There are many reasons to love sugar. It is delicious. When eaten, it turns into energy — short-lived, guilt-filled energy, but energy nonetheless. It only seems natural, then, that scientists would attempt to turn sugar into energy that can be used outside of the human body, as both batteries and biodiesel liquid fuel.
In Virginia, scientists are currently developing a sugar-powered “biobattery” that they say can store 10 times more energy than lithium-ion batteries found in smartphones. In Texas, they’re developing a biofuel made from genetically engineered yeast cells and table sugar.
“Sugar is a perfect energy storage compound in nature,” Y.H. Percival Zhang, an associate professor of biological systems engineering at Virginia Tech, told Virginia Tech News. “So it’s only logical that we try to harness this natural power in an environmentally friendly way.”
The sugar-powered batteries are an interesting idea to combat climate change — specifically the use of energy that comes from coal plants. Though regular lithium-ion batteries do not emit carbon dioxide themselves, the lithium used to power them is potentially toxic, according to Paul Bloom, a telecom researcher at IBM. Almost every landfill is loaded with lithium batteries, he said, which produces pollution.
The real issue, however, is that lithium-ion batteries in smartphones require recharging daily, which cumulatively consumes a massive amount of often coal-generated energy, he writes. As surfing the web via a smartphone becomes more common, Bloom said, we can expect more drainage of lithium-ion batteries, and therefore more coal-fired electricity to be used for charging smartphones.
The batteries being developed in Virginia don’t require regular charging, according to Zhang. They just need to be refilled with more sugar, “much like filling a printer cartridge with ink.”
“Different from hydrogen fuel cells and direct methanol fuel cells, the fuel sugar solution is neither explosive nor flammable and has a higher energy storage density,” Zeke Barlow at Virginia Tech News writes. “The enzymes and fuels used to build the device are biodegradable.”
Sweet Sugar Crude
Another group of researchers are developing a formula that is similar in composition to biodiesel made from soybean oil, only fueled by table sugar. The research, published in the journal Nature Communications on Monday, says the biofuel uses yeast to produce oils and fats, known as lipids, that can be used in place of petroleum-derived products. The yeast cells then grow on the table sugar, leading assistant professor Hal Alper to call the fuel “a renewable version of sweet crude.”
“We took a starting yeast strain of Yarrowia lipolytica, and we’ve been able to convert it into a factory for oil directly from sugar,” Alper told RedOrbit. “This work opens up a new platform for a renewable energy and chemical source.”
Biofuels, however, remain an up-and-coming technology with a commercial viability that’s far from certain. While there is no doubt a necessity to replace oil and gas — both major sources of greenhouse gas emissions — a major issue in replacing them is whether the fuel would be similar enough to gasoline to be used in existing infrastructure, or whether new fuel tanks for cars would have to be built. Though the “sweet crude” does seem to be being developed as a drop-in fuel, the language of the article is not quite clear.
Another question is whether the fuel would use enough sugar to significantly increase demand for sugar cane crops. If it did, and subsequently required more agricultural production of sugar, the fuel’s effect on mitigating carbon emissions would likely be canceled out by increased agricultural greenhouse gas emissions and the amount of land necessary to sustain the amount of crops.
“In the case of yeast and sugar, the big challenge is not the conversion of sugar to biofuel but the generation of the sugar in the first place,” Ken Caldeira, an atmospheric scientist at the Carnegie Institution for Science’s Department of Global Ecology, told Climate Progress. “Biomass energy may prove useful for aviation fuels and other specialty uses, but there just isn’t enough land available for biomass energy to be the primary path to solving the climate problem.”