Lactic acid NatureWorks

Poly(L-lactic acid) EcoPLA, NatureWorks Dow-Cargill Environmental, biomedical Lactic acid from corn starch fermentation... 

Carboxylic Acids Obtained by Fermentation of Carbohydrates Lactic (2-hydroxy-propionic) acid obtained by fermentation of glucose and polysaccharides is used by NatureWorks (Cargill/Dow LLC) to prepare polylactide (PLA), a biodegradable or recyclable polymer with a potential production of 140000 t a-1 (Scheme 3.4) [23], This and other potential useful reactions from lactic acid have been reviewed by Datta and Henry [24],... 

The shift from bio-based specialties to commodities is already visible in the marketplace with biopolymers made from corn. The first example is NatureWorks from Cargill, which is made from corn sugar-derived lactic acid. As in the biochemicals examples described above, the environmental benefits are eye-opening NatureWorks already requires 25 to 55 percent less fossil resources, and it is planned to replace fossil resources completely in the next four to six years (Euro-paBio and McKinsey Company, 2003). Other high-potential biomaterials are a polymer based on 1,3-propanediol from DuPont and Genencor (Sorona ) and... 

Much has been written about Cargill Dow LLC s polylactide (PLA) polymer, also known as NatureWorks PLA. PLA is a thermoplastic produced from biomass sugars by fermentation. The fermentation product, lactic acid, is converted into a lactide that is purified and polymerized using a special ring-opening process (18). 

NatureWorks LLC has set up a 300 million plant at Blair, NE, which is capable of producing about 140,000-tons/year of poly-lactide polymers from com sugar. It employs a fermentation process to produce two chiral isomers of lactic acid from glucose, which are then cracked to form three lactide isomers. The isomers are subsequently polymerized to polylactide. 

Nowadays, various aliphatic copolyesters based on succinate, adipate, ethylene glycol and 1,4-butanediol are being produced. Aliphatic polyesters based on natural feedstock such lactic acid are also being produced on a commercial scale by companies such as NatureWorks TLC. 

The greenhouse-gas-neutral claim is the result of the combination of renewable-resource-based feedstock, along with the purchase of renewable energy certificates (RECs) backed by lifecycle assessment data. These RECs will serve as an offset to cover all of the emissions from the energy used for the production of NatureWorks PLA. The company will purchase certificates for projected 2006 production at its 140,000 tonne capacity manufacturing plant and 182,000 tonne capacity lactic acid plant in Blair, Neb., USA, as well as at its corporate offices in Minnetonka, Minn., USA. The purchase of renewable energy will allow NatureWorks to decrease its fossil fuel footprint by 68%. 

One of the most highly developed biopolymers is poly (lactic acid) (PLA). In the USA, PLA is manufactured by NatureWorks at a plant in Nebraska using lactic acid derived from corn. (Lactic acid can also be obtained from other natural sources such as wheat or potatoes.) Poly (lactic acid) is produced by ring opening polymerization of the lactide, as shown in Figure 8.12. 

Poly(lactic acid) has three typical optical isomeric forms (i) optically active and crystalliz-able poly(L-lactide) (i.e. poly(L-lactic acid) (PLLA)), (ii) optically active and crystallizable poly(D-lactide) (i.e. poly(D-lactic acid) (PDLA)), and (iii) optically inactive and noncrystal-lizable poly(DL-lactide) [i.e. poly(DL-lactic acid) (PDLLA)]. Of these isomeric polymers, PLLA is most frequently used because its production cost is lower due to its joint mass production of 1.4 X 10 metric tons per year by NatureWorks LLC, which is owned by Cargil... 

Poly(lactic acid) (PLA) offers 100% bio-based carbon content for a zero material carbon footprint and both compostability and recycling as viable end-of-life options. NatureWorks LLC (a Cargill subsidiary) manufactures 140 000 tons/year of PLA under the trade name Ingeo for packaging and industrial applications (see www.natureworksllc.com, accessed 23 June 2013). 

Figure 8.6 Barrier properties of commercial PHA resins compared to other bio- and oil-based polymers used for packaging, as measured by oxygen and water permeabilities, (PS1540 Polystyrene from Arkema PP7712 Polypropylene from Total Chemical Company PLA7001D Poly(lactic acid) from Natureworks P228 PHA from Biomer MirelF1006 3002 PHA from Metabolix Enmal YIOOOP PHA from Tianin Biologic PA MXD6 PHA from Mitsubishi Chemical Company).

FIGURE 17.2 SEM micrographs of amorphous PLA (8302D, NatureWorks, 10% D-lactic acid content) foamed at 150°C for 5 s in a batch process. Specimens were saturated with CO2 at room temperature for 48 h at (a) 400 psi and (b) 600 psi (unpublished images from Matuana). 

PLA (NatureWorks 8302D with D-lactic acid content of 9.85%). Samples contained 0.5 wt% talc. 

FIGURE 17.8 SEM of amorphous PLA 8302D (NatureWorks, 10% D-lactic acid content) foamed with 0.5% endothermic CFA (BIH40 from Boehringer Ingelheim Chemicals, which is sodium salt of polycarbonic acid + carbonate compounds) at 40rpm (a) 30 x and (b) 70 x magnifications [86]. 

PLA (NatureWorks PLA 3001D, 1.5% D-lactic acid, density = 1240kg/m ). 

Second-generation biodegradable polymers were commercially introduced around 1990 and are represented by the starch-based products offered by Novamont (Mater-Bi ) and by several families of polyesters. One of these polyesters, poly(e-caprolactone), has been commercially available for more than twenty years other biodegradable polyesters, which have been commercialized very recently, include poly(lactic acid) and other aliphatic polyesters. As a result of plant investments made by Cargill-Dow EEC (now NatureWorks EEC) and others, biodegradable polyesters should become more affordable very soon. 

Mussatto, S., Fernandes, M., Manciha, L, and Roberto, 1. (2008) Effects of medium supplementation and pH control on lactic acid production from brewer s spent grain. Biochemical Engineering Journal, 40 437-444 Natureworks (2013) How Ingeo is made, http //www.natureworksUc.com/The-Ingeo-Journey/Eco-Profile-and-LCA/How-Ingeo-is-Made (last accessed July 2013). 

PLA can be chemically recycled in a process called LOOPLA hydrolysis (NatureWorks 2013). During hydrolysis, the Ingeo PLA plastic is broken down into lactic acid. The lactic acid can then be polymerized back into Ingeo PLA. 

Figure 1.10 Energy requirement for the production of NatureWorks first generation PLA (Vink et al., 2003). LA = lactic acid, WWT = waste water treatment, CWM = corn wet mill (published with permission of Elsevier).

Currently, NatureWorks owns the largest single lactic acid production facility, with 180,000 MT produced per year using corn as the feedstock. The lactic acid produced by NatureWorks is mainly used for conversion to Ingeo PLA. Meanwhile, Purac is the largest lactic acid producer, and their products are widely used in the food, beverage and... 

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