Urea Tank May Soon Be Required For Diesel-Powered Vehicles
From : geekboy
Q: looks like pissing in the pot will be taken literally now ;- the good side of this no longer need pee breaks on a long road trip to save time. -------------------- starting in 2010 owners of diesel-powered cars and trucks may have to fill a supplementary tank with urea an organic compound that fights nitrogen oxide emissions when its injected into a vehicles exhaust system the washington post reports. in anticipation of vehicle makers adopting an emissions-reduction system that depends on urea to meet tight diesel pollution-control rules the environmental protection agency issued guidelines on march 27 telling manufacturers how to earn certification for the new engines. the agency wants to ensure that urea is easily available and that systems will be designed to force owners to keep tanks full. companies must design a system that would meet clean air act rules by 2010 calling for the virtual elimination of nitrogen oxides and compel owners to maintain emission-control systems. according to the washington post the epa cautioned that the systems must be designed so they cant be disabled tampered with or filled with something other than the proper concentration of urea. http//www.fleet-central.com/bf/tinside.cfmaction=pick&storyid=28374 .
Replies:
From : snoman
on wed 18 apr 2007 024024 -0500 geekboy ner@nerdy.com wrote looks like pissing in the pot will be taken literally now ;- the good side of this no longer need pee breaks on a long road trip to save time. -------------------- starting in 2010 owners of diesel-powered cars and trucks may have to fill a supplementary tank with urea an organic compound that fights nitrogen oxide emissions when its injected into a vehicles exhaust system the washington post reports. in anticipation of vehicle makers adopting an emissions-reduction system that depends on urea to meet tight diesel pollution-control rules the environmental protection agency issued guidelines on march 27 telling manufacturers how to earn certification for the new engines. the agency wants to ensure that urea is easily available and that systems will be designed to force owners to keep tanks full. companies must design a system that would meet clean air act rules by 2010 calling for the virtual elimination of nitrogen oxides and compel owners to maintain emission-control systems. according to the washington post the epa cautioned that the systems must be designed so they cant be disabled tampered with or filled with something other than the proper concentration of urea. http//www.fleet-central.com/bf/tinside.cfmaction=pick&storyid=28374 they have been talking about this for a few years and it applies to diesel owners diesels are very big nox generators as one diesel suv makes as much or more nox as about 10 gas powered ones. when the urea solution is injected into exhaust flow it converts to ammonia nh3 and then via a scr cat it breaks down the nox into water vapor and plain nitrogen nx there are few other methods out there but this seems to be most popular. you are only becoming aware of this problem now because diesel have had a free lead in this area for many yearsand now are being brought into compliance. gas motors have been complying for over 30 years now. ----------------- thesnoman.com .
From : midlant
on wed 18 apr 2007 215604 gmt max dodge max340@verizon.net wrote it theory any rpm up to redline but as you have seen much above 2000 rpm in a cruise mpg can take a dump. this has to do with flame speed and increased pumping losses. flame speed in a diesel isnt an issue. the flame is propagated in the direct center of the piston on most if not all diesels. the cummins 5.9 engines have been tuned to turn at over 4000 rpm so flame speed down the cylinder at stock rpms isnt an issue either. the loss of mpg at higher ground speeds can be directly attributed to the exponential increase in aerodynamic drag. actually if you knew what you were talking about you would know that flame speed is a issue because as rpm increases the rate of expansion is not fast enough and the power output is overcome by increased power requirements to pump the engine through next compression and efficency drops off. sure you can spin one up to 4000 rpm but torqie will be way down it will be well past peak hp and efficency will be in the toilet so what have you proved nothing. although i do not own a ctd i have driven many and i do agree that it just does not feel happy above 2300 rpm or so. mine feels great all the way to 2800 rpm and ive pushed it to 3100 numerous times. maybe to you but i can tell when a engine is happy and not and it is not happy at 2800 and sounds strained. part of this reason is displacement because 5.9 is a pretty big six and there is a lot of mass in there to balance. interesting comment considering the 5.9 is a small inline six diesel and the new one is 6.7 liters. not at all. if you knew thoery you would understand why i said what i said and the dynamics behind it. longer stokes are needed to obtain displacement on there is more mass to balance due to forces of heavy pistons on longer strokes and their inertia as they change direction of travel at each end of stoke. the longer the stroke and bigger the bore the more there is to overcome and balance out. for each doubling of rpm the inertia in pistons in increased 4 fold. btw the reason the new engine is a 6.7 is so they can lower boost to reduce nox formation some. no be mystery here at all. ford did same thing with 6.0 ps this is likely why gm and ford stuck with v8 designs because they are easier to balance can have a smaller bore/stroke for same general displacement. the inline six is inherently easier to balance than any v design. gm and ford likely stuck with v8s for the following reasons not so because as the size bore/stroke of it increased the dynamics of balancing the inertia forces in it become difficult. the mitigate this by reducing rpm when possible. 1 higher rpm ability thus quicker acceleration when under no load. 2 low hood line 3 cummins was unavailable due to contractual obligation. 4 could be put into vans not just trucks. more to it than thay it would have been a pain in the arse to thry to fit it in and then there is the issue of the 600 lbs more weight up front that many do not think matters. a 1200lb motor if fine in a 2 ton truck that can weight 10 or 12 k empty but not in a truck half that weight. in theory though your ctd should have the mpg edge because a engine with fewer cylinders with same general displacement has less heat loss due to a better volume to surface area relation one reason they use big displacements in otr trucks the negative of this though is that they do not like to rev up much. the inline six will deliver more torque at low rpm for any given displacement than a v8 will deliver. this is the reason for better efficiency. again you do not understand why. the reason is because of longer stroke which improves piston to crank angularity for its displacement. if you have a big bore short stroke 6 with same displacement as a v8 it would offer no torque advantange over a v8. your logic is wrong on the reason for efficency you would know this too if you had studied ic engine thermodynamic principles is when you take the total surface area of a engines cylinders verse the displacement the few cylinders for a given displacement the less surface area to volume and the less heat is lost to it and a engine be it gas or diesel is a heat engine in that the heat of combustion expanding the gasses in the cylinder drives piston down and this force is coupled to crank. the less heat that is lost to cylinder surface area the more of it is applied as force in the pressure of expanding gas because as mixture cools it contracts and you want the cooling to take place because it is expanding against piston travel not because of surface area contact. ----------------- thesnoman.com .
From : granny grump
on wed 18 apr 2007 131947 gmt snoman admin@snoman.com wrote on wed 18 apr 2007 024024 -0500 geekboy ner@nerdy.com wrote looks like pissing in the pot will be taken literally now ;- the good side of this no longer need pee breaks on a long road trip to save time. -------------------- starting in 2010 owners of diesel-powered cars and trucks may have to fill a supplementary tank with urea an organic compound that fights nitrogen oxide emissions when its injected into a vehicles exhaust system the washington post reports. in anticipation of vehicle makers adopting an emissions-reduction system that depends on urea to meet tight diesel pollution-control rules the environmental protection agency issued guidelines on march 27 telling manufacturers how to earn certification for the new engines. the agency wants to ensure that urea is easily available and that systems will be designed to force owners to keep tanks full. companies must design a system that would meet clean air act rules by 2010 calling for the virtual elimination of nitrogen oxides and compel owners to maintain emission-control systems. according to the washington post the epa cautioned that the systems must be designed so they cant be disabled tampered with or filled with something other than the proper concentration of urea. http//www.fleet-central.com/bf/tinside.cfmaction=pick&storyid=28374 they have been talking about this for a few years and it applies to diesel owners diesels are very big nox generators as one diesel suv makes as much or more nox as about 10 gas powered ones. when the urea solution is injected into exhaust flow it converts to ammonia nh3 and then via a scr cat it breaks down the nox into water vapor and plain nitrogen nx there are few other methods out there but this seems to be most popular. you are only becoming aware of this problem now because diesel have had a free lead in this area for many years and now are being brought into compliance. gas motors have been complying for over 30 years now. scr for nox control is currently used on stationary diesel engines and has been proposed for mobile applications. scr uses ammonia as a nox reducing agent. the ammonia is typically supplied by introducing a urea/water mixture into the exhaust upstream of the catalyst. the urea/water mixture is stored in a separate tank that must be periodically replenished. these systems can be very effective with nox reductions of 70 to 90% and appear to be tolerant of current u.s. on-highway diesel fuel sulfur levels. however there is concern that applying current scr technology to highway vehicles will require use of catalyst formulations that are sensitive to sulfur such as those employing platinum to deal with the broad range of operating temperatures typical of highway diesel engines in use. there is also potential for formation of ammonia sulfate which is undesirable because it is a component of fine pm28 in addition scr systems bring some unique concerns. first precise control of the quantity of urea injection into the exhaust particularly during transient operation is very critical. injection of too large of a quantity of urea leads to a condition of ammonia slip whereby excess ammonia formation can lead to both direct ammonia emissions with accompanying health and odor concerns and oxidation of ammonia to produce rather than reduce nox. second there are potential hurdles to overcome with respect to the need for frequent replenishment of the urea supply. this raises issues related to supply infrastructure tampering and the possibility of operating with the urea tank dry. third there may be modes of engine operation with substantial nox generation in which scr does not function well. finally there is concern that scr systems may produce n2o a gas that has been associated with greenhouse-effect emissions. http//www.epa.gov/fedrgstr/epa-air/1999/may/day-13/a11383.htm .
From : snoman
on thu 19 apr 2007 093243 -0400 granny grump lori@loricase.com wrote scr for nox control is currently used on stationary diesel engines and has been proposed for mobile applications. scr uses ammonia as a nox reducing agent. the ammonia is typically supplied by introducing a urea/water mixture into the exhaust upstream of the catalyst. the urea/water mixture is stored in a separate tank that must be periodically replenished. these systems can be very effective with nox reductions of 70 to 90% and appear to be tolerant of current u.s. on-highway diesel fuel sulfur levels. however there is concern that applying current scr technology to highway vehicles will require use of catalyst formulations that are sensitive to sulfur such as those employing platinum to deal with the broad range of operating temperatures typical of highway diesel engines in use. there is also potential for formation of ammonia sulfate which is undesirable because it is a component of fine pm28 in addition scr systems bring some unique concerns. first precise control of the quantity of urea injection into the exhaust particularly during transient operation is very critical. injection of too large of a quantity of urea leads to a condition of ammonia slip whereby excess ammonia formation can lead to both direct ammonia emissions with accompanying health and odor concerns and oxidation of ammonia to produce rather than reduce nox. second there are potential hurdles to overcome with respect to the need for frequent replenishment of the urea supply. this raises issues related to supply infrastructure tampering and the possibility of operating with the urea tank dry. third there may be modes of engine operation with substantial nox generation in which scr does not function well. finally there is concern that scr systems may produce n2o a gas that has been associated with greenhouse-effect emissions. you raise some good points. one ptentail problem i see with scrs is that require high tempatures to work best in the 300 to 600c range which means a higher exhaust system temp must be maintained even longer which can lead to brush fires on suvs in dry grass. it kinda remains to be seen what the light diesel future will be several years from now. the main reason that there is ulsd today is because it enable the usage of scrs to control nox emissions. furthermore the level of sulpher are to be continually reduced in coming years until 2013 when it will be mostly gone from fuel. starting in 2010 detriot is going to have to make diesel controls tamper proof which will require a bit of technology to enforce and it is supposed to disable engine if tampered with. this will not go over well with diesel owned that want to ship their trucks. i did notice one nic side effect of thisin that i heat with oil and in years past when wind was right you could smell furnace when it was running. the last oil i bought was low sulpher and the furnace has little order to it now. ----------------- thesnoman.com .
From : nosey
bill allemann wrote anyone know the nox issues of biodiesel fuel compared to petroleum diesel bill there is a good chart here on page 4 ii. epa technical report pdf document http//tinyurl.com/395pke -- ken .
From : bill allemann
anyone know the nox issues of biodiesel fuel compared to petroleum diesel bill on wed 18 apr 2007 131947 gmt snoman admin@snoman.com wrote on wed 18 apr 2007 024024 -0500 geekboy ner@nerdy.com wrote looks like pissing in the pot will be taken literally now ;- the good side of this no longer need pee breaks on a long road trip to save time. -------------------- starting in 2010 owners of diesel-powered cars and trucks may have to fill a supplementary tank with urea an organic compound that fights nitrogen oxide emissions when its injected into a vehicles exhaust system the washington post reports. in anticipation of vehicle makers adopting an emissions-reduction system that depends on urea to meet tight diesel pollution-control rules the environmental protection agency issued guidelines on march 27 telling manufacturers how to earn certification for the new engines. the agency wants to ensure that urea is easily available and that systems will be designed to force owners to keep tanks full. companies must design a system that would meet clean air act rules by 2010 calling for the virtual elimination of nitrogen oxides and compel owners
From : snoman
i see not much has changed in the past week. some new players but the script is the same. i managed to get out of ma just ahead of the storm. made the trip in 18 hours stopped 4 times for gas. get to do it the other way the first weekend of june. greg again you were right on the money blew right through dc no problems at all. anything on budd ken larry rabbit ill get my addy to ya once i get some other stuff done. roy great you made it. ken . 222 333574 90gh231cqccbavacn2aml3og1kk4eefveb@4ax.com on fri 20 apr 2007 124647 gmt bill allemann custom4173@sbcglobal.netinvalid wrote forgot to mention the truck seems to roll freely in neutral so i dont think one wheel has the cylinders stuck. it seems more like a proportioning valve if the truck has one is putting all the flow to one wheel. the proportioning valve works from back to front not left to right. i would check for sticky calipers because i have seen them stick in all brands with age as the pads wear and the puck expands and contacts a corroded area in bore. sometimes you can get more life out of them by installing new pads and forces pucks back into bores were there is no corrosion and not let pads wear down to point it sticks. the only real fix though is replacing them if they are sticking. ----------------- thesnoman.com .