Built environments and transportation
Cities, towns and villages, and how we move within them and between them, define our contemporary existence. Our built environments shelter us, provide spaces for education, healing, worship, entertainment, work and rest. As little as 150 years ago, freely moving from place to place was restricted to the wealthy. The discovery, refinement and transportation of oil catapulted us into a mobile and rich society; where mobility once came at great expense, it is now something most of us take for granted, whether it be driving to the local shops, or hopping on an intercontinental flight for a holiday.
The built environment is at once a massive human achievement and an ongoing and increasingly difficult challenge, as we juggle comfort and convenience with the impact on our natural and social environment. As we become more sensitive and aware of our impact, the role of the chemical engineer becomes more significant and visible.
As humans live increasingly concentrated in towns and cities, we influence our surroundings in myriad ways, from air, light, noise, water and visual pollution to municipal waste and wastewater. Our lifestyle impacts the soil, waterways, coastlines and our industrial wastes can cause major disasters (for example Buncefield).
In this context, safety and sustainability have now become central ideals when creating built environments and transport networks. The challenge rests in how to achieve this while maintaining equitable access, reliability and economic and environmental sustainability over the long term.
Chemical engineers can play an extremely important part in achieving this. They provide their knowledge of materials and processes to examine such things as heat transfer and energy loss in buildings, as well as safety standards. The biggest impact of chemical engineering to the liveable modern cities is undeniably access to clean water and the treatment of wastewater. Whether sanitised, filtered or chlorinated, clean water is one of the major contributors to human health and well-being.
Standards are ever rising. Cooling and heating systems in buildings, for example, air conditioning and heat pumps are increasingly in demand in an already complex energy environment. Furthermore, as safety criteria increase, emergency systems in buildings and services are crucial, as are fire safety standards for building materials to avoid a repeat of the devastating Grenfell disaster.
Current major transportation forms are improved through chemical engineering knowhow, ensuring designs are safe and efficient. The economic growth of the 20th Century was driven by the reduction in cost and increase in speed of the transportation of goods. Without this, economies of scale could not be realised. Chemical engineers produced the fuels to make this possible based on refining and further processing crude oil.
Chemical engineers have long been involved in getting us moving, from the design of all forms of bulk transportation of potentially hazardous liquids, gases and other chemicals by pipeline, ships, trucks and rail tankers. The economic impact of pipelines is massive; approximately 60% of global primary energy is moved by pipeline to market.
For the last 50 years, chemical engineers have switched the emphasis to reducing the environmental impact of fuels by eliminating lead in gasoline, reducing sulphur and now reducing greenhouse gas emissions. Decarbonising transport fuels is a major challenge, and chemical engineers are working to find solutions that are affordable, including batteries that can be manufactured at lower costs and using less rare materials or hydrogen-based fuels. Chemical engineers are helping to solve the biggest challenges facing Electric Vehicles (EVs) exploring methods to responsibly extract (and recycle) the metals required, efficiently manufacturing the batteries at large scale and supporting other scientists to deliver technological advances that can deliver the driving range and operating life that owners expect.
While EVs are set to become a standard feature of personal transport, the future of larger vehicles may rely on the successful employment of fuel cell technology. Zero-emission fuel-cell vehicles are powered by hydrogen, which is either stored in tanks as liquid, pressurised gas or alternative modes (such as hydrates or hydrides). Chemical engineering researchers are developing these technologies, along with the delivery of ‘blue’ hydrogen (from fossil fuels backed-up by carbon capture and storage) and ‘green’ hydrogen (from electrolysis of water using renewable electricity).
A sustainable future relies on the successful development of low carbon materials and cleaner products for the built environment, for example ‘green’ steel. Expanding the circular economy, exploring new materials, and engineering products at the interface of biology, physics and chemistry will all offer pathways to achieve sustainable cities.
The challenges are many and varied, but there are promising solutions on the horizon, including research into decarbonization, battery technology, recycling and passive buildings.
COP26 has reinforced that we need to address our carbon footprint as a matter of urgency. Emissions must be slashed in all aspects of human endeavour, a goal that will only be achieved through science and technology. Chemical engineers have a lot to contribute to achieving this outcome. Their systems thinking approach will be critical if we are to achieve liveable cities with sustainable transport.