Rashin fitar da diesel

Ruwa mai fitar da iska (**DEF**; wanda aka fi sani da urea Solution at 32 per cent">**AUS 32** kuma wani lokacin ana tallata shi da **AdBlue** ) ruwa ne da ake amfani da shi don rage yawan gurɓataccen iska da injin diesel ya haifar. Musamman, DEF shine maganin urea mai ruwa wanda aka yi da 32.5% urea da 67.5% deionized ruwa. Ana cinye DEF a cikin raguwar ƙwayoyin cuta (SCR) wanda ke rage yawan nitrogen oxides (NOx)  a cikin hayakin diesel daga injin diesel.

## Sauran sunaye
A cikin ma'auni na kasa da kasa da ke bayyana DEF (ISO 22241), ana kiranta AUS 32 (aqueous urea solution 32%).  Ana kuma sayar da DEF a matsayin AdBlue, alamar kasuwanci mai rijista na Ƙungiyar Masana'antar Motoci ta Jamus.

Yawancin nau'ikan tsarin SCR suna amfani da DEF: BlueHDI ana amfani da su ta motocin PSA Group ciki har da Peugeot, Citroën, da DS Automobiles; BlueTec ta Daimler AG; da FLENDS (Final Low Emission New Diesel System) ta UD Trucks. Blue Sky DEF an yi shi kuma an rarraba shi don sayarwa ta Firayim Lubes, Inc.

## Tarihi
Ana amfani da injunan diesel tare da rabon iska-da-mai (mafi girman stoichiometric) don tabbatar da cikakken konewar soot da kuma hana su daga gajiyar man fetur mara ƙonewa. Iska mai yawa tana haifar da ƙarni na NOx, waɗanda ke da lahani, daga nitrogen a cikin yanayi. Ana amfani da raguwar zaɓaɓɓen catalytic don rage adadin NOx da aka saki cikin yanayi. DEF daga tanki daban ana yin allurar a cikin bututun fitarwa, kuma zafi na fitarwa yana lalata shi zuwa ammoniya. A cikin SCR catalyst, ammoniya ta rage NOx zuwa ruwa da nitrogen, waɗanda duka ba su da gurɓata. Ana fitar da ruwa da nitrogen cikin yanayi ta hanyar hayaki.

Kamfanin Nissan Diesel Corporation ne ya yi amfani da SCR ga motoci, kuma an gabatar da samfurin farko mai amfani "Nissan Diesel Quon" a cikin shekara ta 2004. Tare da hadin gwiwar masana'antar mai da sinadarai, an shirya kayan aikin tashar 1,300 don samar da DEF a watan Satumbar 2005 a Japan.

A cikin shekara ta 2007, Hukumar Kare Muhalli ta Amurka (EPA) ta kafa buƙatu don rage fitar da hayaki mai cutarwa. Don cimma wannan ma'auni, Cummins da sauran masana'antun injin diesel sun haɓaka tsarin bayan magani wanda ya haɗa da amfani da matattarar ƙwayoyin diesel (DPF).

Kamar yadda DPF ba ta aiki tare da man fetur mai ƙarancin sulfur, injunan dizal waɗanda suka dace da ƙa'idodin fitar da hayaki na EPA na 2007 suna buƙatar man fetur na dizal mai ƙaranci (ULSD) don hana lalacewar DPF. Bayan ɗan gajeren lokacin canji, man fetur na ULSD ya zama ruwan dare a famfo na man fetur a Amurka da Kanada.

Dokokin EPA na 2007 an yi niyyar zama mafita ta wucin gadi don ba da damar masana'antun lokaci don shirya don ƙa'idodin EPA na 2010, wanda ya rage matakan NOx har ma da ƙari. A cikin 2008, damuwa game da bin doka ya koma ga ababen more rayuwa don rarraba DEF.

Yawan allurar DEF a cikin hayaki ya dogara da takamaiman tsarin bayan magani, amma yawanci 2-6% ne na yawan amfani da diesel. Wannan ƙarancin sashi yana tabbatar da tsawon lokacin sake cika ruwa kuma yana rage girman tankin da shiga cikin sararin marufi na abin hawa. Wani na'urar sarrafa lantarki yana daidaita ƙarin ruwa daidai da sigogi kamar matakin NOx a cikin iskar gas (kafin mai canzawa, bayan mai canzawa mai canzawa na catalytic, kuma mai yiwuwa tsakanin masu canzawa na catalic idan akwai fiye da ɗaya), matakin cika ammoniya na yanzu,  zafin jiki da saurin aiki.

## Manazarta