One of the major items for making air cleaner is the reduction of particulate matter and (Nitrous Oxide (NOx). Most particulate matter comes from compression ignition (diesel) engines — what we run in the modern fire service today. Original #2 diesel fuels were high in Sulphur content which created copious amounts of block rolling coal soot out of the diesel truck exhaust pipes. Changing the fuel content to ultra-low Sulphur diesel (ULSD) fuels in the early 2000s helped, but still had too much particulate matter being produced and emitted to the air we all breathe.
In 2007, diesel particulate filters (DPF) were added to the exhaust systems which captured 99 percent of the soot which had to be burned off in the DPF (Regeneration/Regen) and sometimes very frequently because emergency vehicles idled for extensive periods on emergency calls. The plugging of the DPF with soot and the burning off of the soot sometimes took an hour or more and sometimes was required daily. The exhaust stream was cleaned up extensively, but then created too much NOx. The cure, induce Urea into the exhaust stream. It worked.
Uncle Ernie still wants to know what chemist came up with the idea that if you induce pig urine into the exhaust stream that it would reduce NOx.
All of these measures were required for the diesel engines running petroleum #2 diesel fuel. The instances of required regeneration of the DPF has taken a toll on emergency vehicles and their ability to respond and arrive on a call. A damaged or extensively packed DPF that cannot be recovered through regen or manual means can cost up to $20,000 to replace. More government money spent to utilize the current exhaust after-treatment systems. But, wait, the fuel market started what is known as “BioFuel” which mixes man made diesel into the diesel fuel at percentages as high as 20 percent. It worked pretty well in mild climates but failed in colder climates and required special storage.
Next to arrive on scene is what I think will be a game changer for the emergency vehicle market, government fleets and far beyond. The new diesel fuel is a fully non-petroleum diesel equivalent and is a fully “drop-in” fuel, which means that it can be dropped into the storage tanks and fully mix with the current #2 diesel fuel. The product is called “Renewable Diesel” (RD). Storage life is much extended which is a major plus for fuel storage in emergency generator sites. Because there are no petroleum-based chemicals in the fuel, there are no negative compounds coming out of the tailpipe — like Benzene, etc.
The product is crystal clear and has no odor — again no negative compounds. The term “drop-in” fuel means that it is the same as petroleum diesel but has no petroleum in the fuel. Engine manufacturers have now authorized the replacement RD fuel to replace #2 ULSD So, the question is asked: “If I utilize RD exclusively in my fleet and I send out one or more fire apparatus or other diesel-powered emergency vehicles to mutual aid calls and they require refueling, do I require the refueling be done with only RD? Answer: No, RD and petroleum diesel are compatible and readily mix. Simply return to refueling with RD upon the return of the apparatus to your agency.
Renewable Diesel is taking over the government diesel fleets and is doing so rapidly, albeit mostly on the East and West coasts. The product currently is coming in from Malaysia at the tune of a million barrels a month to supply the West coast and at the same rate from Norway/Sweden/Denmark/Holland for the East coast. If this single product can supply the government and civilian diesel fleets, much of the diesel exhaust issues will be null. A byproduct of the RD is that it will greatly impact petroleum fuel producers. On the West Coast and Gulf States, major oil companies are modifying or creating new refineries to manufacture RD. They are seeing the handwriting on the wall, so to speak.
Your firefighters and EVTs (Fire Mechanics) are happy for the results of RD. Longer time frames between regens and much less work for the fire mechanics. The big question for all involved at the end user is “Sustainability.” We shall see.
Best wishes, stay safe.