News and Trends

The Federation of Philippine Industries (FPI) is requesting the government to amend the Biofuels Act to allow the use of palm oil, together with coconut oil as a fuel additive. They believe that this will reduce the cost of biofuels in the country.

The specifications, particularly the formulation for the fuel mix, in the Biofuels Act were specifically made so that only coconut can qualify. The Biofuels Act, passed in 2006, mandates mixing a percentage of biofuels in the making of local gasoline and petroleum diesel to decrease dependence on fuel imports and meet environmental goals.

Palm oil is used as a feedstock, particularly in biodiesel, to be mixed with petroleum diesel. Currently, the price of palm oil is half of the coconut oil price in the world market, or $1,500 per metric ton for coconut versus $725 per metric ton for palm oil.

In the law, both bioethanol and biodiesel are governed by the Philippine National Standards. The mandated biofuel percentage to total volume of liquid petroleum is now at 2%.

Research and Development

The production of value-added chemicals alongside biofuels from lignocellulosic sources could be vital in developing economical biorefineries. Xiaoqing Wang from the National Renewable Energy Laboratory evaluated the production of propionic acid (PA), a potential building block for C3-based chemicals, from corn stover using the PA-producing bacterium, Propionibacterium acidipropionici.

A range of conditions and parameters were examined and optimized to maximize the PA yield. It was found that nitrogen gas exhibits improved performance over carbon dioxide. The effects of different hydrolysate concentrations, nitrogen sources, and neutralization agents were also investigated.

One of the best combinations found used yeast extract (YE) as the primary nitrogen source and NH4OH for pH control. This combination enabled high PA yield concentrations, while successfully minimizing lactic acid production, which can hinder biofuel production.

These results demonstrate the feasibility of producing PA from corn stover hydrolysate, which would be a potential additional income in biofuel production.

Integrating cultivation with wastewater treatment improves the economics of microalgal based biofuel production and allows for the sustainable reuse of nitrogen (N) and phosphorus (P) from waste streams. This was the aim of a research led by Mikael Jämsä from University of Turku in Finland.

His team performed a batch-cultivation of a locally isolated green microalga, UHCC00027, and an indigenous algal-bacterial consortium on screened municipal wastewater in pilot reactors. They then evaluated the growth as well as N and P removal of the microbes. Lipid accumulation and fatty acid composition were also examined. The wastewater treatment performance under cold temperatures, were also tested.

Results revealed that vigorous, temperature-dependent growth of microalgae was the most important factor in the removal of N and P in the wastewater. The studied cultivation strategy and organisms achieved regulatory N and P removal levels.

However, the biodiesel properties of the resulting biomass did not meet international standards due to a high proportion of polyunsaturated fatty acids. More studies are required to increase the quality of the resulting biofuel.

High-temperature fermentation (HTF) technology is expected to reduce the cost of bioconversion of biomass to fuels or chemicals. For stable HTF, the development of a thermotolerant microbe is indispensable. However, understanding the molecular mechanisms of thermotolerance in microbes needs to be improved. Kannikar Charoensuk from the Rajamangala University of Technology in Thailand aimed to study genes from the thermotolerant Zymomonas mobilis, an efficient ethanologenic microbe.

Thermotolerant genes essential for survival at a critical high temperature (CHT) were identified via transposon mutagenesis in Z. mobilis TISTR 548. Products of these genes were classified into nine categories, namely metabolism, membrane stabilization, transporter, DNA repair, tRNA modification, protein quality control, translation control, cell division, and transcriptional regulation.

Cells with transposon insertion in these identified genes showed a defect in growth at 39°C but grew normally at 30°C. Among those, more than 60% were found to be sensitive to ethanol at 30°C, indicating that thermotolerance partially overlaps with ethanol tolerance in the organism.

The thermotolerant genes from Escherichia coli and Acetobacter tropicalis can also be classified into 9 categories according to the classification of those of Z. mobilis. Analysis showed that there are 7 conserved thermotolerant genes that are shared by these microbes.

Energy Crops and Feedstocks for Biofuels Production

Although algae are naturally occurring, excessive amounts of nutrients in a body of water can lead to algal blooms that cover the surface. Some algae produce toxins which are harmful to humans and wildlife, having a disruptive effect on marine environments. Scientists in India have studied ways in which toxic algal bloom can be used for cultivating Chlorella pyrenoidosa, a freshwater alga considered as a feedstock candidate for biofuel production.

Scientists from the Indian Institute of Technology used the toxic algal bloom as a low cost nutrient source for cultivating Chlorella pyrenoidosa. Various pretreatment methods, such as acid/alkali and autoclave/microwave were tested for preparing hydrolysates, were also tested for preparing hydrolysates.

It was found that acid autoclave hydrolysis method produced the maximum nitrogen, phosphate and carbon content, boosting the growth of the microalgal cells. The microalga grown in the media prepared through this method also showed enhanced lipid content and lipid productivity.

Biofuels Processing

Researchers from Penn State University have developed a new method for converting potato waste into ethanol. The team used potato mash made from the peelings and potato residues from a Pennsylvania food-processor.

Biofilms are a way of immobilizing microbial cells on a solid support material. Penn State researchers evaluated if biofilm formation on plastic composite supports in the bioreactor can help improve ethanol production. They added Aspergillus niger and Saccharomyces cerevisiae to the bioreactor, which then catalyzed the conversion of the potato waste into bioethanol.

They found that allowing microbes to form a biofilm, the mold (A. niger) provides surface area for the yeasts' (S. cerevisiae) attachment, improving ethanol production. When in the biofilm, the microbial cells were abundant and more resistant to environmental stresses. Thus, the application of biofilm reactors contributed to the increase in production of the microbes.

Biofuels are made from renewable materials and offer an alternative to petroleum-based sources. However, many biofuels are costly to produce because the precursor bio-oil must be processed before it can be turned into liquid fuel. A new research from the University of Illinois Prairie Research Institute could be a key to make fuels produced from biological sources greener and more affordable.

Their research points to a cheaper and renewable catalyst for processing that uses common bacteria and the metal palladium, which can be recovered from waste sources. The bio-oil produced from algae contains impurities such as nitrogen and oxygen, but treating it with palladium as a catalyst during processing helps remove those impurities. For the palladium to do its job, the bio-oil needs to flow past it during processing.

To determine the effectiveness of the new method, the team conducted a variety of chemical and physical analyses and compared the biofuel quality to one made using the commercially produced catalyst. The team found that their bio-oil product was as good or even slightly better than those produced via the commercial catalyst.

However, the commercial catalyst can be used over and over without extensive processing, while the team's palladium-on-bacteria catalyst will need to undergo processing to be reused.

A new biomass pretreatment method developed at University of British Columbia's Okanagan Campus could make biofuels cheaper, safer and much faster to produce.

The new method pretreats the initial organic material with carbon dioxide at high temperature and pressure in water before being fermented, producing methane. The new pretreatment process also uses equipment and materials that are already widely available at an industrial scale.

Cigdem Eskicioglu, an associate professor with UBC Okanagan's School of Engineering also stated that while the traditional process can take weeks to months to complete, the new technique can cut production time in half. Using agricultural or forestry waste, Eskicioglu compared the traditional fermentation process with the new technique and found that it could produce methane 172% faster.

Furthermore, this technique may also make methane production safer since it will not require the use of toxic chemicals. However, work still needs to be done to convert it into an industrial scale.