Biofuels News from Lawrence Berkeley National Laboratory

Fill 'Er Up With Tobacco? Berkeley Lab-Led Team Explores New Path to Biofuels

ARPA-E funded project aims to produce fuel molecules in plant leaves

FEBRUARY 23, 2012

Dan Krotz   dakrotz@lbl.gov

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Feature

It'll take some doing, but Berkeley Lab's Christer Jansson and others hope to create a new recipe for biofuels. The idea is to take hydrocarbon-synthesizing genes from cyanobacteria (in the flask) and introduce them into tobacco plants. Jansson will discuss the project at the Feb. 27-29 ARPA-E Energy Innovation Summit.

Mention biofuels and most people think of corn ethanol. Some may think of advanced biofuels from switchgrass or miscanthus. But tobacco? Not likely.

That could change. A team of scientists led by a researcher from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) is exploring a way to produce gasoline, diesel, and jet fuel from the iconic plant of the South.

Their goal is to engineer tobacco plants that use energy from sunlight to produce fuel molecules directly in their leaves. The leaves would then be crushed, and the fuel extracted and separated. The scientists estimate that about 1000 acres of tobacco could yield more than one million gallons of fuel.

Why tobacco? It’s grown in large tracts throughout the U.S and in more than 100 countries. It generates multiple harvests per year, its large leaves could store a lot of fuel, and it’s amenable to genetic engineering.

But before you fill up with gas squeezed from tobacco, the scientists must first get through a long checklist of pioneering research. Success could give the nation a new source of transportation fuel.

If this sounds promising—albeit a bit of a long shot—that’s by design. The $4.9 million project is funded by DOE’s Advanced Research Projects Agency-Energy (ARPA-E), which focuses on “high risk, high payoff concepts—technologies promising genuine transformation in the ways we generate, store and utilize energy.”

The project is led by Christer Jansson, a plant biochemist with Berkeley Lab’s Earth Sciences Division. He’ll discuss the project at the 3rd Annual ARPA-E Energy Innovation Summit, to be held February 27-29 near Washington, D.C.

Can tobacco leaves hold fuel molecules? An ARPA-E funded project at Berkeley Lab is taking on the challenge.

Jansson will be joined at the summit by other Berkeley Lab scientists who’re pursuing ARPA-E projects, all potential game-changers. These include a way to quickly discover materials that capture CO₂ from power plant emissions, an innovative method to produce biofuel from microbes, and the development of a low-cost flow battery for the grid that could boost the adoption of renewables.
In the tobacco-to-fuels project, Jansson and his collaborators want to create a shortcut in the way in which solar energy is converted to biofuel. Today, one approach to advanced biofuel production requires deconstructing biomass and then using microbes to ferment the resulting sugars into fuel. In contrast, the team hopes to create a plant that grabs CO₂ from the air and converts the carbon into a fuel that’s almost ready for the tank.
“We want to bypass downstream processes like fermentation and produce fuels directly in the crop,” says Jansson. “After the biomass is crushed, we could extract the hydrocarbon molecules, and crack them into shorter molecules, creating gasoline, diesel, or jet fuel.”
To get there, the scientists will work to create tobacco plants that are optimized to take in CO₂, harvest sunlight, and produce hydrocarbon molecules.
For the latter, Jansson will start with cyanobacteria genes that encode for enzymes which produce alkane, a type of hydrocarbon. He’ll then make synthetic versions of these genes that are suited for expression in tobacco. In another approach, Tasios Melis, a UC Berkeley biologist, will conduct a similar exercise with green algae genes that produce isoprenoids, another type of hydrocarbon.

These genes will be introduced into tobacco plants grown by UC Berkeley scientist Peggy Lemaux. Nuclear magnetic resonance imaging of the leaves by UC Berkeley chemist David Wemmer will enable the scientists to spot any carbon bottlenecks in the plant and refine their metabolic engineering. In addition, Cheryl Kerfeld, a scientist at DOE’s Joint Genome Institute, will search the genomes of hundreds of cyanobacteria species for other alkane-producing genes that could also prove useful.

The scientists also want to get as much carbon into the tobacco plant as possible to maximize hydrocarbon production. Ordinary tobacco “fills up” with CO₂ very quickly. To increase the plant’s carbon uptake, the team will again turn to cyanobacteria, which are very efficient at grabbing carbonate from the surrounding water and transporting it into the cell. Jansson hopes to insert cyanobacteria genes that facilitate this carbon transport into the chloroplasts of tobacco plants.

Melis and UC Berkeley scientist Kris Niyogi will also work to enhance tobacco’s use of light during photosynthesis. Melis will use a technique he developed that enables the manipulation of a plant’s light-harvesting mechanisms.

The team hopes to grow their first plant in about 18 months. Their ultimate goal is a plant in which between 20 and 30 percent of its dry weight is hydrocarbon. Promising plants will be grown in Kentucky in a pilot test overseen by the Kentucky Tobacco Research and Development Center, whose scientists will explore ways to optimize the plants’ growth and harvest conditions.

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Executive Summary; Algal Biofuels Roadmap

On December 9 and 10, 2008, the National Algal Biofuels Workshop was held in College Park, Maryland.  In May, 2010, a report based upon the workshop called National Algal Biofuels Technology Roadmap was published.  Below is the Executive Summary of the Roadmap.



"Developing the next generation of biofuels is key to our effort to end our dependence on foreign oil and address the climate crisis – while creating millions of new jobs that can’t be outsourced
— Secretary of Energy Steven Chu at the White Houseceremony on May 5, 2009, announcing $800 million in new biofuel research activities"

In recent years, biomass-derived fuels have received increasing attention as one solution to our nation’s continued and growing dependence on imported oil, which exposes the country to the risk of critical disruptions in fuel supply, creates economic and social uncertainties for businesses and individuals, and impacts our national security. The Energy Independence and Security Act of 2007 (EISA) established a mandatory Renewable Fuel Standard (RFS) requiring transportation fuel sold in the U.S. to contain a minimum of 36 billion gallons of renewable fuels, including advanced and cellulosic biofuels and biomass-based diesel, by 2022. While cellulosic ethanol is expected to play a large role in meeting the EISA goals, a number of next generation biofuels show significant promise in helping to achieve the goal. Of these candidates, biofuels derived from algae have the potential to help the U.S. meet the new RFS while at the same time moving the nation ever closer to energy independence. To accelerate the deployment of advanced biofuels, President Obama and Secretary of Energy Steven Chu announced the investment of $800M in new research on biofuels in the American Recovery and Renewal Act. This announcement included funds for the Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy’s (EERE) Biomass Program to invest in the research, development, and deployment of commercial algae-to-biofuel processes. Additional funding is being directed to algae-to-biofuel research both in EERE and other government agencies and programs.

The term algae can refer to microalgae, cyanobacteria (the so called “blue-green algae”), and macroalgae (or seaweed). Under certain conditions, some microalgae have the potential to accumulate significant amounts of lipids (more than 50% of their ash-free cell dry weight). These characteristics give great potential for an immediate pathway to high energy density, fungible fuels. These fuels can also be produced using other algae feedstocks and intermediates, including starches and sugars from cyanobacteria and macroalgae. In addition to fungible biofuels, a variety of different biofuels and products can be generated using algae precursors.

There are several aspects of algal biofuel production that have combined to capture the interest of researchers and entrepreneurs around the world. These include:

1) high per-acre productivity, 2) non-food based feedstock resources, 3) use of otherwise non-productive, non-arable land, 4) utilization of a wide variety of water sources (fresh, brackish, saline, marine, produced, and wastewater), 5) production of both biofuels and valuable co-products, and 6) potential recycling of CO2 and other nutrient waste streams.

The DOE-supported Aquatic Species Program, an effort undertaken from 1978 to 1996, illustrated the potential of algae as a biofuel feedstock. Much has changed since the end of the program. Rising petroleum prices and a national mandate to reduce U.S. dependence on foreign oil, provide environmental benefits, and create economic opportunities across the nation have renewed interest in developing algal feedstocks for biofuels production.

While the basic concept of using algae as an alternative and renewable source of biomass feedstock for biofuels has been explored previously, a scalable, sustainable and commercially viable system has yet to emerge. The National Algal Biofuels Technology Roadmap Workshop, held December 9-10, 2008, was convened by DOE-EERE’s Biomass Program. The two-day event brought together more than 200 scientists, engineers, research managers, industry representatives, lawyers, financiers, and regulators from across the country to discuss and identify the critical challenges currently hindering the economical production of algal biofuels at commercial scale.

This document represents the output from the Workshop, supporting scientific literature, and comments received during a public comment period. The Roadmap document is intended to provide a comprehensive state of technology summary for fuels and co-products from algal feedstocks and to document the feasibility and techno-economic challenges associated with scaling up of processes. This document also seeks to explore the economic and environmental impacts of deploying algal biomass production systems at commercial scale. By documenting the challenges across the algal biomass supply chain and highlighting research and coordination needs and gaps, this document will serve to guide researchers and engineers, policymakers, federal agencies, and the private sector in implementing national research, development, and deployment efforts.

In summary, the Roadmap Workshop effort suggests that many years of both basic and applied science and engineering will likely be needed to achieve affordable, scalable, and sustainable algal-based fuels. The ability to quickly test and implement new and innovative technologies in an integrated process will be a key component to accelerating progress.