Lactic acid and PLA: Production route
Why fermentation beat chemistry, and the gypsum problem
What this tab covers How it is made: the main production routes or, for product families, the main product types and technologies, compared on share of supply, inputs per tonne, plant scale, yield, co-products and unit cost.Lactic acid is made almost entirely by fermentation, because it gives the pure L-form needed for PLA; chemical synthesis from acetaldehyde and HCN gives a racemic mix and has largely disappeared (indicative). PLA is made in two main ways: through lactide and ring-opening polymerisation, which all large plants use, or by direct polycondensation, which gives low molecular weight. The key cost levers are sugar yield, the recovery step (which can create a tonne of gypsum per tonne) and scale of the lactide unit.
Routes compared
| Route | Share of supply | Inputs per tonne | Typical scale | Yield | Co-products | Unit cost |
|---|---|---|---|---|---|---|
| Lactic acid fermentation with lime neutralisation | most lactic acid capacity (indicative) | about 1.1-1.3 t sugar per t lactic acid; similar tonnages of lime and sulphuric acid (indicative) | 50-200 kt/yr (indicative) | about 0.9 t per t glucose (indicative) | gypsum about 1 t per t (indicative) | sugar dominates cash cost (indicative) |
| Low-pH or gypsum-free fermentation | growing (indicative) | less lime and acid | commercial and demonstration | similar | little gypsum | higher capex, lower reagent cost (indicative) |
| PLA via lactide and ring-opening polymerisation | nearly all PLA (indicative) | about 1.4 t lactic acid per t PLA; 1.5-1.7 t sugar per t PLA (Balrampur figures, 2026) | 75-150 kt/yr lines: NatureWorks Blair 150 kt, Thailand 75 kt; TotalEnergies Corbion Rayong 75 kt | about 90-95% from lactic acid (indicative) | water | PLA sells at roughly $2,000-3,000/t (indicative); Balrampur says it is initially dearer than conventional plastics (S&P Global, 2026) |
| Chinese integrated PLA from maize | a rising share of world PLA capacity (indicative) | about 2.5 t maize per t PLA (indicative) | 30-150 kt/yr (indicative) | not published | maize co-products | not published |
How each route works
Lactic acid fermentation with lime neutralisationLactobacillus or Bacillus strains ferment glucose at near neutral pH; lime keeps pH up and forms calcium lactate, which sulphuric acid splits, leaving gypsum.
Mature; gypsum waste.
indicative Low-pH or gypsum-free fermentationAcid-tolerant yeasts or bacteria, or salt-splitting by electrodialysis or ammonium routes, avoid most gypsum. Corbion and NatureWorks have developed such routes (indicative).
Cleaner; less proven.
indicative PLA via lactide and ring-opening polymerisationLactic acid is condensed to oligomers, cracked to lactide, purified by distillation or crystallisation, then polymerised with a tin catalyst. Ratios of L- and D-lactide set crystallinity and heat resistance.
High molecular weight and full grade range; capital intensive.
MarketsandMarkets 2026; S&P Global 2026; indicative Chinese integrated PLA from maizeChinese groups such as COFCO, BBCA/Fengyuan and Hisun integrate maize milling, lactic acid and PLA (indicative). New Chinese capacity pushed Asian prices down in early 2025 (Procurement Resource).
Low cost; quality and utilisation uneven.
Procurement Resource H1 2025; MarketsandMarkets; indicative Unit economics are indicative ranges from the sources named; costs move with feedstock and energy prices, plant size and region.