Advanced Biohydrocarbon Fuels
CLIMATE TECHBOOK
Quick Facts

Advanced biohydrocarbons – as defined in this fact sheet – are derived from lignocellulosic biomass
(e.g., trees, grasses, wastes, and agricultural or forest residues) or algae and do not compete with
the production of feed or food crops.

Depending on technology advancement and capital investment in biorefineries, some estimates
have advanced biohydrocarbons displacing as much as 30 percent of the amount of petroleum
consumed in the United States by 2050.1
Background
Advanced biohydrocarbons are similar to conventional hydrocarbon fuels such as gasoline or diesel but are
produced from biomass feedstocks, such as woody biomass or algae, through a variety of biological and
chemical processes. Advanced biohydrocarbons are considered a ‗drop-in‘ fuel; in other words, their use
does not require significant modifications to existing fuel distribution infrastructure or vehicle engine
modifications (for gasoline or diesel powered vehicles), unlike ethanol as it is used today. Similarly, the
energy content of advanced biohydrocarbons is equivalent to that of their petroleum-based counterparts
(i.e., gasoline and diesel).
Description
Manufacturers can produce advanced biohydrocarbons by four primary pathways:

Fermentation: In this case, manufacturers pre-treat the biomass with heat, enzymes, or acids to
make the cellulose easier to break down into simple sugars using a chemical reaction called
hydrolysis. The sugars from the biomass are subsequently fermented using genetically engineered
microorganisms. This process is similar to the one used to produce corn or sugarcane ethanol (see
CLIMATE TECHBOOK: Ethanol). However, these microorganisms are engineered to break down the
biomass to produce hydrocarbons rather than alcohols. This is an important distinction in the genetic
modification of the microorganisms because alcohol formation generally would create a poisonous
environment, thereby reducing the efficacy of the catalyst. With the modified microorganisms,
however, hydrocarbons immediately form an organic layer separate from the microorganisms.

Gasification: In this pathway, solid woody biomass is left untreated and then converted at very high
temperatures into a combination of carbon monoxide (CO) and hydrogen (H2), a mixture termed
syngas. Syngas is the starting material for catalytic chemical reactions, such as Fischer-Tropsch
synthesis, which convert the syngas into a liquid fuel.

Pyrolysis: Similar to gasification, untreated woody biomass is heated quickly at high temperatures,
but in the absence of oxygen. The high heating leads to the breakdown of the complex structure of
the lignin to produce an intermediate bio-oil. Typically, this bio-oil is subsequently refined to a liquid
fuel via a catalytic reaction called hydrotreating.
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
Algal conversion: There are currently three main pathways to produce a fuel from algae: 1) algae is
genetically engineered to secrete bio-oils efficiently; 2) a bio-oil extract from algae is chemically
treated to produce a bio-oil; or 3) algae cultures are converted in their entirety via pyrolysis (see
above). In any case, the algae can be genetically modified to thrive in otherwise harsh conditions
(e.g., high salinity or nonpotable water). In all cases, the bio-oil product derived from algae is
subsequently upgraded via hydrotreating and becomes a liquid fuel similar to diesel or gasoline.
Figure 1: Production Pathways for Advanced Biohydrocarbon Fuels
hydrolysis
microbial processing
sugars
pre-treatment
heat
liquid-phase processing
gasoline
biomass
forest waste
agricultural waste
corn stover
switchgrass
gasification
synthetic gas
Fischer-Tropsch
(jet fuel)
steam reforming
pyrolysis
bio-oil
diesel
hydrotreating
algae
process characterization
chemical
biological
thermal
Note: Figure adopted from
1. National Science Foundation, Breaking the Chemical and
Engineering Barriers to Lignocellulosic Biofuels: Next
Generation Hydrocarbon Biorefineries. March 2008
2. Regalbuto, J.R. Cellulosic Biofuels – Got Gasoline?,
Science, Vol 325 no. 5492, pp. 822-824, August 2009
This figure illustrates a) chemical (black), b) biological (green), and c) thermal (red) production
pathways for advanced biohydrocarbons derived from i) woody biomass and ii) algae. The production
of gasoline or diesel equivalents is dependent on the technology and pathway. Note that while jet
fuel can also be produced, it is not discussed further in this summary.

Biological and Chemical Catalysts: In each of these four pathways, liquid biofuels are formed as the
result of biological and chemical catalysis. Catalysis is a process in which a material (the catalyst) is
added to a reactive environment to increase the rate of reaction without being consumed by the
reaction.2 As shown in Figure 1, most of these pathways are processes that are characterized as
chemical catalysis. Chemical catalysts have a number of advantages over biological catalysts. The
advantages of chemical catalysts include: broader range of reaction conditions, lower residence time
(i.e., faster reactions), potential for lower cost fuel production, and the elimination of a sterilization
step. However, compared to biological catalysis, chemical catalysis, as it relates to the complex
structures of the compounds that make up biomass, is a relatively new field. Developing these
processes is a challenge.
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Environmental Benefit / Emission Reduction Potential
The environmental benefits of advanced biohydrocarbons are significant. For instance, they have the
potential to overcome obstacles related to the use of ethanol: land use changes; transportation and
distribution of finished fuel; impacts on other agricultural commodities; and the need for vehicle
modification.
The primary feedstocks for advanced biohydrocarbons are woody biomass (primarily food and agricultural
waste) and algae — neither of which have the same land requirements as biofuels derived from traditional
food or feed crops (such as corn or sugarcane). While there will inevitably be some pressure on agricultural
lands and forestry resources, the impacts are less than first generation biofuels.
The development of heterogeneous chemical catalysts,3 used in combination with biological catalysts to
produce advanced biohydrocarbons, has the potential to improve biofuel production efficiency and reduce
costs. Furthermore, advanced biohydrocarbon fuels are chemically equivalent to the fuels derived from
petroleum, which may make it possible to link biorefining processes to existing petroleum refineries. This
has the potential to reduce the environmental impact of construction of new refineries and distribution
networks (e.g., pipelines), and other fueling infrastructure.
Advanced biohydrocarbons have the potential to reduce significantly the amount of water used in feedstock
production and in fuel processing compared to the crops for ―first generation‖ biofuels and the processing
using dilute sugar solutions for ethanol production.4
The greenhouse gas emissions reduction potential of advanced biohydrocarbons is significant. However,
there are no reliable estimates of the GHG emissions (reported as grams per megajoule, g/MJ) of advanced
biohydrocarbons because there are no commercial scale processes that can be used to develop the
appropriate energy balance equations.
The Department of Energy (DOE) has estimated that the availability of domestic biomass streams, with
―relatively modest changes in land use and agricultural and forest practices,‖ could yield advanced
biohydrocarbons at a volume equivalent to approximately 30 percent of petroleum used in the United States
by 2050.5 The oil yield of algal-based diesels is predicted to be as much as an order of magnitude higher
than other biodiesel crops. Assuming a lower limit for the oil yield of algal-based biodiesel (30 percent by
weight), only 2.5 percent of existing U.S. cropping area would be required to displace 50 percent of
petroleum based diesel use in the United States.6
Cost
The current cost of large-scale production of advanced biohydrocarbons is unknown, as only bench-scale
production has been conducted thus far. As such, only estimates of cost are available at this time.
There are four primary factors that determine the cost of the finished product: the feedstock, chemical
processing (e.g., pyrolysis), refining and finishing the crude product, and the transportation and distribution
of finished fuel.
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Feedstock: The cost of woody biomass feedstocks is dependent on a number of factors including, but not
limited to: crop yield, land availability, harvesting, storage and handling, and transportation costs.7 Huber
estimates a cost of $34 to $70 per dry ton, or $5 to $15 per barrel of oil energy equivalent.8 This is generally
consistent with the BRDI review of the literature. They report costs for a number of advanced biofuel
feedstock types, including agricultural residues (e.g., corn stover), forest biomass, urban woody wastes and
secondary mill residues, herbaceous energy crops (e.g., switchgrass), and short rotation woody crops.
Catalyst: The long-term potential of advanced biohydrocarbons is linked to the ability of producers to
produce liquid fuels using cost-effective catalysts. Looking at existing catalytic processes, the DOE has a
projected cost of cellulase enzymes for the production of ethanol between $0.30–0.50 per gallon of
ethanol.9 In contrast, the chemical catalysts in the petroleum industry are estimated to cost about $0.01 per
gallon of gasoline.10
Refining and Upgrading: Estimates for refining and upgrading the bio-oil produced from pyrolysis or
hydrolysis suggest that these steps account for about 33–39 percent of the capital costs of producing the
finished product.11 The range varies due to the variable amount of refining and upgrading required based on
the pathway.
Transportation: The cost of transporting biomass feedstocks can increase production costs considerably.
The savings derived from economies of scale at centralized facilities are often offset by the increased
transportation costs of the raw material(s). Developing a distribution system that is built on local and
distributed production facilities rather than large centralized facilities will help reduce transportation costs.
In terms of net production, various start-up companies have claimed that they anticipate that in the long
term, advanced biohydrocarbons will be competitive with conventional petroleum products at oil prices of
about $40–60 per barrel.12
Current Status
Advanced biohydrocarbons are currently in the development and demonstration stage. A variety of
processes have been demonstrated using bench-scale reactors to produce liquid fuels and liquid fuel
components (e.g., aromatic compounds). Most estimates suggest that commercial scale production of
advanced biohydrocarbons will begin within the next five to ten years.
Most recently, the DOE‘s ARPA-E awarded seven projects (out of 37) a total of $37.2 million (out of $151
million) in areas related to advanced biohydrocarbons as part of their solicitation for Transformational
Energy Research Projects.13
The DOE awarded $78 million for the development of ‗drop-in‘ renewable hydrocarbon biofuels such as
advanced biohydrocarbons and associated fueling infrastructure.14
Within the past year alone, five major oil companies – BP,15 Chevron,16 ExxonMobil,17 Royal Dutch Shell,18
and Total19 – announced joint ventures with biofuel companies to work on the development of advanced
biohydrocarbons.
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Obstacles to Further Development or Deployment
Currently, there are no low-cost technologies to convert the large fraction of energy in biomass or the bio-oils
derived from algae into liquid fuels efficiently. Production costs must be reduced considerably, and the
production volumes necessary for widespread use still need to be demonstrated. The lower limit benchmark
for commercial scale processing of biomass is about 150,000 metric tons per year.20
Ultimately, the optimization of advanced biohydrocarbon production processes is an essential step to allow
biorefineries to produce up to commercial volumes. These barriers exist in processes such as selective
thermal processing, liquid-phase catalytic processing of sugars and bio-oils, and catalytic conversion of biogas.



Selective thermal processing via pyrolysis
o
The production of bio-oil using fast pyrolysis results in a product that is high in oxygen
content. This bio-oil is not compatible with the existing fueling infrastructure, so the oxygen
needs to be removed, typically via hydrotreatment or hydrocracking. This process can be
expensive and requires large quantities of hydrogen.
o
Another concern is that bio-oils tend to be acidic and can cause corrosion in standard
refinery units. Furthermore, they are toxic and require careful handling.
Liquid-phase catalytic processing of sugars and bio-oils
o
There is a need to increase our understanding of the intermediate processes during liquidphase catalytic processes, namely the composition of the intermediate components, to help
researchers tailor the finished product.
o
Catalyst development for biohydrocarbon production is difficult because of the aqueous (i.e.,
water-based) environment. The catalysts developed in the petroleum and petrochemical
refining industries are unstable under aqueous conditions as they operate in the gas phase
or in organic solvents.
o
There are also limitations related to the stability of the catalyst. For instance, a catalyst that
works on bench scale may break down when applied to biomass feeds because of the
various impurities present in the feedstock.
Catalytic conversion of bio-gas
o
Cost-effective production of bio-gas is challenging because the quantity of biomass required
for commercial production is either not readily accessible or is currently being used for other
purposes. Currently, gasification is done on a small scale (10,000-20,000 barrels per day of
oil equivalent) at the local level which increases the costs of fuel distribution.
o
The clean-up of bio-gas is an important step to streamline the processing of advanced
biohydrocarbons. Bio-gas can contain impurities due to the various biomass feedstocks used
in its production, which may require the development of feedstock-dependent catalysts.
o
In addition to the conversion to bio-gas and the clean-up, the final step of conversion of bioPage | 5
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gas to liquid fuel requires considerable advancement in areas including the Fischer-Tropsch
Synthesis, reactor technologies, and the integration of catalysts and reactors.
Policy Options to Help Promote Advanced Biohydrocarbon Fuels
Federal, state, county, and local governments support advanced biohydrocarbons in a variety of ways.
Although current policies are aimed at alcohol transportation fuels, recent debate over the potential
environmental and societal impacts of using feed and food crops for energy production has bolstered
interest in biofuels produced from non-food feedstocks. Current support for advanced biohydrocarbons
generally falls into three categories: 1) policies that mandate levels of use of biofuels, 2) policies that offer
subsidies or tax credits for fuel production and/or use, and 3) and research initiatives.
Mandates

The Energy Independence and Security Act (EISA) of 2007 established a Renewable Fuel Standard
that requires the production of 100 million gallons of cellulosic biofuel in 2010 and increasing over
time to 16 billion gallons of cellulosic fuel in 2022.

The Low Carbon Fuel Standard in California requires a 10 percent reduction in the carbon intensity
of transportation fuels sold in California by 2020. In order to meet these requirements, one of the
strategies that can be pursued is the introduction of advanced biohydrocarbons. The credit towards
the LCFS is ultimately a function of the volume sold and the reduction in lifecycle emissions of the
fuel as compared to the baseline fuel, i.e. gasoline or diesel.
Existing taxes and subsidies

Registered cellulosic biofuel providers are eligible to receive a tax incentive up to $1.01 per gallon of
biofuel that is sold and used by the purchaser in the purchaser's trade or business to produce a
cellulosic biofuel mixture; sold and used by the purchaser as a fuel in a trade or business; sold at
retail for use as a motor vehicle fuel; used by the producer in a trade or business to produce a
cellulosic biofuel mixture; or used by the producer as a fuel in a trade or business.21
Biodiesel blenders can claim a tax credit of $1 per gallon. Note that only blenders that have
produced and sold or used the qualified biodiesel mixture as a fuel in their trade or business are
eligible for the tax credit.22
Other tax and subsidy policies that may be considered:

Promote additional tax incentives for processes and biorefineries that use biomass feedstocks from
non-food sources.

Support distribution and transportation infrastructure, including tax incentives to attract the required
capital investments.
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Research initiatives

Promotion of public-private partnerships for interdisciplinary research for the entire supply chain of
advanced biohydrocarbons. For example, the recent DOE awards for $78 million of funding for
advanced biofuels research are matched by $19 million in private and non-federal cost share funds.

Support for research on non-food feedstock production in areas such as increased crop yields.

Continued and focused support for the research and demonstration of conversion technologies in
biohydrocarbon processing. The National Advanced Biofuels Consortia, led by NREL, received about
$34 million of the recent DOE award for research to develop ―infrastructure compatible, biomassbased hydrocarbon fuels.‖

Continued and increased support of bench- and pilot-scale research into the production of advanced
biohydrocarbons.
Related Business Environmental Leadership Council (BELC) Company Activities
The Boeing Company
BP
The Dow Chemical Company
DuPont
Royal Dutch/Shell
Weyerhaueser
Related Pew Center Resources
Agriculture's Role in Greenhouse Gas Mitigation, 2006
Biofuels for Transportation: A Climate Perspective, 2008
CLIMATE TECHBOOK: Biofuels Overview, 2009
CLIMATE TECHBOOK: Biodiesel, 2009
CLIMATE TECHBOOK: Cellulosic Ethanol, 2009
CLIMATE TECHBOOK: Ethanol, 2009
MAP: State Mandates and Incentives Promoting Biofuels
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Further Reading / Additional Resources
Biomass as a feedstock for a bioenergy and bioproducts industry: The technical feasibility of a billion-ton
annual supply.
Biomass Energy Data Book, 2008.
Breaking the Chemical and Engineering Barriers to Lignocellulosic Biofuels: Next Generation Hydrocarbon
Biorefineries.
Green Car Congress, Bio-Hydrocarbons.
National Biofuels Action Plan, October 2008, Biomass Research and Development Board
Biomass Research & Development Initiative.
Biomass Research and Development Initiative (BRDi), ―The Economics of Biomass Feedstocks in the United
States, A Review of the Literature,‖ 2008.
Chisti, Y. (2007). Biodiesel from microalgae. Palmerston North: Biotechnology Advances.
Hubert, GW, et al. ―Synthesis of Transportation Fuels from Biomass: Chemistry, Catalysis, and Engineering.‖
Chemical Reviews, 2006, 106, pp. 4044-4098.
Perlack R., L. Wright, A. Turhollow, R. Graham, B Stokes, and D. Erbach, Biomass as Feedstock for a
Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply, USDA/DOE,
DOE/GO-102005-2135, ORNL/TM-2005/66, April 2005.
Regalbuto, J. ―Cellulosic Biofuels – Got Gasoline?‖ Science, Vol 325, 5492, pp. 822-824, August 2009.
NSF. ―Breaking the Chemical and Engineering Barriers to Lignocellulosic Biofuels: Next Generation
Hydrocarbon Biorefineries‖. Ed. George W. Huber, 2008, 180 p.
Green Car Congress, ―Terrabon to Open New Demonstration Facility Next Week for Biomass to Renewable
Gasoline Technology,‖ October 2008.
Wu, M.; Mintz, M.; and Wang, M. Water Consumption in the Production of Ethanol and Petroleum Gasoline,‖
Env Mngmt, 44, 981-997, 2009.
See Perlack R., L. Wright, A. Turhollow, R. Graham, B Stokes, and D. Erbach, Biomass as Feedstock for a ―Bioenergy and
Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply,‖ USDA/DOE, DOE/GO-102005-2135, ORNL/TM2005/66, April 2005. In their report, Perlack et al. answer the question as to whether the ―land resources of the United States are
capable of producing a sustainable supply of biomass sufficient to displace 30 percent or more of the country‘s present petroleum
consumption.‖ Their scenario assumes ―relatively modest changes‖ in land use and agricultural and forestry practices. In other
words, the report evaluates the resource availability, rather than the economic viability of biomass as a feedstock for transportation
fuels.
1
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An example of a biological catalyst is yeast in the fermentation of sugars yielded from the starch in corn or sugarcane. Biological
catalysts in fermentation (to produce alcohol) have been used for thousands of years.
2
3
Heterogeneous catalysts are those that are in a different phase (i.e., gas, liquid, or solid) than the reactants.
Wu, M., Mintz, M., and Wang, M. ―Water Consumption in the Production of Ethanol and Petroleum Gasoline,‖ Env Mngmt, 44, 981997, 2009.
4
5
Perlack et al. 2005.
6
Chisti, Y. Biodiesel from microalgae. Palmerston North: Biotechnology Advances. 2007.
Biomass Research and Development Initiative (BRDi), ―The Economics of Biomass Feedstocks in the United States, A Review of the
Literature,‖ 2008.
7
Hubert, GW, et al. ―Synthesis of Transportation Fuels from Biomass: Chemistry, Catalysis, and Engineering.‖ Chemical Reviews,
2006, 106, pp. 4044-4098.
8
9
http://www1.eere.energy.gov/biomass/printable_versions/cellulase_enzyme.html
National Science Foundation, ―Breaking the Chemical and Engineering Barriers to Lignocellulosic Biofuels: Next Generation
Hydrocarbon Biorefineries,‖ Ed. George W. Huber, 2008, p. 180.
10
11
NSF/Huber 2008.
Regalbuto, J. ―Cellulosic Biofuels – Got Gasoline?‖ Science, Vol 325, 5492, pp. 822-824, August 2009 and Green Car Congress,
―Terrabon to Open New Demonstration Facility Next Week for Biomass to Renewable Gasoline Technology,‖ October 2008,‖ October
2008.
12
13
http://arpa-e.energy.gov/Media/News.aspx
14
http://energy.gov/news2009/8519.htm
15
http://www.bp.com/genericarticle.do?categoryId=2012968&contentId=7055476
16
LS9. ―LS9 Secures $25 Million in Latest Round of Funding.‖ Press Release, September 2009.
17
ExxonMobil. ―ExxonMobil to Launch Biofuels Program.‖ Press Release, July 2009.
Shell and Codexis. ―Shell and Codexis Deepen Collaboration to Speed Arrival of Next Generation Biofuel.‖ Joint Press Release,
October 2009.
18
19
Gevo, Inc. ―Major Oil and Gas Company, Total, Invests in Advanced Biofuels Leader Gevo.‖ Press Release, April 2009.
20
NSF/Huber 2008.
U.S. Department of Energy. Alternative Fuels and Advanced Vehicles Data Center – Federal and State Incentives and Laws. Last
accessed March 19th, 2010.
21
22
Ibid.
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