Oxy-fuel technology: An experimental investigations into oil shale combustion under oxy-fuel conditions

• Published in: Fuel (Guildford) Vol. 103; pp. 421 - 429
• Main Authors: Al-Makhadmeh, L., Maier, J., Al-Harahsheh, M., Scheffknecht, G.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2013; Elsevier
• Subjects: Applied sciences; Combustion; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fuels; Oil shale; Oxy-fuel; SO2; NO; Combustion; Oil shale; Oxy-fuel; SO2; Combustion air; Shale oil; Flue gas recirculation; Experimental study; Pollutant emission; Sulfur dioxide; Fuel oil; Staged combustion; Feasibility; S0
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2012.05.054

► First investigation on oil shale combustion under oxy-fuel conditions. ► A 20kW Once-Through reactor was used. ► SO2 emissions under oxy-fuel conditions is lower than air-firing by around 30%. ► NOx emission was found to be lower under oxy-fuel conditions than air-firing. ► NOx emission can be reduced efficiently by adopting staged combustion. Oil shale utilization has received much attention all over the world due to the rise of oil-prices; Jordan is one of the countries that have just started an intensive research for oil shale utilization. In this study the feasibility of oil shale combustion under oxy-fuel conditions was investigated using a 20kW Once-Through reactor at a combustion temperature of 1200°C. To the investigators best knowledge, this is the first time that oxy-fuel technology is applied for oil shale combustion. So this study is considered a unique with respect to the conditions and the scale of the combustion experiments. Jordanian oil shale samples from El-Lajjun was used. Unstaged air-firing and oxy-fuel combustion were investigated to study oil shale combustion behaviour. It is found that direct combustion of oil shale under oxy-fuel conditions is feasible, 100% oil shale burnout was achieved for OF27 combustion as well as air-firing. In addition, the high S content in oil shale is a well known problem; our study aims to find if oxy-fuel conditions will affect SO2 emissions as well as NO emissions. It is found that SO2 emissions during oil shale combustion under oxy-fuel conditions is lower than air-firing by around 30%. In addition, NOx emission was also found to be lower and can be reduced efficiently by adopting staged combustion technology under oxy-fuel conditions as well as air-firing, however, the oxy-fuel investigations were carried out without flue gas recirculation.