There’s an old saying in the biofuels industry: “You can make anything from lignin except money.” But now, a new study may pave the way to challenging that adage. The study from the Energy Department’s National Renewable Energy Laboratory (NREL) demonstrates a concept that provides opportunities for the successful conversion of lignin into a variety of renewable fuels, chemicals, and materials for a sustainable energy economy.
“Lignin Valorization Through Integrated Biological Funneling and Chemical Catalysis” was recently published in the Proceedings of the National Academy of Sciences. The NREL-led research project explores an innovative method for upgrading lignin.
The process for converting glucose from biomass into fuels such as ethanol has been well established. However, plants also contain a significant amount of lignin – up to 30 percent of their cell walls. Lignin is a heterogeneous aromatic polymer that plants use to strengthen cell walls, but it is typically considered a hindrance to cost-effectively obtaining carbohydrates, and residual lignin is often burned for process heat because it is difficult to depolymerize and upgrade into useful fuels or chemicals.
“Biorefineries that convert cellulosic biomass into liquid transportation fuels typically generate more lignin than necessary to power the operation,” NREL Senior Engineer and a co-author of the study Gregg Beckham said. “Strategies that incorporate new approaches to transform the leftover lignin to more diverse and valuable products are desperately needed.”
Although lignin depolymerization has been studied for nearly a century, the development of cost-effective upgrading processes for lignin valorization has been limited.
In nature, some microorganisms have figured out how to overcome the heterogeneity of lignin. “Rot” fungi and some bacteria are able to secrete powerful enzymes or chemical oxidants to break down lignin in plant cell walls, which produces a heterogeneous mixture of aromatic molecules. Given this large pool of aromatics present in nature, some bacteria have developed “funneling” pathways to uptake the resulting aromatic molecules and use them as a carbon and energy source.
This new study shows that developing biological conversion processes for one such lignin-utilizing organism may enable new routes to overcome the heterogeneity of lignin. And, that may enable a broader slate of molecules derived from lignocellulosic biomass.
“The conceptual approach we demonstrate can be applied to many different types of biomass feedstocks and combined with many different strategies for breaking down lignin, engineering the biological pathways to produce different intermediates, and catalytically upgrading the biologically-derived product to develop a larger range of valuable molecules derived from lignin,” Beckham said. “It holds promise for a wide variety of industrial applications. While this is very exciting, certainly there remains a significant amount of technology development to make this process economically viable.”
A patent application has been filed on this research and NREL’s Technology Transfer Office will be working with researchers to identify potential licensees of the technology.
In addition, researchers from NREL participated in a recent review on lignin valorization published in Science Magazine. This review highlighted the broad potential for manufacturing value-added products from lignin, including low-cost carbon fiber, engineering plastics and thermoplastic elastomers, polymeric foams and membranes, and a variety of fuels and chemicals all currently sourced from petroleum.
The work reported in PNAS initially was financed by the National Advanced Biofuels Consortium via funds from the American Recovery and Reinvestment Act; continuing core project support was provided by the Energy Department’s Office of Energy Efficiency and Renewable Energy.
NREL is the U.S. Department of Energy’s primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for the Energy Department by The Alliance for Sustainable Energy, LLC.
What GAO Found
To develop the 2010 and 2013 social cost of carbon estimates, the Office of Management and Budget (OMB) and Council of Economic Advisers convened and led an informal interagency working group in which four other offices from the Executive Office of the President (EOP) and six federal agencies participated. Participating agencies were the Environmental Protection Agency (EPA) and the Departments of Agriculture, Commerce, Energy, Transportation (DOT), and the Treasury. According to several working group participants, the working group included relevant subject-matter experts and the agencies likely to use the estimates in future rulemakings. According to OMB staff, there is no single approach for convening informal interagency working groups and no requirement that this type of working group should document its activities or proceedings. However, OMB and EPA participants stated that the working group documented all major issues discussed in the Technical Support Document, which is consistent with federal standards for internal control. According to the Technical Support Document and participants GAO interviewed, the working group’s processes and methods reflected the following three principles:
Used consensus-based decision making. The working group used a consensus-based approach for making key decisions in developing the 2010 and 2013 estimates. Participants generally stated that they were satisfied that the Technical Support Document addressed individual comments on draft versions and reflected the overall consensus of the working group.
Relied on existing academic literature and models. The working group relied largely on existing academic literature and models to develop its estimates. Specifically, the working group used three prevalent academic models that integrate climate and economic data to estimate future economic effects from climate change. The group agreed on three modeling inputs reflecting the wide uncertainty in the academic literature, including discount rates. Once the group reached agreement, EPA officials—sometimes with the assistance of the model developers—calculated the estimates. All other model assumptions and features were unchanged by the working group, which weighted each model equally to calculate estimates. After the academic models were updated to reflect new scientific information, such as in sea level rise and associated damages, the working group used the updated models to revise its estimates in 2013, resulting in higher estimates.
Took steps to disclose limitations and incorporate new information. The Technical Support Document discloses several limitations of the estimates and areas that the working group identified as being in need of additional research. It also sets a goal of revisiting the estimates when substantially updated models become available. Since 2008, agencies have published dozens of regulatory actions for public comment that use various social cost of carbon estimates in regulatory analyses and, according to working group participants, agencies received many comments on the estimates throughout this process. Several participants told GAO that the working group decided to revise the estimates in 2013 after a number of public comments encouraged revisions because the models used to develop the 2010 estimates had been updated and used in peer-reviewed academic literature.
Why GAO Did This Study
Executive Order 12866 directs federal agencies to assess the economic effects of their proposed significant regulatory actions, including a determination that a regulation’s benefits justify the costs. In 2008, a federal appeals court directed DOT to update a regulatory impact analysis with an estimate of the social cost of carbon—the dollar value of the net effects (damages and benefits) of an increase in emissions of carbon dioxide, a greenhouse gas.
In 2009, the Interagency Working Group on Social Cost of Carbon was convened to develop estimates for use governmentwide, and it issued final estimates in its 2010 Technical Support Document. In 2013, the group issued revised estimates that were about 50 percent higher than the 2010 estimates, which raised public interest.
GAO was asked to review the working group’s development of social cost of carbon estimates. This report describes the participating entities and processes and methods they used to develop the 2010 and 2013 estimates. GAO reviewed executive orders, OMB guidance, the Technical Support Document, its 2013 update, and other key documents. GAO interviewed officials who participated in the working group on behalf of the EOP offices and agencies involved. GAO did not evaluate the quality of the working group’s approach.
GAO is making no recommendations in this report. Of seven agencies, OMB and Treasury provided written or oral comments and generally agreed with the findings in this report. Other agencies provided technical comments only or had no comments.
For more information, contact J. Alfredo Gómez at (202) 512-3841 or email@example.com.
Read the full post from the National Park Service’s Commercial Services blog.
While the natural world has always served as inspiration for art, there is now a growing movement of artists using nature not only as inspiration, but as the materials for the art itself. Ecological or environmental art uses branches, stones, and other materials local to the area to create sculptures that aim to improve the viewer’s understanding of the natural world. Not only are these pieces interesting to look at, but an important aspect of many ecological art installations is that they actually help restore their natural surroundings.
Read the full story in GreenBiz.
Mars has just published its fourth annual Principles in Action Summary, which details how the company runs its huge business. And it makes for interesting reading.
This 100-year-old family-owned, family-run company has net sales of more than $33 billion. It has six business units (including chocolate, pet care and food and drink), 75,000 staff dotted in locations across the planet and a plethora of well-known brands (from Galaxy and Uncle Ben’s to Sheba and Skittles). And it well understands its position in the world and wants to drive positive change at the intersections where it can make a big difference — not least in driving better practices in farms in the developing world.
At the offices of the company’s London-based communications agency, I caught up with Mars’s global sustainability director, Kevin Rabinovitch, to find out how the business is using its scale to create change where it is needed most.
Listen to the interview from Great Lakes Echo.
Starting in 2017, the state of Minnesota will ban the use of an antibacterial chemical in consumer products. Triclosan has been found in the waters and fish of the Great Lakes, and a number of health organizations in Canada are urging their government to ban the chemical as well.
Recently Bloomberg looked at the process of how triclosan was considered for use in some brands of toothpaste. Current State’s Melissa Benmark speaks with article’s author, Tiffany Kary, to learn more about the potential dangers of triclosan.
Read the full story in Environmental Leader.
Saving money is the no. 1 reason executives give for moving towards more environmentally sustainable business practices, according to a Grant Thornton report.
The firm’s 2014 International Business Report, titled Corporate social responsibility: beyond financials, draws on more than 2,500 interviews with business leaders in 34 economies and looks at what companies are doing to make their operations more sustainable and why.
Read the full story in GreenBiz.
Her financial background wins support, but her grassroots employee efforts for energy efficiency and water conservation deliver results.
Read the full story in The Guardian.
Painting a green veneer on consumer goods is far from a new marketing tactic. In 1992, the US Federal Trade Commission issued its first “Green Guide” aimed at squelching greenwashing long before greenwashing was a household word.
It’s hard to blame marketers – really. It’s not that hard to find low-hanging fruit: non-discerning, green-minded consumers eager to buy bright, shiny new products that will help them lighten their footprint on Mother Earth. Thankfully the volume of egregiously greenwashed boondoggles has decreased in recent years. But it has not – as we shall see below – been washed away.
We’ve picked out some of our favorite dubious green products and rated them on a scale of “meh” to “100% boondoggle”.
Read the full story at EnvironmentalResearchWeb.
A new solar cell made from carbon nanotubes (CNTs) that is twice as good at converting sunlight into power than the best previous such cells has been unveiled by a team of researchers in the US. The National Renewable Energy Laboratory (NREL) has already independently certified the performance of the device – a first for a CNT-based solar cell…
The research is published in Nano Letters.
EPA’s proposed rule to regulate carbon dioxide emissions (“Section 111(d)” or the “CO2 Emission Guidelines”) from electric generating units (EGUs), issued June 2, 2014, has triggered immediate analysis and commentary about the prudence and legality of EPA’s approach under the Clean Air Act. This White Paper approaches the proposed rule from the perspective of states and focuses in particular on the institutional and practical challenges that states face in implementing the proposed rule.