News and Trends 

Biodiesel is helping improve the air quality in the US' Great Smoky Mountains National Park in Tennessee. This is part of their goal to reduce their environmental footprint.

In 2016, the park used 43,085 gallons of biodiesel (B20), which resulted in a 15% reduction in carbon dioxide, a 12% reduction in carbon monoxide, a 20% reduction in both hydrocarbon and sulphur dioxide, and a 12% reduction in particulate matter, according to the NBB's Emissions Calculator. The park first started using biodiesel blends to power vehicles and equipment in 2003, and the fuel has been used widely around the park since 2006. The Great Smoky Mountains' biodiesel is made from used fryer grease and soybean oil.

The park has constantly strived to incorporate technologies that will result in cleaner air. This includes alternative fuels, electric vehicles and charging stations, and greener building construction. Bioheat is also used to heat the park's headquarters.

Passenger planes in the UK could soon be powered by biofuels made from waste under a scheme to cut emissions, UK's Department for Transport (DfT) announced. The DfT have announced this as a step towards its intention to cut carbon emissions.

The DfT also said that the new fuels were "chemically very similar to conventional fuels" and could be used in existing aircraft without engine modifications. Aircraft and lorries powered by these waste fuels could use up to 90% less carbon compared to fossil fuels. Trials of jet fuel made from waste materials have been done in Europe and North America.

Currently, groups have expressed interest in bidding for the DfT funding to develop proposals in the UK. The funding is available to projects producing low-carbon waste-based fuels to be used in planes and lorries that cannot use electric power. It is viewed that the government funding will help develop at least five new low-carbon fuel plants by 2021.

Research and Development 

Chlorella is a freshwater alga which are cultivated on an industrial scale and have potential for the production of biofuels. Researchers from various French research institutions, led by Damien Sorigue from the University of Aix-Marseille, have discovered an enzyme in Chlorella that allows it to convert fatty acids into hydrocarbons using light energy.

Researchers studied the enzyme by following its activity and determining a list of potential candidate proteins. The team then expressed the enzyme, named Fatty Acid Photodecarboxylase or FAP, in Escherichia coli. The transformed E. coli showed evidence of hydrocarbon production, demonstrating that this enzyme is both necessary and sufficient for hydrocarbon synthesis. Furthermore, this activity requires light.

FAP was found to be at least ten times faster than the best-known enzyme for hydrocarbon synthesis, and uses light. It can provide a biotechnological tool for the synthesis of hydrocarbons.

Lytic Polysaccharide Monooxygenases (LPMOs) are abundant in nature and are known to play roles in several processes besides biomass degradation. These enzymes have drastically improved our ability to convert cellulose into fermentable sugar, for the production of second generation biofuels and other biomass-derived products. However, it is still not clear how LPMOs work at the molecular level.

Bastien Bissaro, a guest researcher at Norwegian University of Life Sciences (NMBU) and a team led by Vincent Eijsink have discovered the mechanism by which LPMOs break down cellulose. Researchers found that LPMOs do not need oxygen but hydrogen peroxide, a cheap liquid chemical. Building on their discovery, Bissaro and the team have also found that by controlling the supply of hydrogen peroxide, they can achieve stable enzymatic cellulose conversion processes.

From a scientific point of view, these findings reveal a new type of chemistry that nature uses to break down cellulose.

The yeast Saccharomyces cerevisiae is not capable of metabolizing xylose. In attempts to confer xylose utilization ability in S. cerevisiae, a number of xylose isomerase (XI) genes have been expressed in this yeast. While several of these genes were expressed in S. cerevisiae, the need still exists for a strain with improved xylose utilization ability for the production of bioethanol. Satoshi Katahira of the Toyota Central R&D Labs in Japan led the search for novel XI genes from the protists residing in the hindgut of the termite, Reticulitermes speratus.

Eight novel XI genes were obtained from the protists of the R. speratus hindgut. The gene that exhibited the highest XI activity was then expressed in S. cerevisiae. Growth rate and the xylose consumption rate of the S. cerevisiae strain expressing the novel XI were found to be superior to strains with the other seven genes, as well as the control strains.

A novel XI gene conferring superior xylose consumption in S. cerevisiae was successfully isolated from the protists in the termite hindgut. Isolation of this XI gene might contribute to improving the productivity of industrial bioethanol.

Biofuels Processing

Liquid methanol is believed to have considerable potential as an alternative fuel, and is used as a feedstock to produce other chemicals. However, methane is converted to methanol by the production of synthesis gas at high temperatures and pressures, a process which is both expensive and energy intensive.

A team led by Graham J. Hutchings of the Cardiff Catalysis Institute and Christopher J. Kiely of Lehigh University used colloidal gold palladium (Au-Pd) nanoparticles to directly oxidize methane to methanol at low temperatures. Researchers said that for the reaction to work, the Au-Pd nanoparticles had to be free-floating colloids in a very weak hydrogen peroxide solution. They then injected pressurized methane and oxygen gas into the said solution, producing methanol.

Researchers at Tokyo Institute of Technology have developed a new catalyst to improve the synthesis of primary amines. The newly developed catalyst could also impact the development of biofuels and bio-oils.

Primary amines are compounds used in the preparation of a wide range of dyes, detergents, and medicines. Many attempts have been made to improve the synthesis of amines, but few have been successful. The team developed a catalyst consisting of ruthenium nanoparticles supported on niobium pentoxide. The catalyst is capable of producing primary amines from carbonyl compounds, with negligible by-products.

Michikazu Hara of Tokyo Tech's Laboratory for Materials and Structures and his team also explored how the catalyst could break down glucose into 2,5-bis(aminomethyl) furan, a monomer for aramid production. The new catalyst produced a yield of 93% from the glucose feedstock, with little to no by-products. This new catalyst can be a major player in large scale production of biomass-derived materials, including biofuels.

A University of Delaware research team has invented a more efficient process for extracting sugars from organic waste from forests and farms. This biorenewable feedstock could serve as a cheaper, sustainable substitute for the petroleum used in manufacturing consumer goods.

Industry currently separates sugars from lignin via a two-step process. They use chemicals in the first step, and expensive enzymes in the second step. This process makes the resulting sugars expensive. The process invented at UD, however, is just one step. UD's technology combines the pretreatment step and the hydrolysis of cellulose and hemicellulose in one pot and operates at considerably low temperatures.

The key to the technology is the use of a concentrated solution of an inorganic salt in the presence of a small amount of mineral acid. The concentrated salt solution requires a minimal amount of water. The solution swells the particles of wood or other biomass, allowing the solution to interact with the fibers. The unique properties of the salt solution make the method very efficient.