Until now, most of the lactic acid that is used to produced Poly Lactic Acid (PLA) has come from first-generation feedstocks, such as industrial cane sugar, sugar beet, corn or cassava, more or less depending on where production was taking place. These are crops that are grown following principles of sustainable agriculture and have a high yield per hectare of land used. They are highly efficient feedstocks that are—and will most likely remain—a good choice for lactic acid and PLA production. However, the fact that they are all food crops has, from the very beginning, given rise to controversy and debate. Although studies from nova-Institute in Germany and European Bioplastics have convincingly demonstrated that the production of bioplastics does not compete with food production, the subject continues to be an emotional one.
Yet, consider the following: According to figures published by European Bioplastics, about 97% of the total global agricultural land is used for growing food and feed and as pasture land. Another 2% is to grow the biomass needed for material use, of which bioplastics currently account for less than 0.01%. As they write: “bioplastics are nowhere near being in competition with food and feed.” Moreover, the sheer diversity of available options makes it possible to select the most efficient and least ecologically disruptive choice for a given locale.
Nonetheless, bioplastics producers are acting on the market’s desire to move away from food-based feedstocks and are investigating a wide variety of alternative options, such as second generation lignocellulosic feedstocks (bagasse, corn stover, wheat straw, wood chips) and waste biomass. Taking it a step further, NatureWorks has been working on a project aimed at cutting out the agricultural step altogether, by developing technology to convert carbon dioxide or methane directly to lactic acid.
And while there is still quite a way to go before that goal is achieved, Corbion Purac (Netherlands) has announced that it is the first company in the world to have successfully made PLA from second generation feedstocks. The company says it has produced high grade lactic acid from alternative feedstocks, optimizing the lactic acid fermentation process to fit the special characteristics of the biomass. This lactic acid was then used to produce PLA bioresin.
Corbion thinks that, in the future, these alternative feedstocks could have a high impact on the biochemical and bioplastics industries. In order to fully commercialize and bring PLA based on second generation feedstocks to the market in commercial quantities, significant R&D efforts are still needed. The company is inviting all interested brandowners and converters to join a consortium in order to accelerate the market introduction of second generation feedstock bioplastics.