Materials
Materials that have shaped our lives
Chemical engineering evolved out of an ambition to optimise chemical processes. To facilitate the mass production of existing materials and to upscale new ones. Chemical engineering, even before the profession was styled thus, has been shaping society for millennia. The Anatolians of 1800BCE used steel in their ironware and modern cement has built the cities we live in since the early 1800s.
Chemical engineering has been behind almost every aspect of our daily life since the second world war. The impact of plastics–themselves the result of incredible engineering ingenuity–is undeniable. With their insulation properties, durability, and light-weight, they have improved the manufacture and life of engineered products with immense impact. Could we imagine a life without Perspex, Teflon or silicone or Polythene?
Synthetic fibres have revolutionised the clothing industry, with rayon blazing the trail. Nylon, as strong as steel and fine as silk, was not only a prized item to the fashion-forward 1940s women, but also made the perfect parachute for wartime Europe.
Engineers have made our buildings stronger, clothes lighter, and our lives more comfortable. The materials revolution of the last century has also underpinned unprecedent economic growth.
When the materials juggernaut was taking off 100 years ago, greenhouse gas, global warming, climate change, and circular economy were not part of our collective lexicon. The challenge now is how we can continue to live with these materials, while overcoming the problems created by their production and disposal.
Chemical engineers are the link to much-needed solutions.
New century, new challenges
The United Nations Sustainability Goals provide a clear and ambitious road map for the global community. However, identifying the challenges that lie ahead is one step; realising existing theoretical solutions in practice–within the framework of the triple bottom line of people, planet, profit–is another.
Meeting this challenge will require creative thinking and hard work - the hallmarks that have defined the profession for a century.
Although steel is one of the most recycled industrial substances, new steel is needed in increasing amounts to feed ever-hungry urban development. Steel produces about 8% of global CO2 emissions, and despite great advances in green steel, carbon neutrality is decades away. Natural gas to replace coal is a worthy interim solution and produces half the CO2.
Our other material addiction, cement also produces a great whack of CO2 despite clean and efficient production.
Carbon neutrality is challenging in cement production as more than 60% of emissions result from the chemical breakdown of limestone into CO2 for which there is no practical alternative. The concrete construction industry can reduce up to 80% of these emissions (compared to 1990) with moderate investment. Ten technologies have been identified to improve production, including, kiln improvement, alternative fuels, and concrete mix design, among others.
While the environmental impact of steel and cement would surprise many, not so plastics. Images of choking marine life and overflowing landfill have been seared into our imaginations. A war on plastic has been declared, and any organisation vying for environmental cred is pronouncing themselves plastic free. Governments worldwide are mandating the end of disposable plastic.
Technical developments in recycle, re-use and disposal have not kept pace with the increases in production, despite early acknowledgement of their necessity. Developed nations have, until recently, turned a collective blind eye to the reality of recycling schemes, where mountains of waste are shipped across the oceans to become someone else’s problem. The contamination of plastic waste, huge variance in plastic types, lack of incentives, and consumer inertia all add to the complexity of the plastic problem.
Synthetic fibres, once epitomised in a revered pair of nylons, are now known to degrade to microplastic, causing allergy and respiratory illness from carcinogen compounds, and immeasurable damage to wildlife via contaminated habitats.
Continuous improvement is a key part of the chemical engineer’s repertoire. Once this creativity, knowledge and knowhow was applied to drive down costs and expand production. Now this energy is being directed to sustainability, cleaning up and providing a master class in upcycling. The focus, which in the last century was firmly on production, now needs to include disposal and closed loop sustainability.
The future is bright
If the last century was defined by fast paced innovation, massive consumption and capital growth, the 21st Century may be characterised by dealing with the consequences. Chemical engineers can contribute by developing industrial scale processes for new promising and sustainable materials
Steel, cement, plastics and synthetic fibres all have long, well established histories and heroic profiles in society, however they each have adverse environmental impacts. The chemical engineering profession has been a significant contributor to the development of each of these materials; the profession must now look for new sustainable processes.
In the 100 years of IChemE, the institution has facilitated and witnessed the magic that happens when researchers, practitioners and industrialists collectively work toward solving a problem. The results are inspiring and give us reason to be optimistic.
Good news and promising results abound.
MIT scientists have developed a process to produce cement via electrolysis, which lowers emissions associated with cement production and produces gas streams that can be used in other processes.
Steel has a green future and a clear road map.
However, weaning society off single use plastic and cheap clothes is a challenge that cannot be solved by engineering alone. It will take an equal effort to change human behaviour and consumption habits. Becoming sustainable consumers will be costly, which poses the question, how can we maintain living standards and equality, while moving away from cheap goods?
Polymers produced by renewable raw materials and the rise of new fibres made from wood pulps are becoming common place, but non-degradable plastics are a complex problem. Any enduring solution requires behaviour and regulatory transformation in parallel to an engineering revolution.
While the profession works tirelessly to modify, adapt and clean up existing materials, it is also working on the industrial scale production of a range of new revolutionary materials such as graphene and Metal Organic Frameworks (MOFs). The work on graphene provides us with a contemporary example of engineers actualising decades-old theories.
Graphene is a game-changing material with impressive physical and chemical properties. It is the world's first 2D material and its strength, light weight, flexibility and conductivity offer myriad potential applications. MOFs are future materials with high tunabilty and have promising properties for use in carbon capture and in a broad range electrochemical applications.
The successful commercialisation of graphene and MOFs will revolutionise many industries, but the real challenge of the future is the pursuit of sustainable production of existing and new materials in a circular economy.