Food or fuel... or tequila!

Food or fuel?  When the price of gasoline in the United States rose dramatically, speculation in potential bio-fuel sources led to serious corn shortages in Mexico, a dramatic rise in the price of tortillas and other staples and social unrest.  Corn based bio-fuels would lessen (and do lessen) dependence on oil, but at the cost of diverting a food crop into the energy sector.

For Mexico, where there is still plenty of oil for domestic use, although, having exported oil since the 1880s, there is less and less oil available for export, and balancing domestic needs with the revenue generated by the state oil company, PEMEX, has massive implications for the country’s future.  At the same time, the domestic automotive industry, as well as changing social habits have led to an explosion in the number and availability of private cars.  Which, of course, means more air pollution, GHG or “Greenhouse gas” in science-speak, and the need for clean-burning gasoline.  PEMEX, not having the refining capacity to meet domestic needs, has for a number of years been leasing a refinery in Texas, and re-importing its own oil at a significant cost to the Mexican treasury.

Researchers have recently suggested a possibly workable solution:  tequila.  Well, agave specifically, but — as reported in an article in Energy and Environmental Science — as a agave-derived ethanol provides better energy output than most other bio-fuel sources, much more than corn (the usual source of U.S. ethanol) but less than sugar-cane.  While sugar-cane is a better source, it requires a tropical climate, and where it is grown, it competes with food crops for land use and water resources.  Agave has traditionally been raised in dry climates, often on marginal desert land that is unsuited for other agricultural products.

Xiaoyu Yan, Daniel K. Y. Tan, Oliver R. Inderwildi, J. A. C. Smith and David A. King, in “Life cycle energy and greenhouse gas analysis for agave-derived bioethanol” write:

Agaves are attracting attention as potential ethanol feedstocks because of their many favourable characteristics such as high productivities and sugar content and their ability to grow in naturally water-limited environments… The results suggest that ethanol derived from agave is likely to be superior, or at least comparable, to that from corn, switchgrass and sugarcane in terms of energy and GHG balances, as well as in ethanol output and net GHG offset per unit land area.

The researchers found that the higher the quality agave, the higher the energy production. And what, and where, does the highest quality agave come from?

Tequila in your tank?