By Jennifer Heathcote, vice president, Business Development, GEW (EC) Limited
The NGOs World Resources Institute (WRI) and World Business Council for Sustainable Development (WBCSD) published the Greenhouse Gas Protocol in 2004. In doing so, they defined Scope 1 and 2 emissions. Scope 3 was added in 2011. Scope 4 was proposed in 2017. Scope 4 is illustrated in Figure 4. Additional information on WRI and WBCSD as well as the partner organization, GHG Protocol, and its services, global reporting standard and financial contributors is available at www.ghgprotocol.org.
Scope 1 emissions are direct GHG emissions resulting from equipment controlled or owned and operating on or within company assets as well as emissions from all transportation, construction, mining and off-highway vehicles directly owned and operated by the company.
Scope 2 is indirect GHG emissions resulting from the use of purchased electricity, steam, heating and cooling for a company’s own use.
Scope 3 is all other indirect GHG emissions from upstream and downstream supply chain activities not accounted for in Scope 2.
Scope 4 is emissions reductions that occur outside the value chain or life cycle of a product. Scope 4 supports development and adoption of products and services needed to achieve Net Zero. It often is referred to as mitigated, offset or avoided emissions (Figure 4).
Companies that manufacture goods which reduce reliance on fossil fuels and lifetime GHG emissions can positively promote their products through Scope 4 emissions. Potentially, this includes UV and UV LED curing systems with a theoretical example shown in Figure 4. The example compares lifetime greenhouse gas emissions for three different products used to set inks, coatings and adhesives in manufacturing processes. Scope 4 accounts for emissions incurred during material acquisition and pre-processing, production, distribution and storage, use and end of life.
The visual in Figure 4 is useful for comparing alternative products or solutions for the purpose of selecting the technology that best reduces emissions. In this hypothetical example, UV LED curing clearly has an advantage due to its all-electric, non-hydrocarbon operation; compact footprint; need for less installed transformer power; lower peak demand at start-up; reduced electricity consumption during operation; elimination of consumables, long life, and lack of GHG, VOC, HAP and TAP emissions during operation. Conventional UV curing also reduces lifetime GHG emissions; however, it consumes more electricity than UV LED curing and has ongoing consumables such as lamps and reflectors that must be regularly shipped to the facility, stored and properly disposed at end of life.
UV and UV LED Curing Lower Emissions in Industrial Processes
Manufacturers generally have three main categories they can target for emissions reductions. This includes electricity supply, transportation and industrial processes. Oil, coal and natural gas provide approximately 84% of all the world’s energy and roughly 64% of all electricity. 13 After 20 years and more than 5 trillion USD investment globally, hydrocarbon use has only decreased 2%. 14 As a result, solar and wind are not driving an energy transition. They simply are adding generating capacity to the grid, all of which must be fully backed-up by conventional power generation to prevent blackouts. Due to intermittent, weather-dependent generation and low energy density of solar and wind, insufficient supply of grid transformers, the massive and costly transmission infrastructure that must be built to connect remote solar and wind farms to the grid, and the massive quantities of batteries required, it is unlikely that large scale emissions reductions will come from solar and wind power generation alone. This is compounded by the rapidly increasing and potentially doubling electricity demand due to cloud computing services, artificial intelligence, manufacturing automation, electric vehicles and the overall push toward electricity powered everything.
In terms of transportation, 97% of all global transportation relies on oil. 14 With the exception of electric vehicles used for short travel distances, electric battery technology is unlikely to replace hydrocarbon-based fuels to any significant degree by 2050. Battery power simply is not viable, scalable, practical or affordable for most diesel-powered trains, trucks, earth moving equipment and cargo ships, as well as jet fuel powered airplanes. Oil-based fuels are the everyday workhorse energy source in most transport vehicles.
This leaves industrial processes. Since breakthrough technologies such as carbon capture storage (CCS) and green hydrogen are not yet technically, practically or economically viable and likely will not be operating at scale by 2050, manufacturers should instead focus on existing technologies that already are proven, readily available, easily expanded and scalable now. One of those technologies is UV curing.
UV curing sources are all-electric and require no onsite burning of hydrocarbons. UV curing releases no GHGs, VOCs, HAPs or TAPs to the environment during operation. Since UV curing is a chemical reaction and utilizes 100% solid materials in inks, coatings and adhesives, there is no need for natural gas-powered ovens to evaporate water or solvent-based carriers. All that is needed is for the UV curing system to deliver the minimal threshold irradiance (W/cm2) in the spectral range required to react the molecules. Provided the delivered energy density (J/cm2) is suitable for the application line speed, curing occurs in a fraction of a second and in a relatively small footprint. As a result, UV curing allows for more efficient use of valuable production space. Because there are no long tunnel dryers and cure is instant, there also is less makeready, less scrap and less waste.
Formulations that are 100% solids reduce the weight of shipped raw materials since there is no added water or solvent-based carriers mixed with the resins, make clean-up easier and create little waste. This also means no water or solvent must be flashed away via forced hot-air or natural gas-powered ovens. No oxidizers or afterburners are needed to incinerate evaporated solvents before releasing them to the atmosphere. Workers also are not exposed to harmful solvent fumes, and there is no explosion risk. UV curing and the elimination of solvents make for a safer work environment.
Most notably, UV LED curing saves energy. Due to its lower power requirements, UV LED curing reduces total installed system power. This means a plant can run more equipment off existing transformers and pull less electricity from the grid. UV LED curing is instant ON/OFF and reduces peak demand at start-up. High peak demand is responsible for as much as 40% of a facility’s electricity bill. UV LED curing also consumes less electricity during operation. All of this together means UV LED curing saves energy, saves money and reduces a manufacturer’s carbon footprint, even for facilities that already are net zero.
Because there are no GHG, VOC, HAP or TAP emissions, UV curing means zero Scope 1 emissions. Since UV LED curing reduces electrical needs and requires no on-site use of hydrocarbons, this benefits Scope 2 purchased power emissions. Manufacturers who use UV curing also have a positive impact on Scope 3 emissions in the supply chain due to reduced freight loads and material shipments, reduced scrap, reduced waste disposal and lower Scope 1 and 2 emissions. UV curing also makes the case for avoided emissions, which is Scope 4.
The recent legislative emissions mandates driven by the United Nations and implemented through the SECR, CSRD and SEC’s Climate-Related Disclosures rule are putting increased pressure on companies to reduce scope emissions. While these regulations currently apply to some medium and large private companies, as well as most publicly traded companies, the inclusion of Scope 3 emissions reporting in the European Union means that even small private companies in the supply chain may need to inform publicly traded companies of their scope emissions. Once scope emissions are regularly reported by an increasing number of companies, there will be greater pressure to reduce emissions annually. This is a significant reason there is growing use of UV curing and especially UV LED curing for a wide range of manufacturing processes. UV and UV LED curing reduce scope emissions, which ultimately benefits manufacturers, investors and society at large.
Full article is available on the Plastics Decorating website at www.plasticsdecorating.com.
