Ethanol from Nordic wood raw material by simplified alkaline soda cooking pre-treatment

A. von Schenck (Corresponding Author), N. Berglin, Jaana Uusitalo

Research output: Contribution to journalArticleScientificpeer-review

26 Citations (Scopus)

Abstract

Ethanol production from lignocellulosic raw materials will generate multiple streams, since only a certain fraction of the material can be converted into sugars and then fermented to ethanol. This requires a ‘poly-generation’ approach, where by-products also must have high value (e.g. lignin, sugars from hemicellulose). To reach the large scale required for profitability, it is proposed that the best way is to integrate the new processes with existing industries, preferably those that already operate biomass-to-materials or biomass-to-fuels plants. One of the largest industry branches in this respect is the pulp and paper industry. Production of second generation ethanol (or other products) via sugars from lignocellulosic materials includes a relatively costly pre-treatment of the raw material in order to separate the lignin from the cellulose. This separation of the wood components already takes place in the chemical pulp mill, and the long proven technology in pulp production known as soda cooking (pre-treatment under alkaline conditions) is further evaluated in this study. It can be directly integrated into the recovery of chemicals and energy in the pulp mill. The pre-treatment of the lignocellulosic material studied in this work is alkaline and sulphur-free, and results in a technically pure cellulose to be fed to the hydrolysis stage, which makes it different compared to most of the other processes that aim to produce ethanol from lignocelluloses. The process chain from enzymatic hydrolysis to ethanol is very similar to that being used today for grain ethanol.

The aim of this study was to define the conditions in alkaline pre-treatment stage for the separation of wood to a carbohydrate fraction for hydrolysis and ethanol production, and to a lignin fraction for the production of lignin products. Aspen (Populus tremula) and pine (Pinus sylvestris) wood from Nordic mills were studied. The reference case was alkaline pre-treatment according to the well-known soda pulping technique. The pulps of alkaline pre-treated aspen could be enzymatically hydrolysed very efficiently and fermented to ethanol with high yields (82–88% ethanol yield from theoretical maximum). It should be possible to use raw material of lower quality and cost than wood from the pulp industry. However, it can then be important to be able to take out non-process elements (NPEs) that otherwise accumulate in the process. This can be done by introducing an acidic prehydolysis stage prior to the alkaline fractionation. The content of Mg and Mn ions in the wood was possible to reduce by 85–90% and Ba and Ca ions by 75–80%. Potassium was virtually completely removed during the acidic pre-treatment stage.
Original languageEnglish
Pages (from-to)229-240
JournalApplied Energy
Volume102
DOIs
Publication statusPublished - 2013
MoE publication typeNot Eligible
EventXIX International Symposium on Alcohol Fuels, ISAF 2011 - Verona, Italy
Duration: 10 Oct 201114 Oct 2011
Conference number: 19

Fingerprint

Cooking
ethanol
Wood
Raw materials
Ethanol
Lignin
lignin
Sugars
hydrolysis
mill
Paper and pulp industry
Paper and pulp mills
Pulp
cellulose
Hydrolysis
Cellulose
sugar
Biomass
Pulp cooking
Chemical pulp

Keywords

  • Alkaline pretreatment
  • ethanol production
  • lignin outtake
  • Nordic wood material
  • SSF

Cite this

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title = "Ethanol from Nordic wood raw material by simplified alkaline soda cooking pre-treatment",
abstract = "Ethanol production from lignocellulosic raw materials will generate multiple streams, since only a certain fraction of the material can be converted into sugars and then fermented to ethanol. This requires a ‘poly-generation’ approach, where by-products also must have high value (e.g. lignin, sugars from hemicellulose). To reach the large scale required for profitability, it is proposed that the best way is to integrate the new processes with existing industries, preferably those that already operate biomass-to-materials or biomass-to-fuels plants. One of the largest industry branches in this respect is the pulp and paper industry. Production of second generation ethanol (or other products) via sugars from lignocellulosic materials includes a relatively costly pre-treatment of the raw material in order to separate the lignin from the cellulose. This separation of the wood components already takes place in the chemical pulp mill, and the long proven technology in pulp production known as soda cooking (pre-treatment under alkaline conditions) is further evaluated in this study. It can be directly integrated into the recovery of chemicals and energy in the pulp mill. The pre-treatment of the lignocellulosic material studied in this work is alkaline and sulphur-free, and results in a technically pure cellulose to be fed to the hydrolysis stage, which makes it different compared to most of the other processes that aim to produce ethanol from lignocelluloses. The process chain from enzymatic hydrolysis to ethanol is very similar to that being used today for grain ethanol.The aim of this study was to define the conditions in alkaline pre-treatment stage for the separation of wood to a carbohydrate fraction for hydrolysis and ethanol production, and to a lignin fraction for the production of lignin products. Aspen (Populus tremula) and pine (Pinus sylvestris) wood from Nordic mills were studied. The reference case was alkaline pre-treatment according to the well-known soda pulping technique. The pulps of alkaline pre-treated aspen could be enzymatically hydrolysed very efficiently and fermented to ethanol with high yields (82–88{\%} ethanol yield from theoretical maximum). It should be possible to use raw material of lower quality and cost than wood from the pulp industry. However, it can then be important to be able to take out non-process elements (NPEs) that otherwise accumulate in the process. This can be done by introducing an acidic prehydolysis stage prior to the alkaline fractionation. The content of Mg and Mn ions in the wood was possible to reduce by 85–90{\%} and Ba and Ca ions by 75–80{\%}. Potassium was virtually completely removed during the acidic pre-treatment stage.",
keywords = "Alkaline pretreatment, ethanol production, lignin outtake, Nordic wood material, SSF",
author = "{von Schenck}, A. and N. Berglin and Jaana Uusitalo",
note = "Special Issue on Advances in sustainable biofuel production and use - XIX International Symposium on Alcohol Fuels - ISAF",
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language = "English",
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}

Ethanol from Nordic wood raw material by simplified alkaline soda cooking pre-treatment. / von Schenck, A. (Corresponding Author); Berglin, N.; Uusitalo, Jaana.

In: Applied Energy, Vol. 102, 2013, p. 229-240.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Ethanol from Nordic wood raw material by simplified alkaline soda cooking pre-treatment

AU - von Schenck, A.

AU - Berglin, N.

AU - Uusitalo, Jaana

N1 - Special Issue on Advances in sustainable biofuel production and use - XIX International Symposium on Alcohol Fuels - ISAF

PY - 2013

Y1 - 2013

N2 - Ethanol production from lignocellulosic raw materials will generate multiple streams, since only a certain fraction of the material can be converted into sugars and then fermented to ethanol. This requires a ‘poly-generation’ approach, where by-products also must have high value (e.g. lignin, sugars from hemicellulose). To reach the large scale required for profitability, it is proposed that the best way is to integrate the new processes with existing industries, preferably those that already operate biomass-to-materials or biomass-to-fuels plants. One of the largest industry branches in this respect is the pulp and paper industry. Production of second generation ethanol (or other products) via sugars from lignocellulosic materials includes a relatively costly pre-treatment of the raw material in order to separate the lignin from the cellulose. This separation of the wood components already takes place in the chemical pulp mill, and the long proven technology in pulp production known as soda cooking (pre-treatment under alkaline conditions) is further evaluated in this study. It can be directly integrated into the recovery of chemicals and energy in the pulp mill. The pre-treatment of the lignocellulosic material studied in this work is alkaline and sulphur-free, and results in a technically pure cellulose to be fed to the hydrolysis stage, which makes it different compared to most of the other processes that aim to produce ethanol from lignocelluloses. The process chain from enzymatic hydrolysis to ethanol is very similar to that being used today for grain ethanol.The aim of this study was to define the conditions in alkaline pre-treatment stage for the separation of wood to a carbohydrate fraction for hydrolysis and ethanol production, and to a lignin fraction for the production of lignin products. Aspen (Populus tremula) and pine (Pinus sylvestris) wood from Nordic mills were studied. The reference case was alkaline pre-treatment according to the well-known soda pulping technique. The pulps of alkaline pre-treated aspen could be enzymatically hydrolysed very efficiently and fermented to ethanol with high yields (82–88% ethanol yield from theoretical maximum). It should be possible to use raw material of lower quality and cost than wood from the pulp industry. However, it can then be important to be able to take out non-process elements (NPEs) that otherwise accumulate in the process. This can be done by introducing an acidic prehydolysis stage prior to the alkaline fractionation. The content of Mg and Mn ions in the wood was possible to reduce by 85–90% and Ba and Ca ions by 75–80%. Potassium was virtually completely removed during the acidic pre-treatment stage.

AB - Ethanol production from lignocellulosic raw materials will generate multiple streams, since only a certain fraction of the material can be converted into sugars and then fermented to ethanol. This requires a ‘poly-generation’ approach, where by-products also must have high value (e.g. lignin, sugars from hemicellulose). To reach the large scale required for profitability, it is proposed that the best way is to integrate the new processes with existing industries, preferably those that already operate biomass-to-materials or biomass-to-fuels plants. One of the largest industry branches in this respect is the pulp and paper industry. Production of second generation ethanol (or other products) via sugars from lignocellulosic materials includes a relatively costly pre-treatment of the raw material in order to separate the lignin from the cellulose. This separation of the wood components already takes place in the chemical pulp mill, and the long proven technology in pulp production known as soda cooking (pre-treatment under alkaline conditions) is further evaluated in this study. It can be directly integrated into the recovery of chemicals and energy in the pulp mill. The pre-treatment of the lignocellulosic material studied in this work is alkaline and sulphur-free, and results in a technically pure cellulose to be fed to the hydrolysis stage, which makes it different compared to most of the other processes that aim to produce ethanol from lignocelluloses. The process chain from enzymatic hydrolysis to ethanol is very similar to that being used today for grain ethanol.The aim of this study was to define the conditions in alkaline pre-treatment stage for the separation of wood to a carbohydrate fraction for hydrolysis and ethanol production, and to a lignin fraction for the production of lignin products. Aspen (Populus tremula) and pine (Pinus sylvestris) wood from Nordic mills were studied. The reference case was alkaline pre-treatment according to the well-known soda pulping technique. The pulps of alkaline pre-treated aspen could be enzymatically hydrolysed very efficiently and fermented to ethanol with high yields (82–88% ethanol yield from theoretical maximum). It should be possible to use raw material of lower quality and cost than wood from the pulp industry. However, it can then be important to be able to take out non-process elements (NPEs) that otherwise accumulate in the process. This can be done by introducing an acidic prehydolysis stage prior to the alkaline fractionation. The content of Mg and Mn ions in the wood was possible to reduce by 85–90% and Ba and Ca ions by 75–80%. Potassium was virtually completely removed during the acidic pre-treatment stage.

KW - Alkaline pretreatment

KW - ethanol production

KW - lignin outtake

KW - Nordic wood material

KW - SSF

U2 - 10.1016/j.apenergy.2012.10.003

DO - 10.1016/j.apenergy.2012.10.003

M3 - Article

VL - 102

SP - 229

EP - 240

JO - Applied Energy

JF - Applied Energy

SN - 0306-2619

ER -