On cars, old, new and future; science & technology; vintage airplanes, computer flight simulation of them; Sherlockiana; our English language; travel; and other stuff
WHEN BILL MITCHELL, LARRY BURNS, AND CHRIS BORRONI-BIRD proposed mobility for this century, they envisioned a vehicle mix with propulsion depending upon size and distance.
Based on range and infrastructural constraints, Battery Electric Vehicles occupy the small size/short distance corner of the matrix. Hybrid Electric Vehicles and Plug-in Hybrids fill the midsection. For the largest size and longest distances, the optimal choice is Fuel-Cell Electric Vehicles.
These days, much of the hype and government push is on BEVs, with predictions that they’ll dominate the market by 2030, if not before. However, range, infrastructure—and time spent at the latter—still give credence to that upper right of the Mitchell/Borroni-Bird/Burns graphic.
Here in Parts 1 and 2 today and tomorrow are tidbits gleaned from a variety of sources, particularly on fuel-cell trucking.
Background. “If you got it,” the adage goes, “it got there by truck.” And, for one step or another of the process, this still holds true (despite depictions of neighborhood airspace filled with delivery drones).
“Fuel-Cell Trucking,” SimanaitisSays, September 2, 2016, discussed emissions-free semis having 1200-mile range. And, compared to battery recharging times, FC trucks have relatively quick fillups on par with diesel replenishment—once the hydrogen infrastructure is in place.
Elon Musk has twitted “Fuel cells = fool cells.” Others note progress is being made in exploiting this particular niche of the size/distance matrix.
Hydrogen Sourcing. Though hydrogen is the most common element in the universe, it is also among the most promiscuous. Hydrogen is produced commercially primarily from natural gas (48 percent), oil (30 percent), and coal (18 percent). Each of these breaks up hydrogen’s carbon romance, albeit freeing the latter to its environmental detriment.
The remaining four percent results from electrolysis, a process practiced by anyone taking a secondary school science class: Electricity splits water, H2O, into hydrogen and oxygen.
Efficiency of Production. Wikipedia notes, “Electrolysis of water is 70–80% efficient (a 20–30% conversion loss) while steam reforming of natural gas has a thermal efficiency between 70 and 85%.”
Hydrogen—Green or Blue. Electrolysis produces “green” hydrogen—but only if its required electricity comes from a renewable source. Otherwise, for example, coal-sourced electrolytically generated hydrogen fueling an FC semi may be no better source-to-wheel than its diesel counterpart. (Earlier research has shown that a BEV charged with coal-produced electricity is inferior, source-to-wheel, to its state-of-the-art gasoline-fueled counterpart.)
The term “blue” hydrogen describes steam reformation of methane, a component of natural gas, in which the byproduct carbon dioxide and other impurities are sequestered. This sounds like a good idea—especially because today methane is often flared at refinery stacks.
This time, the challenge focuses on source-to-tank, the to-wheel portion being a fuel cell cinch: Its efficiency exceeds 60 percent (versus internal combustion’s 20-35 percent); its emission is the purest of water.
Tomorrow in Part 2, the research continues: One study says blue isn’t all that green. Others describe cooperative efforts to keep on truckin’ with H2.
© Dennis Simanaitis, SimanaitisSays.com, 2022