fuels of the futureBy Nurhan Dunford, FAPC Oil/Oilseed Chemistnurhan.dunford@okstate.edu

fuels of the future

FOOD VERSUS FUEL

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By Nurhan Dunford, FAPC Oil/Oilseed Chemistnurhan.dunford@okstate.edu

rowing interest in biofuels could put tremendous pressure on agricultural commodities if both food

processors and biofuel producers continue to compete in the same market.

On the other hand, better management of resources and diversification of agriculture to meet feedstock needs of the biofuel industry could lead to growth of the global economy and strengthen agricultural industries. Inedible feedstock, waste biomaterial and biomass that require minimal land use all should be exploited fully to sustain the biofuel industry.

A strong national biofuel industry has very important implications in terms of improving the environment and providing a guaranteed supply of energy to aid in attaining independence from imported petroleum. To be a viable alternative, a biofuel should provide a net energy gain, have environmental benefits, be economically competitive, and be producible in large quantities.

Biodiesel meets most of the criteria desired in a renewable fuel. The energy content of biodiesel varies between 88 percent and 99 percent compared to petroleum diesel, depending on the feedstock and the process used. Biodiesel uses 0.3110 MJ of fossil energy to

produce 1 MJ of fuel product. Use of biodiesel in transportation vehicles also reduces CO

2 emission levels

significantly. Biodiesel can go into the current fuel distribution system, which eliminates the huge cost of revamping the nationwide fuel distribution infrastructure. Hydrogen fuel and, to a certain extent, ethanol have the disadvantage of requiring major changes to the current fuel distribution system.

Currently, ethanol is transported via trucks because it is classified as a flammable material and cannot be put into current fuel distribution pipelines. Hydrogen fuel requires a very expensive and completely new distribution system.

One of the major concerns about expansion of the biodiesel industry is that potentially feedstock production would displace croplands currently used for food crops. Although animal fat and used/waste cooking oil have been utilized to a smaller extent, soybean oil is currently the major feedstock for biodiesel production in the U.S. Soybean oil also is an important commodity product widely used by food processors.

In a recent article authored by Y. Chisti (Biodiesel from microalgae. Biotechnol Adv (2007), doi:10.1016/j.biotechadv.2007.02.001), it was estimated that about 1.5 billion acres of land would be needed to grow enough soybean to replace 50 percent

of the transportation fuel requirement of the U.S. with biodiesel. Considering that about 450 million acres is available for crop production in the U.S., obviously relying on just oilseeds to replace petroleum diesel is not a viable option. The yield of fuel per acre needs to be as high as possible for viability, economic feasibility, and sustainability.

Plants use photosynthesis to convert solar energy into chemical energy stored in the form of oils, carbohydrates, and proteins. The plants that are most efficient at converting the solar energy into chemical energy have a better prospect for being a viable feedstock for biofuel production.

Various types of algae are among the most efficient plants to convert solar energy to chemical energy. Macroalgae, also known as “seaweed,” are fast-growing marine and freshwater plants. Microalgae are microscopic organisms that also are found in both marine and freshwater environments. Microalgae are capable of taking a waste form of carbon, or CO

2, and converting it

into oil.Between 1978 and 1996, the

U.S. Department of Energy Office of Fuels Development funded a research program know as the Aquatic Species Program, or ASP, to develop renewable transportation fuels from algae. The main objective of the

program was to examine the potential of biodiesel production from high lipid-content algae grown in ponds by utilizing waste CO

2 from coal-fired

power plants.More than 3,000 strains of

algae were collected from sites in the western, the northwestern, and the southeastern regions of the continental U.S. and Hawaii. After vigorous screening, isolation, and characterization efforts, the collection was eventually narrowed down to about 300 species.

Unfortunately, ASP was abandoned in 1996. However, the scientists who worked on this project were adamant about the potential of this technology and believed future interest would be revived. Hence, they compiled a 328-page report on the research that had been carried out during the 18 years of the ASP program and posted it on the Department of Energy Web site. The report shows significant potential land, water, and CO

2 resources exist to

support this technology. Microalgae systems use far less

water than traditional oilseed crops. More importantly, many of the algal species studied in this program can grow in brackish water, which means they would not put additional demand on freshwater supplies needed for domestic, industrial, and agricultural use.

According to Chisti, microalgae can produce between 55,000 L oil/acre and 24,000 L/acre, depending on the oil content of microalgae strain, which can vary between 70 percent and 30 percent dry weight. Soybean produces only 180 L oil/acre. Oil from microalgae can easily be converted into biodiesel. In such a case, it would take only 1 to 3 percent of the existing U.S. crop area to replace half of the

petroleum-based transportation fuel with biodiesel.

A number of business initiatives are underway to bring this technology into commercialization. Although algae oil production technology faces many research and development obstacles today, resource limitations are not barriers for viability and the sustainability of the technology. Building microalgae-production

reactors next to coal-fired power plants and ethanol-production facilities is an elegant approach to sequester CO2

released from these plants and reduce greenhouse emission levels.

Obviously, Oklahoma is not a large enough oilseed- and corn-producing state to meet the feedstock needs of even the local biofuel industry, which has been expanding during the last couple of years. Currently, Oklahoma has three large-scale biodiesel production facilities with a total production capacity close to 15 million gallons/year. There are three other biodiesel production facilities under construction that will bring the total capacity to about 40 million gallons/year. There are a number of small biodiesel production operations as well, but it is hard to determine their total production capacity. Currently, most of these operations rely on feedstock coming from outside the state.

As feedstock prices continue to rise and availability diminishes, Oklahoma-based biodiesel operations

face tremendous challenges to stay in production. As Oklahomans, we need to explore other local resources that can be used as biofuel feedstock and could help to produce biomass with high oil content. Although they are not exploited to their full capacity yet, used/waste food oil, animal fat, and canola are being explored as biodiesel feedstock in the state.

Could algae be a viable oil source for the biodiesel industry in Oklahoma? Although currently there are technical issues to be researched before this question can be answered with certainty, in the long term, Oklahoma has a great potential to benefit from algae technology. Certainly Oklahoma gets plenty of solar energy to support potential

algae farms.According to the Oklahoma

Water Resources Board, “Oklahoma has approximately 11,611 miles of shoreline, slightly less than the estimated combined general (nontidal) coastline of the Atlantic, Gulf, Pacific, and Arctic Coasts (12,383 miles). Oklahoma also has about 78,578 miles of rivers/streams (about three times the circumference of the Earth and one-third the distance to the moon.)”

Considering that algae technology requires less water than oilseed crops and Oklahoma has significant water resources and solar energy, it makes sense to direct some research and development resources to examine the potential of this technology for the state.

OSU, particularly the Division of Agricultural Sciences and Natural Resources, along with the FAPC, has the expertise on oil processing, conversion, and engineering required to research and evaluate the potential of this technology for Oklahoma.

Could algae oil be an answer?Could algae be a viable oil source for biodiesel industry in Oklahoma? Although currently there are technical issues to be researched before this question can be answered with certainty, in the long term, Oklahoma has a great potential to benefit from algae technology.

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