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

Abstract

   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

ORGANİK ATIKLARIN FERMANTASYONU SONUCU ELDE EDİLEN BİYOGAZLARIN YANMA KARAKTERİSTİKLERİNİN İNCELENMESİ

Öz

   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

Kaynakça

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