By turning carbon dioxide into products, improving ways to store energy, and finding replacements for dwindling natural resources and minerals, materials chemistry can push sustainability into a number of industries, according to a paper published as the output of a global gathering of chemists.

"With the aid of materials chemistry, we can create a world in which our energy requirements are delivered sustainably, where usable energy can be produced, stored and then supplied wherever it is needed. We can minimise and remove pollutants from our environment as we create new consumer products which place less of a burden upon our natural resources," says the paper, "A Sustainable Global Society: How Can Materials Chemistry Help?"

The paper covers five main topics, which often intertwine to act as a roadmap to what needs to be worked on, and which in some cases already is being worked on. It was written to recap what was discussed at the second annual Chemical Science and Society Summit, a gathering of 30 materials chemists from China, Germany, Japan, the United Kingdom and the United States of America.

While it doesn't provide exhaustive details on who is doing what work, it can give companies insights into what research and work they should be investigating or supporting, depending on how that work could benefit them.

Generating and Storing Energy

When it comes to energy, materials chemistry can create solar cells from new materials, figure out efficient ways to turn waste heat into energy, improve fuel cells and create new ways to store and move energy around to get the most out of wind, wave and solar power.

While chemists could develop solar cells using new materials, which would be more efficient that current offerings, they can also explore cells that mimic photosynthesis by converting water or CO2 into chemicals and fuels. Another promising area is thermoelectric materials, which could convert solar energy and wasted heat into electricity.

When discussing those systems, the paper notes that new materials should be abundant -- a recurring theme in the report, since any change that could become widespread throughout the world also needs to be feasible on a large scale for a long time.

Abundant elements will also come into play with creating new batteries and devices for storing and transporting energy, a critical step in expanding the adoption of renewable energies, most of the sources of which are intermittent and thus need to be stored in batteries.

Making CO2 an Ingredient

For all the discussions of carbon capture and storage, it's still not a commercial process yet, though the paper touches on how materials chemistry can both improve the capture of CO2 and also use it beneficially.

Supercritical CO2, the gas' fluid form, is already used as a refrigerant and in processes like removing caffeine from coffee beans. It could also be used more widely as a solvent and to purify chemicals as a replacement for toxic and expensive solvents.

CO2 can also be combined with hydrogen gas to make methanol (a fuel that can be turned into gasoline), combined with water to make methane (which, as part of natural gas, is burned in many place for energy), or turned into polymers. But in that last case, it could take a decade to work on and scale up technologies.

Not mentioned in the paper are some of the other ways companies have figured out how to use CO2, such as companies that are using CO2 to make cement and bricks.

Replacing Fossil Fuels

Aside from fuel, oil is used to make plastics, fertilizers, pesticides, pharmaceuticals and more. Shifting away from oil will take steps, and in the short term chemists should focus on using low-quality feedstocks like synthetic gas and methane to replace petroleum and coal, the report says.

The long-term ideal is to use biomass in place of fossil fuels and also, as mentioned above, use CO2 as a replacement.

Using low-quality fossil fuels will require new chemical separation technologies, and bacterial processes that turn biomass into chemicals can be improved to use less energy and water.

Avoiding Scarce Resources

Some essential natural resources will eventually be scarce, and recently concerns have been raised about supplies of rare-earth metals. Again, abundant alternatives come into play.

Phosphorus, a key part of fertilizer, could be extracted from soil, river and oceans. Metals like platinum, lithium and the 17 rare earth elements can either be replaced with better-available replacements and also, through better product designed, more frequently recycled and reused when electronics are disposed of.

Here the paper makes its only mention of legislation, in saying that laws to regulate the supply and use of scare resources will be needed in the short term, coupled with research and development into sustainable technologies.

Greener From the Start

The paper notes that about 90 percent of all chemicals are made with the help of catalysts, a process that commonly use a lot of energy and water. What's needed, the paper says, are catalysts that can be regenerated or recycled, and used with benign solvents like water or supercritical CO2.

Eastman Chemical Company just recently started making its first chemical product with a technology that avoids much of the energy, water and waste from the production process.

As mentioned above, biomass can be used to make bio-based plastics, and more larger companies have been dipping their toes into the waters of bioplastics. Coca-Cola and Pepsi both now have bottles made 30 percent and 100 percent, respectively, from biomass, though Pepsi's isn't on shelves yet.

A common concern with bioplastics, noted in the paper, is that plastics designed to degrade could contaminate recycled systems. Both soda companies developed their bottles to work in existing recycling technologies. But since other companies will likely continue pursuing compostable plastics, as well, the paper calls for improvements to recycling processes and systems that separate materials.

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