Science

Light-powered catalyst makes profitable hydrogen from stinky waste gas

Hydrogen sulfide famously stinks like rotten eggs, and contributes that eye-watering, low-hanging punch to the bouquet of the very worst farts. It’s additionally poisonous, corrosive, flammable and produced in massive quantities as an expensive-to-treat by-product at petroleum refineries. Now, researchers have discovered a straightforward, profitable strategy to flip it into hydrogen.

The present technique for coping with these items – an unavoidable waste product once you’re refining oil or pure gas – is to warmth it up with air to between 800-1,100 °C (1,470-2,000 °F), then run it via a sequence of condensers, reheaters and catalytic reactors to transform it into sulfur and water in what’s often called the Claus Process. The sulfur may be offered on, however the excessive temperatures concerned make this an energy-hungry course of.

Now, researchers at Rice University say they’ve discovered a strategy to just about remove that vitality use and its related emissions, whereas nonetheless recovering the sulfur and capturing helpful hydrogen gas in addition.

The new course of makes use of a nano-engineered silicon dioxide powder catalyst, every grain speckled with nanoparticles of gold simply billionths of a meter vast. These gold particles reply strongly to a selected wavelength of seen gentle, taking pictures out short-lived electrons often called “hot carriers,” which carry sufficient vitality to separate H2S molecules effectively into H2 and S for separate seize.

The course of may be fully powered by daylight, and thus kind of free for a refinery when it comes to working prices the place daylight is offered. But in accordance with the analysis group, it really works simply advantageous with synthetic gentle as nicely, and will find yourself being so low cost and environment friendly that you can roll it out with its personal low-powered LED lighting and harvest hydrogen and sulfur whereas cleansing up sewer gas underground.

“Hydrogen sulfide emissions can result in hefty fines for industry, but remediation is also very expensive,” mentioned Naomi Halas, lead writer on the examine and co-founder of Syzygy Plasmonics, which has licensed the brand new technology for commercialization. “The phrase ‘game-changer’ is overused, but in this case, it applies. Implementing plasmonic photocatalysis should be far less expensive than traditional remediation, and it has the added potential of transforming a costly burden into an increasingly valuable commodity.”

While this technique ought to truly cut back carbon emissions as a result of vital vitality use it obviates within the refining course of, it appears unlikely that the ensuing hydrogen will meet the factors for “green” classification, since on the finish of the day it is coming from fossil gasoline.

The examine is offered within the journal ACS Energy Letters.

Source: Rice University

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