Gasification of Waste Medium Density Fibreboard as a Route to Power Generation

Abstract

AbstractMedium density fibreboard (MDF) processing in Northern Ireland generates about 40 tonnes of MDF dust per week, which gives significant disposal problems and costs. The overall aim of this project was to develop an environmentally friendly, energy efficient and economically acceptable means of generating “green” electricity from MDF dust.The project is based on using a down draught fixed bed gasifier with a modified diesel engine generator. Before MDF dust can be used in the gasifier it must first be briquetted. Although many equipment manufacturers claim to be able to briquette MDF dust, only two were able to prove this capability, PLC Products and Kahl. Trials were arranged and as a result a B10 Bio‐Compactor was purchased and installed. However, good quality briquettes could not be produced reliably due in part to a lack of experience in operating the B10 Bio‐Compactor and in part to mechanical failures. Changes were made to the B10 Bio‐Compactor to improve its mechanical integrity and further trials will be performed to establish the conditions required to make MDF briquettes reliably.In order to provide MDF briquettes for the gasification trials it was decided to use MDF off‐cuts sawn to the correct size. The project team was happy that these off‐cuts possess very similar properties to the briquettes produced by the B10 Bio‐Compactor and would therefore give very similar gasification behaviour. The gasification trials were very successful, with 8 hours continuous operation without problems. The calorific value of the fuel gas produced was 4.8 MJ/nm3, which is almost identical to that obtained from normal hardwood chip fuel. From the gasifier a mixture of diesel and MDF fuel gas was fed to the diesel engine generator. This is the normal practice for these types of engines in order to maintain smooth and efficient combustion. No problems were experienced when changing over from diesel to the fuel gas mixture