Contributed by Freya Burton, Director of Communications, LanzaTech
Today there is an abundance of carbon in all the wrong places. We currently recycle metals, plastics and paper. So why not recycle carbon?
Emerging technologies and continued innovation hold the promise of real solutions which enable a reduction in our utilization of “new carbon” while we continue to meet growing global energy demand. Imagine a world where waste carbon is captured and recycled into new products, such as plastics for building materials, toys, synthetic fibers; carbon may even replace the oil-derived nylon in yoga pants! Imagine you can choose the products you use in your daily life based on where the carbon in them has come from. Would you choose material recently taken from the ground (“new carbon”)? Or a “carbon smart” product made from recycled carbon? Our current carbon dilemma is a global opportunity; carbon recycling will change our world.
LanzaTech’s innovative green chemistry pathway is challenging how the world thinks about waste carbon—it is treated as an opportunity instead of a liability. The gas-to-liquid platform uses proprietary microbes to ferment carbon-rich waste gases, such as those from industrial flue stacks, producing liquid fuels such as ethanol and chemicals such as 2,3 butanediol as they grow. This process can be likened to brewing, but instead of sugars and yeast we use waste gases and microbes. Instead of beer, we produce ethanol and chemicals. This is not a lab curiosity. The technology has been demonstrated capturing and recycling steel mill off-gases at scale in China with Shougang Corporation and in Taiwan with China Steel. The first commercial units are under construction in Belgium with the world’s largest steel maker, ArcelorMittal.
The LanzaTech microbe is a naturally-occurring organism in the family of acetogens, or gas-fermenting organisms. The microbes are hypothesized to be one of the oldest on earth, using gases from hydrothermal vents to grow. LanzaTech’s founder, Sean Simpson, made a link between the gases from hydrothermal vents to those produced from industries today. Biomimicry has led to the development of microbes that are tolerant to high levels of toxicity; avoiding expensive conditioning, an economic factor historically stalling gas fermentation technologies.
The design and control of biological conversion processes offer different and distinct advantages for the chemical industry. Biology is capable of catalysis with high specificity and for the production of highly oxygenated products – we should expect to be able to produce and procure molecules that we’ve never had access to before. Then we can ask the question, not what molecules are available, but what is the best molecule or combination for a particular application? Secondly, biological conversion processes operate at a narrow range of temperatures and pressures. This means one process could be swapped out for another, using the exact same hardware, when the markets and prices change. A simple example of this is that a facility that produces ethanol could exchange the biological catalyst to one that produces isopropanol, and it could use the same conversion and separation equipment. Decisions around an asset no longer need to project the 20-year price of a particular molecule. When fully realized, and when combined with the revolution in information, this will serve to stabilize commodity markets and improve their efficiency.
Waste gas is a highly attractive resource for fuel and chemicals production due to its low value and high annual volumetric production. LanzaTech is focused on reusing gas streams rich in carbon monoxide (CO) that are common by-products of established manufacturing processes. Often these gases cannot be utilized efficiently and are therefore wasted. The conversion of CO rich gases through synthetic chemical pathways, for example Fischer-Tropsch or methanol synthesis, requires that H2 be available in the synthesis gas. This is not always the case in waste industrial gases. To overcome this challenge, LanzaTech’s microbes have a highly efficient biological water-gas shift reaction, compensating for any deficit of H2 in the input gas stream by catalyzing the release of H2 from water using the energy in CO.
In addition, current chemical production methods involve commodity raw materials (sugars, petroleum, natural gas) whose value can change dramatically over short periods of time. A gas stream cannot be easily traded and therefore the utilization of a gas stream as a feedstock will result in decoupling the production of commodity chemicals from commodity feedstocks. This means the fluctuations in the cost of raw materials and therefore chemical intermediates will be dampened substantially by introducing chemicals produced from waste gas streams. This will have a game-changing impact on the chemical industry and it's supply chain - a trillion dollar industry shifting the way it thinks about commodity sourcing and supply. Innovation in green chemistry holds the key to our energy future and offers significant solutions to a growing number of societal, environmental and economic challenges. New sustainable technologies are already today changing how we look at energy and food production, chemical manufacture and resource efficiency.
"Consider the cherry tree," Michael Braungart and William McDonough wrote in "Cradle to Cradle: Remaking the Way We Make Things". "A cherry tree produces thousands of blossoms which create fruit for birds, humans and other animals in an effort to grow one tree. The blossoms and fruit that fall to the ground aren’t waste, they are food for other systems and processes that nourish the tree and soil. It’s a question of design and eco-effectiveness, a question we should be addressing in our approach to life and manufacturing."
Carbon recycling does just that. Waste should not be allowed to exist. We have the tools and the innovations at our disposal to be resource efficient and to capture, reuse or recycle waste streams, much like a cherry tree will use the nutrients from its fallen leaves and blossoms as a resource for further growth. We envisage a carbon smart future where a steel mill would be able to produce the steel to make a car and then use the wastes from that process to make the fuel. But why stop there? The chemical derivatives would be used to produce the interior plastic moldings, the seating foam, the structural adhesives, the exterior coatings and paints and the synthetic rubber for that same car!
That is only a glimpse at a carbonsmart future. Innovations in green chemistry will allow us to realize this vision.
“The Nexus Blog” is a sister publication of “The Nexus” newsletter. To sign up for the newsletter, please email email@example.com, or if you have an ACS ID, login to your email preferences and select “The Nexus” to subscribe.
To read other posts, go to Green Chemistry: The Nexus Blog home.