Sunflower oil production byproduct as a renewable energy source

Abstract

Food and agricultural production often leads to generation of various types of by-products. The same is with sunflower oil production. Sunflower is a crop that is widely grown in Serbia, as well as in the world, mainly for edible oil production, and sunflower husk is a by-product which is generated through this production. It is in accordance with European regulative to find an ecologically friendly way of disposal for this kind of waste. Sunflower husk falls in the category of biomass and can be used for energy generation. The most common way to utilize biomass for energy generation is by combustion. In this study sunflower husk was investigated as an energy source, and it was pelleted in order to achieve better energy conversion and combustion characteristics. The optimal conditions of pelleting process were determined, that is optimal water content in the material for pelleting. When the material is well prepared less energy is consumed during pelleting process. The aim was to analyze energy and combustion properties, as well as physical and chemical properties of pellets made from sunflower husk. Sunflower husk had satisfactory characteristic as a biomass fuel, although its pelleting required a lot of energy, and the pellets had poor abrasion characteristics (around 7-14%). The heating value was around 19.00 MJ/kg, and the volatile matter just above 70%. These values are mostly in accordance with European fuel pellets standards, with some aberrations for some of the properties. Since these standards are manly for wood, and wood-residue pellets, lower criteria could be applied for agricultural biomass pellets. Basic chemical and ultimate analyses of sunflower husk were in accordance with literature data for biomass samples, and low level of sulphur were detected (< 1.00%).