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Sep 22, 2023

President Biden: Plastic Is Not the Enemy

Allan Griff | Apr 15, 2023 President Biden recently called for more

Allan Griff | Apr 15, 2023

President Biden recently called for more biomaterials. I’m not surprised. He knows that the use of fossil fuels will put more carbon dioxide into the air, which will collect "up there" to insulate the Earth so it gets warmer. This isn't belief or magic, but heat transfer, which we should understand. It isn't political, either. The rules of science apply to everyone.

Carbon dioxide is one carbon atom plus two oxygens, which is the gas we and all animals breathe out. It is the gas that gives fizz to fizzy drinks, and is very soluble in water as we can see from watching a Sodastream machine. It's the gas that matters, not the carbon element, as commonly and misleadingly used. There is disagreement regarding where it goes and how fast the warming occurs, but the process is not debatable except among miraclists who are afraid of anything science does (including plastics). If this still baffles you, read my simple chemistry column in this publication.

Biden sees voters worried about weather and is aware that rising Earth temperatures will cost us time, comfort, and money in years to come. He can't focus on the less-popular reduction in demand that may come, too, because it's less popular. But I can't agree that biomaterials — materials of plant origin that can be farmed and, thus, renewed – are the answer. First of all, much energy is consumed in making any material, in addition to its chemical basis. Think melting glass to make a bottle, or moving the huge amount of water needed to make paper, the environmentalists’ delight.

Second, cost always matters, and we know the cost of farming, as well as energy production. If and when I see biomaterials using less energy — including in their farming and waste disposal — and being available at a reasonable cost to do their jobs, I’ll sign on. Just plain "bio" may attract investors and even users, but I’m a scientist and I need to see numbers.

The world has been divided into herbivores who eat plants and carnivores who eat herbivores long before there were humans — our success may be attributed to being omnivores, so we don't have to eat each other. We can't digest plastics, but we can digest a large variety of both plant and animal matter, even without farms and fire. The dinosaurs had that division, made famous both by studying fossils and the "Jurassic Park" movies, but the result — their extinction — had unusual and (we believe) unique causes.

Plants can serve us beyond food and that's where the cows come in. Hoofed animals, some rodents (bunny rabbits), and a lot of bugs have been eating plants for millennia, and converting them into energy and body tissue. Our digestive system doesn't convert very well, but the cows do it by fermentation. The internet can tell you how, but it doesn't work for us, and the cows have to be chewing much of their waking time, a solution not very appealing nor functional for humans.

But we can do it chemically and, thus, process agricultural waste like bagasse (squeezed sugar cane), corn stalks and cobs, and straw — no competition with food for land, and hopefully lower costs for all. When I asked my own Chem Engineering department, they said the cow conversion rate was too slow. Cows must work at cow-body temperature (101°F), but we can run hotter (faster) in a chemical process. I suspect much lab research has already been done, but I haven't heard much out in the open (yet). I know about chemical recycling, of course, but have always doubted the energy economics because of collection/separation needs and the need to break atom-atom bonds (less so for pyrolysis systems). Question for biopolymer companies and our trade associations: Can we do better than the cows at practical cost?

However they are made, bioplastics will be extrudable and moldable, as that's the equipment out there. Polymers like PLA and PHA already have known operating conditions and additives to enhance properties. But "bio" also includes conventional polymers made from plant sources, like PP and PE from corn or sugar. I have a special relationship with bio-nylon 11, as I worked for a year in Argentina with the material source, castor beans. The bio origin of the 11-carbon chain doesn't guarantee lower fuel needs, and the extreme toxicity of the beans will affect cost, including cultivation and waste disposal.

Much extrusion must meet accepted standards, usually dependent on the region, and many other places follow the US, UK, and European models. You may need to comply with these, especially if you make pipe or coat wire. Also, some processes require specialized materials, such as outdoor exposure (black, additive, or UV transparency) or paper coating (lower molecular weight and less need for physical strength). It remains to be seen how much the current pro-bio principle will affect cost.

All bioplastics are not the same, as all people are not the same. We must know what we need and how to measure it, and reject the belief that material is everything, which supports the popular appeal to make petroleum the villain. It's not easy — try to convince a herbivore human to eat meat, or vice versa.

In recycling, some bio-sourced plastics are chemically the same as what we use today and can be recycled together. There are additives to regain properties, so recycling doesn't have to result in inferior quality (fuzzy words, need numbers). I expect more progress here. Screening technology can clean up most anything. The popular image is de-fossilize (oil is bad) but not always de-plasticate.

Plastics save energy without restricting demand by making all cars lighter, including EVs, which still need fuel to generate electricity. No magic. Less air pollution in cities but that doesn't mean less energy. Moving people is important in carbon-dioxide reduction, but so are heating, cooling, and lighting. 

Material represents only 50 to 75% of our manufacturing cost, and energy is needed for other materials, too, such as the heat to melt glass.

There are many cost additions on the way to the final prices of extruded products, which are mostly sold to industrial and commercial companies, not us. Climate change is real, and we should worry about it, but plastics aren't the primary cause, even if they are fossil-based. In fact, they often help slow down climate change and they are not pollutants. All of this makes me wonder about the myth of plastics’ toxicity — they aren't — and the desire for degradability — just go away. But that's worth more space than I have here.

About the author

Allan Griff is a veteran extrusion engineer, starting out in tech service for a major resin supplier, and working on his own now for many years as a consultant, expert witness in law cases, and especially as an educator via webinars and seminars, both public and in-house, and now in his virtual version. He wrote Plastics Extrusion Technology, the first practical extrusion book in the United States, as well as the Plastics Extrusion Operating Manual, updated almost every year, and available in Spanish and French as well as English. Find out more on his website, www.griffex.com, or e-mail him at [email protected].

No live seminars planned in the near future, or maybe ever, as his virtual audiovisual seminar is even better than live, says Griff. No travel, no waiting for live dates, same PowerPoint slides but with audio explanations and a written guide. Watch at your own pace; group attendance is offered for a single price, including the right to ask questions and get thorough answers by e-mail. Call 301/758-7788 or e-mail [email protected] for more info.

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