DEF Use in SCR

Print Friendly

Selective Catalytic Reduction (SCR)

Selective catalytic reduction, or SCR,  is a method of converting nitrogen oxides (NOx) into carbon dioxid (CO2) and water. Diesel exhaust fluid, or DEF, is added to a stream of exhaust gas where it reacts with the nitrogen oxides, breaking them down into harmless carbon dioxide and water.

Since the late 1970s, SCRs have been in use on large utility, industrial, and municipal solid waste boilers, and SCR usage in these systems has reduced NOx by 70% – 95%. More recently, diesel engines on large ships, locomotives, gas turbines, and large diesel-powered trucks have seen an increase in SCR usage.

Diesel Exhaust Fluid (DEF)

Diesel exhaust fluid, or DEF, is designed for use in SCR systems to reduce nitrogen oxide emissions. It is a urea-based chemical produced from raw fossil fuel sources such as natural gas, coal, and a variety of other petroleum based products by dissolving solid urea of high purity in de-ionized water. It is non-toxic, non-flammable, stable, and requires no special handling.

DEF must be kept totally pure to allow for proper usage, and the concentrations of urea to water must be exact. Any variations in either of these ares can result in engine damage.

How DEF is Used in SCR Systems

Through SCR technology, nitrogen oxide (NOx) reducing reactions take place in an oxidizing atmosphere. These reactions reduce levels of NOx using ammonia as a reductant within a catalyst system. The amonia reacts with NOx to convert it into nitrogen, water and carbon dioxide (CO2). The reductant source is usually Diesel Exhaust Fluid, or DEF. SCR technology alone can reduce NOx by as much as 70% – 90%.

Filed Under: DEF

One Response to DEF Use in SCR

  1. Great info on SRC and how it works. this is becoming more and more common and more people are becoming aware of DEF, what it is used for, and where to find it.

Leave a reply

Petroleum Equipment Institute Member         UL 2085 Listed       Steel Tank Institute       tank financing option
usa made fuel tanks
Envirosafe Enterprises Inc. is a Disabled Veteran Owned Company
Memco, Inc. 1789 EC 48, Bushnell, FL 33513 352-241-2302 Toll-Free 800-555-4754 Fax: 352-241-9753

Website Design & SEO by Net Marketing Advisers

© 2008-2017 Memco, Inc. All rights reserved