18. April 2017
Since the rise of the environmental movement in the 1970s, scientists have been on a quest for better and more efficient fuel sources, and a shift in thinking about our impact on the world around us.
The scientists have delivered. Cars are more fuel efficient than ever. Cleaner fuel sources have popped up. And some of those new fuels are reducing greenhouse gas emissions.
These innovations are built on other innovations — new materials that make green technologies possible. Quite often, those components are glass. Here’s how glass propels green technology.
A tight seal in fuel cells
Solid oxide fuel cells (SOFCs) offer 95 percent overall efficiency and low emissions, making them a promising energy technology. In most cases, the main byproduct is water.
The challenge has been finding the right materials for the fuel cells. The components need to facilitate the chemical reaction that produces electricity, but have to withstand the extreme temperatures that reaction creates.
On one side of a battery is an anode, and on the other is a cathode. Between them is an electrolyte that oxygen ions pass through. The key to a long-term efficient fuel cell is a gas-tight barrier between the anode and cathode, to prevent any uncontrolled exchange of gas.
This seal between the ceramic and the metallic interconnect must handle temperatures between 600 and 1,000 degrees Celsius, as well as high humidity and the presence of fuel and oxidizing gases.
Glass and glass-ceramic sealants are the materials of choice due to their high heat resistance, chemical stability, and longevity, even in aggressive environments like fuel cells. That not only makes this energy technology possible, but extends its lifespan as well.
Algae cleans water and makes fuel
When towns and cities take water from a river or lake, they are, quite often, only borrowing it. From the water main to our homes and down the drain, water is returned to the river or stream from which it came. But it has to be cleaned before it’s discharged back into rivers.
Wastewater treatment plants have long used algae-filled ponds as an environmentally friendly way to remove phosphorus and nitrogen from water — both are good fertilizer that nourish the algae. The left-over algae can then be used as a fuel, called biomass.
Open ponds, however, suffer contamination risks, evaporation, and low-quality biomass output. Engineers are turning instead to closed systems, called photobioreactors (PBRs). Algae grown in a photobioreactor is shown to have better potential as a biomass fuel source, not to mention that DURAN™ borosilicate glass tubes used in PBRs optimize light transmission for photosynthesis, don’t cloud as they age, and can be used for years.
In one test of a PBR built with SCHOTT DURAN glass, algae in a closed system removed 10 times more phosphorus and three times more nitrogen than a conventional system.
Making green tech possible
Many of the technologies powering a more eco-friendly future face tough technical hurdles. Specialty glass has helped clear many of them. It’s prized precisely because it can work in harsh environments that require high chemical resistance and ability to withstand rapid temperature changes or high heat. Without these breakthroughs, a lot of green technology wouldn’t be possible.