Green Chemistry and Chemicals Policy: Bridging the Policy Gap

By Maggie Wang, Social Media Executive for the Green Chemistry Initiative at the University of Toronto

We often think of green chemistry as something that happens in the lab: using catalysts to conserve energy and reactants, closing fume hoods when not in use, designing more efficient reaction pathways to reduce waste. Yet, policy plays a significant role in supporting the adoption of green chemistry in industry, education, and by the public – in fact the very field of green chemistry was conceived at the US Environmental Protection Agency. Through providing incentives to move away from/towards certain types of chemistry, policy can motivate research, development, and innovation in the direction of greener practices in chemistry. In short, chemical policy drives a demand for safer alternatives, while the science of green chemistry provides the solutions.

It’s easy to confuse green chemistry with sustainable chemical policy, but policy follows the development of science. Advancements in green chemistry require improvements in existing processes, such as using a less hazardous reagent, reducing waste, or using less energy. So green chemists must first invent a technology that can make a material or process greener, and then chemicals policy can be implemented to facilitate the adoption of these practices. Thus, when the two—green chemistry practices in the lab and chemicals policy that promotes green chemistry—intersect, green chemistry advances.

Once these green chemistry practices are developed, how can we use policy to further the implementation of green chemistry beyond the lab? Poorly designed policies can serve as barriers to green chemistry, and currently, green chemistry faces several challenges: mainly, a lack of education that focuses on green chemistry, and a lack of financial incentives that motivate the chemicals industry to move towards greener chemistry practices.

To bridge these gaps and advance green chemistry, we need increased collaboration between green chemists and policymakers to create policy that motivates industry investment in the design/production of green chemistry processes/materials, and an organized effort to integrate green chemistry into chemistry education to develop a workforce that can implement the technologies and processes of green chemistry.

References:

Anastas, P.; Eghbali, N. Green Chemistry: Principles and Practice. Chem. Soc. Rev. 2009,39,

301-312. DOI: 10.1039/B918763B

Cannon, A. S.; Warner, J. C. The Science of Green Chemistry and its Role in Chemicals Policy and Educational Reform. New Solutions. 2011, 21 (3), 499-517. DOI: 10.2190/NS.21.3.m

Jarvis, E. A. A. Green Chemistry in United States Science Policy. Green Chem. Lett. and Rev. 2019, 12 (2), 161-167. DOI: 10.1080/17518253.2019.1609599

Maxim, L. The Birth of Green Chemistry: A Political History. Science, Tech., & Human Values. 2023. DOI: 10.1177/01622439231203063

Tickner, J.; Giraud, R. The Role of Policy in Green Chemistry Research & Adoption. Presented at the Green Chemistry & Commerce CouncilGreen Chemistry Education Webinar Series. June 16, 2015.

Perspective from University of Toronto’s Inaugural Green Chemistry Workshop: Discovering Practical Tools and Resources for a Greener Future

By Alicia Battaglia, Graduate Student and Education and Outreach Coordinator of the Green Chemistry Initiative at the University of Toronto

Goal of the Workshop

The goal of this workshop was to offer graduate students a chance to learn about green chemistry and discover practical methods for integrating it into their own research projects. Additionally, the workshop included discussions on alternative career paths in chemistry, such as opportunities in non-profit organizations.

Workshop Content

During the first portion of the workshop, participants engaged in an interactive session led by Dr. Juliana Vidal from Beyond Benign, focusing on practical applications of green chemistry that can be used in a research context, such as solvent selection, waste prevention, and energy conservation, to name a few. After learning about these resources, students collaborated in small groups to generate ideas on how to integrate these newly acquired tools and insights into their own research projects. This activity allowed students to gather a better understanding of the considerations that one needs to consider to call one’s reaction green. They realized that, in some cases, the electrical equipment (i.e. fumehoods, vacuum pumps, gloveboxes) were what weighted the most in terms of green chemistry.

After lunch, Jasmine Hong, a student representative from Green Chemistry McGill, shared insights on how to bring green chemistry to your own institution. She discussed several ways that you can engage your campus, such as getting your department involved (glove recycling program, GCC signing), starting your own student group (hosting events to engage student body), and making connections with other universities. Other participants can consider adopting these strategies at their own institutions.

Following this, participants took part in a career panel discussion featuring a variety of esteemed figures in the field of green chemistry, including Juliana Vidal (Beyond Benign, non-profit organization), John Warner (President and CEO of The Technology Greenhouse, recognized as the “father of green chemistry”), and Areej Nitowski (educational manager at MilliporeSigma, a leading global chemical corporation). The panelists shed light on their career journey, shared tips on the application process, and discussed a typical day in their profession. One of the most notable pieces of advice that the participants received was from John Warner, in which he stated that “the world needs excellent chemists.” He stressed the importance of collaboration, and that chemists should talk and work together with people in other disciplines (i.e. business, law) to more efficiently tackle today’s issues. Furthermore, Areej Nitowski recommended that students become more active in their local community, specifically interacting with high school students and showing them their passions and the importance of chemistry in today’s society.

Post-Workshop Feedback

After the workshop, a feedback form was sent to all in-person attendees to assess what participants enjoyed, as well as discover actionable ways in which we can improve the event for next year. When asked what part of the workshop participants found most interesting, 88% responded that the reaction activity before lunch was the most useful, with the career panel coming in second at 50%. When considering what aspect of the workshop could be improved, participants suggested that information on how green chemistry can be used for inorganic or polymer/materials fields would be valuable, as most of the examples focused on organic syntheses and processes. Overall, 75% of participants ranked the workshop as a 4 or above out of 5, with 5 being very satisfied, indicating that majority of participants enjoyed the event.

Concluding Remarks

Ultimately, this workshop aimed to address a key requirement within the realm of green chemistry: the absence of sufficient green chemistry education, particularly at the graduate level. Our objective was to bridge the gap between what is learned in undergraduate courses and industry by offering this vital green chemistry workshop tailored to graduate students, thereby narrowing the knowledge gap in this field.

Due to the event’s success and the favourable feedback from the attendees, we plan to hold this workshop annually in the future. Additionally, the workshop was recorded and posted on our GreenChemUofT Youtube Channel, ensuring that everyone has free access to the valuable content in the future.

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. 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 SO_x.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/.

Just Keep Flowing

By Nour Tanbouza (twitter @Nour_Tanbouza), PhD student, Laval University

Flow chemistry is a synthetic technique that enables chemical reactions to take place in a continuously flowing manner as opposed to running a reaction in a flask, sometimes termed batch chemistry. It has become incredibly mainstream and has been adopted by many chemical industries as a means to increase efficiency of large-scale reactions in highly controlled setups.¹ What is flow chemistry, and why is it important? Furthermore, the main question, how does it contribute to sustainability?

Let us start by putting on a lab coat and safety goggles and strolling through a modern synthetic chemistry lab. Now, have a look around. What you will absolutely recognize and remember is a vast space of fume hoods and benches with different apparatus lying around like round bottom flasks, chromatography columns, stirrers, hot plates, etc. After that, take a browse through images of those same types of laboratories from the 1900s or even from the 1700s. Surely you will notice some improved safety features but what will strike you the most is how similar they are in terms of the equipment used then and now. We indeed currently have better stirring and heating equipment etc., but we still do reactions in round bottom flasks as batches.

Figure 1. on the left: 18^th century laboratory used by Antoine Lavoisier (credits Sandstein / CC BY (https://creativecommons.org/licenses/by/3.0)); on the right: Modern synthetic chemistry laboratory ( credits Elrond / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)

In 2005, the catastrophic T2 laboratories explosion occurred after a thermal runaway and high-pressure build-up of their 2,500-gallon batch reactor producing MMT (methylcyclopentadienyl manganese tricarbonyl).² These types of accidents pose a huge risk to human life and the environment in addition to the legal and financial troubles that the company could face. Thus, there is an exigent need for safe and practical technologies that enable an efficient scale up of chemical reactions. These pursuits explain the recent uptake of flow chemistry by many manufacturing companies, especially those in the pharmaceutical industry.

Figure 2. Aerial view of T2 Laboratories explosion

Flow chemistry can be thought of as a bench chemist’s very own cherry tree. The raw material is fed into the roots (pumps). Roots are the heart of the tree, and the same holds for the pumps of a flow system, so it is pivotal that they are well taken care of and are in perfect shape. Those nice healthy roots then flow the raw material over a large surface area up into the stems and leaves where reaction conditions are highly controlled and in perfect balance to elute the desired product continuously. Thus, whether targeting a few milligrams or multi-kilograms of product, it is dependent on how much feed material is flowed into the reactor. A flow reactor can be as small as a chip and still produce the needed amount of product. In 2019, flow chemistry was announced by the IUPAC (International Union of Pure and Applied Chemistry) as one of the ten chemical innovations that will change our world.³ There has been a significant paradigm shift by many industries, especially the pharmaceutical industry, to adopt flow chemistry. It is a technology that promises on-demand drug production, which is vital primarily for developing countries to access drugs in a decentralized manner.¹

Figure 3. An academic flow system (equipped with a photoreactor)

Green chemistry principles and a chemical industry’s agenda align when it comes to large scale reactions. Thus, it is not so surprising to see a significant uptake of flow chemistry by many companies. This kind of endorsement has helped spark research in continuous flow which is beginning to become a dominating area of study. Among the UN Sustainability Goals is responsibility for consumption and production, which is achieved in flow because it minimizes the amount of material needed for screening and allows reactions to take place in highly concentrated media. Reaction conditions being highly controlled (such as temperatures, pressure, mixing, etc.), allow reactions to be more selective and thus decreases any by-products and increases productivity.⁴ Also, hazardous chemicals can be safely manipulated in flow because there is no significant build-up at any given time. It is very versatile and modular where multiple reactions can be installed in sequence to consume any reactive intermediates in situ, and purification systems can be added directly as well. A reaction can be run at extremely high temperatures that go above boiling points which can enable reactions to proceed faster while being inherently safer and consuming significantly less energy when compared to a batch reactor.

Figure 4. Illustration of a flow chemistry setup

This type of “thinking outside the flask” means stepping outside of a long-standing comfort zone which is not always trivial. However, this type of venture and side-by-side work of engineers and chemists is what made flow chemistry possible, and it is changing our world. Flow chemistry is still in its early stages, yet so much innovation has already been introduced. Give it a few years, and when you walk back into that synthetic chemistry lab, prepare to be flabbergasted by a space that resembles nothing of the past.

 

References:

1. Malet-Sanz, L.; Susanne, F., Continuous flow synthesis. A pharma perspective. J. Med. Chem. 2012, 55, 4062-4098.
2. http://www.csb.gov/UserFiles/file/T2%20Final%20Report.pdf
3. Gomollón-Bel, F., Ten Chemical Innovations That Will Change Our World. Chemistry International 2019.
4. Jensen, K. F.; Rogers, L., Continuous manufacturing – the Green Chemistry promise? Green Chemistry 2019, 21, 3481-3498.

Boat Antifouling Technology: the problems and the green chemistry solutions!

By Alana Rangaswamy (Vice-President, Dalhousie University Green Chemistry Initiative)

The iconic Halifax Ferry is one of many boats to traverse the Harbour every day.

One great part of attending Dalhousie University is living steps away from the ocean. Much of Halifax’s history and development is due to its access to water, both as a naval base and port of call. With the massive amount of boat traffic seen daily by the harbour, marine industries strive to maximize the efficiency of travel. And one major way to do that is preventing small creatures from hitching a ride on your boat, causing drag and lowering the efficiency of your vessel. Enter antifoulants: coatings that kill organisms or otherwise block their ability to stick onto your ship. Antifouling is a necessary technology, but introducing biocidal agents into a marine environment, unsurprisingly, poses many environmental challenges. Let’s take a look at two commonly used antifoulants, their issues, and how scientists have tried to fix them:

Tributyltin 

You may have heard of tributyltin (TBT) as a biocidal agent. TBT is an excellent poison – effectively nonpolar due to its alkyl groups, it’s able to accumulate in organisms, rapidly killing them due to the high toxicity of Sn^III. This property makes TBT an extremely effective antifouling agent, however, it easily leaches from boat hull paint into the ocean where it persists due to its high stability. Fortunately, the dangers TBT have been recognized worldwide and use as a biocidal agent has been banned as of 2008¹. Canada jumped on the bandwagon slightly earlier, with the last TBT-containing paint product registered in 1999.² With this restriction, the industry is searching for alternatives that are as effective as TBT, without the environmental drawbacks.

Copper

Copper as a bulk metal is naturally antiseptic, promoting the formation of reactive hydroxyl radical species which lead to cell death in living systems.³ Copper has been used on boat hulls since the 1700s, and now usually shows up in paints as its metal oxide⁴ or as a suspension of copper powder.⁵ Although copper is less bioavailable than TBT, it persists and continually forms unstable radical species (and can, therefore. wreak ecological havoc) in a marine environment. Since copper is widely considered the new “gold” standard in antifouling, the sheer amount of it present on (and leaching off of) boat hulls today points to a long-term impact.

New Antifouling Tech

Green chemistry and engineering are all about designing cleaner systems that work as well as, or better than, the existing standard. TBT and copper are high bars to clear, but scientists are up to the challenge. As early as 1996, the environmentally benign Sea-Nine antifouling compound had received the Designing Greener Chemistry Award as part of the US EPA’s Presidential Green Chemistry Challenge.⁶ Sea-Nine is a derivative of isothiazolinone, a 5-membered heterocycle containing nitrogen and sulfur atoms. The compound is acutely toxic to marine organisms at the surface of boats, but biodegrades rapidly in marine environments through a ring-opening mechanism to form non-toxic by-products. Sea-Nine (and its derivatives) is currently present in commercial boat hull paints,⁷ however, degradation times may vary based on geographical location and local environment⁸ so our job isn’t done yet.

There are many newer studies in the works. For instance, investigation has been done into using natural products as antifouling agents. Natural products are secondary metabolites produced by microorganisms as a defence mechanism in response to stress. As such, they often have antimicrobial properties, while being naturally biodegradable. For example, 1-hydroxymyristic acid, a simple alpha-hydroxy fatty acid, was isolated from the marine bacterium Shwanella oneidensis. When panels were coated with paint containing the fatty acid, and subsequently immersed in a marine environment, no growth of foulants was observed even after 1.5 years.⁹ Other studies have added hydrophobic coatings which disrupt the binding interactions between the microorganism and the vessel’s hull, and promote detachment due to the natural flow of the water over the hull.¹⁰ Some research has diverted away from chemical modifiers altogether, using microtextures, which remove the flat surfaces required for spores to settle,¹⁰ to deter growth. UV-LEDs¹¹ which are mutagenic and cytotoxic at a small scale, have also been used to reduce growth of foulants.

The long history and many methods developed to prevent boat hull fouling demonstrates that this is an important and challenging problem. But many results are promising, and green chemists and engineers are well on their way to solving it.

References:

1. http://wwf.panda.org/?145704/tributyltin-canned
2. Health Canada – Consumer Product Safety Registrar

http://pr-rp.hc-sc.gc.ca/ls-re/result-eng.php?p_search_label=antifouling+paint&searchfield1=ACT&operator1=CONTAIN&criteria1=tin&logicfield1=AND&searchfield2=NONE&operator2=CONTAIN&criteria2=&logicfield2=AND&searchfield3=NONE&operator3=CONTAIN&criteria3=&logicfield3=AND&searchfield4=NONE&operator4=CONTAIN&criteria4=&logicfield4=AND&p_operatordate=%3D&p_criteriadate=&p_status_reg=REGISTERED&p_status_hist=HISTORICAL&p_searchexpdate=EXP

3. Grass, G., Rensing, C., and Solioz, M. Metallic copper as an antimicrobial surface. Environ. Microbiol. 2011, 77, 1541-1547. DOI: 10.1128/AEM.02766-10.
4. https://www.chemistryworld.com/news/antifouling-coatings-cling-to-copper/3010011.article
5. http://coppercoat.com/coppercoat-info/antifoul-how-it-works/
6. https://www.epa.gov/greenchemistry/presidential-green-chemistry-challenge-1996-designing-greener-chemicals-award
7. https://www.epaint.com/product/sn-1-antifouling-paint/
8. Chen, L. and Lam, J. C. W. SeaNine 211 as an antifouling biocide: a coastal pollutant of emerging concern. Environ. Sci., 2017, 61, 68-79. DOI: 10.1016/j.jes.2017.03.040.
9. Qian, P-Y., Xu, Y. and Fusetani, N. Natural products as antifouling compounds: recent progress and future perspectives. Biofouling, 2009, 26, 223-234. DOI: 10.1080/08927010903470815.
10. Salta, M. et al. Designing biomimetic antifouling surfaces. Trans. R. Soc. A, 2010, 368, 4729-4757. DOI:10.1098/rsta.2010.0195
11. https://www.pcimag.com/articles/104484-marine-fouling-prevention-solution-to-use-uv-led-technology

 

 

 

Canada Becomes a Leader in Carbon Capture

By Karlee Bamford, Treasurer for the GCI

The attention of international media has been captured by the remarkable success in CO₂ sequestration achieved by the Canadian company Carbon Engineering, located in Squamish, British Columbia. Sustainability-related, world-saving initiatives often have an easier sell in the media than, say, incremental advances reported by researchers on equally sustainable academic pursuits (rough, eh?). In this instance the craze over Carbon Engineering’s advances has been amplified by the news of their recent partnerships with household-name energy and oil giants, such as Chevron, BHP, and Occidental Petroleum, in the form of a CAD $68 million investment.  So, what is this incredible advance?

From the success of their pilot plant and the data they’ve accumulated thus far, Carbon Engineering implementation of their technology has achieved capture of The technology in question can be split into two major advances. Referred to as direct air capture, or DAC, the first process developed by Carbon Engineering involves the transfer of gaseous CO₂ from ambient air to an absorber fluid, a strongly basic solution of sodium or potassium hydroxide. The transfer process is achieved using an air-liquid contactor, designed and described by the company in 2012,⁴ that involves an array of fans, pumps, cheap PVC piping and structure, and fluid distributors. These components are fundamentally no different than those commonly found in cooling towers used as heat exchangers for water cooling. However, the orthogonal geometry (Figure 1) of air (atmospheric, ~ 400 ppm CO₂) and fluid (the absorber) flow differs significantly, making repurposing of existing cooling tower designs for DAC an inefficient and expensive strategy for CO₂ capture.

Figure 1. Commercial realization of air-fluid contactor designed by Carbon Engineering. M = Na or K. Image obtained from CanTech Letter and modified.5

The CO₂ taken up by the alkaline absorber fluid is converted to carbonate (CO₃^2-) salts and can be precipitated from the aqueous solution by treatment with calcium hydroxide to give calcium carbonate pellets. The captured CO₂ can thus be stored as calcium carbonate or can be cleanly regenerated as pure CO₂ gas, with elimination of a CaO , at high temperatures (650 °C) for commercial resale. The byproduct CaO may even repurposed by conversion back to Ca(OH)₂ in a lime slaker, using water.¹ Carbon Engineering has been piloting this process at their facility in Squamish since 2015, according to their website, after having tested a smaller prototype from 2010 and published the performance results in 2013.⁶ At the time of Carbon Engineering’s founding and until as recently as 2018, no commercial-scale air capture systems had been developed, which was a direct result of the anticipated inefficiency of CO₂ capture using conventional cooling tower designs.⁴ Undeterred, Carbon Engineering has proven otherwise with their innovative use of cross-flow geometry.

The second break-through technology from Carbon Engineering is their patented Air To Fuels^TM process, which they’ve been piloting since 2017. Taking the stored CO₂ from their DAC process, Carbon Engineering has successfully produced a clean, sulfur-free, source of hydrocarbon fuel that requires no further modification for consumer consumption. The process involves passing the regenerated CO₂ gas through a reactor containing hydrogen (H₂) gas to generate synthesis gas (syn-gas), a mixture of CO and . The syn-gas is then passed through a Fischer-Tropsch reactor where the synthetic hydrocarbon fuel is thermally generated over a heterogenous base-metal catalyst (e.g. iron, cobalt, nickel).⁷

The technologies have been developed by the research groups of founder and U of T alumnus Prof. David Keith. Prof. Keith is currently faculty at Harvard University in the School of Engineering and Applied Sciences. To date, the company has filed 13 patents and produced numerous publications describing their innovations. According to media reports,⁸ recent multimillion-dollar investments will allow their and the company has already signed a memorandum of understanding with Squamish First Nations about their intentions.⁹

One of the most attractive aspects of the DAC and Air to Fuels^TM technology is location. Plants could, hypothetically, be built anywhere, as CO₂ is well mixed in the atmosphere and Carbon Engineering’s technology does not require that CO₂ capture occur at the point of CO₂ generation as in, for example, CO₂-scrubbers used in exhaust systems.

However, with the excitement surrounding Carbon Engineering’s projected ability to capture CO₂ at low cost and high volume, controversy has inevitably been close to follow. The interest from large oil corporations in this technology may not be as principled in sustainability as it appears but driven in part by their need for large volumes of CO₂ for so-called green fracking (hydraulic fracturing). Supporting further oil extraction in this way goes completely counter to the need for elimination of emissions that the 2018 Intergovernmental Panel on Climate Change (IPCC) report clearly indicates must accompany advances in carbon capture and storage.¹⁰ Still, perhaps the positives outweigh the negatives in this instance. This very week, Environment and Climate Change Canada reported that Canada is warming at twice the rate of the rest of the globe.¹¹ The need for efficient technologies to address climate change has never been more immediate. Fortunately, Carbon Engineering is not alone: at least two other companies with commercial plans for CO₂ capture have started in Switzerland (Climeworks)¹² and the USA (Global Thermostat).¹³ Whether the Canadian solution is adapted worldwide will depend not only upon Carbon Engineering, but also upon how these alternative approaches evolve.  For once, it is probably best not to pick a team to cheer for but, instead, hope that each country’s company develop a complimentary capture strategy to address the international dilemma that is climate change.

References:

1. Keith, D. W.; Holmes, G.; St. Angelo, D.; Heidel, K., Joule 2018, 2, 1573-1594.
2. American Physical Society. Direct Air Capture of CO₂ with Chemicals: A Technology Assessment for the APS Panel on Public Affairs. June 1, 2011 https://www.aps.org/policy/reports/assessments/upload/dac2011.pdf ; accessed April 24, 2019.
3. Carbon Engineering, https://carbonengineering.com/ .
4. Holmes, G.; Keith, D. W., Trans. R. Soc. A 2012, 370, 4380-403.
5. Artist’s rendition of a commercial scale Carbon Engineering contactor, CanTech Letter. https://www.cantechletter.com/2016/10/squamish-b-c-s-carbon-engineering-begins-scale-co2-capture-new-deal/ ; accessed April 4, 2019.
6. Holmes, K. Nold, T. Walsh, K. Heidel, M. A. Henderson, J. Ritchie, P. Klavins, A. Singh and D. W. Keith, Energy Procedia, 2013, 37, 6079-6095.
7. Heidel, Keton et al. Method and system for synthesizing fuel from dilute carbon dioxide source. WO2018112654A1, 2017.
8. BBC News, Matt McGrath. Climate change: ‘Magic bullet’ carbon solution takes big step. April 3, 2019 https://www.bbc.com/news/science-environment-47638586 ; accesed April 3, 2019.
9. CBC News, Angela Sterritt. In fight to combat climate change, Squamish Nation joins forces to capture carbon. November 29, 2018. https://www.cbc.ca/news/canada/british-columbia/in-fight-to-combat-climate-change-squamish-nation-joins-forces-to-capture-carbon-1.4924017 ; accesesd April 4, 2019.
10. Intergovernmental Panel on Climate Change 2018 Summary for Policy Makers, Global Warming of 1.5 °C. https://www.ipcc.ch/site/assets/uploads/sites/2/2018/07/SR15_SPM_version_stand_alone_LR.pdf ; accessed April 4, 2019.
11. Environment and Climate Change Canada, Canada’s Changing Climate Report, April 1, 2019. https://www.nrcan.gc.ca/environment/impacts-adaptation/21177 ; accesed April 4, 2019.
12. Climeworks, http://www.climeworks.com/
13. Global Thermostat, https://globalthermostat.com/

How green is your bromination reaction?

By Diya Zhu: Symposium Coordinator for the GCI

Electrophilic bromination is a common type of reaction in undergraduate organic laboratories. In these experiments, we rarely use Br₂ as a bromine source. Why? This dense brownish-red liquid is a pain in the butt for a few reasons. First of all, it fumes. Once you open the bottle, orange fumes start migrating everywhere. Without efficient ventilation, soon you will smell an offensive and suffocating odor. Second, bromine is corrosive to human tissue as a liquid and its vapours irritate the eyes and throat. Moreover, with inhalation, bromine vapours are very toxic. Third, bromine is very dense, with a density of 3.1 g/cm³, which makes it very difficult to measure and transfer.

Figure 1. A bottle containing bromine.1

Instead, N-bromosuccinimide (NBS) is often used as a brominating and oxidizing agent in various electrophilic addition, radical addition, and electrophilic substitution reactions. Pure NBS is a white crystalline solid with a melting point of 175-180 ^oC. Even though it’s a solid and easier to handle, you still need to be careful when working with NBS. Due to the higher electronegativity of nitrogen, the Br atom is partially positively charged and thus electrophilic, ready to be attacked by a nucleophile (eg. an alkene).

Figure 2. N-bromosuccinimide (NBS)

NBS will form bromonium ions with alkenes, and when an alcohol or water is added, it will attack the bromonium ion, which will generate bromohydrins. Importantly, the nucleophilic attack only happens on the face opposite the bromonium ion.

Figure 3. Alkene reaction with NBS showing the bromonium ion and attack of water to form a racemic mixture.

Usually, when undergraduate students preform this experiment, we also emphasized the importance of Green Chemistry. Green chemistry and its 12 principles help to improve conventional reactions. For example, increasing the efficiency of synthetic methods, reducing the steps of synthesis, and minimizing toxic reagents and solvents. In the formation of bromohydrins, compared to using Br₂, NBS is less hazardous.  Also, water or alcohol can be used as the solvent which eliminates the use of organic solvents, especially chlorinated solvents.

However, the use of NBS also creates by-products. For example, succinimide and the very strong hydrobromic acid. It also has a reduced atom economy, since only one Br atom of 8 atoms in a NBS molecule is used in bromination.

With all of this taken into consideration, can it be concluded that NBS is a greener alternative to Br₂? What do you think, and which reagent will you be reaching for in your next bromination experiment?

References:

1. https://en.wikipedia.org/wiki/Bromine

Green Chemistry Principle #12: Inherently Safer Chemistry for Accident Prevention

By Brian De La Franier, Member-at-large for the GCI

12. Inherently Safer Chemistry for Accident Prevention: Substances and the form of a substance used in a chemical process should be chosen to minimize the potential for chemical accidents, including releases, explosions, and fires.

In the 12th and final video of the GCI series on the 12 principles of green chemistry, Gabby and Qusai investigate the 12th principle on inherently safer chemistry and note several common issues found in many labs.

The 12th principle is frequently called the safety principle and is often overlooked when considering green chemistry principles.  However, the broad nature of the 12th principle means it both incorporates many of the other principles and is almost impossible to achieve without considering all 12 of them, given that the overall goal of green chemistry is to reduce hazards and pollution.

In the Video #11 blog post, Alex wrote about how driving a car with no windows and mirrors would lead to accidents as there would be no real-time way to analyze your surroundings. The 12th principle is akin to having that car inspected before driving it.  It is insuring that all aspects of the car, from the engine, to the brakes, to the steering are all in working order so that the car is less likely to get into an accident.  With this principle we consider the ingredients of a reaction (the parts of the car), and make sure that they don’t pose excessive hazards.

An example mentioned in the Video #12 of a hazardous chemical that can be replaced in synthesis is methyl isocyanate, a molecule used in the synthesis of the insecticide carbaryl.  In 1984, this toxic compound was released into the air from a pesticide plant in Bhopal, India, immediately killing 3,800 people, and causing premature death in thousands more.¹ This disaster could have been avoided had the plant instead used methylamine to carry out the reaction.²

Figure 1. The remains of the pesticide plant that led to the Bhopal disaster. [3]

Although this principle is specifically about the avoidance of using or producing hazardous compounds, the idea of avoiding hazards can be extended to other areas of the lab.  Storing chemicals that are reactive together, such as oxidizers and flammable materials, leads to a risk of release and reaction.  If these compounds leak from their containers and react, they will create a large fire. This is a hazard that could be easily avoided by storing these chemical types separately.

Another hazard in the lab is liquid spills. Anything that has been spilled should be immediately cleaned up to prevent people from slipping on it or receiving chemical burns from an unknown substance.  If someone comes across an acid spill, but does not know what it is they could easily be burned in attempting to clean it up.  Returning to the car analogy, leaving an unknown spill would be like giving someone a damaged car to drive without telling them. The unfortunate driver could be injured as a result of faulty brakes, just as another lab member could be injured by your spill in the lab.

As with our car, the lab should be kept safe and in good repair. If there are damaged parts in a car you should always repair them before driving it, just as if there are hazardous chemicals or situations in our lab they should be replaced before performing reactions.

References:

1. Broughton, E. (2005). The Bhopal disaster and its aftermath: a review. Environmental Health, 4(1), 6.
2. Thomas A. Unger (1996). Pesticide Synthesis Handbook (Google Books excerpt). William Andrew. pp. 67–68.
3. https://www.dnaindia.com/analysis/column-bhopal-gas-tragedy-will-the-suffering-ever-end-2040370

 

The Future of Sustainability in the Younger Generations’ Hands

By Alex Waked, Co-chair for the GCI

In the last couple decades, there has been an increasing focus on developing sustainable practices in society to reduce our environmental impact. Probably the most notable effort in this endeavour is the signing of the Paris Agreement within the United Nations Framework Convention on Climate Change, in which 194 states and the European Union have set goals to reduce the global carbon footprint to reasonable levels.

As we progress forward, there will be a need to propagate this mindset to the coming generations. Fortunately, I don’t think there will be too much difficulty in achieving this. A growing number of schools have been instituting environmental- and sustainability-related courses in their curricula. In my opinion, this strategy has been the most effective in conveying the importance of being conscious of any consequences of our actions and learning how to improve.

In the last few years, many of the chemistry courses at the University of Toronto have incorporated green chemistry and safety modules in both the laboratory and theory sections of the courses. The number of factors that we now consider when designing experiments is much larger than in the past. For instance, are the molecules we’re synthesizing going to be very toxic? Can they be safely disposed of? Do we use harmful substances or solvents during the experiment? How much chemical waste is produced?

Figure 1. Graphic of the 12 Principles of Green Chemistry, which currently play an important role in designing safe and environmentally benign chemical processes.1

These are all questions that have traditionally been overlooked in the past. However, the description of the 12 Principles of Green Chemistry by Anastas and Warner in 1998² was a huge and essential step forward in the current direction we’re heading of thinking about chemistry from a sustainability and safety perspective. Many student-led groups and schools are now taking initiative in this endeavour.

The earlier and more the students are taught about these topics, the greater the chance it will have of the students developing genuine interests in them. In June of this year, the University of Toronto Schools held their first Sustainability Fair, in which grade 8-9 students participated in a science fair-like event where they worked on sustainability-related projects.

Figure 2. Examples of posters at the University of Toronto Schools’ Sustainability Fair in June 2018.3

The GCI was invited to participate in listening to the students’ presentations describing their projects and to give any advice and encouragement to them; three of us, myself included, attended it. I would say there were at least 40 projects in total. These are just a few examples of some the projects:

• Calculating how much water was saved by reducing shower time over a 2-week period
• Collecting and recycling e-waste (any old electrical parts) that would traditionally be thrown away in the garbage
• Calculating the reduction of carbon footprint by biking to work or school instead of driving

There were two things that really stood out to us: one being the range of topics (water reduction, carbon footprint reduction, recycling plastics and electronic waste, and minimizing food waste), and two being the genuine enthusiasm and interest of the students in their projects.

These are the students that will develop into people that will have important leadership roles in society in the future. The prospect of this is what excites me and gives me confidence that the future generations will continue to propel society forward in terms of being even more environmentally conscious and actually walk the walk, and not only talk the talk!

References:

1. The Green Chemistry Initiative website. Accessed September 13, 2018. <http://greenchemuoft.ca/resources.php&gt;
2. Anastas, P. T.; Warner, J. C. Green Chemistry: Theory and Practice, Oxford University Press: New York, 1998, p. 30.
3. Obtained with permission of the University of Toronto Schools.

 

ACS Summer School on Green Chemistry and Sustainable Energy 2018

By Kevin Szkop and Rachel Hems

The Colorado School of Mines in Golden, CO is a wonderful campus with cutting-edge facilities and a great place to spend a week with 60 young scientists interested in green chemistry. This is where the ACS Summer School on Green Chemistry and Sustainable Energy was held from July 10 – 17. The group consisted of chemists and chemical engineers from North and South America, all with unique perspectives, experiences, and attitudes towards sustainability. Below is a photo of our awesome class!

The 2018 ACS Summer School on Green Chemistry and Sustainable Energy class

The program consisted of technical and professional development sessions. A highlight was a life cycle assessment group project and presentation, led by Prof. Philip Jessop from Queen’s University. During Professor Jessop’s lectures, we learned how to think about the “greenness” of a process, and how this often-nebulous concept is best used as a comparative tool. While every process likely has downfalls, using the green chemistry principles and metrics allowed us to think critically about which process has the least downfalls, and how to address these in our work. The assignment included a group project, during which groups of students had to evaluate the merits and drawbacks of 5 synthetic routes to the same product. In this context, we learned that it is not only the reagents that go into a flask, but everything that happens behind the scenes, including shipping of reagents, the type of waste generated, amount of energy consumed, and much, much more. As a synthetic chemist (Kevin), it really made me think about solvent consumption and work up techniques in my own work!

In addition to learning about green chemistry and sustainable energy, there were some great professional development lectures and activities. Dr. Nancy Jenson, the program manager for the Petroleum Research Fund at the ACS, gave an engaging talk on tips for writing research proposals and common mistakes that are made. While she gave examples from her experience at the Petroleum Research Fund, there were many lessons that could be applied to any type of proposal writing.

Another great professional development lecture was given by Joerg Schlatterer from the American Chemical Society. He gave an overview of the ACS’s many resources for young chemists, such as the Chem IDP website for career planning, workshops for prospective faculty organized by the Graduate & Postdoctoral Scholars Office, and the new Catalyzing Career Networking program at ACS National Meetings. As part of the career planning case study, we took some time to make some SMART goals for ourselves for the next two years. I (Rachel) found it’s really helpful to have others share their goals and give suggestions for yours to make them the SMARTest they can be!

Rafting down Clear Creek

Of course, we also had time to have fun! On the Saturday (also Rachel’s birthday!) we went white water rafting on Clear Creek. The river is mountain fed, so it was very cold, but it was a beautiful warm and sunny day! We had a great time rafting down the river, with a quick stop to jump in for a swim. It was a great way to spend my birthday! Throughout the week-long summer school, there was a decent amount of free time to enjoy the sunshine and the sights around Golden. Some of the fun things we got to do were swim in and raft down the river that goes through ‘downtown’ Golden, an early morning hike up the South Table Mountain, tour the Coors Brewery, and get to know all the other awesome chemists!

Kevin and Rachel enjoying the Golden nightlife after a long day of learning!

We highly recommend attending this summer school. It is a great opportunity to learn and to meet great people who care about sustainable chemistry! Read more about past GCI members that have attended the ACS Summer School in 2014 and  2017.

More information on the summer school and how to apply can be found online here.