Petroleum plastics: a thing of the past?

Materials World magazine
,
7 May 2012

Oil-based plastics could soon be replaced by those made from biomass, say researchers at Utrecht University in the Netherlands.

Led by Professor Krijn De Jong, Professor of Inorganic Chemistry and Catalysis at Utrecht, the team has developed a catalyst that enables the production of plastics from wood-based biomass with the same characteristics as petroleum-derived plastics. ‘The bioplastic is identical to plastics made today from oil,’ says De Jong.

Professor De Jong explains the process behind the research. ‘Biomass is first converted to synthesis gas, a mixture of carbon monoxide and hydrogen. From synthesis gas the lower olefins (such as ethane or propene) are made identical to those used today based on crude oil.’ These olefins then form the crucial building blocks necessary to make plastics suitable for a wide range of uses.

The key ingredient of the work was the catalyst developed by the team. ‘The catalyst contains iron nanoparticles promoted by small amounts of sodium and sulphur,’ says De Jong, adding that the iron nanoparticles in the catalyst convert the synthesis gas into lower olefins.

According to the researchers, any type of wood waste can be used in the process. They add that the raw materials consist of wood-like biomass, such as branches, plant stalks and pruning waste. ‘We can use poor soil not suitable for agriculture,’ says De Jong. ‘Also, we do not use carbohydrates but rather lignocellulose biomass.’

The method is sustainable and efficient, claims De Jong, and could provide a long-term replacement for petroleum-based plastics. For this to happen, a shift in infrastructure would be needed, in particular, towards increasing the sustainable production of biomass that does not compete with food.

No special facilities or technology are needed to produce the material, says De Jong. ‘All technology is [already] known. The missing link was our catalyst.’