Study of combustion in residential oil burning equipment of animal by-products and derived products not intended for human consumption

Alonso et al. International Journal of Energy and Environmental Engineering 2013, 4:31 http://www.journal-ijeee.com/content/4/1/31 ORIGINAL RESEARCH Open Access Study of combustion in residential oil burning equipment of animal by-products and derived products not intended for human consumption Julio F San José Alonso*, I Gobernado Arribas and S Alonso Miñambre Abstract This article studies the use of animal by-products and derived products not intended for humans as possible fuels in residential oil burning facilities. We first offer a chemical and physical description of the various types of animal byproducts and derived products not intended for humans with a view to their possible use as fuels. Animal by-products and derived products not intended for humans have an extremely high viscosity for the pressure pulverisation burners used in residential oil burning equipment. We therefore mixed diesel with animal by-products and other derived products not intended for humans in different percentages so as to obtain suitable viscosity. To achieve this, we carried out a study of the miscibility of animal by-products in diesel. We subsequently performed a series of combustion experiments for mixtures of diesel and animal by-products, in varying (a) percentage of by-products in diesel, (b) injection pressure and (c) excess air in combustion. We analysed the experimental combustion results based on (a) energy efficiency of combustion, (b) CO and NOx emissions and (c) fossil-based greenhouse effect gases. Finally, we present the conclusions that combustion of mixed diesel with animal by-products and other derived products not intended for humans for use as boiler fuel low power does not require specific technology when using a conventional fuel oil burner for proper combustion. One only needs to adjust the burner factors: pressure and air flow. In the study of the combustion of mixtures, once the burner factor is adjusted, it appears that the combustion efficiency and greenhouse gas and emission gases are acceptable. The costs of removing fat through incineration or landfill range from 34 to 59 €/ton. The solution proposed in this work not only avoided the cost but also mentioned the value of residue use as fuel. Keywords: Animal fat; Mixtures; Oil; Cocombustion; Boiler Background In 2007, the Council of Europe set out a series of ambitious goals for 2020, given the name of ‘20-20-20’, which seek to cut greenhouse gas emissions by 20%, cut primary energy consumption by 20% through enhanced energy efficiency and promote up to 20% use of renewable final energy consumption [1]. Through the Directive 2009/28/CE, the European Parliament set a target for 2020 that 20% of final energy should be from renewable sources. The directive promotes energy generated from biofuels and bioliquids. For the latter to be considered sustainable, they must contribute to cutting greenhouse gas emissions by at least 35%. As of 1 January 2017, their contribution to emission reduction must reach 50% [2]. * Correspondence: Departamento Ingeniería Energética y Fluidomecánica, E. Ingenierías Industriales, Universidad de Valladolid, Paseo del Cauce 59, 47014 Valladolid, Spain The directive stipulates that in order to be granted financial support, biofuels and bioliquids must be classified as ‘sustainable.’ This requires biofuels and bioliquids to be generated using raw materials from both outside as well as inside the various regions of UE. In addition, they must not originate from land that has high biodiversity value or large carbon reserves [3]. Bioliquids may be transformed for use in engines or used directly as fuels in burners. When used as fuels in burners, certain advantages are evident such as (a) requiring no specific transformation processes, thereby enabling them to be obtained relatively cheaply; (b) less rigorous specifications when used in burners than when used in engines; and (c) a wider range of technologies linked to burners than to heat engines. In addition, burners have a wider range of regulation vis-à-vis fuel than heat engines [4]. © 2013 Alonso et al.; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Alonso et al. International Journal of Energy and Environmental Engineering 2013, 4:31 http://www.journal-ijeee.com/content/4/1/31 Some authors have explored the use of bioliquids. Batey [5] conducted studies into combustion of biodiesel and mixtures of oil and diesel in residential combustion facilities; Raheman et al. [6] evaluated a 10.3-kW single-cylinder water-cooled direct-injection diesel engine using blends of biodiesel (B10 and B20) obtained from a mixture of mahua and simarouba oils (50:50) with high-speed diesel (HSD) in terms of brake-specific fuel consumption; Vanlaningham et al. [7] analysed combustion of oil and soya seed for heating; San José et al. [8] studied combustion of mixtures of soya oil, rapeseed and sunflower oil with diesel in various proportions over a range of combustion parameters in a pressure pulverization burner and also studied combustion of biodiesel that does not meet biofuel specifications [9]. The fat used for heating purposes has been analysed at the University of Budapest by Lezsovits and Könczöl [10] who researched the use of animal fats in industrial steam generators that conventionally ran on diesel or natural gas. The use of this by-product was intended not only to remove it as a waste product but also to provide an alternative non-fossil fuel. In Germany, F. Pfab [11] treated animal fat from processing plants and subsequently used it in combustion to generate steam in a tubular boiler. Before feeding the fat into the burner, the burner must be cleaned with a decanter and separator. Our study breaks new ground in current technology by performing combustion of animal fat at an injection pressure below 10 bars, compared to conventional 30 bar pressure. In Spain, Dr. J. San José [12] has conducted a number of studies of the combustion of lard in a commercial burner and into the miscibility of lard in diesel. These studies posit an important field of study in the description of animal fats and their use as fuels in conventional diesel facilities. Animal by-products and other derived products not intended for human consumption, which are recoverable in energy terms, are in abundant supply as waste and are found in the animal-based food production chain in (a) intensive livestock holdings, hen manure and other similar products, and in (b) slaughterhouses and retailers. The former are usually processed in the actual livestock holdings themselves, whereas the latter, which provide the case study for the present article, are dealt with by officially accredited firms. The amount generated in slaughterho (...truncated)