Post on 17-Mar-2018
Pulping by-products from fiber crops
What to learn from forest industry?
FIBRA Summer school, Beijing, July 2015
Klaus Niemelä (klaus.niemela@vtt.fi)
VTT Technical Research Centre of Finland
2 30/7/2015
Cai Lun – inventor of papermaking
Cai Lun (Tsai Lun), inventor of papermaking c. 105 AD
(raw materials included hemp waste)
3 30/7/2015
Main topics to be addressed
Introduction to pulping processes
Role of pulping by-products, overview
Discussion on selected by-products from wood and non-wood
raw materials
Some trends
4 30/7/2015
Paper and paperboard demand
5 30/7/2015
World consumption of paper-making fibre
6 30/7/2015
Consumption of bleached hardwood kraft pulp
7 30/7/2015
Global non-wood pulp production
8 30/7/2015
Chemical pulping processes
The main objective is to remove (dissolve) lignin and recover
cellulosic fibers (pulp)
Removal of other non-carbohydrate materials (extractives)
also targeted
Due to the pulping conditions, varying amounts of
hemicelluloses are also lost (sometimes desired, usually not)
Some cellulose losses also take place
Roughly, pulp yield is c. 50% (40-60%) of raw material
Cooking chemicals are recovered for re-use (not in all very
small mills)
Most of pulp is bleached to obtain required brightness
9 30/7/2015
“Pulp mill biorefineries”: pulp, chemicals, biofuels
Pulping process
Harvesting residues
AgromaterialsRecovered paper
Process(es)
Integratedpower/energyproduction
Processstreams
Pulp, paper
Energy
Biofuels
Chemicals
Chips
10 30/7/2015
Sulphite pulping processes
Cooking chemicals are sodium, calcium or ammonium sulphites
The conditions are acidic
Lignin is sulphonated and dissolved (as water-soluble derivative)
Hemicelluloses are partially hydrolysed, to give sugars to the
pulping spent liquor (also furfural, sugar acids, etc)
The process is mainly used for hardwood and some softwood
Was the dominating pulping process in the past, now small (but
important) role. Now new sulphite pulp mills have been
constructed since early 1980s!
Also used for dissolving pulp (high cellulose content) production
11 30/7/2015
The recent end of the world’s latest new sulphite pulp mill
12 30/7/2015
Kraft (or sulphate) pulping processes
”Kraft” is a German word, meaning ”strength” (of pulp derived)
Sulphate refers to sodium sulphate, used as make-up chemical
Uses NaOH and Na2S as the pulping chemicals (alkaline)
Lignin is degraded and dissolved (Na2S needed) and will
contain some organic sulphur (bad smell)
Hemicelluloses are largely converted into hydroxy acids
Used for hardwood and softwood
Huge pulp mill capacities (up to 2 million tons) operate
Numerous huge new mills constructed recently
Special pre-hydrolysis kraft pulp mills use water-vapour
pretreatment step to remove most of the hemicelluloses
(required for the manufacture of dissolving pulp)
13 30/7/2015
Soda pulping processes
Uses NaOH and as the pulping chemicals (alkaline)
Soda refers to sodium carbonate, used as make-up chemical
Used typically for non-wood raw materials
Lignin is degraded and dissolved (without Na2S); does not
organic sulphur (no bad smell)
Hemicelluloses are largely converted into hydroxy acids
Very small mills do not recover sodium for re-use
14 30/7/2015
Sulphite vs. kraft summary table
Constituent Sulphite product(s) Kraft product(s)
Lignin Lignosulphonate Kraft lignin
(with 2-3% org. S)
Hemicelluloses Sugars, furfural, Hydroxy acids,
oligosaccharides some xylan polymer
15 30/7/2015
Organosolv processes
Based on the use of different organic solvents
Planned especially for hardwood and non-wood materials
Planned for selective fractionation of all major raw material
constituents
No industrial scale process currently in operation
Two companies especially aim for Asian straw pulping
markets:
CIMV from France
Chempolis from Finland
They use formic or acetic acids as the main solvents
16 30/7/2015
Pulp production by methods (190-200 Mt in total)
430
40
Plenty!
40
Number of pulp mills
(10 pre-
hydrolysis
mills)
No organosolv processes
industrially operating
17 30/7/2015
Industrial products from sulphite
pulp mill biorefineries
o Glucose (not isolated as pure)
o Xylose; xylose to xylitol
o Arabinose, galactose, mannose
o Ethanol o Baker’s yeast
o Torula yeast
o Pekilo protein
o Ribonucleic acids
o Acetic acid (from fermentation)
o Biogas
Current products shown on bold
18 30/7/2015
Industrial products from sulphite
pulp mill biorefineries
o Lignosulphonates
o Oxidation to vanillin
o Vanillin process by-products
o Acetic acid
o Furfural
o p-Cymene (”turpentine”) for
softwood only
o Glucose (not isolated as pure)
o Xylose; xylose to xylitol
o Arabinose, galactose, mannose
o Ethanol
o Baker’s yeast
o Torula yeast
o Pekilo protein
o Ribonucleic acids
o Acetic acid (from fermentation)
o Biogas
Current products shown on bold
19 30/7/2015
Ethanol from sulphite pulp mill biorefineries: the first
2nd generation ethanol plants
20 30/7/2015
Ethanol-producing sulphite pulp mill biorefineries in Sweden
21 30/7/2015
Ethanol-producing sulphite pulp mill biorefineries in Finland
Summary of the past mills:
- Sweden 30
- Finland 20
- World total 150-200??
- Now only 4 sulphite ethanol
plants (next slide)
22 30/7/2015
Current ethanol-producing sulphite pulp mill biorefineries
23 30/7/2015
Torula yeast and pekilo protein
• Pekilo protein produced only at two plants in Finland (1970s-1980s)
• Torula yeast currently produced in Japan, Russia and Czech Rep.
• Process utilises also pentoses, aldonic acids, uronic acids, acetic acid
24 30/7/2015
Ribonucleic acids
25 30/7/2015
26 30/7/2015
Danisco Sweeteners
Thomson
Lenzing
Anyang co., Ltd
Flambeau River
Paper, US
Lenzing AG,
Austria
Thomson
Kantvik
Vigo
(Kotka)
Tolling Manufacturers
Spent
Liquor
D-Xylose
Xylitol
D-Xylose
Side Stream
L-Rhamnose
L-Arabinose
L-Fucose
D-Mannose
D-Galactose
Suryps
L-Xylose
L-Ribose
ATBR
LTAR
XMAFlavour- / Food Industry
Feed Industry
Pharma Companies
R&D Institutes
Dietary Supplement Companies
Bio Companies
Cosmetics
Raw Material
Suppliers Danisco Sweeteners Customers
Sugars from sulphite spent liquors
27 30/7/2015
Isolation of acetic acid and furfural at Lenzing
sulphite pulp mill biorefinery, Austria
Production 25,000 t
Food-grade product!
Furfural isolated at the
same time, 4,000 t
(the only sulphite pulp mill)
28 30/7/2015
Lenzing pulping mill biorefinery, Austria
The net calorific value corresponds to
abt. 220 kg fuel oil per t of pulp produced!
Dissolving
pulp
Acetic acid
Spent liquor Excess
energy
Beech wood
50%
Pulp
mill
39% Furfural
Xylose
11%
Source: H. Harms, FTP Conf. 2005
29 30/7/2015
Sulphite pulp mill biorefinery in Finland in the 1980s
30 30/7/2015
Borregaard sulphite pulp mill biorefinery, Norway
31 30/7/2015
Lignosulphonates from sulphite processes - production
Annual "production" over 4-5 million tons.
Used as a chemical/material: 1.2-1.8 million tons.
Production in Europe, Asia, North America, Africa.
Several companies operating, LignoTech Borregaard dominating.
32 30/7/2015
Lignosulphonate functionality & substitutes
33 30/7/2015
Lignosulphonate uses 2008
34 30/7/2015
Current lignosulphonate producers (some figures are indicative)
Just announced: Borregaard and Rayonier will construct a new 150,000-ton capacity LS plant in Florida
35 30/7/2015
Where do Chinese lignosulphonates come from?
36 30/7/2015
Chinese lignosulphonate capacity steadily increasing
There is very little sulphite pulp industry in China to explain the volume of lignosulphonates.
Possibly mainly based on post-sulphonation of non-wood soda lignins?
In China, high demand for construction and agriculture
37 30/7/2015
Vanillin from lignosulphonates
Today, 15% of global vanillin production is based on oxidation of
lignosulphonates (yield is c. 10%)
Two producers: Borregaard (Norway), Bailu Papermaking (China)
In the past, also produced in the US, Canada, Japan, USSR, Poland
(and other Chinese plants). Many plants closed 1980-2000.
Isolated by-products include dehydrodivanillin, acetovanillone, and
oxalic acid.
Vanillin Acetovanillone
38 30/7/2015
Latest new lignin vanillin plant operated only for some time
LignoTech Kaishantun, China (joint venture with Borregaard,
Norway)
Planned vanillin capacity 300 tons
Started 1995, closed 1996
39 30/7/2015
Industrial products from kraft
pulp mill biorefineries
Prehydrolysis kraft pulping
o Xylose
o Furfural
o Ethanol
o Fodder yeast
Normal kraft pulping
o Turpentine
o Tall oil (”pine oil”)
o Palmitic acid
o Lignin
o Methanol
o Ammonia
o Dimethyl sulphide
o Dimethyl sulfone and sulfoxide
o Acetone, 2-butanone
o Light and heavy oils
o Biogas
Current products shown on bold
Pre-extraction kraft pulping
o Arabinogalactan (Stractan)
40 30/7/2015
Bratsk prehydrolysis-kraft pulp mill biorefinery in the 1970s Products included yeast 20,000 t/a
41 30/7/2015
By-product potential from kraft pulping
Chips
240 million tons
Kraft pulp (wood)
120 million tons Spent liquor organics
120 million tons
Current by-products
<2 million tons
42 30/7/2015
Main hydroxy monocarboxylic acids in all kraft
pulping spent liquors – potential future by-products
Not yet isolated commercially (not now discussed in more detail)
43 30/7/2015
Indicative turpentine production (1000 tons)
(From softwood resin or softwood pulping)
CST, crude sulphate
turpentine
Collecting resin for
gum turpentine and rosin
44 30/7/2015
Tall oil (“pine oil”)
”Tall” is Swedish meaning pine.
Isolated at numerous softwood kraft pulp mills worldwide
Distilled at c. 20 distilleries to different fatty and resin acid fractions
(and residues). Phytosterols also isolated in many countries
Production figure steady: 1.4-1.5 million tonnes
The main fractions are valuable products
Recent interest also for the manufacture of biodiesel
Softwood (tall oil and gum rosin) are the only sources of pine rosin
Forchem, Rauma (2002) Resitac, Brazil (2009)
45 30/7/2015
Tall oil rosin competitor: gum rosin
46 30/7/2015
Phytosterol producers
Total capacity c. 22,000 tons
More than 50% from tall oil
47 30/7/2015
DMSO – Dimethyl sulphoxide (via DMS)
More valuable product from black liquor processing
Pilot-scale production in Finland from
black liquor in the 1940s
Knowledge transferred to the USA,
where production from the 1960s to
2010 (by Gaylord Chemical). During
the recent years, c. 1/3 of global
DMSO was from black liquor.
Also, dimethyl sulphone (MSM) was
produced.
DMSO also produced in the Soviet
Union (1974-1990s)
48 30/7/2015
Kraft (sulfate) lignins
Annual "production" over 60-70 million tons.
Used as a chemical/material: under 150,000 tons.
Soda lignin isolation status unclear (Chinese lignosulphonates?)
Isolated in the US, Canada, Sweden, Japan, Finland
New capacity under planning or negotiations
All current isolation processes based on CO2-H2SO4 precipitation
49 30/7/2015
Kraft (and soda) lignin uses
Modified for dispersants and related uses
Phenol formaldehyde resins
Increading interest for commercialisation in polyurethanes,
carbon fibers, and different composites or plastic blends
Post-sulphonated kraft lignins are on the markets; uses are
similar to those of proper lignosulphonates
Uncertain future availability of lignosulphonates has strongly
increased attention to post-sulphonate alkali lignin, and also
to recovery of sulphonated lignins from pretreatment
processes in bioethanol production
50 30/7/2015
Flax pulp mill
51 30/7/2015
The lignin plant of ALM India in Punjab receives raw
material (soda lignin) from Kuantum Papers pulp mill
(in Punjab). Also markets post-sulphonated products.
52 30/7/2015
Borregaard is planning to ensure lignosulphonate supply
by a novel pretreatment process (BALI)
Sulphite-based pretreatment yields lignin as water-soluble lignosulphonates,
to ensure sufficient supply.
Commercial plant(s) can be expected in a few years time.
53 30/7/2015
BALI process – indicative mass balances
54 30/7/2015
About some future pulp mill biorefinery concepts
Pre-extraction of hemicelluloses (1)
Heavily studied, aiming at polymeric or mono-/oligomeric products
Sugars usually to ethanol, butanol, succinic acid, etc.
Pilot-demostration project operated several years at a kraft pulp mill
in Maine, USA
Mill recently closed, now new owner (future?)
55 30/7/2015
About some future pulp mill biorefinery concepts
Pre-extraction of hemicelluloses (2)
Industrial project recently announced at Cascades Canada’s Norampac-
Cabano plant
Sodium carbonate process will be changed and hemicellulose extraction starts
Hardwood process, little details on the target products given (xylose, xylitol?)
Options for xylan extraction from hardwood or non-wood processing
Alkaline or hot-water pre-extraction
Alkaline post-extraction from the bleached pulp
Isolation at an initial pulping stage
56 30/7/2015
Organosolv pulp mill biorefineries
Only one mill-scale production (Organocell) tested so far (1991)
Demonstration run of Alcell process in Canada (1989-1996)
Based on ethanol
Lignin production (marketed) 3,700 tons
Some furfural also isolated
Hardwood raw material
Technology later acquired by Lignol (now finacial problems)
Organic acid based processes close to commercialisation for straw
Chempolis, Finland
CIMV, France
57 30/7/2015
Conclusions
If more economical and environmentally sound solution for the utilization of
non-wood raw materials can be developed, it would be possible to raise the
world non-wood pulp production significantly from the present level.
There are promising future potential markets for non-wood soda lignins (as
they have many good properties and lack of smelling sulphur). A growing
area is the production of synthetic lignosulphonates.
An important requirement is secured supply of constant quality pulping raw
material.
The isolation of hydroxy acids will depend on the development techno-
economically feasible recovery and purification methods.
Sugar-based pre-extraction or pre-hydrolysis products also have potential
markets; the feasible recovery process needs to be optimised
The first mill-scale organosolv non-wood pulp mill is possible in near future.
58 30/7/2015
Semichemical (NSSC) pulping: developed in the US for tannin-
extracted chestnut trees before the attack of chestnut blight
59 30/7/2015
NSSC pulp mills
High-yield pulp mills (hardwood) for corrugated board, NSSC
process originally developed in the US in the 1920s to pulp wood
from tannin extraction
Pioneering acetic and formic acid separation processes developed
in the USA and Finland
Sonoco 1958-1970s
Savon Sellu 1979-1991,
chlorinated product used
for the manufacture of
CMC at Äänekoski.
Other products:
lignosulphonates
60 30/7/2015
Chestnut extraction-pulping mill operated in Italy 1957-2009
NSSC
pulping
Hot water
extraction
Tannin
Chips
Pulp