How the manufacturing industry can minimize its carbon footprint

Manufacturers can make a real impact on reducing greenhouse gas emissions if they choose to reduce their carbon footprint. Getty Images

The actions people take can affect the environment either positively or negatively. This is the concept behind the carbon footprint, which is a method to measure the environmental effect of our lifestyle. A carbon footprint, measured in tons, indicates the amount of CO₂ and other greenhouse gases that are produced as a result of our daily activities.

We all are involved directly or indirectly in discharging greenhouse gases (GHGs) into our surrounding environment. Whether we are at home, buying food, on the road, or at work, the energy we use in our daily life affects climate change. The very production of food and goods releases some quantity of CO₂ into the atmosphere.

Greenhouse Gases and Global Warming

The greenhouse effect, which is the capacity of certain gases in the atmosphere to trap heat emitted from Earth’s surface, thereby insulating the planet, has warmed Earth for more than 4 billion years. Here’s how it works:

When sunlight hits the surface of the Earth, it is absorbed and the visible light (short wave/radiation) is converted to heat (long wave/infrared), which is radiated back into the atmosphere toward space. Some of the GHGs in the atmosphere (mainly water vapor, CO₂, methane, chlorofluorocarbons, ozone, and nitrous oxide) absorb the infrared radiation, which is converted into kinetic and potential energy. Eventually these molecules emit heat back into the atmosphere as infrared radiation. Some of this infrared radiation is absorbed by other GHGs, and the rest is absorbed at the Earth’s surface.

The greenhouse effect is an important, natural phenomenon that slows the loss of heat to space, keeping the planet’s surface warmer than it would be without GHGs. In fact, without the greenhouse effect, the Earth's average global temperature would be too cold to sustain life.

However, if the greenhouse effect becomes stronger, it could make the Earth warmer than usual. Even a little extra warming can cause problems for humans, plants, and animals. Human activities in abundance are modifying the natural greenhouse effect, with potentially dangerous consequences. It is possible that as the climate changes and as species are eliminated from an area, ecosystem functions will change, and that could mean more land degradation, changes in agricultural productivity, and a reduction in the quality of water delivered to human populations.

And while each person is responsible to help prevent an enhanced greenhouse effect, the U.S. Environmental Protection Agency reports that in 2018, industry accounted for 22% of U.S. GHG emissions, as compared to 12% for residential and commercial.

Every action to counter carbon footprint is important. When manufacturers adopt measures that contribute to overall sustainability and reduce their contributions to global warming and climate change, they are helping to ensure a safe, healthy environment not only now, but for generations to come.

Transitioning away from the practices established by decades of industrial development might be a tough task, but there are many steps manufacturers can take toward containing carbon footprints. They can contribute to lower CO₂ emissions by actively minimizing the environmental impact of a product across its entire lifecycle, from material extraction and supply to the end of its life

Design engineers can follow the principle of ecodesign by considering factors such as the amount of energy and materials consumed in production, or how the product and its manufacturing byproducts may affect biodiversity. Engineers and manufacturers then can investigate alternative processes, systems, and materials to minimize their impact. ISO/TR 14062:2002, Environmental Management — Integrating Environmental Aspects into Product Design and Development, is a helpful reference for achieving ecodesign.

Substitute Materials

In industries such as packaging, environmental issues have driven the need for a shift in materials. Concerns about plastic pollution have led consumers to demand more environmentally friendly alternatives. This has driven a rise in the use of biopolymers/biodegradable polymers, which are designed to replace traditional, petroleum-based plastics in such applications as beverage bottles and ready-made meal packaging.

Vehicle lightweighting is being recommended to improve a vehicle’s fuel economy.

Remanufacturing

Most manufacturers already are familiar with the three Rs of sustainability:

1. Reduce. Avoid using disposable products; eliminate excess packaging; use email instead of paper mail; buy durable goods that can be repaired; use raw materials in the most efficient way possible; purchase multitasking equipment that can perform different kinds of jobs in one.
2. Reuse. Make use of scrap materials; fix/upgrade old equipment rather than purchasing new.
3. Recycle. Buy products and materials that are made from recycled materials; recycle metals, paper, and plastics; avoid the use of hazardous substances and opt for nontoxic products.

There’s a fourth R for industry, and that’s remanufacturing. With materials such as steel and alloy steel, manufacturers can reduce their carbon emissions in the production chain by remanufacturing. This involves the reclamation of used, durable materials, such as steel shafts, bearings, and other products that can be reused. This practice is relatively common in the automotive industry, which often remanufactures such parts as engines, steering systems, and transmissions.

Salvaging or reclaiming these parts requires cleaning processes such as sand blasting or abrasive blasting. Abrasive blasting uses compressed air or water to direct a high-velocity stream of an abrasive material to clean an object or surface, remove burrs, apply a texture, or prepare a surface for the application of paint or other types of coatings. Pressure washing is another alternative, which uses water-based detergent and biodegradable solvents to clean parts.

Today’s remanufactured products are as good as new and more cost-effective, and the cleaning processes create much lower carbon emissions than the original manufacturing process.

Additive Manufacturing

Another alternative manufacturing technique that can reduce carbon footprint is additive manufacturing (AM), which continues to grow in popularity.

Traditional manufacturing techniques such as forming and molding are subtractive processes, as products are made from larger blocks of material. This means waste is inherent to the processes, and not all the material that is removed can be recycled or reused.

In contrast, AM, or 3D printing, builds an object one thin layer at a time. It uses only the material that is required, reducing waste and carbon footprint. This technology requires materials in specific forms, such as powdered forms of metal alloy, steel, resin, and biopolymer, which can be used to build new types of structures and designs previously impossible with subtractive manufacturing.

Reduced Yield Losses

Yield losses affect not only performance and productivity, but also the amount of energy used and the carbon footprint. Typical yield losses are:

• Equipment breakdown/failure.
• Planned stoppages.
• Idling of cycle or machinery.
• Reduced speed.
• Production defects.
• Reduced yield (first time through).

Manufacturers have many options to address these losses, from implementing data-driven maintenance strategies to automating production lines.

Energy Efficiency

Ensuring a manufacturing facility is energy-efficient can involve anything from replacing incandescent lightbulbs with LEDs (they use 80% less energy and have 20 times the lifespan) and installing motion-sensor lighting to purchasing energy-efficient machinery and equipment. It also includes the use of sustainable and renewable energy.

Fossil fuels, coal, nuclear, and natural gas are not renewable sources of energy because they are not infinite. Plus, they release CO2 into the atmosphere, which contributes to climate change and global warming. Sustainable, renewable energy meets a manufacturer’s current needs without compromising the ability of future generations to meet their needs. Solar, wind, hydroelectric, and biomass energy are widely considered to be sustainable.

Solar. Sunlight is one of Earth’s most abundant and freely available energy sources. According to Business Insider, the amount of solar energy that reaches the Earth’s surface in one hour is more than the planet’s total energy requirements for a whole year.

Wind. Wind is the cleanest source of energy. To harness electricity from wind energy, turbines are used to drive generators, which then feed electricity into the national grid.

Hydroelectric. A dam and large reservoir can be used to create a controlled flow of water to drive turbines, which generate electricity. This energy source often can be more reliable than solar or wind power and allows electricity to be stored for use when demand reaches a peak.

Biomass. Biomass involves burning organic materials to produce electricity. This is not the burning of wood, but a much cleaner, more energy-efficient process. By converting agricultural, industrial, and domestic waste into solid, liquid, and gas fuel, biomass generates power at a low cost, economically and environmentally.

Fuel cell systems offer another option for clean energy. A fuel cell converts stored chemical potential energy of molecular bonds into electrical energy. It follows a simple chemical reaction to convert hydrogen gas and oxygen gas (available freely in the atmosphere) into electricity, with byproducts of water and heat. This is a big improvement over internal combustion engines, coal-burning power plants, and nuclear power plants, all of which produce harmful greenhouse gases that contribute alarmingly to a carbon footprint.

Fuel cells and batteries are similar, as they both generate electricity. But while batteries store energy in electrodes, a fuel cell uses an external fuel, allowing it to continue operating as long as hydrogen is available. Unlike conventional batteries however, fuel cells do not contain harmful materials, nor do they have moving parts, minimizing maintenance requirements.

Green Building

The U.S. Green Buildings Council (www.usgbc.org), the organization that created the LEED program for green buildings and communities, offers advice and programs to help manufacturers ensure their buildings are as environmentally friendly as possible, from paving to paint to plants.

Speaking of plants, the landscaping around the building can be just as important. In fact, one of the best ways to help keep the planet green is to plant trees. According to Grantham Institute - Climate Change and Environment, one tree saves 1 ton of CO₂ during its lifespan.

Sustainability Today for a Healthy Tomorrow

Sustainability means meeting our own needs without compromising the ability of future generations to meet their needs. It aims to safeguard nature, the environment, biodiversity, and our climate. The industrial and manufacturing sectors, transportation systems, power-generation plants, and agricultural sectors must be well-equipped and efficient in the way they use raw materials, energy, water, and land.

Using energy carefully and encouraging the use of sustainable and renewable sources is everyone’s responsibility, including manufacturing, to help ensure a healthy planet for future generations.