ST2-01: Processes to modify fatty acid methyl esters – some recent developments

Opportunities for further developments in biofuels for diesel engines are discussed with the aim to use them also in modern and even future diesel engine generations. For this purpose, the actual problems with biofuels are discussed. For the neat fuel, the high boiling curve is the main obstacle to use this fuel in modern passenger cars with particle filter. In order to avoid the problems associated with the disadvantageous boiling behavior we are actually carrying out a research project in which a catalytic shortening of the fatty acids by a so-called metathesis reaction is applied. This leads to fuels with improved boiling behavior. With blends, problems are encountered when the biogenic share is in the range of 10 to 20% and the fuel is aged, which means oxidized. Then oligomers are formed that precipitate as sediments and can lead to filter blocking or undesirable combustion products in the exhaust gas. In this case one can try, by means of polar solvents, like alcohols, to re-dissolve the sediments or to prevent the oligomers from sedimentation. The presentation will show some results that were gained during our attempts to solve these problems.