Practicality and economic viability of replacing bisphenols with lignin?

[u/Thunder_Burt]

Recent closures in pulp and paper industry have made me think about whether these pulp and paper plants could pivot to making lignin as a bisphenols replacement in plastic especially with the growing awareness of bisphenols harmful effects. Do you guys have any insights on how practical this would be and if it could become a cost effective alternative in the future? What would it take?

[u/Caesars7Hills]

You can make anything from lignin, except money.

[u/AlarmedForm630 → u/Caesars7Hills]

Unfortunately yes, while the chemical process (kraft process) used is so interesting.

Also, the pulp mills can be converted to biomass power plant (they can convert the recovery boiler to BFB boiler, use the existing bark boiler and increase the condensation power of the steam turbines).

[u/Lord_Earthfire → u/Caesars7Hills]

Yeah, thats my impression as well.

It's a kinda inexpensive educt, but you need to add a lot of modification steps to bring it to a stage you can use it for polymer synthesis. And even then it can only be used for materials where colour isn't a concern. Last but not least, quality control is a problem, because the polymer structure depends on the wood it is extracted from

This makes it a niche product and removes the benefit of ot being a rather cheap/available substance. Quite frustrating when you think about it.

[u/pker_guy_2020]

It's possible. Difficult in large scale, but possible to replace up to ~50% of phenol with lignin. We tried this in the company I work for, it was actually my first project. Currently, EU funded project called VIOBOND is spearheading the development. Latvijas Finieries is producing the phenol-lignin-formaldehyde resin. Lignin is coming from an Estonian company Fibenol. I personally think lignin won't be replacing 100% of phenol, but sooner or later we'll see replacement rates of around 50%.

[u/Substandard_eng2468]

I am not sure about using lignin to replace BPA. But ligin is a small fraction of the pulp process. I don't believe it is economically viable as a mill's main product.

[u/pker_guy_2020 → u/Substandard_eng2468]

It could be an additional side-stream to generate more value instead of burning the black liquor for electricity.

[u/Substandard_eng2468 → u/pker_guy_2020]

At some mills, lignin is an additional side stream where it is separated from the black liquor. The purpose of burning black liquor is to reduce the NaSO4 to Na2S so it can be used in the cooking, and the steam generation is the byproduct.

As the main product and current market, lignin wouldn't be viable.

[u/reptheevt → u/Substandard_eng2468]

Yeah I feel like the only times lignin extraction is valuable is if you’re at the edge of your maximum steaming rate on your recovery boilers and want to to squeeze more liquor burning by lowering heating value. 

[u/Redcrux → u/pker_guy_2020]

If it generated more income than burning it for electricity or steam they would have been doing it.

[u/Ambitious-Schedule63]

Um, wut?

Why would you think that lignin could substitute for a bisphenol?