INTEGRATED POSSIBILITIES OF PRODUCING CHEMICALS AND BIOFUELS IN CHEMICAL PULPING

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1 INTEGRATED POSSIBILITIES OF PRODUCING CHEMICALS AND BIOFUELS IN CHEMICAL PULPING International Forest Biorefining Conference (IFBC) May 9-11, 2017, Thunder Bay, ON, Canada Raimo Alén University of Jyväskylä, Finland Laboratory of Applied Chemistry

2 OUTLINE GENERAL ASPECTS PRETREATMENT OF WOOD CHIPS Acidic and alkaline conditions BY-PRODUCTS OF KRAFT PULPING Lignin, aliphatic carboxylic acids, and extractives BY-PRODUCTS OF OTHER PULPING METHODS CONCLUSIONS

3 GENERAL ASPECTS

4 RAW MATERIAL AGES (Mabee & Saddler, 2008)

5 BIOREFINERY CONVERSION METHODS PHYSICAL UPGRADING METHODS (drying, pulverisation, briquetting, and pelletizing) CHEMICAL AND BIOCHEMICAL METHODS (hydrolysis followed by fermentation or chemical conversion) THERMOCHEMICAL METHODS (torrefaction, pyrolysis, gasification, liquefaction, and combustion) OTHER METHODS (e.g., production of composites or fractionation followed by chemical conversion - cellulose derivatives)

6 PROCESS SCHEME FOR THE CONVERSION OF BIOMASS-DERIVED CARBOHYDRATES

7 PRODUCT GROUPS FROM THERMAL CONVERSION OF CELLULOSIC BIOMASS

8 PRINCIPAL CONVERSION ROUTES FOR CELLULOSIC BIOMASS TO PRODUCE VARIOUS ENERGY SOURCES

9 INTEGRATED BIOREFINERY CONCEPT The first industrial biorefineries were operated in the pulp and paper industry already about 160 years ago

10 From forest to paper

12 BIOMASS BIOREFINERY CONCEPTS Chemical and thermochemical conversion techniques Energy Electricity Heat Biodiesel Wood Non-wood crops (agricultural residues) Natural-growing plants Pretreatment (acidic or alkaline) Carbohydrates Other materials Pulping (alkaline process) By-product recovery Extractives Black liquor Energy Chemicals Chemicals Ethanol Other chemicals FIBER

13 PRINCIPLES FOR THE INTEGRATED PRETREATMENT PROCESS FIBER IS THE MAIN PRODUCT EFFICIENT RECOVERY OF COOKING CHEMICALS AND EXTRACTIVES SULFUR-FREE NOVEL BY-PRODUCTS SUITABLE BALANCE BETWEEN THE CARBOHYDRATE AND LIGNIN DEGRADATION PRODUCTS STRAIGHTFORWARD SEPARATION TECHNIQUES VERSATILE MODIFICATION POSSIBILITIES

14 COMMERCIAL PULPING METHODS Method Yield (% of wood) Chemical pulping Kraft, polysulfide kraft, prehydrolysis kraft Soda-anthraquinone (AQ) Acid sulfite, bisulfite, AQ alkali sulfite Multistage sulfite Semichemical pulping Neutral sulfite semichemical (NSSC) Soda Chemimechanical pulping Chemithermomechanical (CTMP) Chemigroundwood (CGWP) Mechanical pulping Thermomechanical (TMP) Refiner mechanical (RMP) Stone groundwood (SGWP) Pressure groundwood (PGWP)

15 KRAFT PULPING Chemical pulping accounts for 70 % of the total worldwide production Currently about 90 % of chemical pulps (about 130 million tons) are produced by the kraft (sulfate) process White liquor containing mainly the active cooking chemicals NaOH and Na 2 S is used for cooking the chips

17 BASIC PRINCIPLES OF TYPICAL PRETREATMENT STAGES IN KRAFT PULP MILL

18 Typical pre-treatment phases in the alkaline delignification

19 PRETREATMENT OF WOOD CHIPS Acidic conditions

20 ACIDIC PRETREATMENTS AUTOHYDROLYSIS (only with H 2 O) HYDROLYSIS WITH AQUEOUS MINERAL ACIDS (mainly with H 2 SO 4 )

21 CHEMICAL COMPOSITION OF BIRCH- AND PINE-BASED HYDROLYSATES (% of the initial dry matter) Component Birch Pine Carbohydrates Monosaccharides Oligo- and polysaccharides Uronic acids Furans Volatile acids Acetic acid Formic acid Lignin Total The chips are treated at 150 o C for 90 min (liquor-to-wood ratio 5 L/kg)

22 PRETREATMENT OF WOOD CHIPS Alkaline conditions

23 THE FIRST PHASE OF ALKALINE (KRAFT) PULPING A RATHER LOW SELECTIVITY AN INTENSE ALIPHATIC ACID FORMATION COMPARED TO THE LIGNIN DISSOLUTION MOST OF THE EXTRACTIVES ARE REMOVED TURPENTINE SAPONIFICATION OF ESTERS ( FATTY AND RESIN ACIDS) NEUTRAL SUBSTANCES ( NONSAPONIFIABLES )

24 Behavior of the major wood components during kraft pulping of pine (Aurell, R. & Hartler, N., Svensk Papperstidn. 68(3)(1965)59-68)

25 MAIN REACTIONS OF POLYSACCHARIDES IN ALKALINE PULPING - 1

26 MAIN REACTIONS OF POLYSACCHARIDES IN ALKALINE PULPING -2

27 THE SOLUBLE DRY MATTER FORMED DURING THE ALKALINE PRETREATMENT OF BIRCH (% of the initial dry matter) (Lehto, J. & Alén, R., J. Wood Chem. Technol. 33(2)(2012)77-91) Component 6 (b) 8 (b) Aliphatic carboxylic acids Volatile acids (c) Hydroxy acids (d) Lignin Other organics (e) Total (a) - The chips are treated at 150 o C for 90 min (liquor-to-wood ratio 5 L/kg); (b) - alkali charge (% of NaOH on o.d. feedstock); (c) - acetic and formic acids; (d) - mainly glycolic, lactic, 2- hydroxybutanoic, 3,4-dideoxy-pentonic, 3-deoxy-pentonic, xyloisosaccharinic, and glucoisosaccharinic acids; and (e) - mainly extractives and carbohydrates

28 SOME PARAMETERS OF THE ALKALINE PRETREATMENTS (30 min, 150 o C (pine) or 160 o C (birch)) Alkali charge, % of NaOH on wood Mass ratio aliphatic acids/lignin Residual alkali, g/l 8 10 Pine Birch Pine Birch ph (after treatment)

29 Estimated production (tons/year) of the organic fractions formed during the alkaline pretreatments (8 % NaOH on wood/30min/150 o C) a Fraction Pine Birch Aliphatic acids 88,100 83,700 Volatile acids 37,000 45,200 Hydroxy acids 51,100 38,500 Lignin 40,200 38,200 Extractives 39,100 24,000 Total 167, ,900 a Calculated for an annual production of 500,000 o.d. tons of unbleached pulp.

30 HARVESTING RESIDUES and BARK 47 CONVERSION i) BURNING ii) GASIFICATION iii) CHEMICAL TREATMENT SYNTHESIS GAS FT-PROCESS Energy Chemicals (e.g., ethanol) Energy (elecric power, steam) Liquid fuel Chemicals TREE 100 FIBER % PRETREATMENT (acid or alkali) DELIGNIFICATION i) KRAFT ii) SODA-AQ iii) O 2 /alkali % Energy SPENT LIQUOR % BLACK LIQUOR RECOVERY PROCESSES RECOVERY FURNACE (diesel fuels) Organic fractions Cooking chemicals Energy Cooking chemicals

31 BY-PRODUCTS OF KRAFT PULPING Black liquor - general

32 WOOD (100) % Cellulose Hemicelluloses Lignin Extractives < 5 EXTRACTIVES (< 5) UNBLEACHED PULP (45-55) % Cellulose Hemicelluloses Lignin < 5 ORGANICS (5) BLACK LIQUOR (40-50) % Aliphatic acids Lignin Other organics OXYGEN-DELIGNIFIED and BLEACHED PULP (40-50) % Cellulose Hemicelluloses Lignin -

33 COMPOSITION OF THE DRY MATTER OF BIRCH AND PINE KRAFT BLACK LIQUORS (% of the total dry matter) Component Birch Pine Lignin Aliphatic carboxylic acids Volatile acids (a) Hydroxy acids (b) Other organics 9 7 Extractives 3 4 Carbohydrates (c) 5 2 Miscellaneous 1 1 Inorganics (d) (a) - Acetic and formic acids; (b) - mainly glycolic, lactic, 2-hydroxybutanoic, 3,4-dideoxypentonic, 3-deoxy-pentonic, xyloisosaccharinic, and glucoisosaccharinic acids; (c) - mainly hemicellulose-derived fragments; and (d) - including the sodium bound chemically to organics

34 COMPOSITION OF THE DRY MATTER OF PINE AND BIRCH KRAFT BLACK LIQUORS AND ALKALINE BIRCH HYDROLYSATE (% of the total dry matter) Component Pine (a) Birch (a) Birch (b) Lignin Aliphatic carboxylic acids Formic acid Acetic acid Glycolic acid Lactic acid Hydroxybutanoic acid ,4-Dideoxy-pentonic acid Deoxy-pentonic acid 1 1 <1 Xyloisosaccharinic acid <1 4 2 Glucoisosaccharinic acid Others Other organics Inorganics (a) - Black liquor and (b) - alkaline pretreatment hydrolysate (8 % NaOH, 150 o C, 90 min)

35 MAIN UTILIZATION POSSIBILITIES COMBUSTION IN THE RECOVERY FURNACE (for recovering energy and cooking chemicals) GASIFICATION (for recovering energy and cooking chemicals as well as for producing chemicals) RECOVERY OF ORGANIC FRACTIONS (for making fuels and chemicals)

36 BY-PRODUCTS OF KRAFT PULPING Black liquor - lignin

37 RECOVERY OF LIGNIN IN PRACTICAL APPLICATIONS, IT IS ADVANTAGEOUS TO USE CO 2 FROM FLUE GAS (ph 9.5, yield 35 %) FOLLOWED BY THE USE OF PURE CO 2 UNDER PRESSURE (ph 8) (at 80 o C, <20 atm, total yield 75 %) THE LIBERATION OF PHENOLIC HYDROXYL GROUPS (pk a 9-11) TAKES PLACE LIGNIN PRECIPITATES pk a VALUES OF CARBOXYLIC ACIDS ARE 3-5

38 SOME PRACTICAL DATA (Alén, R., Patja, P. & Sjöström, E., Tappi 62(11)(1979) ; Alén, R., Sjöström, E. & Vaskikari, P., Cellulose Chem. Technol. 19(1985) ) TAPPI

39 SOME PRACTICAL DATA (Alén, R., Patja, P. & Sjöström, E., Tappi 62(11)(1979) ; Alén, R., Sjöström, E. & Vaskikari, P., Cellulose Chem. Technol. 19(1985) )

40 INFLUENCE ON THE HEATING VALUE OF BLACK LIQUOR HEATING VALUES: Black liquor (15-35 % water and % inorganics, and about 45 % organics) MJ/kg d.s.; lignin MJ/kg; aliphatic carboxylic acids 5-18 MJ/kg; and extractives about 35 MJ/kg DECREASES IN HEATING VALUE (MJ/kg d.s.): 5-10 % (precipitated lignin yield 35 %) and % (precipitated lignin yield 75 %) BEHAVIOR OF COMBUSTION PROPERTIES: Carbonated black liquors swell clearly less than untreated black liquors

41 SOME UTILIZATION POSSIBILITIES OF THE PRECIPITATED LIGNIN PHENOLIC RESINS POLYURETHANES PHENOLS (AND CARBON FIBER) FUEL PURPOSES

42 BY-PRODUCTS OF KRAFT PULPING Black liquor aliphatic carboxylic acids

43 Schematic representation of a possible black liquor fractionation process

44 One of the process alternatives (Alén and Kumar 2016)

45 THE MAIN ALIPHATIC CARBOXYLIC ACIDS OF BLACK LIQUOR

46 UTILIZATION POSSIBLITIES OF ALIPHATIC CARBOXYLIC ACIDS ONLY A MINOR PROPORTION OF ALIPHATIC CARBOXYLIC ACIDS CAN BE UTILIZED AS SUCH IN THE FORM OF THEIR SODIUM SALTS ( their liberation, pk a values 3-5) REALISTIC FRACTIONS: VOLATILE ACIDS including formic and acetic acids LOW-MOLAR-MASS HYDROXY ACIDS (with 2-4 carbon atoms) including glycolic, lactic, and 2-hydroxy-butanoic acids HIGH-MOLAR-MASS HYDROXY ACIDS (with 5 and 6 carbon atoms) including 3,4-dideoxy-pentonic, 3-deoxypentonic, and xylo- and glucoisosaccharinic acids

47 UTILIZATION POSSIBLITIES OF ALIPHATIC CARBOXYLIC ACIDS LIBERATION WITH MINERAL ACIDS (mainly with H 2 SO 4 ) OR ELECTRODIALYSIS FRACTIONATION AND PURIFICATION BY VACUUM DISTILLATION ( kpa) OR ION-EXCLUSION CHROMATOGRAPHY

48 UTILIZATION POSSIBLITIES OF ALIPHATIC CARBOXYLIC ACIDS FORMIC, ACETIC, GLYCOLIC, AND LACTIC ACIDS ARE COMMERCIALLY IMPOPRTANT CHEMICALS BY REDUCTION (i.e., the production of polyalcohols) BY OXIDATION (i.e., the production of polycarboxylic acids) BY ESTERIFICATION (i.e., the production of emulsifying agents) BY OTHER METHODS (e.g., the production of various polyesters or a wide range of derivatives)

49 CONDENSATION OF LOW-MOLAR-MASS ACIDS (Alén, R. & Sjöström, E., Acta Chem. Scand. B 34(1980) )

50 BY-PRODUCTS OF KRAFT PULPING Black liquor - extractives

51 CRUDE TALL OIL (CTO) TALL OIL SOAP the removal from the evaporated black liquor by skimming the liberation of carboxylic acids (resin and fatty acids) with H 2 SO 4 CTO (the average yield kg/ton of pulp, corresponding to % of the initial amount) PURIFICATION AND FRACTIONATION BY VACUUM DISTILLATION (3-30 mbar, o C): LIGHT OIL % FATTY ACIDS % ROSIN % PITCH RESIDUE %

52 UTILIZATION OF CRUDE TALL OIL SOAP AN INTERESTING NEW APPROACH PRODUCTION OF BIODIESEL BY PYROLYSIS PRODUCTION OF Na 2 CO 3 (no external H 2 SO 4 is needed) NOTE ALSO VOLATILE TURPENTINE (5-10 kg/ton of pulp)

53 PYROGRAM OF TALL OIL SOAP (at 750 o C for 20 s) (Lappi, H. & Alén, R., BioResources 6(2011) )

54 The main products formed in the pyrolysis experiments (700 o C and 20 s) with hot-water-extracted birch sawdust (left) and with soda-aqdelignified pulp from hot-water-extracted birch sawdust (right). Letters indicate compound groups to which identified products belong: A (anhydrosugar derivatives), B (benzene derivatives), C (cyclopentenone derivatives), E (catechol and benzenediol derivatives), F (furan derivatives), G (guaiacol derivatives), I (indene derivatives), L (lactone derivatives), N (naphthalene derivatives), P (phenol derivatives), S (syringol derivatives), X (fatty acids derivatives), and Y (pyrone derivatives). Ghalibaf et al. 2017

56 Liquefaction of black liquor McKeough, Alén, Oasmaa & Johansson, Holzforschung 44(1990)

57 BY-PRODUCTS OF OTHER PULPING METHODS

58 THE MAIN METHODS ACID SULFITE PULPING VARIOUS ORGANOSOLV METHODS

59 COMPOSITION OF BIRCH AND SPRUCE ACID SULFITE SPENT LIQUORS (kg/ton pulp) Component Birch Spruce Lignosulfonates Carbohydrates Monosaccharides Oligo- and polysaccharides Aliphatic carboxylic acids Acetic acid Aldonic acids Extractives Others 55 30

60 ORGANOSOLV PULPING Pulping in the presence of organic solvents ( organosolv methods ) dates back to the beginning of the 1930s (T.N. Kleinert) Was not considered seriously for practical use until in the 1980s For both woods and non-woods The most important solvents include alcohols (e.g., methanol and ethanol), aliphatic carboxylic acids (e.g., formic and acetic acids), phenols (e.g., phenol and cresol) and many other systems also in the presence of alkaline or acidic catalysts

61 SIMPLIFIED FLOWCHART OF ORGANOSOLV PROCESSES

62 CONCLUSIONS PRETREATMENT OF WOOD CHIPS UNDER VARYING CONDITIONS OFFERS AN INTERESTING APPROACH FOR MAKING BIOPRODUCTS BLACK LIQUOR ORGANICS REPRESENT A HUGE AMOUNT OF RENEWABLE RAW MATERIAL AND THE PARTIAL RECOVERY OF THESE FRAGMENTS SEEMS ATTRACTIVE (AND TECHNICALLY POSSIBLE) THERE ARE SOME POTENTIAL UTILIZATION POSSIBILITIES FOR ALL THESE BY-PRODUCTS (CAN THESE PRODUCTS BE MARKETED?)

THE RELATIONSHIP BETWEEN TWO METHODS FOR EVALUATING FIVE-CARBON SUGARS IN EUCALYPTUS EXTRACTION LIQUOR

THE RELATIONSHIP BETWEEN TWO METHODS FOR EVALUATING FIVE-CARBON SUGARS IN EUCALYPTUS EXTRACTION LIQUOR Congcong Chi, a,b* Zeng Zhang, a Weiwei Ge, a and Hasan Jameel b Alkaline pre-extraction and hydrothermal