Influence of Heating Oil Formulation on the Combustion and Emissions of Domestic Condensing Boilers Using Fossil Fuel and Renewable Fuel Mixtures

Abstract

The residential sector is responsible for approximately 40% of final energy consumption in the European Union, being a potential target to increase energy efficiency and improve urban air quality. New high-efficiency heating oil boilers have been developed requiring fuel adaption by diminishing the sulfur content in the fuel. The present work has led to the conclusion that further fuel development, including the use of alternative fuels, may be directed to reduce fossil fuel consumption and decrease the formation of pollutants. Specific fuel properties, such as distillation curve and nitrogen content, show an influence on pollutant emissions, especially NO x , which can be reduced below the lowest limit required for gas domestic boilers, which, until now, set the state of the art in terms of NO x emissions. The addition of renewable fuels in heating oil formulations, contributing to a global CO2 decrease, does not affect the reduction in NO x emissions as far as it does not affect the nitrogen content and distillation curve of the fuel. Besides, a map of NO x emissions, useful to predict NO x emissions from the latest generation heating oil boilers, independent upon the type of fuel, has been inferred, and an equation has been proposed to guarantee low NO x emissions depending upon fuel properties.

Absorption of pollutants from exhaust gases by low-temperature heating surfaces

“…Conversion and absorption of higher oxides of sulfur and nitrogen by water and solutions of other liquids is used in a number of technologies for cleaning exhaust gases from toxic ingredients SOx and NOx [20,21]. The introduction of ozone into exhaust gases ensures the oxidation of lower oxides of sulfur and nitrogen (SO2 and NO) to higher oxides (SO3 and N2O5), well absorbed by water and aqueous solutions.…”

Research on the experimental performance of gas-fired boiler based on the total heat recovery technology of absorption heat pump

“…In recent years, some scholars and scientific research institutes in China have begun to study this kind of condensing boiler. By means of direct contact heat exchange 5 or adding condensing heat exchanger [6][7][8] , this part of heat can be partially recycled. The thermal efficiency of condensing boiler is about 5 ~ 15% higher than that of conventional gas boiler.…”

Statistical Study of Combustion Characteristics and Optimal Operation Factor Determination in an Emulsion Burner Fueled with Vegetable Oils

“…The lowest emissions of CO and NOx were obtained with blends containing 25% PlO. Recently, Esarte et al [14] studied the performance and emissions of different blends of fossil fuels with renewable fuels such as VOs and their fatty acid methyl esters (FAMEs) in a domestic condensing boiler.…”

“…The combustion of blends of palm oil (PlO)-diesel fuel in an industrial oil burner with and without secondary air was studied by Mohd Jaafar et al The lowest emissions of CO and NO x were obtained with blends containing 25% PlO. Recently, Esarte and Delgado studied the performance and emissions of different blends of fossil fuels with renewable fuels such as VOs and their fatty acid methyl esters (FAMEs) in a domestic condensing boiler.…”

“…Recently, Esarte and Delgado 16 studied the performance and emissions of different blends of fossil fuels with renewable fuels such as VOs and their fatty acid methyl esters (FAMEs) in a domestic condensing boiler. Despite their high viscosity, direct combustion of VOs in commercial burners can be carried out by simply correctly adjusting the device parameters.…”