Lead adsorption and subsequent gasification with Pinus elliottii waste

Abstract

PurposeThe purpose of this paper is to investigate the use of Pinus wood waste in lead adsorption as a remediation technique in aqueous medium and its subsequent use in obtaining synthesis gas.Design/methodology/approachThe capacity of the timber in the lead adsorption was studied in aqueous medium at various pH, determining the amount adsorbed in equilibrium. Then, the same timber was added in a fixed bed, co-current flow of two stage gasifier type, working temperature of 900°C, for obtaining synthesis gas. The synthesis gas composition was evaluated by the spectrophotometry in the infrared region and the gas chromatography and lead content in the ash and gas was determined by the atomic absorption spectrophotometry.FindingsIn laboratory tests carried out, the optimal pH for lead removal was pH 4 with 96.15 percent removal rate, reaching equilibrium after 180 min. In pilot scale the lead removal after 72 hours was 96 percent. The average production of syngas was 11.09 m³h−1. For tests with the motor-generator, the best condition occurred with charge of 2.0 kW, wherein gas consumption per kW produced reached 4.86 m³ kW−1, resulting in a 14.81 percent efficiency rate. The gas analysis showed an average concentration of 14.85 percent H2, 30.1 percent CO2, and 50.49 percent of atmospheric air. The concentration of lead in the gas was below the limit established by law. Pinus elliottii waste proved to be an excellent adsorbent, with removing more than 96 percent of the Pb ion present in aqueous solution and a starting material in the gasifier to generate synthesis gas.Research limitations/implicationsThis paper describes the waste wood application in the treatment of contaminated environments and for obtaining syngas providing a sustainable process.Originality/valueThis paper shows a process that combines the remediation of contaminated environmental with power generation systems, allowing efficient management of contaminated environments.