Recently I went to an interesting place. A 1000 years old paper mill. The goal was to convince the director to try something “new”. Hemp paper. Currently they use wood celulose but for generations main production was based on hemp. Hemp rugs to be precise. As there is no easy access to wornout, old, degraded hemp fabrics we are going to try to use biomass.
The museum will have about 10 plants next year but just to show them to people visiting the place. They are not able to process it and anyway for a single batch they need 50-100kg of pure cellulose.
We were able to make some paper but we failed to fully separate the fiber and the paper wasn’t of a great quality.
Anyway we’ve signed a deal for a series of hemp related workshops, help with their grow and a little project to develop a tek to extract celulose from hemp stalks. Everything is pro publico bono and to spread the news that there is this cool plant that can be used to make paper. Poland used to grow 300k hectares of hemp but then some assholes pushed a bill making it illegal and generations of people though about cannabis onlly in context of a drug.
So how to get cellulose in an environmental friendly way. Ideally using old techniques so it’s fitting for the museum? I was thinking about ensymes but cellulase for instance attacks fibers from their ends slowly incresing amount of simple shugars rather then breaking celulose chains in random places.
I have few tones of this years hemp hay but the fibers are too strong for modern machines not designed for hemp. Even so called dutchman that is able to deal with flex fiber fails to cut hemp.
So I guess I have one option really. Few cycles of retting and then base to get rid of lignin and then acid to neutralise the base and at the same time to bleach the fiber. Ideally the cellulose sheets for the museum should be as white as possible and with fibers up to 3-5mm long.
Try soaking in hydrogen peroxide and sodium sulfite. Soak time will be up to you on when is good and when is too long. You will kill “all” the lignin and most of the hemicellulose. Wait too long and you lose a good amount of cellulose as well.
Looks promising. 10% sodium hydroxide with hydrogen peroxide. I’d guess that the brown stuff is dissolved lignin but there is still quite a lot of it so I’m going to add more base.
I am extremely interested in this project and am bookmarking it for when I finally have two minutes to sit down- would love to contribute research into this
Nice, try adding heat and those other two chemicals I mentioned above. Chemically you will have to at some point pick how much you value efficiency versus quality. Happy to help out on this project, again I’ll post some literature soon, I’m just following references far enough back that they are simply and general in terms of lignin, hemicellulose, and cellulose.
Here is a start. I need to be at work to chase down the references from that one that lead you directly there. Use hydrogen peroxide at 30% or whatever the pool store sells. Then add sodium sulfite and sodium hydroxide at decent concentrations. Then heat between 30 and 90°C. You will have essentially all cellulose for whatever use and it will be roughly bleached already.
