Possibility of the Utilization of Waste Glycerol as an Addition to Wood Pellets

Abstract

Production of liquid biofuels derived from vegetable oils in recent years significantly increased which causes surplus of by-product (waste glycerol) from this process. Therefore it is of great importance to find cheap and fast method of use its utilization. In this study, a possibility of the utilization of technical purity glycerin as an addition to wood pellets intended for heating purposes has been investigated. Usefulness of pellets contained glycerol additions has been compared in terms of applicable quality standards for wood pellets. Effects of waste glycerol addition on concentration of combustion products as well as temperature in heat exchanger have also been examined. The experimental results show that co-combustion of waste glycerol with wood sawdust does not worsen heating efficiency in a standard boiler. Moreover, 4.5 and 7% presence of glycerol in wood pellets correlated to a nearly twofold decrease of NOx concentration in flue gas. Therefore, the use of the waste glycerol as a binder for the production of pellets can be a simple and cost-effective solution of its utilization.