Julian Peter Cox

Development and validation of a one-dimensional computational model of the continuously regenerating diesel particulate filter (CR-DPF) system

Diesel emissions legislation continues to tighten around the world, and Particulate Matter (PM) emissions are currently the focus of much attention. Diesel PM can be controlled using Diesel Particulate Filters (DPFs), which can effectively reduce the level of carbon (soot) emissions to ambient background levels. In the Heavy Duty Diesel (HDD) area, the Continuously Regenerating Trap (CRT®) [1] has been widely applied in the retrofit market. This system will henceforth be referred to as the Continuously Regenerating DPF (CR-DPF). There are currently over 100,000 of these systems in use in retrofit applications worldwide. This system comprises a specially formulated Diesel Oxidation Catalyst (DOC) upstream of a DPF; the NO 2 generated by the DOC is used to combust the carbon collected in the DPF at low temperatures. A model describing the performance of the CR-DPF has been developed. This model comprises two basic components: i) a 1-D DOC model based on laboratory microreactor data, and ii) a 1-D DPF model. The DOC model includes Langmuir-Hinshelwood expressions to describe the kinetics of the NO, CO and HC oxidation reactions. This model has been validated using engine data measured over both low and high temperature driving cycles. The DPF model has been validated using engine bench pressure drop data measured over the ESC (European Stationary Cycle). These 2 models have been combined to create a full model of the CR-DPF system, which has been validated over a wide range of conditions. Very good agreement between the experimental data and the model has been achieved.

An Update in Heterogeneous Catalysis

as the current president, J. M. Armor, describes it on the NACS website (1). The 19th North American Meeting (19th NAM) organised by the NACS took place in Philadelphia, Pennsylvania, from 22nd to 27th May, 2005 (2). Historically, the organisers aim to cover the most relevant aspects of catalysis for the needs of society both today and tomorrow (3). The meeting was attended by over 1000 attendees and, as has become customary at recent NACS meetings, had a strong international flavour. The twenty-two oral sessions were conducted in parallel over five days in six separate conference halls, while the twenty poster sessions were organised over three days in one conference hall. The scientific programme covered the broad topics of: Petroleum, Environmental, Chemical, Fuel Cells and Fuel Processing, and each of these topics had several subtopics, such as fuel desulfurisation and processing, gasoline and diesel emissions control, photocatalysis, pharmaceuticals, gas to liquids, nanotechnology, surface science, advances in spectroscopy, etc., covering most of the fields in catalysis. This selective review describes some of the highlights reported on the platinum group metals (pgms), especially platinum (Pt), palladium (Pd), rhodium (Rh) and ruthenium (Ru), grouped into sections on environmental catalysis for gasoline and diesel engines (particularly emissions control), fuel reforming and surface science in catalysis. The commencement of the oral sessions was preceded by the Houdry Award Plenary Lecture given by Dr Henrik Topsøe, winner of the 2005 Eugene J. Houdry Award in Applied Catalysis. The rest of this day was taken up by six parallel oral sessions followed by a poster session. The oral session on “Environmental: Gasoline Engines” seemed to be attended by more participants than the other sessions of the day.