Flame characteristics of glycerol/methanol blends in a swirl-stabilised gas turbine burner. (15th April 2021)

• Record Type: Journal Article
• Authors: Agwu, Ogbonnaya; Valera-Medina, Agustin; Katrašnik, Tomaž; Seljak, Tine
• Is Part Of: Fuel. Volume 290(2021)
• Publication Date: 2021-04-15
• Subjects: Glycerol -- Combustion -- Characteristics -- Methanol -- Dual-phase; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2020.119968
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Blending with methanol circumvents glycerol pre-heating in gas turbine fuelling. Increasing glycerol volume in blend raises viscosity but promotes flame stability. Glycerol/methanol blends burn over a very lean equivalence ratio range (0.29–0.51). Abstract: Finding alternative value-added usage for glycerol is imperative as existing uses are inadequate due to the vast excesses of glycerol generated mainly as a result of increased biodiesel production. This paper explores a mid-term, cost-efficient, technically viable utilisation in power generation applications and exposes the nature of its combustion. Blended with methanol to avoid the heat loss and fuel coking problems associated with preheating, glycerol was combusted in a model swirl-stabilised gas turbine burner utilising a standard pressure-swirl injector for fuel atomisation. Stable flames resulting from the tested blends – 70/30 and 50/50 combinations of methanol/glycerol by volume – were achieved over an equivalence ratio (ER) range between 0.29 and 0.51. The upper and lower limits of stable operating ER for the 70/30 case were accompanied by significant flame lift-off from the nozzle exit orifice – a phenomenon that was not pronounced in the 50/50 case. Also, the temporal variation of CH* species integral intensity suggested a reduction in the fluctuation of heat release rate, hence better flame stability, as ER increased for both blends. Overall, the 50/50 case showed greater flame stability compared with the 70/30 case based on the CH* chemiluminescence data and spectral analysis by means of fast Fourier transform.