The production of engineered materials, such as metals, cement, or plastics, requires a lot of energy. Before the industrial revolution, natural resources were of relatively high value compared to labour, and this ensured that products “were maintained, repaired and upgraded” (Allwood et al. 2011). Today, the relative value of labour and natural resources has reversed, and energy use has become a greater concern because of its associated environmental impact. Steel, petrochemicals, cement and aluminium rank among the most energy-intensive materials – alone they generate just under 20% of global energy-related CO2 emissions. Future projections for the consumption of these materials are no less worrying: expected increases in wealth and population will require the demand of steel and aluminium, for example, to at least double by 2050.
Global climate agreements aim to reach carbon neutrality between 2050 and 2100. In the EU, where some of the most stringent policies exist, the Commission is committed to reducing energy use by 20% before 2020 and by 27% before 2030; this is mirrored by 20% and 40% CO2 emission reduction targets. Theoretically, myriad options are available for achieving these targets. In practice, however, scientific studies advise that not enough is being done (Fischedick et al. 2014) (IEA, 2017).
Given the unhurried deployment of disruptive technologies, such as carbon-capture and storage, and the difficulties associated with large shares of renewable electricity supply, policymakers have begun to move their mitigation eggs into the more appealing energy-efficiency basket. For manufacturers, whose energy and material costs today are still relatively high, this policy focus on energy efficiency is a bringer of glad tidings; not only because improving energy efficiency is the industry’s bread and butter, but because the associated technological and behavioural changes required for climate-change adaptation promise to be less draconian and the required capital investments less steep (than for more disruptive technologies).
Despite producers´ continued efforts to improve energy efficiency, there is still opportunity to improve process monitoring and control and to reduce industrial waste heat. The US Department of Energy estimates that as much as a quarter of US industry´s energy input could be recovered from high-quality waste heat, i.e. from hot exhaust gases, cooling water and heat lost from hot surfaces (BSC Incorporated, 2008). But even if energy efficiency was fully optimised across all industry sectors, globally imposed energy use and CO2 emission reduction targets would remain out of reach. The recent focus on energy efficiency policies, therefore, has limited potential in industry.
What neither policy makers nor material producers have endorsed to date is the role that reducing material (non-energy carriers) use plays in these mitigation efforts. Energy efficiency improvements are attained by reducing direct fuel inputs or by recovering heat produced as a result of the consumption of these fuels. But as materials are transformed within a site (and along entire value chains), they acquire “embodied” energy (see Figure 1). This cumulative energy, which is input to transform raw materials into valuable finished products, is not entirely carried by material products; but if a tonne of material is lost after going through several processing steps, the energy invested up until that point is discarded with it. A more holistic understanding of industrial production is needed to capture this phenomenon.
In academic spheres, energy reductions generated by improving material use are often termed “material efficiency” measures. Experts believe material efficiency could be a complementary strategy to address the emissions gap – especially in the production of energy-intensive materials (steel, cement, chemicals, aluminium and paper). A group of UK researchers (Cooper et al. 2017) estimate that 6–11% of the energy used to support economic activity globally could be saved by improving material efficiency. In fact, the International Energy Agency holds that “material efficiency could deliver larger energy savings in energy-intensive industries than energy efficiency” (IEA, 2015).
During production, companies can yet reduce the amount of scrap material and waste generated as a result of inefficient operation. Inevitable scrap material and material by-products can be reused or recycled. In most cases, recycling energy-intensive materials generates fewer carbon emissions than producing them from virgin ores (cement, ceramics and composites are exceptions). In steelmaking, researchers from Cambridge University in the UK (Cullen, Allwood and Bambach, 2012) reveal that over a quarter of the global liquid steel produced every year is lost in casting (74 Mt), forming (99 Mt) and fabrication (186 Mt). Values for wasted aluminium are even greater, at around 40% (Cullen and Allwood, 2013). Every year, over 400 million tonnes of iron and steel slag is produced worldwide – in China for example, only about 22% of the steelmaking slag is actually reused – and their market is predicted to be worth US$29.896 billion by 2025 (from US$23.463 billion in 2016). Potential for improvement is strongest if opportunities across the entire supply chain are considered.
How industry manages its valuable energy and materials is integral to its productivity goals, and to transitioning to a more resource-efficient, digital, low-carbon production era. And in fact, some companies have started to recognise this. Emerson is now in a unique position to help manufacturers of energy-intensive materials improve both their energy and material efficiency, that is, to become more resource-efficient, and thereby top-quartile performers. We can provide energy-intensive producers with a systems-wide understanding of their resource use: a transparent, pragmatic and flexible tool that identifies opportunities for resource efficiency improvements across entire sites during daily operations.
From Jim: Learn more about ways to improve energy and material efficiency in the Top Quartile Operational Certainty section of the Emerson.com website.