Biodegradable plastics will start a low-carbon life

Biodegradable plastics are polymers that are degraded by bacteria and other microorganisms in a specific time range. According to the Markets & Markets Consulting Company's Global Markets Forecast Report on the Types and Use of Biodegradable Plastics in the Market from 2015 to 2020, the market of biodegradable plastics will grow slightly at a compound annual growth rate of 10.8% from 2015 to 2020, and its output will increase from $2 billion in 2015 to $3.4 billion in 2020.

The report shows that, in terms of quantity, polylactic acid (PLA) has become the main force of biodegradable plastics market because of its excellent mechanical properties and easy processing characteristics, accounting for 45.1% of the market share, and will continue to grow at the fastest rate in all types of biodegradable plastics. However, in terms of market value, starch blends are slightly better than polylactic acid because of their higher production costs.

At present, Ingeo, a biodegradable plastic produced by Natureworks, has been gradually extended from food packaging, soft packaging, cards to durable goods. About two to three years ago, Natureworks began to study Ingeo's characteristics and found that it could also be applied to durables, or even replace ABS or polystyrene.

The new Ingeo formulation routinizes "high temperature resistance" to achieve the required functionality through crystallization, and the renewable carbon content in the new formulation will reach 90%. Its impact force and modulus are optimized, which makes them more suitable for injection moulding use - especially those products currently suitable for ABS with high temperature resistance and high impact strength or high modulus requirements. Compared with ABS, the bending modulus of ABS can be increased by up to 50%, which makes it possible to make the product lighter and thinner. In addition, Ingeo, which is suitable for durable goods, has better chemical resistance.

Direct extraction of carbon from the atmosphere as raw material

In order to improve product performance and reduce production costs, Natureworks may also consider sugarcane as a raw material to build new factories in regions with rich sugarcane production in Southeast Asia. In the next 3-5 years, lignocellulose will be extracted from straw, sawdust, switchgrass or rice straw to extract sugar.

"We also made the bold assumption that we could bypass the intermediary of plants and directly extract carbon from the atmosphere as raw materials. To this end, we cooperated with Catalysta in the development of a fermentation process to convert regenerated bio-based methane into lactic acid as Ingeo's structural monomer. This skill is still in the stage of experimental discussion. It is expected that the basic research and development work will be completed in 2-3 years and pilot production will be carried out in 3-5 years. If the conversion of methane to lactic acid can be completed, it will bring a revolutionary breakthrough to the plastic industry. The renewable origin of methane from wastewater treatment, landfill, agricultural waste decomposition and anaerobic digestion will be the source of raw materials for extracting Ingeo structural monomers. It will not only achieve sustainable development better, but also make PLA more competitive in price.

Converting biomethane into lactic acid is not only a bold innovation in skills, but also a useful way to reduce greenhouse gas emissions and carbon footprints. In September, during his state visit to the United States, Chinese President Xi Jinping also announced that China will launch the cap and trade system in 2017, which will also bring opportunities for the development of biodegradable plastics in China.