Gas-to-protein agriculture: decoupling food from environment

By Eloi Grignon, Ph.D. student, Member-at-Large for the GCI

Faced with a worsening climate crisis and growing food insecurity, humans have begun to produce food from the air. While you’d be forgiven for assuming this plot to be that of an Asimov story, it is, in fact, the reality that several start-ups envision for the future of agriculture. Indeed, a wave of firms have developed gas-to-protein technologies that employ bacteria to convert feed gases into an edible flour.

In truth, none of the technologies designed to date rely solely (if at all) on air. For instance, Solar Foods, a Finnish biotech company, combines carbon dioxide from the air with green (i.e. not derived from fossil fuels) hydrogen and water to feed a carefully selected bacterium. The result of this fermentation is their proprietary Solein protein, which they currently produce at a rate of 1 kg per day.1 Others in the gas-to-protein industry have developed their fermentation processes around different gases: Calysta uses methane supplied by the energy giant BP while Lanza Tech relies on the waste carbon monoxide generated by a nearby steel plant.1

Solar Foods’ recipe for their Solein protein. From [5].

The synthesized proteins are generally viewed and marketed as alternatives to other plant-based proteins, such as those derived from soy, whose cultivation is land-intensive and can come at the cost of intense deforestation.2 Here, gas-to-protein agriculture has the tantalizing potential to produce food on similar scales while requiring only a fraction of the area. A 2018 study estimated that widespread adoption (roughly 10-20% market share) of gas-to-protein could reduce farmland area by 6% and associated GHG emissions by 7%.3

Land intensity of various protein sources. From [4].

Gas-to-protein agriculture may also help phase out animal-based proteins. One suitable target for replacement is fishmeal, the powder obtained from drying and grinding the bones and offal of commercial fisheries’ by-catch.  Fishmeal, which is used as the primary source of protein for farm-raised fish, consumes approximately one quarter of the global wild fish catch and is strongly linked with the depletion of aquatic environments and collapse of local fisheries.1 As a more sustainable alternative, Calysta produces a bacteria-sourced protein with all the amino acids required to feed farmed fish. The potential impact is huge: Calysta’s CEO claims that the presence of a 100,000-tonne plant of synthetic protein can allow 500,000 wild fish to remain in the ocean.1

The boons of gas-to-protein agriculture are pushed to truly stupendous heights when CO2-consuming processes are employed. According to Solar Foods, the operation’s economic use of energy coupled with its inherent carbon sequestration could translate to a protein with only 1% of the carbon footprint of its plant- and animal-derived counterparts.1

Beyond the increased protection of forest and aquatic ecosystems along with huge water and energy savings, gas-to-protein agriculture has other, more intangible advantages. For instance, the liberation of food production from environmental dependence means that the protein’s annual tonnage need not be subject to environmental crises or day-to-day weather. Moreover, scaling production up or down can be achieved far more easily when no marginal land or animals come into the equation.

Although there is great promise for gas-to-protein firms to gain an established foothold, there remain several economic hurdles impeding widescale production. Chief among these is the high cost of green hydrogen – a key ingredient of many firms’ protein recipe. Green hydrogen is produced from the electrolysis of water and, as such, its price is contingent on the supply of low-cost electricity. It is hoped that the economies of scale associated with the advent of renewables will lower the price of electricity sufficiently to render gas-to-protein agriculture the economically favourable option. The balance may also be tipped in favour of gas-to-protein agriculture if alternative, non-monetary costs, such as those of land and wildlife, are factored into consumer decision-making.

The first agricultural revolution saw us take mastery of our environment and irreversibly change the course of human history. If gas-to-protein agriculture is to become a mainstay, could we now, 12 millennia later, be on the brink of witnessing an equally important turning point?

References

[1] Scott, A. (2020). Food from the air. CHEMICAL & ENGINEERING NEWS98(35), 18-21.

[2] Phillips, D. (2020). The Cerrado: how Brazil’s vital ‘water tank’ went from forest to soy fields. https://www.theguardian.com/environment/2020/nov/25/the-cerrado-how-brazils-vital-water-tank-went-from-forest-to-soy-fields

[3] Pikaar, I., De Vrieze, J., Rabaey, K., Herrero, M., Smith, P., & Verstraete, W. (2018). Carbon emission avoidance and capture by producing in-reactor microbial biomass based food, feed and slow release fertilizer: potentials and limitations. Science of the Total Environment644, 1525-1530.

[4] https://www.calysta.com/feedkind/. Accessed February 20, 2021.

[5] https://solarfoods.fi/impact/#bioprocess. Accessed February 27, 2021.

The Looming Problem of Lithium-Ion Battery Waste

By Eloi Grignon, Ph.D. student, Member-at-Large for the GCI

Since their commercialization in 1991, lithium-ion batteries (LIBs) have gradually come to pervade our daily lives. Their ubiquity is achieved through our phones and laptops (you are likely reading these words via energy supplied by a LIB), where they are used to power not only our communication with one another, but also the myriad other tasks that we have come to delegate to our devices. Increasingly, LIBs are powering how we move, too, as is evidenced by the several million battery electric vehicles already on the road.1 With the production of electric vehicles set to skyrocket – the British and French governments have already pledged to ban sales of fossil-powered vehicles by 2040 – and the possibility of using LIBs for storage of grid electricity, it is clear that LIBs are not going anywhere, either.2 Indeed, spent batteries are expected to be generated at a rate of 2 million metric tons per year by 2030.3

And yet, there is no clear idea of what is to happen to these batteries once they’ve served their purpose. Currently, fewer than 5% of LIBs in the US and Europe are recycled while the rest end up in landfills.3

Since a LIB is densely comprised of several costly metals (Figure 1), it is fair to liken used batteries to enriched ore.3 It follows, then, that complete disposal of millions of metric tons of such a material represents a tremendous waste.

Figure 1.

Figure 1. Breakdown of LIB constituents. From Ref [3].

Recycling could curb the waste by salvaging this ‘ore’ and supplying it to LIB manufacturers at a cheaper price than that of virgin materials, thereby reducing LIB cost. Moreover, less of the material would have to be mined and treated in the first place. This is especially important when considering the impacts of both processes: mining has obvious environmental consequences while ore treatment is typically energy-intensive and can release harmful gases such as SOx.4 Furthermore, 10-25% of global cobalt production is mined by ‘artisanal’ workers in the DRC, many of whom lack proper wages and equipment. The UNICEF estimated in 2012 that 40,000 children were employed in such mines.5 From this perspective, LIB landfilling has a heavy economic, environmental, and moral opportunity cost attached.

In addition to wastefulness, landfilling LIBs also has direct negative consequences. Over time, the toxic constituents of the LIBs tend to flow into the soil, eventually leaching into the groundwater and accumulating in various organisms. These toxins can make their way up to humans, thus extending the health hazard to people. The harm imposed by discarded LIBs on the environment is not without some degree of irony, as LIBs have long been celebrated as a key cog in the establishment of a greener future. Evidently, this detrimental end-of-life scenario presents an incongruity.

Given the benefits of LIB recycling, it is clear that technical and economic barriers, rather than lack of purpose, are responsible for the poor recycling rates.

One such barrier results from the complicated composition within LIBs, which renders separation and recovery of all components difficult. For instance, smelting can effectively recover the heavy metals nickel, cobalt, and copper but fails to salvage lithium and the electrolyte. While hydrometallurgical (chemical leaching) methods can recover more components, they necessitate acids, hydrogen peroxide, and 7 m3 of water per ton of LIB.6 Needless to say, this is not ideal.

Another technical issue is the great variability between LIBs – different manufacturers tend to use different components and so there is no one universal composition (this pertains mainly to vehicles). As such, a recycling firm is at the mercy of its feedstock – for an input collected from many sources, there is no guarantee that 1 ton of batteries will yield a given amount of, say, cobalt.

These issues appear blatant when considering as a counterexample the success story of lead-acid battery recycling, whose simple and standardized composition – about 60% lead – enables an easy recycling process that claims nearly all (99%!) of used batteries.4

The low recycling rates are also due to economic factors. The end-to-end recycling process is energy-intensive and requires many steps, thus increasing costs. A firm operating such a process must carefully assess whether their repurposing protocol is cheap enough to supply materials that are price-competitive with mined materials. Due to the lack of LIB standardization and high volatility of constituent prices, this assessment is far from trivial and the business represents a clear risk. This risk is further exacerbated by the uncertainty of what the future of energy storage may resemble. In the arms race for higher energy density, new technologies arise frequently, thus threatening to render state-of-the-art materials (and so, recycling processes) obsolete.

While the above paragraphs appear rather pessimistic, it should be noted that we are only at the onset of the LIB boom. Indeed, the field of LIB recycling is still gaining traction and it is expected that serious investments will aid in the development of more efficient recycling techniques. To this end, the US DoE (through the $15 million ReCell Center) and the UK-based ReLib project have pledged to fund and support R&D in LIB recycling.3

There is also a clear interest from the private sector as is evidenced by the numerous startup firms currently designing their own protocols, including the Toronto-based company Li-Cycle.7

Another approach to sustainable energy storage is to circumvent the need for recycling breakthroughs altogether by designing the LIB differently from the start. For instance, the use of organic materials that are easily recyclable is increasingly explored for use in devices.1 Not only are these materials favourable in the end-of-life stage, but their production is also cheap, accessible, and environmentally benign.

In any case, scientists, engineers, and policymakers must come together to address the issues caused by LIB landfilling. And quickly, too, because the storm is coming (Figure 2).

Figure 2. A possible scenario for the growth of electric vehicle sales in the next decade. PLDVs = passenger light duty vehicles; LCVs = light commercial vehicles; BEVs = battery electric vehicles; PHEV = plug-in hybrid electric vehicles. From Ref [1].

References

  1. Poizot, P.; Gaubicher, J.;  Renault, S.;  Dubois, L.;  Liang, Y.; Yao, Y. J. C. R., Opportunities and Challenges for Organic Electrodes in Electrochemical Energy Storage. 2020.
  2. Gardiner, J. J. T. G., The rise of electric cars could leave us with a big battery waste problem. 2017, 10.
  3. It’s time to recycle lithium-ion batteries. C&EN Global Enterprise 2019, 97 (28), 29-32.
  4. Gaines, L. J. S. M.; Technologies, The future of automotive lithium-ion battery recycling: Charting a sustainable course. 2014, 1, 2-7.
  5. Frankel, T. C.; Chavez, M. R.; Ribas, J. J. T. W. P., The cobalt pipeline. Tracing the path from deadly hand-dug mines in Congo to consumers’ phones and laptops. 2016, 30.
  6. Larcher, D.; Tarascon, J.-M. J. N. c., Towards greener and more sustainable batteries for electrical energy storage. 2015, 7 (1), 19-29.
  7. https://li-cycle.com/about-us/.