN, M., KARYEYEN, S., “Combustion Behaviours of Different Biogases in an Existing Conventional Natural Gas Burner: An Experimental Study”, International Journal of Renewable Energy Research, 6, 1178-1188, 2016.
[9] ILBAS, M., SAHIN, M., KARYEYEN, S., “3D numerical modelling of turbulent biogas combustion in a newly generated 10 KW burner”, Journal of the Energy Institute, 91, 87-99, 2018.
[10] TENG, Z., HUA, J., WANG, C., LU, X. “Reactor and Process Design in Sustainable Energy Technology”, (First Edition) USA: Elsevier, 99-110, 2014.
[11] LINDMARK, J., THORIN, E., FDHILA, R. B., DAHLQUIST, E. “Effects of mixing on the result of anaerobic digesiton: Review”, Renewable and Sustainable Energy Reviewes, 40, 1030-1047, 2014.
[12] S̆ARAPATKA, B., “Factors influencing biogas production during full-scaleanaerobic fermentation of farmyard manure”, Bioresource Technology, 49, 17-23, 2003.
[13] VERSTEEG, H.K., MALALASEKERA, W., “An introduction to computational fluid dynamics” Second Edition, PEARSON Prentice Hall, 2007.
[14] ILBAS, M., “Studies of Ultra Low NOX Burners”, PhD Thesis, University of Cardiff, 1997.
[15] ILBAS, M., “The effect of thermal radiation and radiation models on hydrogen– hydrocarbon combustion modelling”, International Journal of Hydrogen Energy, 30, 1113-1126, 2005.
[16] KHALIL, A.E.E., GUPTA, A.K., “Flame fluctuations in Oxy-CO2-methane mixtures in swirl assisted distributed combustion”, Applied Energy, 204, 303-317, 2017.
[17] KHALIL, A.E.E., GUPTA, A.K., “Thermal field investigation under distributed combustion conditions”, Applied Energy, 160, 477-488, 2015.
[18] ILBAS, M., KARYEYEN, S., “Experimental analysis of premixed and non-premixed methane flames by using a new combustion system”, Research on Engineering Structures & Materials, 4(1), 1-14, 2018.