258145 Non-Catalytic Oxidation of Carbon Black and Diesel Engine Soot Samples - Kinetics and Structure-Activity Relationships
More than 13 million [] diesel vehicles are responsible for transportation of 94% of the goods in US [] and use 4 million barrels of diesel per day []. Diesel cars contribute up to 53% of the passenger cars sold in the European market []. Despite the efficiency, durability, low operating cost, and reliability of diesel engines, Particulate Matter (PM) emissions remain responsible for various human health and environmental problems []. Diesel Particulate Filters (DPFs) are the most popular aftertreatment technology to meet the stringent PM emissions standards [, ]. However, periodic regeneration of DPF through efficient oxidation of PM or soot remains a major challenge, especially due to the complex nature of soot. Structure and oxidation activity of diesel soot is attributed to the combined effects of fuel, lubricating oil, operating conditions, and engine type []. A wide range of kinetic parameters have been reported for soot oxidation, e.g., activation energy lies in the range of 40-300 kJ/mol []. Current understanding about the soot morphology and its quantitative impact on the oxidation activity is also limited. In this work, we have investigated the non-catalytic oxidation kinetics of 14 carbon black samples including diesel engine soot using Thermo Gravimetric Analysis and various characterization methods such as SEM, TEM, XRD, BET, and Raman (see Figure below for an example). Effect of various parameters, such as partial pressure of oxygen, ramp rate, flow rate, is also investigated in the Temperature Programmed Oxidation (TPO) experiments. Based on this comprehensive study – carried out for the first time – we will present insights regarding how the soot morphology affects its oxidation activity and the corresponding structure-activity correlations.
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[] “National Ambient Air Quality Standards (NAAQS)”, http://epa.gov/air/criteria.html8 Nov. 2011.
[] “Emissions Standards”, http://www.dieselnet.com/standards/eu/hd.php
[] Yezerets, A., Currier, N.W., Kim, D.H., Eadler, H., Epling, W.S., and Peden, C.H.F., “Differential kinetic analysis of diesel particulate matter (soot) oxidation by oxygen using a step–response technique”, Applied Catalysis B: Environmental, 61(1-2), 120-129 (2005).
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