(481c) Realizing the Potential of Advanced Biofuels



Advanced
biofuels or ?drop-in? fuels is the terminology used to refer to hydrocarbon
fuels that are direct replacements or supplements for existing gasoline, diesel
and jet fuels currently refined from conventional petroleum feedstocks. Drop-in
fuels from biomass will need to meet all of the refinery and ASTM
specifications for any blending ratio up and including 100% to truly qualify as
drop-in fuels. Achieving this will ensure complete infrastructure compatibility
and thus these drop-in biofuels will have a streamlined path to market by not
facing the infrastructure compatibility limitations of current biofuels such as
ethanol or biodiesel. This accelerated path to market by utilizing the existing
infrastructure will minimize the amount of greenfield capital investments that
will be required. Hence these market advantages afford drop-in biofuels the
ability to contribute as rapidly as possible to the national objectives of
increased U.S. energy security, reduced greenhouse gas emissions and a more
diverse environmentally sustainable transportation fuel supply.

The objective of
the National Advanced Biofuels Consortium (NABC) is to develop cost-effective
technologies for advanced ?drop-in? biofuels that are compatible with today's
transportation infrastructure and are produced in a sustainable manner. Our
overarching goal is to expedite transfer of the resulting biofuel technology to
industrial practice, in order to contribute as rapidly as possible to the
national objectives.

The most
effective means to meet these critical national objectives is to supplement
petroleum at the refinery gate. This will avoid the costs of new infrastructure
and accelerate broad utilization of biofuels by the existing transportation
fleet. However, the chemical and physical complexity of biomass has prevented
its use as a refinery feed. As a consequence, the primary source of biofuels
to-date has been fermentation of starch (corn) to ethanol, which has two
fundamental challenges: 1) competition with food/feed supply, and 2) inability
to take full advantage of existing infrastructure. Cellulosic-based ethanol
mitigates the food/feed supply competition but does not address the second
fundamental challenge?full infrastructure compatibility. Hence it faces the
same market growth limitations, such as blend wall, low energy density and
limited applicability for diesel and jet use. The objective of this project is
to develop one or more biofuel technologies that address both these fundamental
challenges and thus take full advantage of the cost savings that are possible
by use of existing refineries, distribution networks and vehicle fleets using
high impact lignocellulosic feedstocks.

To achieve this
objective, the NABC team evaluated the petroleum refinery and its potential to
accept biomass. Key barriers to introducing biomass into a refinery are that it
is solid, heterogeneous, and has high oxygen content. A successful technology
must reduce oxygen content, improve miscibility with petroleum, and minimize
critical contaminants that can poison catalysts. We identified three plausible
refinery insertion points (Figure 1). For insertion point one (In Pt 1),
biomass is converted to a bio-crude that can be co-processed with conventional
crude oil. For insertion point two (In Pt 2), biomass is upgraded into
refinery-ready intermediates that have properties compatible with refinery streams,
which will then be further, co-processed. The third insertion point (In Pt 3)
is a near-finished fuel or blendstock that could take advantage of the refinery
for minimal processing (e.g. hydrotreating, isomerization).

We
then performed a systematic evaluation of a broad spectrum of biomass
processing pathways consistent with the identified insertion points. Based on a
number of criteria such as sustainability, economic and process viability,
diversity of approach and commercialization potential we chose the most
promising ?next generation? process strategies. We also identified specific
barriers to commercialization within each strategy associated with the use of
high impact lignocellulosic feedstocks. The selection process was carried out
in a series of meetings that included biofuels experts from the petroleum
industry, national labs, and academia. These six process strategies provide a
broad and robust suite of technologies to maximize the production of biofuels
from the physically and chemically diverse range of lignocellulosic feedstocks
that are projected to be available on a sustainable basis in the future. These
process strategies provide technical diversity and flexibility with respect to
refinery insertion points. The diversity of process strategies helps mitigate
project risks, provides an opportunity to examine the relative merits of
alternative process strategies and promotes synergies among technologies.

The
NABC team members were chosen based on two criteria: 1) world-class expertise
to pro vide
full coverage of the entire value chain from feedstock to fuel and 2) technical
expertise and background intellectual property in areas relevant to the six
process strategies. Developing the team along these lines has allowed us to
assemble a consortium fully able to achieve the objectives of the project and
the FOA. The industrial partners include 1) refiners?BP, Tesoro, 2) technology
developers?UOP (with USDA-ARS and Ensyn as subcontractors), Amyris, Virent,
Albemarle, RTI, 3) a separation expert?Pall, and 4) a feedstock technology
developer?Catchlight
Energy. The university partners?Colorado School of Mines, Iowa State University
(with Northwestern as a subcontractor), University of California at Davis and
Washington State University?bring expertise in bioprocessing, catalysis, and
mechanistic and kinetic modeling. The National Laboratories?NREL, PNNL, ANL, and
LANL?bring top experts in biofuels, including bioprocessing, catalysis,
computational modeling and engineering and sustainability analysis.

Through
novel catalytic and fermentative approaches the NABC will transform biomass
into a form that is suitable for insertion into the current refinery and
distribution infrastructure. The research program will be conducted in two
stages. In Stage 1, targeted research will be done to address our abilities to
overcome the key barriers within a three-year project for each strategy. At the
conclusion of Stage 1 we will down-select from the six process strategies and
identify one to three most likely to succeed. The down-select criteria include
technical, economic, and environmental metrics. Research in Stage 2 will focus
on science and engineering activities to integrate the selected processes into
the refining infrastructure. Underpinning all that we do will be a robust
sustainability and technoeconomic analysis (TEA) function to ensure that we are
selecting and developing only those pathways that will be competitive and
sustainable. At the conclusion of the NABC, we will deliver a pilot-ready
process, a detailed design report, and a life cycle analysis.

In
summary, displacing oil at the refinery gate avoids cost in new infrastructure
and increases the rate of broad deployment into the existing fleet. This
approach provides a cost-effective way to supplement the existing market with
drop-in fuels made from biomass, and achieve the goals of enhancing U.S. energy
security, reducing greenhouse gas emissions and creating economic opportunities
across the nation. This is the objective of the research of the NABC.