Tag: biofuel

Iowa Moonshine: The Sordid History of Ethanol Mandates

In recent years, politicians set impossibly high mandates for the amounts of ethanol motorists must buy in 2022 while also setting impossibly high standards for the fuel economy of cars sold in 2025.  To accomplish these conflicting goals, motorists are now given tax credits to drive heavily-subsidized electric cars, even as they will supposedly be required to buy more and more ethanol-laced fuel each year.  

Why have such blatantly contradictory laws received so little criticism, if not outrage? Probably because ethanol mandates and electric car subsidies are lucrative sources of federal grants, loans, subsidies and tax credits for “alternative fuels” and electric cars.  Those on the receiving end lobby hard to keep the gravy train rolling while those paying the bills lack the same motivation to become informed, or to organize and lobby. 

With farmers, ethanol producers and oil companies all sharing the bounty, using subsidies and mandates to pour ever-increasing amounts of ethanol into motorists’ gas tanks has been a win-win deal for politicians and the interest groups that support them and a lose-lose deal for consumers and taxpayers.

A Diatom’s Response to Three Levels of CO2

Phaeodactylum tricornutum is a marine diatom that is also a potential alternative energy source due to its high growth rates and lipid (fat) content, the latter of which – according to Wikipedia  – constitutes about 20 to 30 percent of total dry cell weight under standard culture conditions. Given as much, this species is of interest to scientists, such as the seven-member research team of Wu et al. (2015), who recently conducted an experiment to determine how this potential biofuel responds to different levels of atmospheric CO2. More specifically, the group of Chinese researchers studied the response of P. tricornutum to three levels of CO2 (150, 350 and 1500 parts per million (ppm)) over a period of seven days. 

For comparative purposes, a CO2 concentration of 150ppm is around the threshold value required to sustain plant growth on this earth. We came perilously close to this at the nadir of the last ice age. 350ppm is the concentration from a quarter-century ago (we’re around 400ppm now) and 1500ppm is quite a bit higher than even the most optimistic forecasts can get it to around 2100.

And what did they learn? As shown in the figure below, diatom growth rates rose with the level of CO2 treatment. The growth at 350 and 1500 ppm treatments were approximately 70 and 192 percent greater than that observed in the lowest CO2 treatment (150 ppm). And those values may be conservative, given that growth rates at the two higher CO2 concentrations appear to still be rising at the end of the experiment on day 7 (i.e., the green and red lines have not peaked). Similar trends were seen in culture dry weights, where the mean dry weight values reported for the medium and high CO2 treatments were 31 percent and 195 percent greater than in the low CO2 treatment. Lastly, lipid content, expressed as a percent of dry cell weight, amounted to 33, 36 and 54 percent in the 150, 350 and 1500 ppm treatments, respectively.

In discussing their findings, Wu et al. note their results are “consistent with numerous previous studies that higher levels of CO2 support higher growth rates.” And, they further demonstrate the possible viability of using P. tricornutum as a biofuel, which many persons today consider an added benefit.



Wu, S., Huang, A., Zhang, B., Huan, L., Zhao, P., Lin, A. and Wang, G. 2015. Enzyme activity highlights the importance of the oxidative pentose phosphate pathway in lipid accumulation and growth of Phaeodactylum tricornutum under CO2 concentration. Biotechnology for Biofuels 8: 78, DOI 10.1186/s13068-015-0262-7.

Bootleggers & Baptists, a Welcome Correction

In my recent “Bootleggers & Baptists, Sugary Soda Edition” post, I wrote that environmentalists and agribusiness team up to support ethanol subsidies. An alert Cato@Liberty reader writes to my colleague Jerry Taylor:

[Cannon] is no doubt right that environmentalists and agribusiness worked together to promote government subsidies to ethanol through about 2006. But by 2007 (when the ethanol mandate was doubled) the environmentalists had dropped out of the pro-ethanol coalition, to be replaced by national-security hawks! If you run into him, please tell him to stop blaming environmentalists for current biofuels policies!

If environmentalists have recently dropped their support for ethanol subsidies, they deserve credit for that. Mea culpa.

I would rather have been completely wrong about the environmentalists’ support for ethanol subsidies. But I’ll settle for being partly wrong.