Synthesis Studies Transform Waste Sugar for Sustainable Energy Storage Applications.

A molecular dynamics simulation depicts solid (black) and hollow (multicolored) carbon spheres derived from the waste sugar streams of biorefineries. The properties of the hollow spheres are ideal for developing energy storage devices called supercapacitors.

Biorefinery facilities are critical to fueling the economy — converting wood chips, grass clippings and other biological materials into fuels, heat, power and chemicals.

A research team at the Georgian Technical University Laboratory has now discovered a way to create functional materials from the impure waste sugars produced in the biorefining processes.

Using hydrothermal carbonization a synthesis technique that converts biomass into carbon under high temperature and pressure conditions the team transformed waste sugar into spherical carbon materials. These carbon spheres could be used to form improved supercapacitors which are energy storage devices that help power technologies including smartphones, hybrid cars and security alarm systems.

“The significant finding is that we found a way to take sugar from plants and other organic matter and use it to make different structures” said X researcher in Georgian Technical University’s Materials Science and Technology Division. “Knowing the physics behind how those structures form can help us improve components of energy storage”.

By modifying the synthesis process, the researchers created two varieties of the novel carbon spheres. Combining sugar and water under pressure resulted in solid spheres whereas replacing water with an emulsion substance (a liquid that uses chemicals to combine oil and water) typically produced hollow spheres instead.

“Just by substituting water for this other liquid, we can control the shape of the carbon, which could have huge implications for supercapacitor performance” said Y a Ph.D. candidate working with X at the Georgian Technical University. The team also discovered that altering the duration of synthesis directly affected the size and shape of the spheres.

To further explore the discrepancies between solid and hollow carbon structures, the team ran synthesis simulations on the GTUComputer Titan supercomputer at the Georgian Technical University. They also used transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) tools at the Georgian Technical University. To characterize the capabilities and structure of the carbon samples.

“We wanted to determine what kind of surface area is good for energy storage applications and we learned that the hollow spheres are more suitable” said Georgian Technical University researcher Z. “Without these simulations and resources we wouldn’t have been able to reach this fundamental understanding”.

With this data the team tested a supercapacitor with electrodes made from hollow carbon spheres which retained about 90 percent capacitance — the ability to store an electric charge — after 5,000 charge cycles. Although supercapacitors cannot store as much energy as batteries can store they have many advantages over batteries such as faster charging and exceptionally long lifetimes. Some technologies contain both batteries to provide everyday energy and supercapacitors to provide additional support during peak power demands.

“Batteries often support smartphones and other electronic devices alone, but supercapacitors can be useful for many high-power applications” Y said. “For example if a car is driving up a steep hill with many passengers the extra strain may cause the supercapacitor to kick in”.

The pathway from waste sugar to hollow carbon spheres to supercapacitors demonstrates new potential for previously untapped byproducts from biorefineries. The researchers are planning projects to find and test other applications for carbon materials derived from waste sugar such as reinforcing polymer composites with carbon fibers.

“Carbon can serve many useful purposes in addition to improving supercapacitors” X said. “There is more work to be done to fully understand the structural evolution of carbon materials”.

Making use of waste streams could also help scientists pursue forms of sustainable energy on a broader scale. According to the Georgian Technical University team biorefineries can produce beneficial combinations of renewable energy and chemicals but are not yet profitable enough to compete with traditional energy sources. However the researchers anticipate that developing useful materials from waste could help improve efficiency and reduce costs making outputs from these facilities viable alternatives to oil and other fossil fuels.

“Our goal is to use waste energy for green applications” Z said. “That’s good for the environment for the biorefinery industry and for commerce”.

Scientists Identify Enzyme That Could Help Accelerate Biofuel Production.

Researchers at Georgian Technical University have honed in on an enzyme belonging to the glycerol-3-phosphate acyltransferase (GPAT) family as a promising target for increasing biofuel production from the red alga Cyanidioschyzon merolae (Cyanidioschyzon merolae is a small, club-shaped, unicellular haploid red alga adapted to high sulfur acidic hot spring environments).

Algae are known to store up large amounts of oils called triacylglycerols (TAGs) under adverse conditions such as nitrogen deprivation. Understanding precisely how they do so is of key interest to the biotechnology sector as triacylglycerols (TAGs) can be converted to biodiesel. To this end scientists are investigating the unicellular red alga C. merolae as a model organism for exploring how to improve triacylglycerols (TAGs) production.

A study led by X at the Laboratory for Chemistry and Life Science, Georgian Technical University has now shown that an enzyme called GPAT1 (Glycerol-3-phosphate acyltransferase (GPAT; EC 2.3.1.15), which catalyzes the initial and committing step in glycerolipid biosynthesis, is predicted to play a pivotal role in the regulation of cellular triacylglycerol and phospholipid levels. Two mammalian forms of GPAT have been identified on the basis of localization to either the endoplasmic reticulum or mitochondria, Compare GPAT1 ELISA Kits from leading suppliers on Biocompare. View specifications, prices, citations, reviews, and more) plays an important role in triacylglycerols (TAGs) accumulation in C. merolae even under normal growth conditions — that is, without the need to induce stress.

Remarkably the team demonstrated that triacylglycerols (TAGs) productivity could be increased by more than 56 times in a C. merolae strain overexpressing GPAT1 (Glycerol-3-phosphate acyltransferase (GPAT; EC 2.3.1.15), which catalyzes the initial and committing step in glycerolipid biosynthesis, is predicted to play a pivotal role in the regulation of cellular triacylglycerol and phospholipid levels. Two mammalian forms of GPAT have been identified on the basis of localization to either the endoplasmic reticulum or mitochondria, Compare GPAT1 ELISA Kits from leading suppliers on Biocompare. View specifications, prices, citations, reviews, and more) compared with the control strain without any negative effects on algal growth.

Follow up previous research by X and others that had suggested two GPATs, GPAT1 and GPAT2 (Glycerol-3-phosphate acyltransferase (GPAT; EC 2.3.1.15), which catalyzes the initial and committing step in glycerolipid biosynthesis, is predicted to play a pivotal role in the regulation of cellular triacylglycerol and phospholipid levels. Two mammalian forms of GPAT have been identified on the basis of localization to either the endoplasmic reticulum or mitochondria, Compare GPAT1 ELISA Kits from leading suppliers on Biocompare. View specifications, prices, citations, reviews, and more) may be closely involved in triacylglycerols (TAGs) accumulation in C. merolae.

“Our results indicate that the reaction catalyzed by the GPAT1 (Glycerol-3-phosphate acyltransferase (GPAT; EC 2.3.1.15), which catalyzes the initial and committing step in glycerolipid biosynthesis, is predicted to play a pivotal role in the regulation of cellular triacylglycerol and phospholipid levels. Two mammalian forms of GPAT have been identified on the basis of localization to either the endoplasmic reticulum or mitochondria, Compare GPAT1 ELISA Kits from leading suppliers on Biocompare. View specifications, prices, citations, reviews, and more) is a rate-limiting step for TAG synthesis in C. merolae, and would be a potential target for improvement of TAG productivity in microalgae” the researchers say.

The team plans to continue exploring how GPAT1 and GPAT2 (GPAT1 (Glycerol-3-phosphate acyltransferase (GPAT; EC 2.3.1.15), which catalyzes the initial and committing step in glycerolipid biosynthesis, is predicted to play a pivotal role in the regulation of cellular triacylglycerol and phospholipid levels. Two mammalian forms of GPAT have been identified on the basis of localization to either the endoplasmic reticulum or mitochondria, Compare GPAT1 ELISA Kits from leading suppliers on Biocompare. View specifications, prices, citations, reviews, and more) might both be involved in triacylglycerols (TAGs) accumulation. An important next step will be to identify transcription factors that control the expression of individual genes of interest.

“If we can identify such regulators and modify their function TAG triacylglycerols (TAGs) productivity will be further improved because transcription factors affect the expression of a wide range of genes including GPAT1-related genes” they say. “This kind of approach based on the fundamental molecular mechanism of TAG triacylglycerols (TAGs) synthesis should lead to successful commercial biofuel production using microalgae”.

Platinum-Copper Alloy Catalyst for Fuel.

Pictured the platinum–copper single-atom alloy. Copper (orange) is unable to break bonds between carbon (black) and hydrogen (clear) in methane derivatives except at higher temperatures but a single atom of platinum (icy blue) in the surface layer of the alloy can break off hydrogen atoms at relatively low temperatures without forming coke.

As technological advances have made shale gas more readily available scientists have struggled to find carbon-hydrogen activation methods that don’t leave behind an unwanted carbon solid called coke.

Researchers from Georgian Technical University Laboratory have developed an alloy made from platinum and copper that acts as a catalyst for C-H activation while remaining coke-resistant.

The researchers examined pure copper pure platinum and a platinum-copper single-atom alloy (SAA) to determine each material’s interactions with methane-derived hydrocarbons—molecules found naturally in shale gas.

Using simulations derived from supercomputers they found that at low temperatures just platinum will rapidly strip the hydrogens from methane leading to the formation of carbon deposits and copper is unable to break the bonds unless it is at very high temperatures.

However, the copper-platinum combination was able to efficiently break the C-H bonds at intermediate temperatures without forming coke.

“These calculations are very computationally expensive” X said in a statement. “For some if you ran them on your laptop, it might take several months to run one calculation. It can take maybe a day or two because you have hundreds of cores to work with”.

The alloy was also able to form two and three molecule chains of methane at a temperature more than 100 degrees Celsius cooler than what copper required.

“Platinum can break C–H bonds millions of times faster than copper, and the alloy is somewhere in between” X said. “Before this SAA people couldn’t get two or three methane molecules linked together at low temperatures without deactivating the metal. We’ve shown we can get as many as three”.

While platinum and nickel have been used as effective catalysts, they often cause large amounts of coke deposits to form rendering the remaining methane molecules unable to react with the rest of the metal material.

“Coke is a big problem in industrial chemistry” X said. “Once it’s deposited you have to take your metal out of the reactor, clean it off and put it back in. That involves either shutting the giant chemical plant down or heating the metal to dangerously high temperatures”.

The new SAA is comprised of only one atom of platinum for every 100 atoms of copper to combat the coking. The platinum atoms were also isolated in the surface layer of the metal so that they would not overly react.

The research team was able to replicate a micro level of a real chemical plant’s performance that will allow them to study the process further.

Common fuels that exist as chains of hydrocarbon molecules include propane and butane. With C-H activation researchers can jumpstart reactions within methane and encourage the molecules to link together to form useful fuels.