The year Ed Saxman graduated university and began his first job at an OEM was the same year that the Clean Air Act was passed: 1970.
Last week, Volvo announced they’ve been building dimethyl ether (DME) powered class 8 trucks. DME is an alternative, sustainable fuel that is said to mirror diesel in performance (you can learn more about it over here). Volvo plans to start rolling trucks off the line in 2015.
And Saxman? He’s Volvo’s first Alternative Fuels guy. Today’s Trucking caught up with Saxman to talk DME, the early days of the Clean Air Act, and what has been the best emissions improving device since 1970.
The 99 Percent
TT: How’d you get started?
Ed Saxman: I was crazy about trucks since I was a kid and I joined Mack right out of college. I’ve been trucking for 43 years now. My first job was engine design. Everybody thinks of me as an engine guy, but I have more time in trucks than powertrains — but I’ve been going back and forth this whole time.
The Clean Air Act was passed that year and it was the first time that there was an effort to define how many emissions engines made — because people didn’t know! The first measurements we had were taken — and I remember being a part of that and I remember the numbers. I recently looked at the numbers and since 1970 the trucking industry, by virtue of meeting EPA ’10 emission standards, has reduced the pollutants from diesel trucks by 99 percent — each of those regulated pollutants — we’re 99 percent cleaner than we used to be. NOx for example: we were 16 in 1970, then in 2007 it went to 1.2 and then in 2010 to 0.2 and if you divide that out, it’s practically 99 percent. Our heavy-duty diesel truck emissions are near zero today and it’s an accomplishment we should all be proud of.
An Emission-Beating, Power Increasing, Fuel Saving Slam Dunk
TT: What was the biggest leap forward when it came to meeting emission regulations?
ES: The absolute single best device to improve emissions was the air-to-air chassis cooling. My first employer was Mack Trucks and I was on the design team that brought to life the first air-to-air charge air-cooled engine in the history of diesel trucks.
Let’s review air-to-air charge-air cooling. Number one: they had water-to-air or coolant-to-air earlier. And air coming out of a turbo is, let’s say 350 degrees fahrenheit, so you need to reduce that temperature to reduce emissions. Now let’s say a typical coolant number is 180 — what do you think you can get the air down to using a 180-degree coolant to cool 350 degree air? Someplace in the middle, let’s say 240. So if you use air, which is, say, 70… Ah! Better! Our first execution at Mack brought it down to about 150, and that was an engine mounted charge-air-cooler and it was the industry’s first.
Later, I joined Volvo. Volvo happened to be the first with an air-to-air charge-air-cooler in the United States that was mounted on the radiator. That was in 1978 with the F7 model. It was a simple “radiator in front of the radiator,” if you will. That design reduced the air down to 110 into the engine, which was even better.
So what does air-to-air do? Number one, we found in those early months that you can lower the NOx emissions by reducing the combustion temperature. NOx happens whenever you get nitrogen really, really hot. Normally, nitrogen is inert and it won’t burn except in lightning storms and if you get air really, really hot. Trace amounts of nitrogen combine with oxygen to form the chemicals NO or NO2 or NO3. If you cool down that temperature, then you reduce those emissions. Air-to-air does that, it makes it cooler, and so we reduced NOx.
Number two, because it chills the air, making it more dense, it allows you to put more oxygen in and that allows you to put more fuel in — Aha! Now we have a power increase!
Number three, it puts less stress on the engine because it reduces peak combustion pressure because the temperatures are down, so you can have more power with less stress to the engine, and number four, it improves the efficiency of the engine.
So let’s see: you get lower NOx, more power, less stress and better fuel economy. Wow. What a slam dunk! And today, every single turbo-charged engine, whether it’s in a pick-up or a heavy-truck, has air-to-air charge-air-cooling.
So that was cool, now what are you going to do for an encore? Well, unfortunately, that was the best and every incremental thing we’ve done to reduce emissions has been less effective. But that was pretty good, and that was number one.
Hand-Made Fuel Injectors and Smashing Down Molecules
TT: What are the challenges going forward with DME?
ES: The one big thing we have to change on the engine is the fuel injection system, primarily to increase it’s flow rate; it’s pumping gallons, not DGE (diesel gallon equivalent) — DGE is the amount of energy — and to get a DGE we have to get as twice as much fuel in terms of liters. So that means a bigger fuel injection system. That’s not a technical challenge, it just needs to be designed, and there also needs to be investment made. The products that we had at the DME event last week were put together from test equipment that was literally hand-made in many instances. It works, but is in no means representative of a final design. Now we have to do that — that’s why we said 2015.
One of the benefits of the injection of DME is we don’t need to have the ultra-high pressure injection that we do to obliterate diesel fuel and try to smash down the molecules. DME is already a molecular gas — you can’t do it any better than it already is. So injection pressure will be a small fraction of where we are today and that’s a pretty easy system to design.
Other than that, we have to do a production design for the fuel tanks. We need to work with suppliers and tweak it with different lengths and widths to make sure we got the design right — but that’s not a major challenge either. So you can see there’s no big obstacle to making a truck that burns DME.
TT: If you could go on a long-haul with anyone living or dead, who would it be?
ES: I think if you look at the growth of industry, trucking is an area where, over the years — within the span of a single generation — you’ve had countless times where an individual is able to start out as a small entrepreneur and grow his business to the point where he employs hundreds or thousands. That’s who I would like to meet: somebody who has nurtured his company like a family; somebody who has developed a business that employs a lot of people, that provides a lot of sustenance for a lot of families and provides a lot good for the country, for the GDP. That kind of guy — I would like to just talk about his experiences and what he’s enjoyed doing as this industry’s evolved during his period of 50 or so years behind the wheel.
Ed Saxman was appointed Volvo Trucks marketing product manager for alternative fuels in January 2013. Saxman has been employed in the heavy-duty truck industry for 43 years. He joined Volvo Trucks in 1983 and has held a variety of positions within the company’s product planning and marketing departments. He is a graduate of the University of Pittsburgh and holds a degree in mechanical engineering.
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