Experimentelle Untersuchungen zur inner- und außermotorischen Partikelreduktion an einen Nutzfahrzeugdieselmotor zur Erfüllung der Abgasstufe IV im Betrieb mit biogenen Kraftstoffen

Abstract The development of combustion engines in mobile machineries is in conflict to emission limits and ensuring a low carbon and resource efficient energy supply. With introduction of the exhaust gas limitation interim Tier 4 according to EN 97/68 exhausts gas after treatment systems were used for the first time. These components are developed and evaluated for the use of fossil diesel fuel. The bioavailability and the result increase of price for fossil fuels, as well as the climate impact of carbon dioxide and inevitably result from the combustion, lead to a search for alternative energy sources. Especially for mobile working machines canola oil is an interesting alternative because it can be produced in oil mills from rape seed with relatively simple methods. The use of vegetable oil or intrinsic canola oil exhibits the opportunity of a decentralized, regenerative energy supply and at once a significant CO2 saving potential up to 60%. In the past vegetable oil has been successfully used within the bounds of provision of energy in mobile machines. In this case the engine was not equipped with an exhaust gas after-treatment system. To achieve current exhaust gas requirements the engines have to be equipped with a DPF or with a SCR system. With introduction of the Tier 4 standard a combination between a DPF and SCR system has to be used. In this context especially the wall flow particulate filter has to be evaluated referring to vegetable oil. In these walls flow particulate filters the non-combustible ingredients of the fuel will accumulate over lifetime. Due to the DIN standard 51605 the ash formers in rapeseed oil are reduced to the level of the diesel fuel. Therefore ash loads will be comparable to diesel fuel over the life time. The soot loading behavior and the catalytic regeneration of the particle filter require a separate consideration. In addition the combined combustion of canola oil and methane or even CNG offer the possibility to reduce the engine particle emissions and potentially enable to set the particle filter aside. In addition to that the use of methane provides further CO2 savings.