Developments in the field of green chemistry are already affecting the supply chains of many manufacturing and industrial firms, and the effects are only going to increase as time goes on. That’s the message from engineers, scientists, business decision-makers, sustainability executives, and other industry experts who attended the American Chemical Society’s (ACS) recent Green Chemistry and Engineering Conference in Bethesda, Md.
Companies in all industries are paying increasing attention to the environmental impacts of their supply chains. A supply chain sustainability program naturally focuses on the chemicals and materials that get incorporated into a company’s products and that get used in its production operations.
As reported recently in IMT Green and Clean Journal, green chemistry is based on the development of products and materials that prevent waste; produce fewer hazards to health, safety, and ecosystems; use renewable feedstocks; consume less energy and produce fewer greenhouse gas (GHG) emissions; and incorporate other important sustainability principles.
Many chemical companies are working to develop chemicals from bio-based sources that can function as greener drop-in substitutes for conventional petrochemicals. Downstream customers “inherit” supply-chain sustainability benefits by purchasing such materials. Bio-based chemicals producers say their performance and cost approaches those of traditional chemicals.
DuPont is producing greener chemicals that are entering the market at large scale. Robert Giraud of DuPont Research and Technology told the conference audience about bio-based 1,3-Propanediol (PDO), which is derived from cornstarch. DuPont uses its bio-PDO to make Sorona, a biopolymer used in such applications as carpets, apparel, and automobile interiors. Not only is the bio-PDO sourced from renewable materials, but technology breakthroughs allowed DuPont to produce the material using “40 percent less energy than the chemical route.” The product is now “fully commercial at 150 million pounds per year” capacity, Giraud told his audience. DuPont uses its bio-PDO as a building block for other chemical products as well.
David Hedlund, fermentation scientist at BioAmber Inc. of Plymouth, Minn., outlined efforts to produce bio-based succinic acid (SA) and other renewable chemicals. Succinic acid is an important precursor used for producing polymers, coatings, adhesives, solvents, lubricants, and even cosmetics and food products. Hedlund told IMT that BioAmber is currently producing and selling SA at “demonstration scale.” He said, “We are producing at a 3,000 metric-ton capacity per year right now,” at a plant in France, which he called “the launching ground for what will be a new 30,000-metric-ton-per-year facility,” now being built in Canada.
Often, chemicals can be “greener,” not necessarily by being sourced from renewable feedstocks, but by virtue of the more sustainable processes used to produce them. Addressing the conference audience, Milton Hearn, associate director of Green Chemical Futures at Monash University in Melbourne, Australia, pointed to one of the key principles that should be considered in the development of sustainable supply chains and products: “the whole question of materials usage… the challenge of more from less… how do you ‘de-materialize’ your products?”
Decision-makers in industry need to understand “the energy content that exists in their products,” said Hearn. He brought up the example of concrete, which he called “the world’s largest commodity chemical product.” He spotlighted one method of “de-materializing” concrete. It uses nanotechnology to create a lightweight, flexible product with similar structural strength but much lower use of material, and thus lower greenhouse gas emissions. He cited Australian firm Nanokote as one of the important innovators of this technology.
DuPont’s Giraud pointed to insecticide Rynaxypyr as an example of a substance that is “greener” not because of its feedstock but because of the process used to produce it. The chemical is effective with low rates of application and has a very low toxicity to wildlife. But even more important is the way Rynaxypr was developed. “We had a strong collaboration of chemists, chemical engineers, environmental engineers, and toxicologists to work out a greener process,” Giraud said. For example, product developers worked to minimize the use of solvents and recycle those solvents that are used.
In his keynote address at the conference, Michael J. Pcolinski, vice president for innovation and technology for North America at chemical manufacturer BASF, highlighted a similar approach to green chemistry pioneered by his company in partnership with The Dow Chemical Co. In an unusual collaboration between competitors, Dow and BASF developed a more sustainable technology that uses hydrogen peroxide to produce propylene oxide, an important chemical intermediate used in insulation, appliances, automobiles, furniture, coatings, fluids, pharmaceuticals, and other applications. The companies were joint recipients of a Presidential Green Chemistry Challenge Award for the new process.
Dow uses lifecycle analysis (LCA) to assess the sustainability of the chemicals it produces. Lifecycle analysis is particularly useful in developing a greener supply chain, as it gives a company a broad, systems-based perspective of the environmental impacts of its products and operations, evaluating those impacts from materials sourcing through manufacturing, product use, and even end-of-life. While LCA is hard to do, Dow’s Pamela Spencer admitted in a conference presentation, it allows the company to demonstrate whether a new proposed product is truly “greener” than the conventional product.
Spencer highlighted some of the company’s products that have been proven to provide big-picture sustainability benefits. One such product is Dowtherm A heat transfer fluid, used to collect, transport, and store solar energy in concentrating solar power stations, generating renewable energy, and preventing GHG emissions. Another example she cited is Dow’s Protected Membrane Roof (PMR) system used for green roofs. “Studies worldwide,” she noted, “have clearly demonstrated that green roofs make positive impact on their local environment that really ripples through the larger eco and economic systems.” Results show, she said, “that vegetative roofs help to clean the air of particulate matter, create habitat areas for indigenous wildlife, add aesthetic appeal to the surroundings, reduce the urban heat-island effect in metropolitan areas, and control water runoff.”
Spencer and many other conference presenters emphasized that a lifecycle approach to developing and evaluating materials is the real key to sustainable chemistry and greening the supply chain.