On Making Diesel from Coal Pt. 3
Change of subject, briefly. We have buried you in basic chemistry; here is the refresher: adding oxygen to stuff is burning it (oxidation); taking carbon into living systems and using it to store energy, adding hydrogen to it, is reduction. Reduction is storing energy; oxidation is releasing it. Coal seams and oil deposits and trees are concentrated reservoirs of stored (reduced) energy. Making a 2 x 4 is a very effective form of carbon sequestration. Building a bonfire, burning gasoline in that Ferrari, or firing a coal power plant; those are all forms of oxidation. Burning Rome was a bit of uncontrolled oxidation.
Now we finally get to the point which started this discussion; my ex-Montana enviro dude buddy who is upset because the Montana Democratic Gov. Schweitzer, a farmer/policy wonk, wants to build coal-to-diesel plants in eastern Montana. Enviros recoil in horror; this would mean digging up coal (messy), building huge factories (boom towns), luring farmers to better-paying jobs (well at least they can afford to keep the farms), offending the Northern Cheyenne tribe, and seducing state government into relying on mineral-based revenues instead of service jobs and income taxes on waitresses.
Back to chemistry: making diesel from coal means breaking down the long solid carbon chains in coal into methane, removing many of the impurities, and recombining the methane into longer chain C=C=C=C=C etc., molecules, which become diesel. Each step takes energy, which emits CO2. Burning the diesel generates more CO2.
Everything you do, from breathing to farting to trucking to heating, uses carbon and emits CO2. (Farting, whether by cows, pigs, penguins or polar bears, also emits methane, another greenhouse gas.)
If you don’t want CO2, use hydro, nuclear, wind and solar to break water into oxygen (O2) and hydrogen (H), then fuel trucks and trains with H, and replace cars with bicycles and skateboards, and hold conferences via internet instead of traveling. Generate power for refrigerators, high-rises, computers, lights, etc., with similar no-emissions technology. Of course, the capital costs to build enough capacity to meet such staggering loads is beyond the zeros in my calculator. I actually have a concrete and steel base in my back yard for a wind generator; for another $15,000 I can build a big enough generator to fire my electric baseboard heaters, sometimes; it would run some lights and maybe the refrigerator. The capital cost would never be recovered.
There are no free lunches. It takes large energy inputs to convert coal to clean energy, to build wind and solar generators, to clean up pollution and to make ethanol and bio-diesel. All of those things involve CO2 emissions.
My friend: True enough. But the coal liquefaction agenda is very disturbing.
I do not know why it is disturbing. Coal contains long-chain carbon molecules and impurities. The process rearranges the carbon chains and removes the impurities.
My friend: Despite the wishful thinking, it’s a dirty and expensive technology, not to mention the hazards coal mining itself poses to human life and the environment.
The process is not dirty. It is expensive, but wind, solar, CO2 injection, etc., are all expensive. Coal mining is less dangerous in the West than oil exploration and most other industrial activity, including driving on highways. Strip mines producing hundreds of millions of tons of coal have one or two lost time accidents per year; fatalities are extremely rare. But al of these activities generate CO2.
Next: we need to quantify these inputs and outputs. It is time to move beyond concepts and put numbers to these processes.