Dodge Cummins Diesel Forum - View Single Post

BillG · 08-07-2008, 04:42 PM

For people who still have their emissions crap in place, you're lucky if you run LSD without problems. The change to ULSD was to help meet the emissions requirements for reducing the nitrogen compounds (NOx). The deal is that they invented the NOx adsorber (sits before the DPF) to collect the nitrogen compounds and the cooled EGR helps reduce the formation of nitrogen compounds. The picture gets complicated by the fact that sulfur in the fuel will fill up the NOx adsorber so that it doesn't have room to collect the NOx. They call it sulfur poisoning. So, the regen cycle you see on some monitors called DeSOx cleans the sulfur out of the NOx adsorber. Now, since the NOx adsorber is so sensitive to sulfur, the industry had to move from LSD which is 500ppm max sulfur to ULSD which is only 15ppm max.

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08 6.7 2500 Mega, 68RFE, Stock!, Edge Insight (thinks it's a DashHawk!), ELM327 & Perl/TK monitor/data logger. Truck crying for stacks & EGR delete, 2nd turbo smothering.
3rd diesel (06 5.9 killed by tree, 03 5.9 sold, sorely missed!)

08-07-2008, 04:42 PM	#9 (permalink)
BillG Cummins Fanatic Join Date: Apr 2008 Location: Columbia, SC Posts: 112 BillG's Truck Pics	For people who still have their emissions crap in place, you're lucky if you run LSD without problems. The change to ULSD was to help meet the emissions requirements for reducing the nitrogen compounds (NOx). The deal is that they invented the NOx adsorber (sits before the DPF) to collect the nitrogen compounds and the cooled EGR helps reduce the formation of nitrogen compounds. The picture gets complicated by the fact that sulfur in the fuel will fill up the NOx adsorber so that it doesn't have room to collect the NOx. They call it sulfur poisoning. So, the regen cycle you see on some monitors called DeSOx cleans the sulfur out of the NOx adsorber. Now, since the NOx adsorber is so sensitive to sulfur, the industry had to move from LSD which is 500ppm max sulfur to ULSD which is only 15ppm max. __________________ 08 6.7 2500 Mega, 68RFE, Stock!, Edge Insight (thinks it's a DashHawk!), ELM327 & Perl/TK monitor/data logger. Truck crying for stacks & EGR delete, 2nd turbo smothering. 3rd diesel (06 5.9 killed by tree, 03 5.9 sold, sorely missed!)