Issue Date: December 7, 2015
Eliminating The Need For Chemistry
Humanity has always relied on Nature for survival. We have used natural resources for food, shelter, heat, and transportation. In times of plenty, we have developed inventive products to improve the quality of life. For example, cotton and wool are used for clothing and minerals for tools and colorants.
Chemists have also looked to Nature for inspiration. Many of our early discoveries were based on understanding and manipulating materials such as cellulose and rubber. In modern times, we chemists have gone a step further in figuring out how to elegantly control the covalent bond. We can now take oil as a feedstock and use its basic molecular building blocks to produce simple or complex chemicals to suit any purpose, from fuels and medicines to plastics.
In other words, we have reduced our reliance on Nature by taking control ourselves. But have we forgotten our respect of Nature in the process, by relying too heavily on synthetic chemistry and by being poor managers of the pollution and waste that is created?
We as chemists clearly know how to make new chemicals and that has led to the development of a chemical industry that knows how to sell chemicals. The more chemicals we make, the more the industry seeks new and better markets to sell them into.
Our success, however, has led to a crisis. Society has been pushing back against chemistry and the chemical industry, charging us with pollution, global warming, and a general lack of a sustainable lifestyle. To be fair, chemistry is not solely to blame. But we do need to answer the question of whether the chemical profession is doing all it can to help solve and prevent environmental problems with an eye toward social justice and economic equality for all.
Because chemists know how to manipulate the covalent bond and the chemical industry knows how to sell chemicals, our general response to the push for green chemistry and sustainable living has been to develop better methods to manipulate the covalent bond and to look once again to Nature to source the chemical feedstocks we need. There are nascent and quite good efforts at directing chemical synthesis to make less toxic or even nontoxic chemicals. But the focus is still on chemicals because that is what we know.
As a remedy, what if we could stop doing synthetic chemistry or bypass the design of engineered plants and bacteria and use our accumulated knowledge and technologies to repurpose what Nature gives us directly into products, the way we used to do it? We could skip covalent modification of feedstocks and isolation of intermediate chemicals and go right to making products that replace those made with all those chemicals we make and sell.
For example, one of today’s breakthroughs has been to replace polyethylene terephthalate in water bottles with biobased polylactic acid. We can source the lactic acid needed from plant sugars by depolymerizing natural carbohydrate polymers. We then sell lactic acid as a monomer to a company that will polymerize it into a plastic material that can then be used to make water bottles.
What if we could extract a natural polymer from biomass and use it to directly make products such as water bottles without covalent modification? Admittedly, this is only one step closer to making products without doing chemistry because the ultimate breakthrough would be delivering water without a bottle. But who knows where our first steps might lead?
The difficulty in our profession is that we chemists aren’t trained to think this way and it isn’t how chemical companies operate. Chemists are brought up to make new chemicals, not new water bottles. The chemical industry wants to sell more chemicals—it does not sell water bottles. There doesn’t seem to be a major focus by chemists on looking for transformational technologies that would eliminate the need for chemicals.
In my own work, my colleagues and I have used new chemistry to extract and manipulate natural biopolymers such as chitin from shrimp shells and cellulose, hemicellulose, and lignin from trees. The chemicals our team uses are not always well characterized for human or environmental hazard. But the beauty of these biopolymers as Nature made them, contrasted with current efforts to deconstruct them into monomers that can be burned or made into other polymers, reminded me that perhaps green chemistry as practiced and understood today misses the point of sustainability.
The short-term truth of what we can realistically do lies somewhere between business as usual and finding technologies that are—dare we say it—chemical-free. For the long term, we need to review our current practices and see if we are not simply caught in a rut of expectations based on what we were taught, what we sell, and what we currently believe we can do.
The question we should all be thinking about is this: Should greening organic synthesis or finding new, nontoxic chemicals and materials be necessary, when we might more simply eliminate the need for synthetic chemistry?
Views expressed on this page are those of the author and not necessarily those of ACS.
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