Worlds first sulfuric acid-free kraft lignin recovery system

Project Information

LignEasy

Grant agreement ID: 190123865

DOI

10.3030/190123865

Project closed

EC signature date 31 August 2023

Start date 1 September 2023

End date 28 February 2026

Funded under

• The European Innovation Council (EIC)

Total cost

€ 2 901 500,00

EU contribution

€ 2 031 050,00

Coordinated by

LIGNEASY OY
Finland

Periodic Reporting for period 1 - LignEasy (Worlds first sulfuric acid-free kraft lignin recovery system)

Reporting period: 2023-09-01 to 2024-08-31

Summary of the context and overall objectives of the project

Lignin is a substance in the cell walls of plants (20-30 w-%) that strengthens their structure. When wood is processed into pulp, lignin is dissolved and becomes a waste product. The current state-of-the-art method to remove lignin from the pulp requires heavy chemistry and the end-product is not easily suitable for further processing. Thus, the pulp industry usually burns lignin to recover energy, even though it is a rather low-grade fuel.

LignEasy is the first sulfuric acid-free, low-impact lignin recovery system for pulp mills. Our patented technology fits any kraft pulp mill without disrupting chemical balance or productivity. Our process can be integrated into existing pulp mills' production systems to produce high-quality lignin suitable for a diverse range of applications.

Any kraft mill is suitable for implementing our technology and benefit from its advantages. First, our process produces a high-quality biomaterial with applications in a wide range of sectors. Second, it also allows debottlenecking the pulping process: the bottleneck step is usually the recovery boiler, especially in old kraft mills. When compared to competing technologies, it also eliminates sodium sulphate dumping, reducing the costs of chemical make-up.

The LignEasy product’s benefit is its high suitability for several end-product use cases as it can be chemically modified. A flagship application has already been demonstrated: phenolic resin for ply-wood manufacturing. The product is scalable to applications in the chemical and packaging indus-tries, and multiple more will be demonstrated.

The project aims to carry out the following:

- Developing and demonstration in pilot scale a lignin recovery process that will be integrated next to a operating pulp mill where the mill’s side stream is utilized to produce lignin.
- Demonstration of several end-use cases in applying Lignin product to the products of the chemi-cal industry. Contacting customers from the chemical industry and testing of the product in pilot scale.
- On the basis of the results from pilot scale studies a full-scale plant for 50 000 ton per year will be designed. Discussions with pulp mills will be initiated to find a location to the flagship plant.

LignEasy website address: https://www.ligneasy.fi/partnership/

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

LignEasy has performed scale-up testing of the core separation technology. An agreement with the pilot test site (RISE, Sweden) has been signed, and the work at the site was started to install the pilot unit. The first part of testing of the process was done in our own in-house laboratory, with a small-scale test unit for defining basic process parameters. The second part of testing was per-formed with commercially available filtration modules using a rental unit to assess the process variables in a similar type of set-up as the pilot unit under design. The third part of the scale-up testing was performed at the LignEasy pilot test area in Sweden Lignocity, already using fresh raw material from a nearby pulp mill, using larger equipment capable of continuous processing in steady-state mode. The last design parameters were confirmed during the testing for the pilot plant design. The pilot plant will be operating exactly the same way as it would on an industrial scale, on a smaller scale, of course.

LignEasy is now commissioning the pilot plant for demonstration of the patented lignin separation technology and for the production of lignin for end-use customers pilot scale. The capacity of the pilot plant is designed at 1 tn of lignin per day and can be considered already at a semi-commercial level.
A market study of lignin opportunities in more than 15 different applications was conducted, showing that the most promising end-uses are in phenolic resins and in polyurethane.

Application development has been done for the both top candidates in bilateral cooperation with a companies in the industry. Also other use-cases such as lignin use in plastics, cardboard manufacturing and bitumen has been tested with very positive results.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

LignEasy’s technology represents a significant step forward from the current competitors, as it utilizes an advanced filtration instead of the usual acid-based system. Our innovative approach does not entirely eliminate the odor associated with lignin, as kraft lignins are already exposed to sulfur in the kraft pulping. However, it provides a better starting point by reducing exposure to sulfur in the extraction process. As a result, the initial sulfur content, and consequently the odor is less pronounced. Additionally, our lignin can be obtained in a liquid state or dried to a fine-grained powder, increasing its versatility. This allows for various end-uses, providing more flexibility in product design and application.

Several end-use cases for the use of lignin as raw material in bio-based application will be demonstared. The naturally soluble nature of LignEasy lignin product makes it a viable alternative for many applications, such as phenolic resins used in plywood glues, cardboard applications and many others. In a short peri-od of time, LignEasy's lignin product has been tested to work at least in three application areas.

Increasing interest is emerging in LignEasy's ability to scale up in a short range of time from kg-scale to a pilot plant able to produce tons of lignin material. Companies researching the use of lignin in their processes are moving into ton-scale pilot operations, and there is a lack of lignin products in the market. The key needs for the further uptake of the lignin products are various certifications needed for application areas.

LignEasy’s first full-scale production plant for 50 000 tn of lignin products is on the commercialisation roadmap following the midterm production scale-up. The key competitive advantage of the high scalability of the LignEasy technology is that the process has no effect on the pulp mill’s chemical balance: LignEasy requires much less chemical use and decreases waste generated, even compared to a situation without any lignin separation.

Dried Lignin Product