News and Trends

Scientists at the National Renewable Energy Laboratory (NREL) in Colorado are developing ways to improve the production of algae-based biofuels and bioproducts.

The US Department of Energy's Bioenergy Technologies Office has announced its support for the project "Rewiring Algal Carbon Energetics for Renewables,", giving the project a $3.5 million grant. The overall goal of the project is to double the yield of biofuel precursors from algae.

In the project, scientists will aim to increase the algae yield through different approaches including increasing its productivity, optimizing the biomass composition, and separating different algal lipids to reduce the costs converting it to renewable diesel.

The scientists from NREL will be joined by specialists from Colorado State University (CSU), the Colorado School of Mines, Arizona State University, Utah State University, as well as experts from the industry.

The researchers will focus on the algae species Desmodesmus armatus, and how it will efficiently channel carbon dioxide into useful fuel intermediates. Other partners on the project will work on the algae-to-bioproduct life cycle, including modification of growing pond conditions, and separating algal solids from water to remove lipids.

The idea of recycling waste cooking oil into biodiesel fuel is nothing new. Researchers have studied the process and companies have recycled when possible. However, cost is often a determining factor for making the effort to recycle.

Dr. Joseph Smith, a Missouri University of Science and Technology professor believes that we need to make the process on a smaller-scale, for it to be a feasible local project for towns and cities. This prompted Smith and his colleagues to develop a small, modular facility that could start many small plants that would still benefit the entire industry.

However, waste cooking oil recycling projects also produces glycerol which, when mixed with salt and water, is relatively unused. Smith explains that their developed process eliminates salt production. The excess glycerol and water mixture can now be fermented to methanol to make more biodiesel.

Their research could lead to biodiesel-propelled vehicles and could boost several green technologies.

Research and Development

Production of olive oil creates a vast stream of wastewater that can foul waterways, reduce soil fertility and damage ecosystems. Hence, a study from Institut de Science des Matériaux de Mulhouse in France developed an environment friendly process that could transform this pollutant into "green" biofuel, bio-fertilizer and safe water for irrigation.

During processing, olives are crushed and mixed with water in mills. The oil is separated out of this mixture, and the olive mill wastewater (OMW) is discarded. The process developed by the Institute first impregnates OMW on raw cypress sawdust (RCS), another common waste product.

Then the mixture is dried and the evaporated water is collected. This water will be safe enough for irrigation. The OMW-sawdust mixture is then subjected to pyrolysis, turning it into combustible gases and charcoal. The researchers then collected and condensed the gas into bio-oil, a biofuel precursor. The charcoal pellets left can now be used as fertilizer.

These results indicate the possibility of converting OMW to green fuels, agricultural water source, and fertilizer.

In a biofuel refinery, co-production of valuable chemicals from both plant material and microbial biomass is desirable. Fungal production of steroids was among the first industrial transformations allowing corticosteroid production. The team of Claire M. Hull from Swansea University Medical School in Wales reports the co-production of ethanol and hydroxyprogesterone, an intermediate in corticosteroid production, by yeasts using perennial ryegrass juice.

Genes encoding the 11α-steroid hydroxylase enzymes from Aspergillus ochraceus (11α-SHAoch) and Rhizopus oryzae (CYP509C12) were transformed into two separate Saccharomyces cerevisiae strains. Both recombinant yeasts exhibited efficient hydroxyprogesterone conversion. Ethanol yields of both recombinants showed ≥75% conversion of glucose to alcohol.

This study demonstrates the application of recombinant yeasts in biorefinery processes where co-production of value-added products is an attractive possibility.!

Rice is one of the main agricultural products of Vietnam. Rice straw is a significant by-product, which, when used in a biorefinery, would contribute to the bio-based transformation of Vietnam.

To find novel efficient enzyme mixtures for the hydrolysis of rice straw and other agricultural residues, Vietnamese researchers led by George E.Anasontzis from Chalmers University of Technology in Sweden screened 1,100 new fungal isolates for their CMCase activity. The samples were collected from soil and decaying plant tissues around Vietnam.

The team selected 36 strains and evaluated them for their cellulases, xylanases, and accessory enzymes' activities. Most of these isolates belonged to the genera Aspergillus and Trichoderma. The team also identified promising isolates, such as A. brunneoviolaceus FEC 156, A. niger FEC 130 and FEC 705, and A. tubingensis FEC 98, FEC 110 and FEC 644. The produced enzyme mixtures of these selected strains released a huge fraction of the sugar content of alkali-treated rice straw.

The team found that the black Aspergilli are efficient in saccharification. Strains with low amounts of cellulases and xylanases but has enzyme mixtures with high saccharification efficiencies indicating a synergistic effect, were also identified.

Energy Crops and Feedstocks for Biofuels Production

Photosynthetic microalgae are emerging as potential biomass feedstock for biofuel production. Mitigation of carbon dioxide release through these organisms can be a promising alternative to the existing carbon sequestration methods. However, the relatively low photosynthetic capacity of microalgae has hampered its use in carbon dioxide mitigation.

The team of Bo Yang from Peking University in China improved the photosynthetic capacity of the green microalga Chlorella vulgaris by manipulating its Calvin cycle. The team introduced the cyanobacterial fructose 1,6-bisphosphate aldolase into the C. vulgaris chloroplast, leading to enhanced photosynthetic capacity and cell growth.

Analysis suggested a possible role for aldolase overexpression in promoting the regeneration of ribulose 1,5-bisphosphate in the Calvin cycle and energy transfer in photosystems. This study is a proof-of-concept of enhancing the photosynthetic capacity by engineering the Calvin cycle in green microalgae.

In the future, homes and vehicles could be powered by fuel from seaweed. Researchers at the Woods Hole Oceanographic Institution (WHOI) are working to make that scenario a reality sooner with funding from the U.S. Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E).

WHOI was awarded a $5.7 million grant from ARPA-E's Macroalgae Research Inspiring Novel Energy Resources (MARINER) Program. The grant will cover two projects that would develop tools and technology to advance the mass production of seaweed for biofuels.

Seaweed is primarily used in food and food processing for humans and animals, and mostly comes from imports or wild harvests. Expanding seaweed farming relieves pressure on wild stocks and would create jobs. Larger production will then lead to expanded markets, including feedstocks for biofuels.

One of the projects will see a team of seaweed biologists, geneticists and entrepreneurs aiming to develop a breeding program for sugar kelp (Saccharina latissima), one of the most commercially important species of seaweed, using the latest breeding technologies. The breeding program will also build a library of genetic resources associated with plant traits that could improve plants.

The remaining $2 million will be used to develop an autonomous underwater observation system for monitoring large-scale seaweed farms for extended periods of time without human intervention.

Biofuels Processing

Researchers from the University of Liverpool have recently developed a plasma synthesis process for the direct, one-step conversion of carbon dioxide and methane into higher value liquid fuels and chemicals such as acetic acid, methanol, ethanol and formaldehyde.

Converting carbon dioxide and methane into liquid fuels using a single step process has been a challenge since they are both inert molecules. The conversion will require high temperature and pressure. The scientists' process of liquid fuel production was achieved using a unique atmospheric-pressure, non-thermal plasma reactor with a water electrode and a low energy input.

This study proves that non-thermal plasmas can overcome the thermodynamic barrier for the direct transformation of CH4 and CO2 into important chemicals and synthetic fuels at ambient conditions. Furthermore, plasma systems are flexible and can be scaled up and down.

The process could also be used to convert flared methane from flaring gas in oil and gas wells into valuable liquid fuels and chemicals, which can be easily stored and transported.