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SELECTIVE CATALYTIC REDUCTION. “Nuking the NOx”. Ed Saxman Arkansas Trucking Association November 11, 2008. Emission Development. .25 g / hp-hr. .1 g / hp-hr. .01 g / hp-hr. regeneration. Emission Development. regeneration. Emission Development. 6. 5. 4.
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SELECTIVE CATALYTIC REDUCTION “Nuking the NOx” Ed Saxman Arkansas Trucking Association November 11, 2008
.25 g / hp-hr .1 g / hp-hr .01 g / hp-hr regeneration Emission Development
regeneration Emission Development 6 5 4 2.5 1.2 0.5 0.2 “The technology does not exist to achieve 0.2 without regeneration”
NEAR ZERO NEAR ZERO NEAR ZERO NEAR ZERO CO Carbon Monoxide HC Hydrocarbons NOx Oxides of Nitrogen PM Particulate Matter Carbon (Soot) Regulated Emissions
99% Fewer Pollutants With EPA’10, using Selective Catalytic Reduction (SCR), we will have achieved a 99% reduction in all regulated pollutants from untreated levels. NEAR-ZERO EMISSIONS
All About Selective Catalytic Reduction • Why use SCR? • SUPERIOR fuel economy, compared to other solutions for EPA’10. Total fuel costs will be significantly reduced, even allowing for the DEF. • Improved engine performance. Less EGR needed, less heat rejection into cooling system results, greater power density, and higher efficiency. • Very little maintenance required • Reliable, proven approach (High volume production in other markets) • What additions to the truck will be included? • DEF tank, on the driver’s side. Heated. Various sizes depending on fuel capacity. Includes pump and filter. • Heated lines, pump to injector • DEF injector, mounted to today’s frame-mounted Diesel Particulate Filter • SCR catalyst, behind DPF or vertically mounted
PLAIN AND SIMPLE WITH UREA YOU SIMPLY “NUKE THE NOx” YOU CAN MAKE ALL THE ENGINE-OUT NOx YOU WANT AND NUKE IT IN THE AFTERTREATMENT YOU CAN TUNE THE ENGINE TIMING AND PRESSURE RATIOS THE WAY THEY USED TO BE AND STILL HAVE A GENUINE NEAR-ZERO EMISSION COMPLIANT ENGINE
Diesel Exhaust Fluid (Urea) • The after-treatment system utilizes an injection of a solution of urea. • Urea is a compound of nitrogen that turns to ammonia (NH3) when heated. When a urea solution is injected into the exhaust stream and passed over a catalyst, the urea reacts with the NOx to form just nitrogen and water vapor – both clean components of ‘air’. In essence, NH3 + NOx = N2 + H20
Diesel Exhaust Fluid (Urea) • The main component of DEF is an organic nitrogen-rich compound called urea. • Urea is synthesized from natural gas and carbon dioxide. • Urea is very widely used in agriculture as a fertilizer, most often distributed in wax-coated pellets. (Not a water solution) • Urea is a compound of nitrogen that turns to ammonia (NH3) when heated. • Why call it DEF? • Automotive industry wanted a generic name • What is Diesel Exhaust Fluid made from? • 32.5% urea, 67.5% demineralized water • Must be kept extremely pure • Why 32.5%? • Water solution with lowest freezing point, 12oF. • AUS32. Will also be an API standard. • The main component of DEF is an organic nitrogen-rich compound called urea. • Urea is synthesized from natural gas and carbon dioxide. • Urea is very widely used in agriculture as a fertilizer, most often distributed in wax-coated pellets. (Not a water solution) • Urea is a compound of nitrogen that turns to ammonia (NH3) when heated. • Why call it DEF? • Automotive industry wanted a generic name • What is Diesel Exhaust Fluid made from? • 32.5% urea, 67.5% demineralized water • Must be kept extremely pure • Why 32.5%? • Water solution with lowest freezing point, 12oF. • AUS32. Will also be an API standard.
Diesel Exhaust Fluid Water Diesel Exhaust Fluid Crystalline Solid Slurry 12oF Ice
So This Stuff Freezes? • DEF Freezes at 12oF. • You can walk up to a truck that has been standing over a frigid weekend and drive it away with no additional warm-up time. • A few cc’s will melt immediately due to the heat from the exhaust. • The tank heater will eventually melt the rest as you drive. • Oh, by the way – one of the other uses for urea is as a de-icer. Google it.
How Much Extra Does That Stuff Cost? • For every $1.00 of Diesel Exhaust Fluid you put in your truck with SCR technology, your diesel fuel costs will be reduced by nearly $2.00. • "The total COST of fuel PLUS Diesel Exhaust Fluid for EPA'10 will be 5% LESS than our EPA’04 engine, under similar conditions." Quick, Gimme a Buck
DEF Q&A How much Diesel Exhaust Fluid is required? • Volvo is optimizing the amount of Diesel Exhaust Fluid (DEF) to be injected for US’10 standards, but the rate will probably fall in the 2-4% range. • The more DEF, the lower the diesel fuel consumption. The less DEF, the more diesel fuel consumption. We will optimize for the lowest total cost. What will be the price of Diesel Exhaust Fluid? • According to Volvo’s information, it is estimated at about 3/4 the price per gallon of diesel fuel. The exact price will, as always, be set by the market. Can the UREA infrastructure meet the additional demand? • Easily. Globally over 100 million tons of urea were produced last year, primarily for agriculture, and also for cosmetics.
Changes for EPA’10 What about the base engine? • Base engine will only experience minor changes. • Same proven injection system • Same camshaft • Same cylinder head • Same block
EFFICIENCY vs. NOx more Efficiency, % less less more NOx Reduction, % NOx: At Odds with Fuel Economy In general, the more efficient the combustion, the higher the NOx output. The lower the NOx output, the lower the efficiency
How Have We Been Ableto Reduce NOx and Still Maintain Fuel Economy? Major improvements in NOx came with ultra high pressure fuel injection. • Higher fuel injection pressure gives finer atomization for better combustion • Shaped fuel injection delivery allows pressure rise to be controlled for best possible release of power. • Proven Delphi Dual Solenoid fuel injector used since EPA’02 now delivers 35,000 psi for EPA’07 Dual Solenoid Fuel Injector
Exhaust Gas Recirculation • The big step in the evolution of the low-emission diesel was Exhaust Gas Recirculation. Some of the exhaust gas is recycled back through the engine under certain circumstances. • The purpose of the EGR is not to ‘re-burn the exhaust’ • EGR dilutes the amount of oxygen in the intake charge. This reduces the temperature of combustion and lowers formation of NOx. EGR Cooler
D11, D13, D16 EGR Valve Hydraulic Actuator Solenoid hydraulic control valve Pressure balanced poppet design Near zero force to open, combined with powerful actuator => the valve will never stick G. W. Lisk Co., Inc.
EPA’10 Testing Experience October 2, 2007 -- FIRST FIVE EPA’10 TEST TRUCKS DELIVERED
EPA’10Testing Experience • About Twenty EPA’10 Customer Function Trucks • ~ Well Over a Million Miles • 23 SCR Evaluation Trucks since 2002 • ~ 9 Million Miles • ~150,000 SCR Euro IV and Euro V trucks globally • We know what we’re doing
Fuel EGR OBD Exhaust Outlet Diesel Exhaust Fluid Reservoir Engine Fuel Mixing zone SCR DPF Sensors: 3 Temperature sensors 1 Differential Pressure sensor 2 NOx-sensors DEF Mixing zone On Board Diagnostics (OBD)
Ready For CO2 In March, we exhibited seven CO2-Neutral trucks, each powered by a totally fossil carbon-free fuel (plus a diesel electric hybrid) at the Washington International Renewable Energy Conference (google WIREC). The message was to policymakers was, “pick the RIGHT alternative fuel for the future, and we will develop an engine for it.”
