Energy Recovery from High Salinity Biomass

Abstract

Phytoremediation is a biological remediation technique where plants take contaminants from the soil into their biological structure. This technique removes pollutants from the ground leaving the grown biomass requiring disposal or additional treatment. Ideally, the biomass is converted to a valuable product. The aim of this study is to recover a solid biomass fuel from plants used for phytoremediation on high salinity soils. This will entail the application of pretreatments on Phragmites Australis, the plant type used, in order to render it suitable for combustion in a cement kiln. Presently, the combustion of the biomass is considered as a sustainable pathway to low carbon fuels in cement manufacturing industry. The investigation characterized Phragmites Australis by energy content (16.29 MJ/kg raw) and salt content (3.81%) using conductivity measurements. In order to lower the salt content, a series of washing experiments were performed followed by analytical testing to determine the suitability of the fuel produced. Further analysis consists of thermal analysis by TGA and calorimetry as well as conductivity measurements Best results observed were 88% chloride removal and 56% ash content decrease. Subsequent dewatering steps were performed to reach a 15% moisture content in final product. The results were used to a preliminary process design for the treatment of biomass produced via phytoremediation of high salinity soils.