Operation Section 1 ± 29 7.3 Selective Catalytic Reduction (SCR) System (2010 Model Only) Outline The SCR system is an exhaust gas cleaning system that injects an aqueous solution of urea known as "AdBlue" into the exhaust pipe just before the catalyst to create a chemical reaction with the exhaust gas. As a result, approximately 40% of the NOx contained in the exhaust gas is converted into non-hazardous nitrogen. Until now, the SCR system was large, and was therefore only equipped in heavy-duty vehicles.
)RKMRI)'9 7'67]WXIQ7]WXIQGSQTSRIRXWEVIQEHIF] QERYJEGXYVIVWSXLIVXLER()273 1IXIV(MWTPE] ('1 9VIE4YQT '%2'SQQYRMGEXMSR 9VIE8IQTIVEXYVI 7IRWSV 9VIE 8ERO JVSQ)RKMRI 9VIE%HHMXMSR:EPZI (MJJIVIRXMEP 4VIWWYVI 7IRWSV XS8EMPTMTI )\LEYWX+EW 8IQTIVEXYVI 7IRWSV 7'6 23\7IRWSV (3' )\LEYWX+EW 8IQTIVEXYVI 7IRWSV (3' (4* %*7IRWSV )\LEYWX+EW 8IQTIVEXYVI 7IRWSV 5) SCR The SCR is a urea selective type reduction catalyst. Urea is used to chemically decompose and convert the NOx contained in the exhaust gas into non-hazardous materials. Urea is added to the exhaust gas via injection, causing NOx decomposition. The resulting non-hazardous water (H 2 0) and nitrogen gas (N 2 ) are then discharged.