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Production and deploying of high purity lignin and affordable platform chemicals through wood-based sugars

Periodic Reporting for period 2 - SWEETWOODS (Production and deploying of high purity lignin and affordable platform chemicals through wood-based sugars)

Reporting period: 2019-12-01 to 2021-05-31

The SWEETWOODS project aims to develop a first-of-a-kind wood fractionation flagship plant in Estonia that uses sustainable hardwood biomass. The process combines innovative pre-treatment technology with enzymatic solutions to provide sugar recovery levels of over 90 % with exceptionally high-quality hydrolysis lignin. Sugars and lignin can be further processed and converted to high-value biomaterials for replacing fossil-based chemicals in a wide range of products. The SWEETWOODS project has six core objectives. It targets to: 1) Show the successful and profitable production - on an industrial scale - of high-purity lignin along with penta- and hexa-carbon carbohydrates from hardwood; 2) Use all main components of the biomass feedstock while minimising any diversion of carbon content streams to low-value uses; 3) Produce high-purity lignin for drop-in applications and validate depolymerised lignin fractions for a range of novel applications, namely elastomer foams for tube insulation, rigid polyurethane foam panels for building insulation and polymer compounds intended for injection moulding; 4) Produce high-purity sugars - glucose, xylose and demonstrate production of derivates of those (fructose, glucosone) - for novel end-use cases, namely producing bio-IBN, xylitol and lactic acid; 5) Establish markets for lignin and novel sugar-based platform chemicals; 6) Evaluate the environmental and socio-economic performance of the SWEETWOODS plant process and of the developed products through a Life Cycle Sustainability Assessment, as well as a viability analysis.
The first phase of the SWEETWOODS flagship plant, scale-up of the innovative wood fractionation process has been built and commissioned. In parallel also pilot scale equipment for enzymatic hydrolysis and conditioning for lignin and cellulosic sugars is established to produce samples at ton scale. By the end of the Reporting Period 2, the SWEETWOODS flagship plant is producing uniform and high-quality cellulosic sugars and hydrolysis lignin in ton-scale. MetGen has tailored an enzyme cocktail (MetZyme SUNO™) for the hydrolysis of the specific Estonian hardwood biomass used as a feedstock material of the flagship plant. MetGen has actively developed new enzyme variants to improve the performance of its enzyme products (MetZyme SUNO™ and MetZyme PURECO™) and with both products the expected process yields have been reached.

The crude lignin of SWEETWOODS flagship plant has been successfully tested by TECNARO in injection moulding compounds. By the end of RP2, the injection moulding compounds having SWEETWOODS crude lignin as a main component has been produced in hundreds kg scale. The SWEETWOODS crude lignin is odourless, and it has shown very good performance in injection moulding compounds.

MetGen has developed the METNIN™ Technology to depolymerize solubilized crude lignin. By enzymatic depolymerization, the lignin is converted for example into phenolic platform chemicals. Armacell has been testing the depolymerized lignin in elastomer foam production process and Recticel in rigid foam formulations for building insulation application. In both cases, further optimization will be done to increase the incorporation rate of depolymerized lignin in final products.

Global Bioenergies has tested the SWEETWOODS sugars in the bio-IBN production and over 200kg of pure IBN has been produced and further processed. In addition, Global Bioenergies has developed a new version of its isobutene production process, now comprising of two consecutive stages. The first step covering the entire chain up until isobutene precursor can now be done using tollers’ existing fermentation capacities in order to produce very large volumes at significantly reduced costs. The suitability of SWEETWOODS sugar hydrolysates have been validated also in fermentation-based production processes of lactic acid and xylitol.

2B has performed an LCA study on the whole fractionation process from feedstock to end products lignin and cellulosic sugars, proving the expected assumptions related to low environmental impacts of the SWEETWOODS biorefinery. Based on the LCA data, a sensitivity analysis was carried out, in order to analyse how the final environmental impact results could be improved even further.
The reduction of ‘waste’ from a biorefining operation by at least 80 % compared with the state-of-the-art remains a feasible target. It is still expected that compared to the conventional pulp mills and ethanol biorefineries, the main difference of SWEETWOODS is related to the fact that over 95 % of the feedstock is converted to useful primary products and only 2 % lost as CO2 from hydrolysis and 2-3 % recovered via anaerobic digestion.

In the SWEETWOODS project, the Sunburst pre-treatment technology has been upscaled first time to a flagship plant scale. The Sunburst technology fractionates biomass into its basic components faster and more efficiently than any other technology available on the market.

MetGen has introduced the first of its kind of enzymatic treated lignin able to refine the full bulk of lignin and defining application areas for all the created products. In addition, MetGen hydrolysis solution offers optimized enzymes and tailored cocktails not available in the market. Finally, MetGen provides innovative business models for on-site manufacturing of enzymes and proposes MetZyme® PURECO™ as a new chemical pathway to bio-based chemicals.

First time, the bio-IBN has been produced successfully in m3 scale from second-generation sugars as a feedstock material. Global Bioenergies has further improved the yield of its isobutene process by dividing the process into two consecutive stages. This new patented process makes the manufacturing process more flexible and economically efficient.

At the end of the project, all the lignin end-use cases (elastomer foams for tube insulation, rigid polyurethane foam panels for building insulation, biopolymer compounds intended for injection moulding) and bio-based IBN utilizing second generation sugars are expected to be novel and beyond state-of-the-art.
SWEETWOODS flagship plant in May 2021. Ton scale lignin and cellulosic sugars production has started