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The ABCs of DEF

Posted: August 1, 2014 by Passenger Service: State troopers ride-along with truckers in crash study

As a motto, ‘change’ has been exceptionally fashionable lately. For better or worse, it’s been used to sell just about everything from soda pop to the American presidency. And while we all know that very little reformation actually goes on in Washington — or Ottawa, for that matter — the trucking industry, instead, can boastfully say different.

Commercial vehicle manufacturers and their customers are used to change. They’ve been adapting to rapid technological upheavals to fuel and emission standards for the last 20 years — yes, sometimes begrudgingly — but they meet their targets nonetheless; even when the challenge at some points seems too technologically daunting, such as at the start of this decade when the Environmental Protection Agency (EPA)  told engine makers they had less than 10 years to virtually eliminate particulate matter and nitrous oxide (NOx) emissions from diesel engines.

We’re now quickly approaching the final chapter of that three-pronged mandate. This last round of emissions rules specifically deals with reducing NOx to just 0.2 grams per brake hp in all 2010 commercial diesels. 

It’s already been well documented that all engine manufacturers with the exception of Navistar will use selective catalytic reduction (SCR) exhaust aftertreatment to meet the "10" standard. That’s the emissions reduction solution that’s been in place in Europe and other countries for a number of years.

International Trucks, instead, will go with an updated version of cooled exhaust gas recirculation (EGR) — same as in 2007. (Cummins says it’ll use both depending on the market). 

So why the split among OEMs? Well, it depends on whom you talk to, but basically, Navistar says EGR is a much cheaper, proven system in North America, which requires no aftertreatment; specifically, Diesel Exhaust Fluid (DEF) like SCR does. That means no extra DEF tank, a lighter truck, and no dependence on drivers to routinely fill it up. 

Competitors point out that although SCR trucks will be pricier, their technology is the first since 2002 to reduce emissions while at the same time providing up to five-percent in fuel savings, unlike EGR, which once again carries a three-to-five-percent fuel-economy penalty.

Put’er There: Mack makes the best of
DEF tank real estate on vocational trucks.

Furthermore, DEF will be dosed at about two or three gallons (from on-board tanks ranging anywhere between six and 23 gallons, depending on the application) for every 100 gallons of diesel. With a 13-liter DEF tank, trucks will be set for 3,000 to 3,600 miles per fill-up.

So, although this is the first time drivers will be an active part of the emissions standard, it’s not much more burdensome than "topping up windshield washer fluid tanks," as Daimler Trucks’ Director of Infrastructure Development, David Uschwald, puts it.

And while packaging constraints can exist on some complicated vehicle layouts, truckmakers’ creative use of chassis real estate and a variety of DEF tank shapes has solved most spacing impediments apropos specialty equipment, hydraulics, or other doodads hanging off the frame.

FIRST SIGNS OF DEFNESS

Regardless, truck buyers will get their fill of this marketing war over the next 12 months, to be sure, so let’s move on to the issue of DEF as a requirement for any SCR unit.

First off, what is it? DEF as a spec is made from urea, a common ammonia-based chemical used to eliminate NOx when injected into the hot exhaust gas downstream of the diesel particulate filter (DPF).

How much it will cost in North America depends on a number of things. Right now it’s about $2.60 a gallon, but like in Europe, it can vary based on such things as production costs and the commodity price of urea. (The good news is that urea’s main raw material is natural gas, which we have an abundance of). Of course, there are all the other usual supply-and-demand nuances that are still taking shape as the production and distribution infrastructure matures here.

This latter point was the source of much anxiety once upon a time. Today, though, it seems only Navistar is expressing doubts that the supply and sales infrastructure for DEF might not be ready to meet 2010 demands.

Wanting to make sure that SCR in North America wasn’t going to be trucking’s version of the BETA cassette player, it’s natural more than a few urea makers — especially smaller niche players already doing very well in the high-margin, tight-capacity fertilizer sector — chose to sit on the fence while OEMs made up their minds whether to follow in Europe’s SCR footsteps. 

At a recent DEF summit in San Diego, Gerry Kroon of Calgary-based urea producer, Agrium Inc., said most of his product is already spoken for in agriculture and he’ll be careful before spending money to revamp plants and change logistic patterns for the DEF market.

The good news, he says, is that he has some time to react to conditions on the ground. Although the emissions deadline is Jan. 1, 2010, he doesn’t expect the market to be instantly flooded with SCR trucks until a year or two later. "(DEF) is an exciting product. Luckily, the (demand) will be gradual."

In the meantime, though, other producers are making their moves. Two of the world’s largest, Terra Environmental Technologies and Brenntag North America, recently announced a multi-year strategic alliance to supply the U.S. and Canada with TerraCair DEF.

 

Road to 0-10: All new trucks except Navistar’s will
require DEF to comply with the last round of EPA rules

Cummins Filtration is among several others also preparing for wide-scale DEF production for both commercial trucks and the passenger vehicle market, which is welcoming several SCR cars and SUVs this year. "This growing demand has already contributed to the expansion of industry capacity in time for 2010," promises David Siler of Detroit Diesel.

PUMPING UP THE VOLUME

Distribution and point of sale are slightly different animals, though, with their own unique issues, particularly in Canada.

Pilot Travel Centers and Travelcenters of America are two truckstop chains in the U.S. that are leading the way in over-the-road retail, which is especially counted on to accommodate the domicileless owner-op segment. The latter chain is committed to equipping every one of its locations with DEF pumps, while Pilot will start off with dispensers at about 100 sites. Most truckstops will at the very least offer pre-packaged, top-off or "tote" containers.

Petroleum companies are another matter. They’re said to be closely observing DEF infrastructure development, but so far the extent that retail fueling stations will be involved is unknown.

That could be somewhat concerning for some short-haul LTL carriers and package deliverers that operate almost exclusively in urban areas or around airports and whose trucks hardly see the interstate.

Doug Wertz, senior manager of Global Vehicles for FedEx, says that ideally it would be nice if trucks could operate on a single DEF fill-up between PM schedules. But since that isn’t going to happen too often, home depot DEF fueling will be a necessary solution for many fleets, including most of FedEx’s local SCR trucks, Wertz says.

Stakeholders insist such a multi-faceted supply chain strategy is essential for this "chicken and egg technology." This is especially true in Canada, where some believe the lack of a vast truckstop network and dependence on unmanned cardlocks could lead to isolated DEF shortages for some rural truckers a little too north of the 49th parallel.

David McKenna isn’t particularly concerned, though. As a former Torontonian, the Powertrain marketing manager for Mack Trucks says he spends a lot of time thinking what the impacts might be in Canada.

"Weather, weights, distances and isolated areas always spring to mind," he says. "What I see unfolding as EPA 2010 chassis hit the road, is that DEF is scalable, meaning that depending on the location and amount of DEF consumed, there will be a right-sized dispenser and system available."

If there’s a lack of retail supply in a specific region, an individual fleet’s best option is to acquire their own home depot dispensing systems, from 750-gal. Independent Bulk Containers (IBCs) to a complete ground installation — although a carrier would need to have a lot of new engines to justify the expense of the ­latter approach.

Also, McKenna and Siler both confirm that heavy truck franchise dealers in Canada, in particular, will sell DEF as stock material, including an abundance of 2.5-gal "tote" jugs which alone can carry a truck 800 miles). "Most of our dealers will supply exchange IBCs that a customer would order and a replacement will be shipped to that location, not unlike fuel or bulk lube oil today," says McKenna.

Most, if not all, North American truck models will fit the DEF tank on the driver’s side, just ahead of the fuel tank. Logically, then, it’s hoped that truckstops and fuel stations install their dispensers accordingly so drivers don’t have to adjust the truck forward or backward after filling up with diesel.

That isn’t the only wrinkle fleets are urging retailers to iron out. As Michele T. Calbi, VP of Procurement and Shop Operations for Swift Transport, points out, most facilities will start out with just one dedicated DEF lane.

She urges, then, a degree of equipment redundancy and a heightened level of vigilance in making sure dispensers work properly at all times since, depending on the area, incoming truckers relying on that location as an official DEF depot may not have another option for hundreds of miles.

With likely thousands of SCR trucks in her fleet come next year, Calbi also wants to make sure that the billing process is streamlined at the point of sale. "They have to figure out billing for DEF separate from diesel," she says. Like many carriers, she wants the two itemized separately for accounting and tax purposes, but there should only be one card swipe and transaction fee. "This is extremely important," says Calbi.

Word from fuel retailers and truckstops is that they’re working on it.

A MATTER OF ICE AND DEF

Many critics of SCR have been quick to observe that DEF can slush or "waxes" at temperatures below 12°F, a common thermo reading on a February morning in Regina. Still, winter trucking won’t come to a halt across the Prairies, assures McKenna. Upon cold starting an engine, the engine air pre heater instantly warms some ambient air, while small heater coils at the base of the DEF tank start to thaw a miniscule amount of DEF to be used as required.

"NOx is produced via very high combustion temperatures and these are not seen during cold starts," he explains. Also, each time the key is turned off, all DEF will be pumped back to the tank so lines won’t freeze.

The American Petroleum Institute is still determining a final North American spec and quality-control regulations for commercial DEF. An industry-wide certification standard and uniform labeling requirements are expected shortly.

In order to properly meet the EPA’s NOx-fighting benchmarks, these performance specifications for DEF will be strict, however.

As was the case in Europe, there will undoubtedly be a handful of folks with a lot of time on their hands who will attempt — either for profit, sheer laziness, or to save a few pennies — to "fool" the engine with homemade DEF or other grade urea.

This "bathtub DEF," as McKenna dubs it, isn’t a good idea. The Aftertreatment Control Module will recognize it via very sensitive NOx sensors monitoring the required flow of DEF and, depending on the degree of imbalance, the engine will go into a power derate.

The same goes for DEF tanks that are allowed to run empty. Flashing monitoring system gauges (which will be generally uniform among all OEMs) will indicate DEF is low; then the engine top speed will be automatically cut down to 100 km/h, and finally a "limp home" effect of about 15 clicks kicks-in.

Of course, it should never get to that point. As McKenna asks rhetorically, "why mess with DEF in the first place? DEF economy is something around 226 miles per gallon. That’s pretty good value."

 

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