EMISSION CONTROL (J08E)
EN10–8
SELECTIVE CATALYTIC REDUCTION (SCR)
GENERAL DESCRIPTION
EN0110610C100002
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What is SCR?
SCR is an abbreviation of "Selective Catalytic Reduction", a general
term for aftertreatment equipment which promotes a chemical reac-
tion by using a catalyst for eliminating or detoxifying particular chemi-
cal ingredients. To meet the EPA2010 regulation the vehicle out NOx
level will be extremely close to zero (0.2 Grams per brake horse-
power). By mixing the NOx with the ammonia contained in DEF, it will
be separated it to harmless water and nitrogen. It is an extremely
effective, dependable efficient and economical selection.
•
What is DEF?
DEF is an abbreviation for "Diesel Exhaust Fluid", a solution made
from 67.5% purified water and 32.5% automotive-grade urea that
serves as a carrying agent for the ammonia needed to reduce nitro-
gen oxide (NOx) emissions from diesel engines. When DEF is
injected into the engine exhaust gas downstream of the DPF, it will be
rapidly hydrolyzed producing the oxidizing ammonia needed by the
SCR catalyst to complete NOx emissions reductions.
•
The system consists of the DEF adding device and its accessories,
SCR (Selective Catalytic Reduction) catalyst, DCU, and sensors.
