Biorefinery concepts in the paper industry

Transcription

1 Biorefinery concepts in the paper industry Graziano Elegir, Tullia Maifreni, Daniele Bussini Innovhub, Paper Division Azienda Speciale della Camera di Commercio di Milano

2 OUTLINE General aspects on the pulp & paper industry Wood based biorefinery Recycled based biorefinery Example of alternative fibre source from biowaste

3 Paper industry raw materials major raw materials : Wood (pulp production and integrated mills) Recovered paper (Paper production) minor raw materials: Non-wood annual plants Lignocellulosic wastes (e.g. sawdust)

4 Fibre supply balance Wood Virgin fibres Balance requires 30% of virgin fibres Annual plants Virgin fibres Recovered paper Recycled fibres

5 The wood fibre cycle Wood based biorefinery Pulp Chemical pulping Cellulose solid residue Paper machine Recycled fibre based biorefinery Black liquor sorting deinking Paper machine PAPER Lignin Extractives Hemicelluloses + R P Non paper rejects materials + SLUDGE rejects energy biofuels energy

6 Biorefinery in the paper industry A biorefinery converts biomass to physical products, commonly thought of as fuels and/or chemicals, and to energy. In fact, this is exactly what a pulp mill does, converting wood to fiber and generating heat and power; the pulp mill is the original biorefinery. Wood Pulp Paper By-products Alkaline pulping: Tall oil soaps (sitosterol) Acidic pulping: Lignosulfonates (vanillin) Fermentable sugars (ethanol) Xylose, xylitol

7 Wood based biorefinery Bark Bioactive components Wood Chemical pulping Cellulose pulp Paper production Black liquor Hemicelluloses Primary sludge Lignin Xylans Fermentable sugars

8 Example of a biorefinery concept

9 LignoBoost process Lignin isolated from kraft black liquor (25%). After drying Lignin is an excellent biofuel. Today: It can be burnt with bark it can replace fossil fuel (yearly saving of m 3 ) Tomorrow: Fuel motor vehicles Chemical industry (phenols, carbon fibre composites, binders, soil improver etc..)

10 Recycling based biorefinery pulping sorting Paper machine PAPER R P Non paper rejects Sludge rejects Fibre yield is normally the major concern Coarse rejects: Plastic wood, coarse fibres Sludge rejects & process water: Cement products Biogas production Energy recovery (on-site or fuel pellets) Composites

11 Re-thinking the recycling mill concept Future?: sorting Recovered Paper in the mill site along with other raw materials (e.g. agro-biomass residues ) Best fibres: paper technology composites Side streams & by-products: Biochemical processes (e.g. ethanol etc..) Thermo-chemical processes (e.g. gasification) Chemicals ( e.g. hemicellulose recovery from process water)

12 Italian paper industry In Italy chemical cellulose pulp production is very limited Imported cellulose pulps & recovered paper are the major raw materials used for paper production Wood availability for P&B industry will decrease due to increase used in the energy sector RP quality/availability decreases (asian market, energy sector..) Exploring the potential locally based lignocellulosic waste residues

13 Rice husk It is a relevant industrial waste in Northern Italy accounting for approximately t/year Rice husk, the outer cover of rice grain, is among the principal processing side-products of the rice milling industry and accounts for about 20% by weight of rice; Because of the elevated ashes and lignin content, rice husk is not appropriate as animal feed raw material; Rice husk can be burnt to recover energy or under controlled conditions to obtain a large amount of silica.

14 Rice husk for cellulose pulp production or additives? Major advantages: Available throughout the year Production (90%) located in relatively small area. Major disadvantages: Low density High silica content

15 Rice husk composition Chemical composition (%), w/w rice husk rice straw wood Cellulose Hemicellulose Lignin Extractives Starch Ashes Chemical composition is similar to annual plants but ash content is higher

16 Rice husk Pretreatment Alkaline extract Rice husk Alkaline Organosolv pulping Acid precipitation Solid Cellulose residue Pulp fibres or fibre additives Supernatant Precipitated lignin Enzymatic hydrolysis Fractionation Xylans Lignin (Purity 90%) glucose Fermentation Bioethanol Biogas

17 Organosolv treatment

18 Cellulose pulp Alkaline Organosolv cooking C, NaOH charge (20-50%) Unscreend pulp-120 C Uncreened pulp-180 C

19 Cellulose pulp yield CELLULOSE PULP Klason Lignin % Yield % Temperature C

20 Pulp properties Properties Cooking temperature Unscreened yield Screened yield Kappa no Cellulose DP Drainability RP/RHP 75: Work is now in progress to establish papermaking properties

21 Lignin recovery from cooking liquor LIGNIN RECOVERY Yield % Purity % Temperature C

22 Isolated Lignin GPC Time (min) Sample Mn Mw Mp I 120 C C C

23 31 P NMR- ISOLATED LIGNIN (mmol/g) 120 C 150 C 180 C Aliphatic-OH 2,84 2,24 1,70 S-OH + cond. 0,52 0,81 0,93 G-OH 0,65 0,87 0,81 P-OH 0,29 0,46 0,44 -COOH 0,87 0,99 0,70 Lignin shows a high amount of phenols and acid groups

24 Conclusions (i) Biorefinery play a key role for the future of the paper industry Widening the spectra of products will help competitiveness Locally based biowaste biorefineries may help process sustainability.

25 Conclusions (ii) Rice husk is an interesting lignocellulosic waste materials. Its use as a source of fibres/additives for the paper industry deserve further investigation. Critical factor is to find best use for the different chemical components.

26 Grazie per l attenzione gelegir@sperimentalecarta.it