Plastic from plants instead of oil

So far we have heard about the production of fuel for cars from plants (biofuel) Now it turns out that it is possible to develop plastic products that today are produced from crude oil by a chemical process applied to biomass

Researchers from the University of Berkeley in California succeeded, using a chemical reaction known in the literature for decades and modifying it, to develop a mild and inexpensive method for removing oxygen from biomass. This process, if it can be adapted to industry, could allow the production of many and varied petrochemical products, such as plastics, from biomass instead of oil.

"We found and improved a one-step and selective process of deoxygenation (removal of oxygen, deoxygenation) based on the substance formic acid," said Robert Bergman, one of the researchers of this project carried out in the Department of Chemistry at the University of California, Berkeley.

The formic acid converts glycerol, an unwanted and quantitative by-product in the production of biodiesel, into an allyl alcohol, which can be used as a starting material in the production of various polymers, medicines, organic compounds, pesticides, herbicides and other chemical products. Today, allyl alcohol is produced from the oxidation of petroleum.

Jonathan Ellman, professor of chemistry and one of the other researchers, explains: "Currently, about five percent of the world supply of oil is used as a starting material for the preparation of chemical goods. If it will be possible to produce these goods from biomass, which is a renewable source, instead of oil, then this production will no longer harm the environment."

Biomass attracts a lot of public attention due to its inherent ability to be a substitute for carbon-based fuels, such as oil and natural gas, but it also has a great possibility of being used as a raw material for other chemical products. It can be safely said that not a single day goes by without one of us, all over the world, making use of such a chemical product. Products made from biomass instead of oil will be from both renewable and biodegradable sources. However, unlike petrochemical raw materials, which are produced by adding oxygen to oil, biomass raw materials actually require the removal of oxygen from them.

The researchers used a unique distillation system to take a fresh look at an old chemical reaction in which formic acid, the substance found in bee venom, was used to remove oxygen from glycerol. In this original reaction, the recovery was low, mainly due to the burning of the material. This charring was obtained following indiscriminate combustion and resulted in the formation of a complex mixture of products at high temperatures. The researchers discovered that simply shielding this reaction from air allows for a more improved process for removing the oxygen from glycerol.

One of the researchers explains: "Injecting a stream of gaseous nitrogen during the reaction of glycerol and formic acid completely eliminated the burning of the material. Besides protecting the product from the oxidation of the air, the nitrogen also helped in the distillation of the alcohol itself. The final product was obtained with an improved utilization of eighty percent and in a selective manner."

One of the researchers explains: "From the experiments we conducted we were also able to obtain a better understanding of the basic chemistry behind this reaction. We believed that the burning was a random oxidation process since the reaction took place in the open air and we predicted that performing it in a nitrogen atmosphere would improve the results. However, in examining the basic chemistry, we uncovered an unexpected reaction mechanism that really expanded the generality of this reaction and increased its possible applications."

With this state-of-the-art reaction mechanism, the state-of-the-art oxygen removal method using the researchers' formic acid, the reaction can be used to convert sugars found in biomass, as well as other polyhydroxy compounds, into chemical raw materials such as olefins (alkanes) that are currently produced from oil. The method could also prove its application in the process where biomass is converted into liquid motor fuels.

Says the lead researcher: "Our first findings with inexpensive biomass-derived polychlorinated biphenyls show that the reaction of compounds of this type with formic acid will be a valuable alternative also for the production of materials that have undergone oxygen removal. However, adapting this process to industry is going to be a serious engineering challenge."

"Adapting this process to an industrial level may require the combined efforts of academic and industrial laboratories, but this is necessary, if we wish to prepare commercial chemicals and fuels from biomass in the future, and protect the atmosphere from future damage while helping to reduce the levels of the greenhouse gas carbon dioxide."

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