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Monday, October 8, 2018

First International Lignin Conference: Summary

The First International Lignin Conference, presented by PAPTAC, took place September 18-20, 2018 in Edmonton, Alberta. Over 170 people attended, from 14 countries and every continent except Africa and Antarctica. A highlight was a tour of the first commercial LignoForce lignin extraction plant, installed and operated by West Fraser at their kraft pulp mill in Hinton, Alberta.

I am still waiting for the organisers to post presentation material. Once that is available, I'll verify and update my conference notes, which follow.


This conference was of particular interest to me, as I was research manager in charge of developing the LignoForce system prior to retiring from FPInnovations in September 2016. My colleague Mike Paleologou was responsible for the process development and the underlying chemistry; Kirsten Maki built and operated the pilot plant in Thunder Bay that proved the technology. So I won't claim credit any significant technical component; given the excellent contributions by the world-class team of Mike, Kirsten and their supporting staff, my contribution was keeping financing flowing and ensuring research activities stayed on track and focused.

The story begins in late 2005 with a couple of workshops held in Montreal and Edmonton, where industrial and academic experts in a wide range of fields were invited to advise on potential biorefinery options for pulp mills. Most attendees listed lignin extraction high on their list of feasible approaches.

By 2008, Mike had generated some very interesting data which would eventually be the basis of the LignoForce patent. On my recommendation, a decision to redirect significant levels of effort to this project was made by senior management at FPInnovations, with the agreement and financial support of the federal government.

By 2010 it was obvious that we needed to be able to supply tonne-scale samples of lignin to prospective end-users. As the labs could generate at best 20 kg per day, this obviously required a pilot plant, and a 200 kg/d plant (financed by the Province of Ontario through CRIBE) was duly installed in the mill operated by Resolute Forest Products in Thunder Bay, Ontario. Data obtained from the pilot also served to support our licensee, NORAM Engineering and Constructors of Vancouver, as they worked to design a full-scale plant to commercialise the patent. By 2013, we had sufficient data to show both pulp mill operators and producers of engineered wood products what the process and end product would look like, and more importantly what it would cost. FPInnovations Member Companies were approached to identify a promising site for a full-scale plant, and West Fraser stepped up to the challenge. So while it took much longer than I had hoped back in 2008, it was very nice to see the commercial 30 tonne per day plant in operation. And it was very exciting to see that there is a critical mass of people working in the field, in industry, academia and industrial research institutes, so that the conference organisers could put together a superb 2-day program and attract attendees from around the world.

A summary of some of the more interesting presentations follows. As noted I will update and make corrections once the conference presentations are available.

Commercialisation: approaches, risks and rewards

Keith Carter of West Fraser opened the conference by outlining West Fraser's approach to product diversification. Biofuels were considered, but most technologies are pre-commercial, and markets, scale-up and post-startup support by small technology companies were all very uncertain. Given the risk level, this pathway was set aside for the time being. The risk level for lignin extraction seemed less severe and the company committed to a lignin plant in 2014. Financial support from provincial and federal governments, technical support from FPInnovations and NORAM, and the potential for use of a portion of the lignin within the company's own plywood mills all served to reduce the risk of scaling up the pilot plant by a factor of over 100X. Among the remaining challenges: a sustainable resin replacement is still not quite there; the plant is being run intermittently on demand and thus requires multiple starts and shuts; each customer has unique product performance requirements. Nonetheless the company is happy and continues to develop the process and the markets. 

During the visit to the mill in Hinton, Dave Pors, also of West Fraser, documented the timeline leading to startup. Approval by the Board was obtained in December 2013, and demolition of an idled pulp machine to make space for the lignin plant started March 2014. Equipment, in the form of skids shipped from NORAM's Vancouver fabrication shop, began arriving in January 2015. Commissioning began March 2016 with the first successful production run in May 2016. The project was completed on budget and, excluding some external factors over which the mill had no control, on time. Dave and colleagues then hosted a mill tour where we saw the press operated. Lignin is available in acid-washed form, or in alcaline unwashed form. Neither product exhibits any strong sulfur smell, and reduced sulfur compounds in the mill are well managed by a couple of vents to the DNCG system; this is a testament to the efficacy of the oxidation stage.

Production processes

Hanne Karlsson, of Valmet, and Maria Björk, of Stora Enso, described the LignoBoost process and its installation at the Sunila mill operated by Stora Enso. They report good operating history, and Valmet is supporting development of new products such as a hydrophobic thermoplastic and an ABS-lignin compound. 

The Sunila plant makes 50 kT/y of lignin and 375 kT/y of softwood kraft pulp. Sulfur content in the lignin is below 2% by weight, or 800 g/GJ fuel content. The lignin plant takes up to 22% of the lignin in liquor, a large amount, and some issues around sodium-sulfur balance have arisen. Lime kiln flue gas is used to dry the lignin, which is then air-blown to the lime kiln for combustion, or to a packaging plant for sale. In the lime kiln, lignin makes up 80% of the fuel requirement with natural gas supplying the balance. Stora Enso has its own product development activities, supported by a staff of 90 researchers in a new building in Stockholm. 

Shane vanCaeseele of NORAM described the competing LignoForce technology. The key difference  with LignoBoost is the liquor oxidation stage, which, contrary to Tomlinson's teachings, turns out to be beneficial. Oxidising black liquor creates acidic sugar compounds that start the acidification process, reducing demand for carbon dioxide; it also oxidises harmful reduced sulfur compounds. Finally it leads to much improved pressing, which reduces capital cost. Of course, having been intimately involved with the development of this process, I can be accused of a certain bias; but the health and safety benefits of not dealing with reduced sulfur compounds alone are a big reason for considering this process. 


Early emerging markets are those where lignin can be used essentially as-is. Combustion in the lime kiln remains a useful backup plan which displaces fossil fuels, but this does not unlock the full economic value of lignin extraction when natural gas prices are low.

Four papers, two from VTT and two from FPInnovations, described using lignin as a (perhaps partial) substitute for phenolic resins. So-called lignin-phenol-formaldehyde (LPF) resins were described by Tarja Tamminen of VTT and Martin Feng of FPInnovations. Yaolin Zhang of FPInnovations described using nanomaterials to reinforce these LPF resins; he concluded that carbon black provided the best improvement at lowest cost. Tiina Liitia of VTT described converting lignin to dispersants. Most of these applications are essentially ready for commercial applications, and do not require large post-production processes beyond washing and drying.

The other 'easy' application is in polyurethane foams. Armand Langlois of Enerlab 2000, a producer of such foams, described replacing the isocyanate component of PU foams, while others addressed the polyol component.

Moving on to products requiring lignin modification processes, Ludo Diels of VITO provided an overview of depolymerisation techniques, with a viewpoint from the chemical industry rather than the forest sector. This viewpoint made it a particularly important paper. The chemical industry is used to very high purity feedstocks; a propylene stream will consist of nothing but C2H6 with perhaps the odd ethylene molecule having managed to sneak in. Using lignin as it comes from the press or dryer is obviously cheaper than a highly modified lignin, and market applications where this is feasible will justify building initial capacity. Eventually, though, the industry will need to move towards the level of purity expected by the chemical industry.

Other presenters covered depolymerisation, hydrogenation and enzymatic processes. In particular, several papers from Pedram Fatehi's group at Lakehead described depolymerising lignin for use in floculants, in particular a process for grafting lignin to poly-acrylamide polymers for reducing the cost of these chemicals while maintaining performance. As the poly-acrylamide polymers are very expensive, and as they are used for environmental remediation where there is no immediate economic benefit to the user, this could be an important step.

Other markets outlined included lignosulfonates (J. Gargulak, Borregaard), and uses in in oil and gas (N. Bjornadalen, Innotech Alberta). In terms of market analysis, Luana Dessbesell of Western University and Lakehead University described a model for identifying logistics and integration opportunities between lignin plants and end-users. The work is part of her PhD studies and provides a good basis for the business modeling that will be necessary as this new industry grows.

Several other papers, in particular on the topic of lignin in thermoplastics and coatings, will not be reviewed here, as these were presented in parallel sessions on the afternoon of Day 2 which I did not attend. 

Fundamentals of lignin chemistry

Wolfgang Glasser, professor emeritus at Virginia Tech, walked through the fundamental chemistry of lignin. As a non-chemist, I won't attempt to describe his presentation in any detail, but there were a few comments that caught my eye. In particular, his view is that lignin from a particular wood supply is essentially invariable; the variability comes from the processing required to separate it from the wood. So variability from day to day, assuming stable wood supply, is due to process variability, not inherent wood variability; variability from mill to mill is additionally due to wood variability. So even with similar wood supplies, each lignin plant may be expected to produce a slightly different product prior to any downstream treatment (depolymerisation, deoxygenation, hydrogenation, etc.); in addition, lignin plants would do well to ensure decent process control, both in the lignin plant and in the pulp mill. This mirrors pilot plant experience, where an 'off' batch of lignin could often be traced to operating conditions in pulping or recovery also being somewhat off, if not so far off as to impact pulp production. 

Lignin analysis

A large number of presentations focused on the difficult topic of lignin analysis and characterisation. Suffice it to say that it is still not clear how to measure molecular weight, which will be a key specification for commercial grades of high-purity lignin; the heated discussions following most of the presentations attest to this fact. Presentations came from academia, research institutes and industry.

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