Jana Holm - Academia.edu (original) (raw)
Papers by Jana Holm
Biomass and Bioenergy, 2017
One-step absolute solvent-free acid-catalyzed mechanical depolymerization of pine sawdust (PSD) a... more One-step absolute solvent-free acid-catalyzed mechanical depolymerization of pine sawdust (PSD) and commercially available α-cellulose to water-soluble sugars was carried out using ball milling. For comparison purposes, the commonly reported "solventfree" mechanocatalytic depolymerization of lignocellulose method, which normally involves three steps (acid impregnation in solvent, vacuum drying, and mechanical depolymerization of lignocellulose), was performed. The 3,5-dinitrosalicylic acid (DNS) method was used to measure the total reducing sugar (TRS) of the obtained sugar solution, and major monosaccharides in the solution were analyzed by capillary electrophoresis (CE). More than 90% of the PSD became water-soluble through milling. Furthermore, most of the PSD was converted into TRS in approximately 30 min, and the highest TRS yield obtained was 31%, based on the dry mass. Interestingly, the TRS solutions obtained from the processed PSD were much darker than those obtained from α-cellulose due to the chromophores that formed during the depolymerization of lignin.
Biomass and Bioenergy, 2016
Abstract This study performed a direct solvent-free acid-catalysed mechanical depolymerisation of... more Abstract This study performed a direct solvent-free acid-catalysed mechanical depolymerisation of fibre sludge to reducing sugars which involves one step of acid milling in a planetary mill. The common reported ‘solvent-free’ mechanocatalytic depolymerisation of lignocellulose which includes 1) acid impregnation, 2) vacuum evaporation and 3) mechanocatalytic depolymerisation was also performed as a reference. The major converted monosaccharides were determined by capillary electrophoresis and the results of total reducing sugar (TRS) yields were carried out based on the 3,5-dinitrosalicylic acid (DNS) method. The results showed that the TRS conversion of direct acid-catalysed mechanical depolymerisation of biomass is 35%, whereas, the commonly reported method yields 31% under the same milling conditions. In addition, the direct acid-catalysed mechanical depolymerisation simplifies the reaction procedures to one step and shortens the total reaction time. Moreover, the present study indicates that the frequency of the transferred energy which is caused by the collisions, acid concentration, milling time and moisture content of the sample are the major factors in influencing yield of converted TRS in acid-catalysed mechanical depolymerisation of fibre sludge.
This paper deals with the pre-treatment of bark sludge, bio sludge and fiber sludge by ionic liqu... more This paper deals with the pre-treatment of bark sludge, bio sludge and fiber sludge by ionic liquid, and the fractionation of these cellulose-based samples into different fractions. Bark sludge, bio sludge and fiber sludge are secondary products and/or waste products in the forest industry, and it is important to find new opportunities to utilize these sludges e.g. in the biofuel production. The sample pre-treatment was carried out in the ionic liquid, 1-butyl-3- methylimidazolium chloride ((BMIM)(Cl)), which is a good solvent for cellulose. Before the chemical analysis, the dissolved fiber sludge was extracted into different fractions with liquid-liquid extraction. These fractions were analyzed using mass spectrometry. The pre-treatment of real samples, e.g. sludges from the pulp mill, is the most challenging step in the utilization of these raw materials in the biofuel production. If the cellulose dissolved from the pulp mill sludge can be successfully converted to sugars through ...
Biomass and Bioenergy, 2014
The dissolution and hydrolysis of wet fibre sludge in ionic liquids (ILs) with different reaction... more The dissolution and hydrolysis of wet fibre sludge in ionic liquids (ILs) with different reaction conditions are performed in this study. Novel types of hydroxyalkylimidazolium hydrogensulphate ILs, [glymim]HSO 4 , [hemim]HSO 4 and [hpmim]HSO 4 , are especially designed and aimed to combine the dissolution and hydrolysis of wet fibre sludge in a one-step pretreatment. The results were obtained based on the analysis of total reducing sugars (TRS) with the DNS method. The dissolution and hydrolysis of fresh wild horse chestnut seed (Aesculus hippocastanum) with the same ILs were also carried out as a comparison reference. Since fibre sludge is cellulose based and horse chestnut seed is starch based, a direct comparison of the difference in functions between these ILs in one-step dissolution and hydrolysis were analysed based on the results.
Biomass Conversion and Biorefinery, 2013
ABSTRACT The main goal of this research is the enzyme-catalyzed conversion of fibre sludge into r... more ABSTRACT The main goal of this research is the enzyme-catalyzed conversion of fibre sludge into reducing sugars, which can further be transformed into higher alcohol biofuels by fermentation. Enzymatic hydrolysis of 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) pretreated fibre sludge demonstrated that this cellulose-rich waste fraction can be successfully converted into reducing sugars. The organic material content of this fibre sludge was determined to be about 80 %. The relative yields of total reducing sugars (glucose) in this study were higher (maximum >95 %) compared with our earlier studies (34 %) of the same pretreatment procedure followed by acid hydrolysis and enzymatic hydrolysis. Due to the ionic liquid used in this study, we were able to recover 85 % (compared with 50 %) of the initial dry fibre sludge with [AMIM]Cl pretreatment.
Ionic Liquids: Applications and Perspectives, 2011
Biomass and Bioenergy, 2013
ABSTRACT Fibre sludge is a cellulose-rich by-product obtained from the chemical pulping process o... more ABSTRACT Fibre sludge is a cellulose-rich by-product obtained from the chemical pulping process of wood chips. In this study, a one-step pretreatment procedure is considered in which fibre sludge can be simultaneously dissolved and depolymerised in an ionic liquid media. Task-specific ionic liquid (TSIL), i.e. 1-(4-sulfonylbutyl)-3-methylimidazolium chloride [SBMIM] Cl, is used as an ionic liquid media. Based on the results, [SBMIM]Cl has the ability to dissolve and hydrolyse fibre sludge in a one-step reaction. Yields of total reducing sugars (TRS) after [SBMIM]Cl pretreatment were not high (a mass fraction around 4-5%), but still comparable to yields of TRS after acid hydrolysis (a mass fraction between 2 and 8%). Furthermore, [SBMIM]Cl is able to dissolve and depolymerise both dry and wet material even up to a moisture mass fraction of 50%, which is a significant advantage when wet fibre sludge is used as a raw material.
Catalysis Today, 2012
Pretreatment of fibre sludge in ionic liquids and enzyme or acid catalysed hydrolysis of fibre sl... more Pretreatment of fibre sludge in ionic liquids and enzyme or acid catalysed hydrolysis of fibre sludge is studied. Ionic liquids, i.e. 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and 1-butyl-3methylimidazolium chloride ([BMIM]Cl), are used in the pretreatment step. Effect of ionic liquid (IL) pretreatment on the acid and enzyme catalysed hydrolysis of fibre sludge is considered. Cellulose content of fibre sludge is more than 80 wt%, and therefore, reducing sugars obtained as a result of hydrolysis contain mostly glucose. To maximize the yield of reducing sugars during the enzymatic hydrolysis, the combinations of selective enzymes are required. Results also show that the use of ionic liquids in the pretreatment step before acid and enzyme hydrolysis increases significantly the yield of total reducing sugars.
Decreasing oil reserves, the need to reduce CO2 emissions and increasing energy demand are issues... more Decreasing oil reserves, the need to reduce CO2 emissions and increasing energy demand are issues that are forcing scientists to search for new opportunities in the field of energy. As a result, biofuels have been considered as one possible solution to solve part of these challenges. This research is one small part of that effort. For both human and economic reasons the use of edible raw materials for biofuel production is not sustainable. This study aims to convert forest industry waste, namely fibre sludge, into reducing sugars (glucose). This platform chemical can then be converted to value-added products, biofuels such as ethanol or butanol for example. Depolymerisation of fibre sludge (cellulose) to glucose monomers was performed firstly by pretreatment with ionic liquids [BMIM]Cl and [AMIM]Cl and secondly hydrolysed by acids (dilute maleic and sulphuric acids) and enzymes. To go further with the research the two pretreatment steps, dissolution and hydrolysis were combined into...
Ionic Liquids - Current State of the Art, 2015
Biomass and Bioenergy, 2014
ABSTRACT The dissolution and hydrolysis of wet fibre sludge in ionic liquids (ILs) with different... more ABSTRACT The dissolution and hydrolysis of wet fibre sludge in ionic liquids (ILs) with different reaction conditions are performed in this study. Novel types of hydroxyalkylimidazolium hydrogensulphate ILs, [glymim]HSO4, [hemim]HSO4 and [hpmim]HSO4, are especially designed and aimed to combine the dissolution and hydrolysis of wet fibre sludge in a one-step pretreatment. The results were obtained based on the analysis of total reducing sugars (TRS) with the DNS method. The dissolution and hydrolysis of fresh wild horse chestnut fruit (Aesculus hippocastanum) with the same ILs were also carried out as a comparison reference. Since fibre sludge is cellulose based and horse chestnut fruit is starch based, a direct comparison of the difference in functions between these ILs in one-step dissolution and hydrolysis were analysed based on the results.
Biomass Conversion and Biorefinery, 2013
ABSTRACT The main goal of this research is the enzyme-catalyzed conversion of fibre sludge into r... more ABSTRACT The main goal of this research is the enzyme-catalyzed conversion of fibre sludge into reducing sugars, which can further be transformed into higher alcohol biofuels by fermentation. Enzymatic hydrolysis of 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) pretreated fibre sludge demonstrated that this cellulose-rich waste fraction can be successfully converted into reducing sugars. The organic material content of this fibre sludge was determined to be about 80 %. The relative yields of total reducing sugars (glucose) in this study were higher (maximum >95 %) compared with our earlier studies (34 %) of the same pretreatment procedure followed by acid hydrolysis and enzymatic hydrolysis. Due to the ionic liquid used in this study, we were able to recover 85 % (compared with 50 %) of the initial dry fibre sludge with [AMIM]Cl pretreatment.
Ionic Liquids: Applications and Perspectives, 2011
Catalysis Today, 2012
ABSTRACT Pretreatment of fibre sludge in ionic liquids and enzyme or acid catalysed hydrolysis of... more ABSTRACT Pretreatment of fibre sludge in ionic liquids and enzyme or acid catalysed hydrolysis of fibre sludge is studied. Ionic liquids, i.e. 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), are used in the pretreatment step. Effect of ionic liquid (IL) pretreatment on the acid and enzyme catalysed hydrolysis of fibre sludge is considered.Cellulose content of fibre sludge is more than 80 wt%, and therefore, reducing sugars obtained as a result of hydrolysis contain mostly glucose. To maximize the yield of reducing sugars during the enzymatic hydrolysis, the combinations of selective enzymes are required. Results also show that the use of ionic liquids in the pretreatment step before acid and enzyme hydrolysis increases significantly the yield of total reducing sugars.
Biomass and Bioenergy, 2013
ABSTRACT Fibre sludge is a cellulose-rich by-product obtained from the chemical pulping process o... more ABSTRACT Fibre sludge is a cellulose-rich by-product obtained from the chemical pulping process of wood chips. In this study, a one-step pretreatment procedure is considered in which fibre sludge can be simultaneously dissolved and depolymerised in an ionic liquid media. Task-specific ionic liquid (TSIL), i.e. 1-(4-sulfonylbutyl)-3-methylimidazolium chloride [SBMIM] Cl, is used as an ionic liquid media. Based on the results, [SBMIM]Cl has the ability to dissolve and hydrolyse fibre sludge in a one-step reaction. Yields of total reducing sugars (TRS) after [SBMIM]Cl pretreatment were not high (a mass fraction around 4-5%), but still comparable to yields of TRS after acid hydrolysis (a mass fraction between 2 and 8%). Furthermore, [SBMIM]Cl is able to dissolve and depolymerise both dry and wet material even up to a moisture mass fraction of 50%, which is a significant advantage when wet fibre sludge is used as a raw material.
This paper deals with the pre-treatment of bark sludge, bio sludge and fiber sludge by ionic liqu... more This paper deals with the pre-treatment of bark sludge, bio sludge and fiber sludge by ionic liquid, and the fractionation of these cellulose-based samples into different fractions. Bark sludge, bio sludge and fiber sludge are secondary products and/or waste products in the forest industry, and it is important to find new opportunities to utilize these sludges e.g. in the biofuel production. The sample pre-treatment was carried out in the ionic liquid, 1-butyl-3- methylimidazolium chloride ((BMIM)(Cl)), which is a good solvent for cellulose. Before the chemical analysis, the dissolved fiber sludge was extracted into different fractions with liquid-liquid extraction. These fractions were analyzed using mass spectrometry. The pre-treatment of real samples, e.g. sludges from the pulp mill, is the most challenging step in the utilization of these raw materials in the biofuel production. If the cellulose dissolved from the pulp mill sludge can be successfully converted to sugars through ...
Biomass and Bioenergy, 2017
One-step absolute solvent-free acid-catalyzed mechanical depolymerization of pine sawdust (PSD) a... more One-step absolute solvent-free acid-catalyzed mechanical depolymerization of pine sawdust (PSD) and commercially available α-cellulose to water-soluble sugars was carried out using ball milling. For comparison purposes, the commonly reported "solventfree" mechanocatalytic depolymerization of lignocellulose method, which normally involves three steps (acid impregnation in solvent, vacuum drying, and mechanical depolymerization of lignocellulose), was performed. The 3,5-dinitrosalicylic acid (DNS) method was used to measure the total reducing sugar (TRS) of the obtained sugar solution, and major monosaccharides in the solution were analyzed by capillary electrophoresis (CE). More than 90% of the PSD became water-soluble through milling. Furthermore, most of the PSD was converted into TRS in approximately 30 min, and the highest TRS yield obtained was 31%, based on the dry mass. Interestingly, the TRS solutions obtained from the processed PSD were much darker than those obtained from α-cellulose due to the chromophores that formed during the depolymerization of lignin.
Biomass and Bioenergy, 2016
Abstract This study performed a direct solvent-free acid-catalysed mechanical depolymerisation of... more Abstract This study performed a direct solvent-free acid-catalysed mechanical depolymerisation of fibre sludge to reducing sugars which involves one step of acid milling in a planetary mill. The common reported ‘solvent-free’ mechanocatalytic depolymerisation of lignocellulose which includes 1) acid impregnation, 2) vacuum evaporation and 3) mechanocatalytic depolymerisation was also performed as a reference. The major converted monosaccharides were determined by capillary electrophoresis and the results of total reducing sugar (TRS) yields were carried out based on the 3,5-dinitrosalicylic acid (DNS) method. The results showed that the TRS conversion of direct acid-catalysed mechanical depolymerisation of biomass is 35%, whereas, the commonly reported method yields 31% under the same milling conditions. In addition, the direct acid-catalysed mechanical depolymerisation simplifies the reaction procedures to one step and shortens the total reaction time. Moreover, the present study indicates that the frequency of the transferred energy which is caused by the collisions, acid concentration, milling time and moisture content of the sample are the major factors in influencing yield of converted TRS in acid-catalysed mechanical depolymerisation of fibre sludge.
This paper deals with the pre-treatment of bark sludge, bio sludge and fiber sludge by ionic liqu... more This paper deals with the pre-treatment of bark sludge, bio sludge and fiber sludge by ionic liquid, and the fractionation of these cellulose-based samples into different fractions. Bark sludge, bio sludge and fiber sludge are secondary products and/or waste products in the forest industry, and it is important to find new opportunities to utilize these sludges e.g. in the biofuel production. The sample pre-treatment was carried out in the ionic liquid, 1-butyl-3- methylimidazolium chloride ((BMIM)(Cl)), which is a good solvent for cellulose. Before the chemical analysis, the dissolved fiber sludge was extracted into different fractions with liquid-liquid extraction. These fractions were analyzed using mass spectrometry. The pre-treatment of real samples, e.g. sludges from the pulp mill, is the most challenging step in the utilization of these raw materials in the biofuel production. If the cellulose dissolved from the pulp mill sludge can be successfully converted to sugars through ...
Biomass and Bioenergy, 2014
The dissolution and hydrolysis of wet fibre sludge in ionic liquids (ILs) with different reaction... more The dissolution and hydrolysis of wet fibre sludge in ionic liquids (ILs) with different reaction conditions are performed in this study. Novel types of hydroxyalkylimidazolium hydrogensulphate ILs, [glymim]HSO 4 , [hemim]HSO 4 and [hpmim]HSO 4 , are especially designed and aimed to combine the dissolution and hydrolysis of wet fibre sludge in a one-step pretreatment. The results were obtained based on the analysis of total reducing sugars (TRS) with the DNS method. The dissolution and hydrolysis of fresh wild horse chestnut seed (Aesculus hippocastanum) with the same ILs were also carried out as a comparison reference. Since fibre sludge is cellulose based and horse chestnut seed is starch based, a direct comparison of the difference in functions between these ILs in one-step dissolution and hydrolysis were analysed based on the results.
Biomass Conversion and Biorefinery, 2013
ABSTRACT The main goal of this research is the enzyme-catalyzed conversion of fibre sludge into r... more ABSTRACT The main goal of this research is the enzyme-catalyzed conversion of fibre sludge into reducing sugars, which can further be transformed into higher alcohol biofuels by fermentation. Enzymatic hydrolysis of 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) pretreated fibre sludge demonstrated that this cellulose-rich waste fraction can be successfully converted into reducing sugars. The organic material content of this fibre sludge was determined to be about 80 %. The relative yields of total reducing sugars (glucose) in this study were higher (maximum >95 %) compared with our earlier studies (34 %) of the same pretreatment procedure followed by acid hydrolysis and enzymatic hydrolysis. Due to the ionic liquid used in this study, we were able to recover 85 % (compared with 50 %) of the initial dry fibre sludge with [AMIM]Cl pretreatment.
Ionic Liquids: Applications and Perspectives, 2011
Biomass and Bioenergy, 2013
ABSTRACT Fibre sludge is a cellulose-rich by-product obtained from the chemical pulping process o... more ABSTRACT Fibre sludge is a cellulose-rich by-product obtained from the chemical pulping process of wood chips. In this study, a one-step pretreatment procedure is considered in which fibre sludge can be simultaneously dissolved and depolymerised in an ionic liquid media. Task-specific ionic liquid (TSIL), i.e. 1-(4-sulfonylbutyl)-3-methylimidazolium chloride [SBMIM] Cl, is used as an ionic liquid media. Based on the results, [SBMIM]Cl has the ability to dissolve and hydrolyse fibre sludge in a one-step reaction. Yields of total reducing sugars (TRS) after [SBMIM]Cl pretreatment were not high (a mass fraction around 4-5%), but still comparable to yields of TRS after acid hydrolysis (a mass fraction between 2 and 8%). Furthermore, [SBMIM]Cl is able to dissolve and depolymerise both dry and wet material even up to a moisture mass fraction of 50%, which is a significant advantage when wet fibre sludge is used as a raw material.
Catalysis Today, 2012
Pretreatment of fibre sludge in ionic liquids and enzyme or acid catalysed hydrolysis of fibre sl... more Pretreatment of fibre sludge in ionic liquids and enzyme or acid catalysed hydrolysis of fibre sludge is studied. Ionic liquids, i.e. 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and 1-butyl-3methylimidazolium chloride ([BMIM]Cl), are used in the pretreatment step. Effect of ionic liquid (IL) pretreatment on the acid and enzyme catalysed hydrolysis of fibre sludge is considered. Cellulose content of fibre sludge is more than 80 wt%, and therefore, reducing sugars obtained as a result of hydrolysis contain mostly glucose. To maximize the yield of reducing sugars during the enzymatic hydrolysis, the combinations of selective enzymes are required. Results also show that the use of ionic liquids in the pretreatment step before acid and enzyme hydrolysis increases significantly the yield of total reducing sugars.
Decreasing oil reserves, the need to reduce CO2 emissions and increasing energy demand are issues... more Decreasing oil reserves, the need to reduce CO2 emissions and increasing energy demand are issues that are forcing scientists to search for new opportunities in the field of energy. As a result, biofuels have been considered as one possible solution to solve part of these challenges. This research is one small part of that effort. For both human and economic reasons the use of edible raw materials for biofuel production is not sustainable. This study aims to convert forest industry waste, namely fibre sludge, into reducing sugars (glucose). This platform chemical can then be converted to value-added products, biofuels such as ethanol or butanol for example. Depolymerisation of fibre sludge (cellulose) to glucose monomers was performed firstly by pretreatment with ionic liquids [BMIM]Cl and [AMIM]Cl and secondly hydrolysed by acids (dilute maleic and sulphuric acids) and enzymes. To go further with the research the two pretreatment steps, dissolution and hydrolysis were combined into...
Ionic Liquids - Current State of the Art, 2015
Biomass and Bioenergy, 2014
ABSTRACT The dissolution and hydrolysis of wet fibre sludge in ionic liquids (ILs) with different... more ABSTRACT The dissolution and hydrolysis of wet fibre sludge in ionic liquids (ILs) with different reaction conditions are performed in this study. Novel types of hydroxyalkylimidazolium hydrogensulphate ILs, [glymim]HSO4, [hemim]HSO4 and [hpmim]HSO4, are especially designed and aimed to combine the dissolution and hydrolysis of wet fibre sludge in a one-step pretreatment. The results were obtained based on the analysis of total reducing sugars (TRS) with the DNS method. The dissolution and hydrolysis of fresh wild horse chestnut fruit (Aesculus hippocastanum) with the same ILs were also carried out as a comparison reference. Since fibre sludge is cellulose based and horse chestnut fruit is starch based, a direct comparison of the difference in functions between these ILs in one-step dissolution and hydrolysis were analysed based on the results.
Biomass Conversion and Biorefinery, 2013
ABSTRACT The main goal of this research is the enzyme-catalyzed conversion of fibre sludge into r... more ABSTRACT The main goal of this research is the enzyme-catalyzed conversion of fibre sludge into reducing sugars, which can further be transformed into higher alcohol biofuels by fermentation. Enzymatic hydrolysis of 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) pretreated fibre sludge demonstrated that this cellulose-rich waste fraction can be successfully converted into reducing sugars. The organic material content of this fibre sludge was determined to be about 80 %. The relative yields of total reducing sugars (glucose) in this study were higher (maximum >95 %) compared with our earlier studies (34 %) of the same pretreatment procedure followed by acid hydrolysis and enzymatic hydrolysis. Due to the ionic liquid used in this study, we were able to recover 85 % (compared with 50 %) of the initial dry fibre sludge with [AMIM]Cl pretreatment.
Ionic Liquids: Applications and Perspectives, 2011
Catalysis Today, 2012
ABSTRACT Pretreatment of fibre sludge in ionic liquids and enzyme or acid catalysed hydrolysis of... more ABSTRACT Pretreatment of fibre sludge in ionic liquids and enzyme or acid catalysed hydrolysis of fibre sludge is studied. Ionic liquids, i.e. 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), are used in the pretreatment step. Effect of ionic liquid (IL) pretreatment on the acid and enzyme catalysed hydrolysis of fibre sludge is considered.Cellulose content of fibre sludge is more than 80 wt%, and therefore, reducing sugars obtained as a result of hydrolysis contain mostly glucose. To maximize the yield of reducing sugars during the enzymatic hydrolysis, the combinations of selective enzymes are required. Results also show that the use of ionic liquids in the pretreatment step before acid and enzyme hydrolysis increases significantly the yield of total reducing sugars.
Biomass and Bioenergy, 2013
ABSTRACT Fibre sludge is a cellulose-rich by-product obtained from the chemical pulping process o... more ABSTRACT Fibre sludge is a cellulose-rich by-product obtained from the chemical pulping process of wood chips. In this study, a one-step pretreatment procedure is considered in which fibre sludge can be simultaneously dissolved and depolymerised in an ionic liquid media. Task-specific ionic liquid (TSIL), i.e. 1-(4-sulfonylbutyl)-3-methylimidazolium chloride [SBMIM] Cl, is used as an ionic liquid media. Based on the results, [SBMIM]Cl has the ability to dissolve and hydrolyse fibre sludge in a one-step reaction. Yields of total reducing sugars (TRS) after [SBMIM]Cl pretreatment were not high (a mass fraction around 4-5%), but still comparable to yields of TRS after acid hydrolysis (a mass fraction between 2 and 8%). Furthermore, [SBMIM]Cl is able to dissolve and depolymerise both dry and wet material even up to a moisture mass fraction of 50%, which is a significant advantage when wet fibre sludge is used as a raw material.
This paper deals with the pre-treatment of bark sludge, bio sludge and fiber sludge by ionic liqu... more This paper deals with the pre-treatment of bark sludge, bio sludge and fiber sludge by ionic liquid, and the fractionation of these cellulose-based samples into different fractions. Bark sludge, bio sludge and fiber sludge are secondary products and/or waste products in the forest industry, and it is important to find new opportunities to utilize these sludges e.g. in the biofuel production. The sample pre-treatment was carried out in the ionic liquid, 1-butyl-3- methylimidazolium chloride ((BMIM)(Cl)), which is a good solvent for cellulose. Before the chemical analysis, the dissolved fiber sludge was extracted into different fractions with liquid-liquid extraction. These fractions were analyzed using mass spectrometry. The pre-treatment of real samples, e.g. sludges from the pulp mill, is the most challenging step in the utilization of these raw materials in the biofuel production. If the cellulose dissolved from the pulp mill sludge can be successfully converted to sugars through ...