The effect of natural deterioration on selected properties of rapeseed oil methyl esters

Abstract

The article discusses the results of research into properties of rapeseed oil methyl esters of and diesel oil subjected to deterioration process at room temperature for 20 years. The heat of combustion and heating values have been measured in laboratory conditions using an automatic calorimeter. The results show a slight decline in energy properties, with a change of 3.45 % on average. An image analysis has been used to evaluate the effects of ageing and combustion quality to compare the two fuels. The main purpose of research on rapeseed oil methyl esters in relation to diesel oil was to determine the energy properties of the tested fuels, i.e., the heat of combustion and the heating value. The side aims of research were to determine selected functional properties of the tested fuels.Changes in density, kinematic viscosity, acid value and water content at the beginning and end of the experiment have also been examined. Deposits formed after combustion in a calorimetric bomb in crucibles and on the injector nozzles in a self-ignition engine have been examined with the use of the weight method and images analysis.After a long period of storage, density, and acid number of rapeseed oil methyl esters have been slightly changed, while kinematic viscosity and water content increased significantly to exceed the limit values. The acid value of diesel oil increased by 75% as a result of natural deterioration.