Thoughts from a cellulosic ethanol agnostic
“If America can win a race to the moon, we can win a race for a battery,” Bill Clinton said last night on TV, stumping for Hillary. He also pointed out that if our cars got 100 mpg, the rise in fuel prices — which is inevitable — will have a much smaller economic impact. In short, he thinks America needs to get its shit together and start leading the world again with innovation.
Easier said than done, in my opinion. We seem to be going backwards at present. All three of the remaining presidential hopefuls claim to be big supporters of corn ethanol.
Keep in mind that there is no such thing as commercially produced cellulosic ethanol, so the following is based on an assumption that may never come to fruition. Imagine for a moment that the picture to the right, a power plant being fed a continuous supply of coal, is instead a cellulose ethanol refinery, and instead of coal in those cars, you have cellulose.
Now, instead, assume it is a power plant again, but keep the cellulose in the train cars.
There have been plenty of tests that burn biomass in coal-fired power plants. It works fine and would be mostly carbon neutral. The only reason we don’t burn cellulose in them today is because the cost of growing, harvesting, and shipping this bulky substance can’t compete with coal, which is energy-dense and comes from a hole in the ground.
My point here is that the cost of transport will be similar for cellulosic fuel … except that cellulosic ethanol refineries would also have to build new rail lines from scratch, and 80 percent of the energy in that liquid fuel will be lost as waste heat moving a car.
OK, switch your mental image back one more time to the biofuel refinery, and put the coal back into the train cars. The Nazis made diesel fuel from coal with the Fischer-Tropsch process, and South Africa does it presently. It is a tried and true technology, but unfortunately it retains all the disadvantages of coal.
- Power plant using coal
- Biofuel refinery using cellulose
- Power plant using cellulose
- Biofuel refinery using coal
Let’s assume we finally have a price on carbon. Suddenly, coal isn’t the cheapest thing going, which possibly makes burning biomass cost competitive. But wait — the cellulose refineries want that biomass, too. Who gets it? Power plants or fuel refineries?
Coal is more carbon intensive than oil. Coal is our major contributor of greenhouse gases. Who should get it? There isn’t anywhere near enough cellulose to meet our liquid fuel consumption, let alone our other energy requirements.
Increase the efficiency of transport by a factor of four and the price of liquid fuel can increase to $14 a gallon without impacting your budget (the Prius was a factor of two). With efficiencies like that, we will be using four times less liquid fuel, and even converting coal to liquid (which I’m not suggesting we consider) would release about three times less carbon than our cars today. That would (in theory) spread our oil use out for something like 200 years and free up our limited biomass (cellulose) to help the other renewables displace coal’s CO2 footprint.
Humanity must make radical advances in energy efficiency and find ways to stay happy using much less energy. The internal combustion car was a creature spawned by dirt-cheap liquid fuel. It will soon become history. This idea that we will simply displace gasoline and diesel with ethanol and biodiesel in today’s cars is a short-sighted and destructive distraction. The biofuels being produced with today’s technologies and methodologies, with a few minor exceptions, are even worse than fossil fuels for global warming and are also directly exacerbating the biodiversity extinction event.
We will always have need of liquid fuels, of course, but we will have to stop squandering it in cars. It won’t be a voluntary thing, either. We will get around mostly on electrified transport. A tank of liquid fuel may be in many vehicles, but it will be treated like liquid gold — something you use only when a battery poops out or you need more range for a short burst. Driving more than, say, 100 miles a day will be something that will need extra budgeting. How many of us drive more than 100 miles in a day, and how often do we do it? How hard would it be to rent a liquid-fueled vehicle for a vacation or road trip? How many people who do live in their cars will find a way not to?
We only have about 50 years of oil left, give or take a decade or two. But one thing is certain: the price is only going up. The priority should not be to find ways to replace it in our cars. The priority should be finding ways to reduce liquid fuel use by a factor of least three or four … or more.
A comment made in a post by James Hansen has been sitting in the back of my mind:
Available oil reserves will be exploited eventually, regardless of efficiency standards on vehicles, and the CO2 will be emitted to the atmosphere. The climate effect of oil is nearly independent of how fast we burn the oil, because much of the CO2 remains in the air for centuries … the point is this: oil will not determine future climate change. Coal will.
This argument rests on the assumption that all oil will be burned in the next fifty years or so. However, if it gets expensive enough, and if we can increase transport efficiency fourfold, we may be leaving most of it in the ground for centuries. Cellulosic biofuels, should they ever arrive, may well be competing with power plants for biomass in the future, hobbling our efforts to displace coal. But the biggest danger is that we will begin coal-to-liquid conversion once oil prices make it economically competitive, which would be worse than burning coal in power plants.
I repeat: The priority should be finding ways to reduce liquid fuel use by a factor of least three and finding ways to displace coal. This emphasis on finding biofuel substitutes for oil is a short-sighted and counterproductive distraction.