The sunliquid technology – a unique and validated pre-treatment approach to 2G ethanol 

By Markus Rarbach, Head of Start-up Business Biofuels and Derivatives, Clariant
Special to The Digest

In an article published by novaCana.com on January 26^th entitled; “Dilema do Etanol 2G: os desafios da matéria-prima celulósica” pre-treatment was identified as the key challenge for the six current commercial cellulosic ethanol plants worldwide.

Our approach at Clariant when developing the sunliquid® technology was to deliver an entirely integrated process from feedstock to finished product including our proprietary enzyme and fermentation organism platform, where all process steps are optimized to guarantee technical as well as commercial performance. So from the beginning all process steps were co-developed towards a fully integrated solution. We put a strong focus on only using established process equipment from other industries, to reduce the risk of technology upscaling.

sunliquid follows a pre-treatment approach that is unique: it uses a very simple 1-step pre-treatment technology with validated equipment that has demonstrated stable performance in the pulp and paper industry for years. Clariant has adapted its own proprietary enzyme platform to perform with a standard process protocol so no technical modification was necessary to the process equipment. This combination of a validated pre-treatment technology and our integrated enzyme production process ensures best performance in the following hydrolysis step. We have run performance tests at our pre-commercial plant in Straubing, Germany for different feedstock including sugarcane residues where we demonstrated a yield of up to 300 litre (80 gallons) per dry ton of feedstock.

In addition, our pre-treatment process is chemical free. This translates into a reduction of overall chemical costs by 50% compared to other technologies and CAPEX is kept low and risks associated with chemical handling and up-scaling are mitigated. This approach is more sustainable and environmentally friendly as it allows for optimized water recycling, does not require to dispose of harsh chemicals, risk of spills or contamination of water ways.

All process steps of the sunliquid technology have been thoroughly evaluated, optimized and validated in performance runs in our pre-commercial plant. The plant converts 4,500 tons of biomass producing up to 1,000 tons of ethanol (330.000 gallons, 1.25 million liters) output. The capacity of the pre-commercial plant services as the basis to demonstrate performance to customers on their respective feedstock and reduces up-scale risks. The engineering process design package has been completed for a commercial plant starting at 50,000 kta/year (20 million gallons, 75 million liters) of cellulosic ethanol output.

Clariant is offering a complete technology and service package and a technology licensing package to the Brazilian industry. For questions or more information please contact us at [email protected].