Process description

The Green Sugar process uses a pre-treatment of the biomass feedstock followed by a two-step acid hydrolysis, which enables the separation of all types of lignocellulosic biomass into its main fractions glucose derived from cellulose, monomeric hemicellulose sugars (xylose, arabinose, mannose, galactose) and lignin.
The hydrochloric acid is kept in a closed cycle, and after the biomass has been pre-treated and hydrolysed, the acid is recovered by evaporation in a closed loop. As an output of the Green Sugar process different sugar hydrolysates (C6 sugars and C5 sugars) are separated. Those hydrolysate is cleaned and raffinated and can be used for various biochemical fermentation processes in the chemical industry to produce high quality bio-based chemicals like bioplastics, biochemical or biofuels. Further, the lignin within the biomass is used as an energy source to provide heat and steam for the biorefinery process.



Competitive advantage

The multi-phase hydrochloric acid hydrolysis bears several advantages compared to other lignocellulosic biomass separation processes:

  • The sugar yield, its concentration and purity in the hydrolysate is very high
  • All types of lignocellulosic biomass can be processed, including highly lignified biomass
  • The sugar output contains very low concentrations of degradation products
  • Separation of C6 and C5 sugar hydrolysate is possible
  • The process efficiency is higher due to the short treatment period in the reactors compared to hydrolyses using enzymes

Compared to enzymatic biomass separation processes, Green Sugar is a superior way of separating biomass in terms of competitiveness and the key to an efficient way of utilizing lignocellulosic biomass as a source of sugar for the fermentation and bio-based chemicals industry.

Historical technology development

The Green Sugar acid hydrolysis process is based on the wood saccharification process invented by Friedrich Bergius (Nobel prize winner in 1931). Until the 1960s the two-step acid hydrolysis process operated in an industrial scale plant in Germany before it became uneconomical. Green Sugar invented several key processes and apparatuses, ranging from pre-treatment of biomass to the acid handling and closed loop acid recycling. Today, the hydrochloric acid biomass separation process is, due to various key improvements done by Green Sugar, economical and can be commercially applied in the field of lignocellulosic biomass separation for bio-based chemical down-stream purposes.


The core mission of Green Sugar, as an innovative and research driven chemical company, is to provide solutions in the area of lignocellulosic biomass separation and saccharification processes.

As the chemistry of renewable carbohydrates bears many ways of adding value to the biomass, Green Sugar investigates potential extraction and chemical processing techniques through research and development activities to generate bio-based chemicals of highest value.

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