To explain the goals of green chemistry, John Warner uses the metaphor of the toolbox. Rather than wrenches, nuts and bolts, the drawers in the chemical industry's "toolbox" contain commonly used processes, such as ways to make carbon compounds or oxidation-reduction reactions. Most of these processes involve hazardous chemicals. Green chemists aim to create a new toolbox filled with less harmful alternatives, so that in the future when chemists set out to design a molecule, they'll be able to put their hands on benign tools to get the job done.
Here are some promising new technologies destined for the green-chemistry toolbox.
TAMLs: There's no pretty way to say it—TAML is short for tetra-amido macrocyclic ligand—but these apparently harmless chemicals break down a variety of stubborn pollutants, including pesticides, dyes and industrial runoff. Developed by Terrence Collins, a chemist at Carnegie Mellon University in Pittsburgh, TAMLs mimic the enzymes in our bodies that have evolved to fight off toxic assaults. Collins and his team worked for two decades to develop these smaller, easy-to-build versions of biological enzymes. When combined with hydrogen peroxide, TAMLs neutralize many contaminants by breaking their chemical bonds.
Noncovalent derivatization: A longtime passion of Warner's (his license plate reads "NCD"), noncovalent derivatization is chemistry with a light touch. Covalent bonds are the strong connections between atoms that hold molecules together. Normally, when chemists are dissatisfied with some aspect of a molecule they are creating, they alter its structure by breaking or adding covalent bonds. Such changes can involve multiple steps and hazardous ingredients. Warner's breakthrough was to posit that sometimes there's no need to create a new molecule. Simply combine the existing molecule with another substance that interacts with it, and the transient forces between them can effect the desired change. "With no energy they find each other and form," he says. "Why does a bunch of lipids fold up to form a cell membrane? Why does DNA form a double helix? It's always these weak molecular structures."
Liquid CO2: Most of us know carbon dioxide as a gas (we exhale it) or a solid (think: dry ice in fog machines). But when you put carbon dioxide under pressure, it becomes a liquid. Liquid CO2 is a benign substitute for the nasty solvents typically used to decaffeinate coffee. Just mix it with green coffee beans, then take the pressure off. The carbon dioxide evaporates, leaving behind a pile of white powder—caffeine. Do the same thing to dirty clothes and you extract oils and grime without using perchloroethylene, the notorious dry cleaning chemical.
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7 Comments
Add CommentGreat article. Nonetheless I think you’ve missed an important aspect of the debate about regulations and Green Chemistry.
Reply | Report Abuse | Link to thisIf nasty chemicals are regulated out and desirable chemical characteristics specified, then by definition companies have to make "greener" chemicals. By default they will have to employ Green Chemistry to do this.
Regulating out (or in) endpoints makes sense, regulating *how companies innovate* does not.
Lastly, the "stick" companies face is the regulation. The "carrot" is greater profitability through innovation. Green Chemistry is a carrot, not a stick. Don't hit companies with the carrot.
This article is a mix of noble feel-good goals and inaccurate factoids. It would take a comment longer than the article to list them all.
Reply | Report Abuse | Link to thisThe one statement that is accurate is that the producers of "chemicals" would be better off making safer products. Most of them have been trying for decades. If you want to ban a dangerous but ubiquitous synthetic material, start with gasoline.
Bravo Wilson and Co. for taking an ailing 12-step program for academics that was never going to gain traction and developing smart, nimble regulations that generate incentives to innovate. Their success proves once again that without forward-looking players in California, this country would be even further behind the rest of the developed world in environmental policy.
Reply | Report Abuse | Link to thisI think lili spent too much time in the chemical storeroom. That is a nasty stuttttter, you might want to have doctor look at that. I know a voodoo...., never mind.
Reply | Report Abuse | Link to thisI worked in pest management on the family farm from 1993 to 2004. When I started we were using 'brain frying' chemicals for most pest control. Organophosphates were predominant and most of our chemicals carried either the 'warning' or 'danger' signal words. By the time I left in '04 most of those chemicals were no longer available and newer safer classes of chemicals with a signal word of 'caution' were the norm.
These newer chemistries were not only more pest specific, but were significantly less toxic to the user with vastly reduced environmental persistance and shorter re-entry intervals (the amount of time a field is off limits to workers after chemical application).
Some of this was the result of regulation. The EPA was no longer re-certifying certain classes of chemicals. Some of it was basic research driven as more was learned about the biology of the target pests and how they responded to various chemistries. One of the more effective classes of pesticides that became available at that time was insect growth regulators (IGR's). They would 'simply' not allow juvenile stage pests to molt into mature breeding adults.
As for more regulation, I get queasey at notion of having to jump through more bureaucratic hoops. However, appropriately defined and applied regulation can produce good results for the manufacturers, consumers, and the environment. Go Big Green!
Great article! Chemicals are doing untold damage to our bodies and are morphing the DNA of future generations. We are only scratching the surface of the negative effects of chemicals on our bodies; asthma, auto-immune diseases, heart disease, cancer and autism are all effects of chemical intolerance. The sooner companies switch to green chemistry the better for both our collective health and for their bottom line... always the biggest motivator. My story of how chemicals effected my health are on www.bublgrl.com.
Reply | Report Abuse | Link to thisBiocatalysis is becoming increasingly important in green chemistry. Enzymes are truly renewable catalysts and allow for greater atom efficiency in reactions that require stereoselectivity.
Reply | Report Abuse | Link to thishttp://livinggreenandsavingenergy.com/green-chemistry-enzymes-are-playing-a-larger-role-in-green-chemistry.html
Can <a href="http://www.royalbuilding.ca">stone cutting</a> ever be considered an efficient (and "green") way to retrieve rare minerals? I know that there are other minerals that would probably be more important to have that we can get elsewhere, but should it work I think in the future those materials will be good to have. Anyway, thoughts?
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