Published on January 8th, 2016 | by Tina Casey9
Moorella The Solar Powered Cyborg Turns CO2 Into Something Useful & Good
January 8th, 2016 by Tina Casey
Yes, it’s a thing. Solar energy can be used to transform the greenhouse gas carbon dioxide into useful chemical products. CleanTechnica has been following a number of these “artificial photosynthesis” systems through the R&D phase and we just caught wind of a new one from Lawrence Berkeley National Laboratory that involves a cyborg bacterium with a name that sounds like a scream queen from the glory days of the B movie: Moorella thermoacetica.
Another Nail In The Coffin Of Carbon Sequestration
Before we take a closer look at M. thermoacetica, let’s step back and look at the implications for the carbon sequestration movement. Sequestration adds a significant category of waste to the growing pile that future generations will eventually have to deal with in one form or another, so it doesn’t really solve a problem, it simply shoves it aside.
More to the point, sequestration can be prohibitively expensive — look what happened to FutureGen — and in the case of underground storage a sequestration facility could be exposed to disruption from emerging conditions and episodes such as drought or earthquakes.
As capably demonstrated by the ongoing leak from a large natural gas storage facility in California, external disruption is not the only risk faced by underground storage systems, and all bets are off when facility owners make irresponsible decisions.
As one indicator of where things are going in the US, the Department of Energy recently pulled the funding rug out from under the FutureGen sequestration project while pumping up the carbon recycling company LanzaTech.
Moorella And Solar Energy
That brings us back to solar energy and M. thermoacetica. This particular bacterium is actually not photosynthetic, but the research team got it to perform photosynthesis by doping it with nanoscale particles of the semiconductor cadmium sulfide, which explains the “cyborgian” aspect as described by lead researcher Peidong Yang:
By inducing the self-photosensitization of M. thermoacetica with cadmium sulfide nanoparticles, we enabled the photosynthesis of acetic acid from carbon dioxide over several days of light-dark cycles at relatively high quantum yields, demonstrating a self-replicating route toward solar-to-chemical carbon dioxide reduction.
As for M. thermoacetica, this particular bacterium is highly efficient at producing acetic acid through photosynthesis, to the tune of almost 90 percent. The result is a cyborg system that is almost as efficient as natural photosynthesis. Compared to fully artificial photosynthesis systems, the hybrid system has the potential for lower costs, partly due to the advantage of biological self-assembly and repair.
You can get more details from the study under the title “Self-photosensitization of non-photosynthetic bacteria for solar-to-chemical production” in the journal Science.
Commercializing Carbon Conversion
Speaking of LanzaTech, the Energy Department is mainly interested in the company for the development of a bio-based method for converting methane to a transportable liquid, through an initiative called REMOTE.
The main target is fossil natural gas but there could be potential to apply the process to biogas as well. In particular, the Energy Department has tasked LanzaTech with developing small-scale systems that could be used economically at remote natural gas drilling sites, so we’re thinking that it could also be used at livestock farms and other facilities that can produce biogas.
Meanwhile, LanzaTech is also barreling down the road to commercializing its fermentation based gas-to-products system for recycling waste carbon, so stay tuned.
Image: via Berkeley Lab.