Mechanical thermal expression (MTE) is a pressure dewatering process, which is carried out at elevated temperatures. The process is being investigated as a means of lowering greenhouse gas emissions from existing lignite fired power stations by reducing the moisture content of lignites. The investigation was carried out to identify how variations in temperature and pressure during the MTE process affect the physicochemical properties of MTE treated Loy Yang lignites. Increases in MTE temperature (< 250 degrees C) and pressure (< 12.7 MPa) resulted in significant reductions in residual moisture content, moisture holding capacity and sodium levels, which have been largely attributed to the destruction of porosity in the lignite. (c) 2005 Elsevier Ltd. All rights reserved.