DEF Logistics Keeps the Tractors Rolling

Dan Miller
By  Dan Miller , Progressive Farmer Senior Editor
This mobile DEF storage system helps with logistics on Seven Springs Farm in Cadiz, Kentucky. (DTN/The Progressive Farmer photo by Dan Miller.)

The introduction of Diesel Exhaust Fluid (DEF) into the nation's diesel refueling system a few years ago gave U.S. farmers the logistics challenges of buying, storing, distributing and using another liquid.

There is a lot of DEF out there. North American use is expected, by one estimate, to reach 1 billion gallons by 2019 -- most of it used by trucks, SUVs and other diesel-powered highway vehicles. But off-road use by the ag, construction and timber industries -- all dependent on long and remote supply chains -- is a large and growing source of demand.

Of course you know that DEF is injected into the exhaust stream of a diesel engine. DEF is never added to diesel fuel. It is an after-treatment applied after combustion.

DEF is a non-hazardous solution of 32.5% urea in 67.5% de-ionized water. It is clear and colorless, and looks exactly like water. It has a slight smell of ammonia. DEF is used by Selective Catalytic Reduction (SCR) technology to remove harmful NOx emissions from diesel engines.

This is accomplished when DEF is sprayed into the exhaust stream, breaking down NOx gases into nitrogen and water. New diesel trucks, pickups, SUVs, and vans are fitted with SCR technology and have a DEF tank that must be regularly refilled.

DEF must remain uncontaminated. DEF is sensitive to chemical impurities, and if it is contaminated it may cause the SCR system to malfunction. This means pumps and containers used for DEF must not be used for other fluids. It is important that tanks, pumps, hoses and nozzles previously used for other products like diesel or lube oil are not used for DEF.

All this to say that I and fellow editor Jim Patrico were interested to discover a well-executed farm designed DEF handling system at Seven Springs Farms outside Cadiz, Kentucky. The farm is managed/owned by managing partner Joe Nichols and partner Micheal Oliver.

On the day of our visit, operations manager John Croft was showing us around. And, we came upon the farm's bulk fuel trailers (seen here) sporting new stainless steel rear ends that carry DEF to the field. At 37,000 acres across eight counties, the farm needs an efficient, reasonably priced system to move a lot of DEF.

Croft had conceived of the idea to weld the 110-gallon stainless DEF storage tanks onto one end of the farm's bulk fuel tanks. He plumbed the DEF storage units with their own pumps and distribution hoses. The stainless tanks are welding into place by the welding tabs you can see here.

Certain stainless steels and plastic materials are suitable for storing DEF. Carbon steels, copper, copper-containing alloys and zinc-coated steels should not be used.

"They weren't cheap," Croft said. "But they work well."

The tanks are however, only the final piece of the Seven Springs DEF handling system.

Croft explained that the farm purchases DEF in bulk, 6,000 gallons at a time. It is stored in a tank located in what was an unused corner of an equipment shed. Now secured by walls and behind a locked door, the DEF is maintained at a fairly constant temperature by a heating and cooling system.

And, temperature is important. The shelf life of DEF is two years if the fluid temperature remains between 12 degrees F and 86 degrees F. When DEF is stored outside in bulk tanks or totes, heating and cooling must be provided.

From the bulk tank, the DEF is moved up to a new pumping unit installed as part of the farm's fueling station. The pumping station also is heated to prevent the DEF from falling below 12 degrees F in the winter.

Seven Springs Farms has put together a good, closed loop distribution storage, distribution and delivery system for its DEF needs. Better, it was designed and executed by a farmer-manager with a good idea.



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6/9/2016 | 7:03 AM CDT
DEF. Seems like anothergovernment boondoggle where the solution is more of a problem than the original ailment.