Abstract
Synthetic fuels and fuel blends like OMEs can contribute to tank-to-wheel CO2 emission savings. At the same time, it is known that these fuels have a lower exhaust temperature compared to conventional diesel. This effect has major impact on the exhaust after-treatment system, particularly in cold start conditions. This paper investigates the light-off behavior of exhaust gases containing OMEs by temperature-programmed oxidation experiments using a state-of-the-art oxidation catalyst. The main side product of catalytic oxidation of OMEs between 100 °C and the oxidation temperature T50, which was around 160 °C, was shown to be formaldehyde. While alkane oxidation, in this case heptane, was little influenced by OME oxidation, the oxidation temperature T50 of CO increases by more than 10 °C by OME addition. Nitrogen monoxide impeded the oxidation of OME in a similar way to the other components investigated. Due to the amount of FA produced and its toxicity, it could be concluded that it is necessary to heat up exhaust after-treatment systems of OME diesel engines even faster than conventional diesel exhaust after-treatment systems. The relatively high reactivity of OME on oxidation catalyst can be used by active thermal management approaches.
Highlights
In accordance with climate protection targets for greenhouse gas emissions, vehicle fleet operators and freight companies are looking to increase engine efficiency
Light-off experiments were performed with carbon monoxide (CO), heptane, and Oxymethylene ethers (OMEs) in order to identify the corresponding T50, while analyzing the effect on T50 by varying parameters such as concentration and mixing with other exhaust gas components
H2O The and CO2), gas hourly space velocity (GHSV) T50 oxidation temperatures of OME are given in the graph
Summary
In accordance with climate protection targets for greenhouse gas emissions, vehicle fleet operators and freight companies are looking to increase engine efficiency. Oxidation catalysts are an integral component in exhaust after-treatment systems of combustion engines They oxidize pollutants, like HC and CO, in the exhaust gas, to unreactive CO2, thereby generating heat. Because of the beforementioned increase of engine efficiency, the behavior (reactivity, secondary products) of OME and OME blends on oxidation catalysts in cold start condition is important to analyze for emission control and future exhaust after-treatment systems. Based on its reactivity at low temperatures, OME could form different reaction products whose absorption properties and whose interaction with other exhaust gas components on the catalyst are largely unknown. To the best of the author’s knowledge, there is still uncertainty about the light-off behavior of OME on oxidation catalysts in the presence of other exhaust components like heptane (C7) and nitrogen and carbon oxides. A new, renewable fuel will only find social acceptance if it can be burned without emitting toxic pollutants or strong greenhouse gases
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
