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Sunday, July 7, 2019

Bans on single use products: What do they mean for bioproducts?

For the last 15 years of my career, and in the almost three years since I retired, I've been working on putting wood-based chemicals into places where the incumbent is petroleum-based. The argument was that replacing petroleum is inherently a Good Thing; and that petroleum refineries get their steam from burning carbon-intensive, petroleum-based residuals, while pulp and paper mills largely get theirs from carbon-neutral, wood-based residuals. (No, we never did a proper LCA to quantify this.)

One little snag I'd run into now and then, when discussing this with non-technical folks, is that a lot of people do not understand the difference between bio-based, recyclable and biodegradable (or compostable).

There is a technically easy path from sugar cane to ethanol, and another equally simple path from ethanol to ethylene. The Brazilian company Braskem offers a bio-based polyethylene from sugar cane; it's expensive and I gather that they make it on demand for people such as cosmetics manufacturers, where the advertising benefit of a bio-based packaging makes a difference and the added cost of a few pennies is not an issue. But no matter if it is bio-based: it's still ethylene. I can think of other examples. I'm no longer so sure this is a Good Thing.

Next is recyclability. This has suddenly become an issue as Asian countries, sick of getting mixed, contaminated waste instead of a nice clean single-product stream, have decided to stop taking feedstocks for their recycling plants from the West. (The fact that they mostly have a large enough internal market to generate the necessary residual streams is not entirely coincidental). But there were problems before this. Some years ago I recall hearing a producer of an accepted bio-plastic complaining that there was no recycling stream for his product, which, when mixed with ethylene (for example), was seen as a contaminant and thus reduced the value of the supposed recovered ethylene stream. So large customers were refusing packaging made with his material, limiting his potential for growth.

Finally biodegradeability is not always desirable. I don't want my coffee cup to start degrading before I am finished drinking the coffee; and while this example is a bit silly, there are plenty of cases where neither the petroleum-based product, nor its bio-based substitute, are biodegradeable, and for good reason: we need some products to last longer. Mother Nature has made lignin, for example, to be difficult to bio-degrade, as an evolutionary reaction to attacks from insects and fungi; this property makes it a good substitute for plywood glues.

So the conversation with the lay public has been challenging, and people have occasionally asked hard questions when I describe what I have been doing. The conversation is arguably about to get a whole lot more challenging.

This is because of the viral growth in the awareness of the problems around single-use plastics; the point I want to make is that it is only a matter of time before all single use products are seen as a waste of precious resources, regardless of the source.

Plastic drinking straws are to be replaced with paper, as are plastic shopping bags; but arguably the best carbon policy around forest harvesting is to lock that carbon up in long-term applications, such as tall buildings or furniture, and quickly plant some more trees. Simply putting more carbon into the loop, even if we are still replanting to compensate, only maintains the status quo, and does nothing to reduce the amount of carbon in the atmosphere. The same holds true for the mother of all single-use products, namely fuels.

So it may be misguided going forward to assume that a bio-based substitute for a petroleum-based product is still a Good Thing, especially if that petroleum-based product is being phased out because it is going into a single-use product. We are generating way too many leftover single-use products, and shifting from one resource to another may be a short-term solution but does nothing in the long term.

My message is that it may be time to focus on locking up carbon, no matter where it came from, in products that will be in use for months if not years or even decades. Products like my old row house (pictured, in the middle of renovations a couple of years ago) that will be 100 years old next spring. There's a lot of sequestered carbon here, some new and some old.

Just my $0.02 worth. Drop me a line to discuss, specifying if you want the conversation private. You can also sign up to receive notification of updates to this newsletter by putting your e-mail address (which I don't see, so I can't sell it) in the box at right.

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