Life Cycle Analysis, International Land Use Change and Uncertainty

Bruce Dale, University Distinguished Professor of Chemical Engineering at Michigan State University, shared this presentation that he gave during a webinar hosted by the North Central Bioeconomy Consortium. In it, he highlights the number of factors in Life Cycle Analysis and Indirect Land Use Change (ILUC) models that produce uncertainty – in other words, if the assumptions or data for these factors change, how much do the results change.

Dale is primarily examining the “carbon debt” concept that was introduced in the February 2008 Science papers by Searchinger and Fargione/Tilman. Dale argues that those papers failed to take into account how land converted to crop production might be managed. Dale recently submitted a paper to Environmental Science and Technology, testing the effect on land use change emissions if crop production is managed in a sustainable manner:

Sustainable cropping management practices (no-till and no-till plus cover crops) reduce the payback period to 2 years for the grassland conversion case and to 14 years for the forest conversion case. It is significant that no-till and cover crop practices also yield higher soil organic carbon (SOC) levels in corn fields derived from former grasslands or forests than the SOC levels that result if these grasslands or forests are allowed to continue undisturbed.”

Aside from assumptions about land management, life cycle analysis can be affected dramatically by changes in the amount and kinds of energy used in the biorefinery. American Fuels recently posted a note about some forthcoming research on the energy balance of biofuel production:

University of Nebraska at Lincoln researcher Kenneth Cassman concluded in a upcoming study that ethanol production has become more energy efficient.
‘Recent research conducted at the University of Nebraska clearly shows that estimates for the energy balance of corn-based ethanol are much more favorable – in fact two to three times more favorable, than previous estimates.'”

Since energy inputs are such a large factor in biofuel production, improvements in efficiency will significantly reduce the life cycle greenhouse gas emissions of biofuels when compared to gasoline.

Chemurgy Is Back with a Vengeance

The Economist recently published two stories that succinctly make the case for continuing to reduce our reliance on oil. The more recent story outlines the use of industrial biotechnology for plastics, and another earlier story details research and development of biotech fuels that go beyond ethanol.

In “Better Living Through Chemurgy,” reporter Vijay Vaitheeswaran compares today’s industrial biotechnology companies with the chemurgy movement of Henry Ford, who sought to make cars and fuels from agricultural products, and George Washington Carver, who developed hundreds of industrial uses — paints, dyes, glues — for peanuts, sweet potatoes, and other crops that would diversify the cotton-dominated agricultural economy of the South. What’s new today, according to Vaitheeswaran, is

Advances in bioengineering, environmental worries, high oil prices and new ways to improve the performance of oil-based products using biotechnology have led to a revival of interest in using agricultural feedstocks to make plastics, paints, textile fibres and other industrial products that now come from oil.”

Why replace oil with agriculture?

The big advances in oil-based polymers happened decades ago, whereas the number of patents granted for industrial biotechnology now exceeds 20,000 per year. Such is the pace of innovation, says Tjerk de Ruiter, chief executive of Genencor, a industrial-biotech firm that is now a division of Denmark’s Danisco, that processes that once took five years now take just one. And Steen Riisgaard, the boss of Novozymes, insists that new technologies can indeed push old ones out of the way, provided they are clearly superior (and not just greener).

In an article just a week prior to Vaitheeswaran’s, reporter Geoff Carr surveyed the landscape of biotech fuels that are coming in the near future, in an article called, “Grow Your Own.” Carr calls an announcement by Amyris and Brazil’s Crystalsev to develop a new form of biotech diesel a parable about how “biotechnology may have cut its teeth on medicines, but the big bucks are likely to be in bulk chemicals. And few chemicals are bulkier than fuels.”

All parts of the chain of developing biofuels — feedstocks such as grasses, trees and algae, transformation of feedstock to sugar, and fermentation of the sugar into chemicals and fuels — are “the subjects of avid research and development,” according to Carr.

Carr concludes, “If America wants it, biofuel autarky looks more achievable than the oil-based sort.”