Slashdot Mirror
MIT Says We're Overlooking a Near-Term Solution To Diesel Trucking Emissions (arstechnica.com)
Despite efforts from Tesla, Daimler, Nikola and Siemens to reduce emissions from heavy-duty, diesel-powered trucks, either by producing their own electric- or hydrogen-powered alternatives, "trucking in the U.S. is still driven by diesel-fueled, compression-ignition (CI), internal combustion engines," reports Ars Technica. According to a new paper from MIT researchers, "the best way forward is not to wait for all-electric or hydrogen-powered semis, but to build a plug-in hybrid electric (PHEV) truck with an internal combustion engine/generator that can burn either gasoline or renewable ethanol or methanol." From the report: Such a setup preserves the range and affordability that's expected of diesel long-haul trucks while significantly reducing the emissions associated with diesel. To boot, it's a near-term solution; no waiting for battery weight to fall or hydrogen refueling stations to be installed. [T]here are some distinct problems with all-electric and all-diesel trucks that a hybrid flex-fuel truck could solve. First, freight companies are looking for the cheapest way to transport goods from point A to point B, so expensive electric vehicles don't make short-term economic sense, especially if you're competing with other freight companies using cheaper diesel engines.
Using flex-fuel gasoline-alcohol engines has also been shown to reduce nitrogen oxide emissions by 90 percent, the MIT researchers wrote, if the emissions reduction system on the truck uses a three-way catalyst (TWC) instead of the diesel-focused selective catalytic reduction (SCR). (The paper notes that this isn't theoretical. A 90-percent reduction in tailpipe NOx from diesel has already been achieved in light-duty gas vehicles and in the heavy-duty Cummins Westport 9 liter natural gas engine.) A flex-fuel gasoline-alcohol engine could also help freight companies achieve "both the lowest air pollution and lowest greenhouse gas emissions when the internal combustion engine operates," the paper notes. In addition, "the relative use of battery power, gasoline power, and alcohol power can be optimized for meeting varying prices and availability of these energy sources as a long-haul truck travels through various regions."
Using flex-fuel gasoline-alcohol engines has also been shown to reduce nitrogen oxide emissions by 90 percent, the MIT researchers wrote, if the emissions reduction system on the truck uses a three-way catalyst (TWC) instead of the diesel-focused selective catalytic reduction (SCR). (The paper notes that this isn't theoretical. A 90-percent reduction in tailpipe NOx from diesel has already been achieved in light-duty gas vehicles and in the heavy-duty Cummins Westport 9 liter natural gas engine.) A flex-fuel gasoline-alcohol engine could also help freight companies achieve "both the lowest air pollution and lowest greenhouse gas emissions when the internal combustion engine operates," the paper notes. In addition, "the relative use of battery power, gasoline power, and alcohol power can be optimized for meeting varying prices and availability of these energy sources as a long-haul truck travels through various regions."
It's been a while since we had a both-on-the-front-page dupe!
They use diesel because it is considerably more efficient. All this would accomplish is to make a truck that is very expensive and uses a less efficient engine, while also requiring it to be plugged in and charged in order to reach its full potential. I find it highly unlikely that would actually happen.
MIT REALLY want to make sure we don't overlook this near term solution.
Shipping companies are only interested in cost and getting the jobs done.
Environmentalists will only accept zero emissions because "we only have 12 years left" (5 months ago).
There's no constituency for half measures and no tolerance for disagreement.
As a former diesel mechanic, I would greatly prefer not to have large gasoline tanks hanging off the side of semi trucks. Gasoline is much easier to ignite and burns more vigorously than diesel. Fuel tanks are frequently damaged in accidents, by tire failure, or by road debris. A switch to gasoline means that people will die by fire if this change occurs.
Walmart is leading on electric, with huge turbines at many DCs they want to power trucks for local runs. Long haul takes hybrid.
I can tell you from driving rigs there are two elephants in the room on waste: 1) idle time 2) wasted kinetic energy. 1 You need to decouple AC & heat from engine, and have it powered through mandated electric plugs at truck stops selling kWh for profit, to save $30 a night per truck in idle fuel. 2 is huge, itâ(TM)s shocking to drive hundreds of miles at 9.2 mpg (at 40 tons) on i5 nb in CA, only to watch your avr mpg for the *whole trip* drop to 6.1 when you get into the mountains. Money bleeding through jake brake that could be saved with Prius style regenerative braking.
The real model you need is something like an 10 liter diesel (shrunken from 12-15 normal size but able to drive) plus electric with maybe 90 miles of range on its own, but mostly doing torque assist and regenerative braking.
-The art of programming is the pursuit of absolute simplicity.
Why not focus on transcontinental hyper-loop shipping lanes.
High costs to build out the infrastructure, maybe? This is a proposal that can be adopted now as opposed to 10-15 years from now. Why should we let the perfect be the enemy of the good?
'He who has to break a thing to find out what it is, has left the path of wisdom.' -- Gandalf to Saruman
I've always wondered why no one has ever successfully tested a hybrid turbine-electric system for large trucks. It would seem as if the ability to burn almost anything would future-proof the system, and since the turbine would charge the batteries, you could run it at a constant speed.
Make love, not reality television.