Comparative evaluation of base catalysts in biodiesel production from waste frying oil

Year 2025, Volume: 14 Issue: 3, 142 - 153, 30.09.2025

Hüseyin Söyler

https://doi.org/10.18245/ijaet.1713346

Abstract

The urgent need for alternative fuels has propelled biodiesel research into the spotlight, particularly focusing on cost-effective and sustainable feedstocks such as waste frying oil. This study investigates the technical and practical impact of four different base catalysts (NaOH, KOH, K₂CO₃, and Ca(OCH₃)₂) on the transesterification efficiency of waste frying oil. Experimental trials were systematically conducted by altering catalyst concentration and methanol-to-oil molar ratios to determine optimal production conditions. Statistical analyses confirmed that all process parameters had a significant impact on the biodiesel yield. Technically, NaOH and KOH yielded the highest conversion rates, while K₂CO₃ showed markedly lower performance. The study supports the process's cost-effective goal by demonstrating that NaOH and KOH, which provided the highest yields, are also the most economical and practical options due to their low cost and industrial availability. The developed multiple linear regression model affirmed the collective influence of the examined parameters with a strong predictive capability (R² = 0.933). Ultimately, this work highlights both the technical superiority and economic practicality of strong bases, particularly NaOH and KOH, for efficient biodiesel synthesis from waste frying oil, contributing to optimized processes that support the transition to greener energy alternatives.

Keywords

Biodiesel production , base catalysts , waste frying oil , transesterification , process optimization

Biyodizel üretimi, baz katalizörler, atık kızartma yağı, transesterifikasyon, proses optimizasyonu

Abstract

Alternatif yakıtlara olan acil ihtiyaç, biyodizel araştırmalarını ön plana çıkarmış ve özellikle atık kızartma yağı gibi maliyet etkin ve sürdürülebilir hammaddelere odaklanılmasına neden olmuştur. Bu çalışma, NaOH, KOH, K₂CO₃ ve Ca(OCH₃)₂ gibi çeşitli homojen baz katalizörlerin atık kızartma yağı ile gerçekleştirilen transesterifikasyon verimliliği üzerindeki etkisini incelemektedir. Deneysel çalışmalar, katalizör konsantrasyonu ve metanol/yağ mol oranı değiştirilerek sistematik olarak yürütülmüş ve optimum üretim koşulları belirlenmiştir. Tek yönlü ANOVA ve Tukey HSD çoklu karşılaştırma testi gibi istatistiksel analizler, süreç parametrelerinin biyodizel dönüşüm verimi üzerinde anlamlı etkiler yarattığını doğrulamıştır. Test edilen katalizörler arasında, NaOH ve KOH en yüksek dönüşüm oranlarını sağlarken, K₂CO₃ belirgin şekilde daha düşük performans göstermiştir. Ayrıca, yüksek düzeyde açıklayıcılığa sahip (R² = 0.954) bir çoklu doğrusal regresyon modeli geliştirilmiş ve parametrelerin birlikte etkili olduğunu ortaya koymuştur. Parametre etkileşimlerini görselleştirmek amacıyla oluşturulan yüzey grafiklerinde, maksimum verim bölgeleri belirlenmiş ve özellikle katalizör yüklemesi ile metanol oranı arasındaki sinerjik etkileşimler vurgulanmıştır. Elde edilen sonuçlar, özellikle NaOH ve KOH gibi homojen katalizörlerin atık kızartma yağından verimli biyodizel üretimi için uygulanabilirliğini ortaya koymakta ve biyodizel üretim süreçlerinin optimizasyonuna katkı sağlayarak daha yeşil enerji alternatiflerine geçişi desteklemektedir.

Keywords

Biyodizel üretimi , homojen katalizörler , atık kızartma yağı , transesterifikasyon , proses optimizasyonu

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