1,720,963 research outputs found
Pyrolysis of brewer’s spent grain biomass to form functional adsorbers
No full textPYROLYSIS OF BREWER’S SPENT GRAIN BIOMASS TO FORM FUNCTIONAL ADSORBERS
D. BLEUS 1, B. JOOS 2,3, W. MARCHAL 1, D. VANDAMME 1
1 Analytical and Circular Chemistry (ACC), Institute for Materials Research (IMO), Hasselt University, Hasselt, Belgium.
4 Design and Synthesis of Inorganic Nanomaterials (DESINe), Institute for Materials Research (IMO-IMOMEC), Hasselt University, 3590 Diepenbeek, Belgium
3 EnergyVille, Thor Park, 3600 Genk, Belgium
1. Keywords
Biomass, valorisation, pyrolysis, adsorbers
2. Highlights
- Brewer’s spent grain and malt dust biomass streams were extracted using bio-based solvents to recover (poly-)phenolic compounds.
- The extracted biomass was pyrolyzed using a lab-scale pipe furnace setup.
- The resulting biochar was then physically activated to obtain activated carbon (AC).
- The AC adsorbers will further be employed as adsorber material in solid phase separation/purification of (poly-)phenolic compounds.
3. Purpose
The proposed research abstract elaborates a novel, circular valorization methodology for
brewer spent grain (BSG) through green solvent-extraction and subsequent pyrolysis and
activation of the biomass resource to produce activated carbon (AC) materials. Finally, the
obtained AC will be investigated for use as adsorber for separation and purification of
extraction mixtures.
BSG is a nutrient-rich side product obtained from the beer brewing process. Many types of
BSG have proven to be naturally abundant in phenolic compounds, which could find
application as anti-oxidants 1 in a variety of food, feed, non-food products and
pharmaceuticals. As an industrial side stream that exceeds 3.4 million tons per year in the EU
alone 2 , a viable valorization route would create both economic and ecological opportunity.
Malt dust, on the other hand, is a lesser-known and underexplored waste stream that
encompasses all fine particulate matter separated from the freshly germinated and dried
barley. It is captured before the brewing process, and therefore still retains most naturally
present nutrients and extractable components.
To create a sustainable 3 valorization route for these biomass streams, extractions should be
carried out using bio-based or biocompatible solvents, while also minimizing the required
energetic budget.
Biomass-based adsorbers show well-documented potential in traditional solvent purification
and extractive recuperation procedures. 4- 5 Hence, in this project biomass-based adsorber
materials are put forward as a promising tool in the efficient recuperation of solvent after
the extraction step has been carried out. Extraction or ‘washing’ pretreatment steps have an
impact on the obtained pyrolysis products, and can yield increased surface area
carbonaceous materials. 6,7 It is therefore postulated that an optimized extraction process can
have a synergistic effect in the production of high surface area AC materials. Not only would
the successful implementation of these adsorbers boost the applicability of bio-based
solvents in the industry, but it would also increase the utilization of biomass side streams
that would otherwise be discarded as waste in landfills or incineration plants. 8
4. Materials and methods
BSG and malt dust were obtained from a local brewery. The samples were dried at 60°C and
stored at -20°C until further use. Different bio-based solvent systems are prepared and
evaluated for their efficiency. The mixtures were extracted using maceration at 70°C, 90°C,
and 120°C, respectively. The mixture was then centrifuged at 4000 rpm for 30 minutes,
before being filtered off under vacuum. The filtered extracts were then analysed on HPLC-
MS.
The solid biomass precipitate obtained after centrifugation was collected, excess bio-based
solvent was removed by vacuum filtration, and finally dried in vacuo at 60°C to remove
remaining water. The extracted biomass with residual bio-based solvent was then pyrolyzed
in a tube furnace at 700°C, under N 2 atmosphere. The resulting biochar was collected and
yield was determined gravimetrically, before performing physical activation on part of the
biochar material.
Resulting biochar and AC materials were then analysed using BET (Brunauer–Emmett–Teller)
specific surface area using gas adsorption measurement, scanning electron microscopy for
surface morphology, Ultimate analysis for elemental CHNO-composition, and
thermogravimetric analysis for volatiles and ash content determination.
5. Results and discussion
Preliminary results confirm the findings of earlier studies regarding the extraction efficiency
of bio-based solvents as a valid alternative to optimized extraction methods that utilize
classical solvents, such as acetone:H 2 O mixtures. 9 Using an optimized extraction setup at
elevated temperatures (120°C), extraction efficiencies were improved over classical
maceration methods.
Through the combination of centrifugation and vacuum filtration, (poly-)phenolic extracts
have been separated from the extracted solid biomass residue, obtaining pure liquid extracts
suitable for direct analysis on HPLC-MS. Qualitative identification of various (poly-)phenolic
compounds was performed through an optimized separation method on C18 column, with
acidified H 2 O:MeOH elution gradient.
‘Wet’ biomass was pyrolyzed at 700°C and steam-activated at 800°C in small scale
experiments, obtaining AC materials with promising surface areas, exceeding 500 m 2 /g.
6. Conclusions and perspectives
Promising preliminary results confirm the plausibility of the above-mentioned methodology
for circular valorisation of BSG and malt dust biomass. On one hand, phenolic anti-oxidant
compounds were qualitatively extracted from BSG and malt dust biomass streams, using
green solvents.
The obtained AC materials will be further analysed for chemical and phyiscal functionality,
with additional optimizations of the lab-scale pyrolysis and activation process still to be
performed. Future perspective includes the setup of small-scale preparative phenolic
isolation, and elution tests, which will be performed with the obtained AC adsorbers.
7. References
[1] L. F. Guido, Food Bioprocess Technol., 2017, 10, 1192–1209.
[2] J. Steiner, Eur. Food Res. Technol., 2015, 241, 303–315.
[3] J. C. W. P.T. Anastas, Oxford University Press, 1998.
[4] B. Chen, Environ. Sci. Technol., 2008, 42, 5137–5143.
[5] J. Li, J. Hazard. Mater., 2014, 280, 450–457.
[6] W. Vercruysse, Journal of Analytical and Applied Pyrolysis, 2021, 159, 105294.
[7] J. Castro, Polymers, 2020, 12(1483), 1–13.
[8] A. Korus, Fuel Process. Technol., 2019, 185, 106–116.
[9] A. Zuorro, Processes., 2019, 7(3), 126
Pyrolysis of brewer’s spent grain biomass to form functional adsorbers
No full textPYROLYSIS OF BREWER’S SPENT GRAIN BIOMASS TO FORM FUNCTIONAL ADSORBERS
D. BLEUS 1, B. JOOS 2,3, W. MARCHAL 1, D. VANDAMME 1
1 Analytical and Circular Chemistry (ACC), Institute for Materials Research (IMO), Hasselt University, Hasselt, Belgium.
4 Design and Synthesis of Inorganic Nanomaterials (DESINe), Institute for Materials Research (IMO-IMOMEC), Hasselt University, 3590 Diepenbeek, Belgium
3 EnergyVille, Thor Park, 3600 Genk, Belgium
1. Keywords
Biomass, valorisation, pyrolysis, adsorbers
2. Highlights
- Brewer’s spent grain and malt dust biomass streams were extracted using bio-based solvents to recover (poly-)phenolic compounds.
- The extracted biomass was pyrolyzed using a lab-scale pipe furnace setup.
- The resulting biochar was then physically activated to obtain activated carbon (AC).
- The AC adsorbers will further be employed as adsorber material in solid phase separation/purification of (poly-)phenolic compounds.
3. Purpose
The proposed research abstract elaborates a novel, circular valorization methodology for
brewer spent grain (BSG) through green solvent-extraction and subsequent pyrolysis and
activation of the biomass resource to produce activated carbon (AC) materials. Finally, the
obtained AC will be investigated for use as adsorber for separation and purification of
extraction mixtures.
BSG is a nutrient-rich side product obtained from the beer brewing process. Many types of
BSG have proven to be naturally abundant in phenolic compounds, which could find
application as anti-oxidants 1 in a variety of food, feed, non-food products and
pharmaceuticals. As an industrial side stream that exceeds 3.4 million tons per year in the EU
alone 2 , a viable valorization route would create both economic and ecological opportunity.
Malt dust, on the other hand, is a lesser-known and underexplored waste stream that
encompasses all fine particulate matter separated from the freshly germinated and dried
barley. It is captured before the brewing process, and therefore still retains most naturally
present nutrients and extractable components.
To create a sustainable 3 valorization route for these biomass streams, extractions should be
carried out using bio-based or biocompatible solvents, while also minimizing the required
energetic budget.
Biomass-based adsorbers show well-documented potential in traditional solvent purification
and extractive recuperation procedures. 4- 5 Hence, in this project biomass-based adsorber
materials are put forward as a promising tool in the efficient recuperation of solvent after
the extraction step has been carried out. Extraction or ‘washing’ pretreatment steps have an
impact on the obtained pyrolysis products, and can yield increased surface area
carbonaceous materials. 6,7 It is therefore postulated that an optimized extraction process can
have a synergistic effect in the production of high surface area AC materials. Not only would
the successful implementation of these adsorbers boost the applicability of bio-based
solvents in the industry, but it would also increase the utilization of biomass side streams
that would otherwise be discarded as waste in landfills or incineration plants. 8
4. Materials and methods
BSG and malt dust were obtained from a local brewery. The samples were dried at 60°C and
stored at -20°C until further use. Different bio-based solvent systems are prepared and
evaluated for their efficiency. The mixtures were extracted using maceration at 70°C, 90°C,
and 120°C, respectively. The mixture was then centrifuged at 4000 rpm for 30 minutes,
before being filtered off under vacuum. The filtered extracts were then analysed on HPLC-
MS.
The solid biomass precipitate obtained after centrifugation was collected, excess bio-based
solvent was removed by vacuum filtration, and finally dried in vacuo at 60°C to remove
remaining water. The extracted biomass with residual bio-based solvent was then pyrolyzed
in a tube furnace at 700°C, under N 2 atmosphere. The resulting biochar was collected and
yield was determined gravimetrically, before performing physical activation on part of the
biochar material.
Resulting biochar and AC materials were then analysed using BET (Brunauer–Emmett–Teller)
specific surface area using gas adsorption measurement, scanning electron microscopy for
surface morphology, Ultimate analysis for elemental CHNO-composition, and
thermogravimetric analysis for volatiles and ash content determination.
5. Results and discussion
Preliminary results confirm the findings of earlier studies regarding the extraction efficiency
of bio-based solvents as a valid alternative to optimized extraction methods that utilize
classical solvents, such as acetone:H 2 O mixtures. 9 Using an optimized extraction setup at
elevated temperatures (120°C), extraction efficiencies were improved over classical
maceration methods.
Through the combination of centrifugation and vacuum filtration, (poly-)phenolic extracts
have been separated from the extracted solid biomass residue, obtaining pure liquid extracts
suitable for direct analysis on HPLC-MS. Qualitative identification of various (poly-)phenolic
compounds was performed through an optimized separation method on C18 column, with
acidified H 2 O:MeOH elution gradient.
‘Wet’ biomass was pyrolyzed at 700°C and steam-activated at 800°C in small scale
experiments, obtaining AC materials with promising surface areas, exceeding 500 m 2 /g.
6. Conclusions and perspectives
Promising preliminary results confirm the plausibility of the above-mentioned methodology
for circular valorisation of BSG and malt dust biomass. On one hand, phenolic anti-oxidant
compounds were qualitatively extracted from BSG and malt dust biomass streams, using
green solvents.
The obtained AC materials will be further analysed for chemical and phyiscal functionality,
with additional optimizations of the lab-scale pyrolysis and activation process still to be
performed. Future perspective includes the setup of small-scale preparative phenolic
isolation, and elution tests, which will be performed with the obtained AC adsorbers.
7. References
[1] L. F. Guido, Food Bioprocess Technol., 2017, 10, 1192–1209.
[2] J. Steiner, Eur. Food Res. Technol., 2015, 241, 303–315.
[3] J. C. W. P.T. Anastas, Oxford University Press, 1998.
[4] B. Chen, Environ. Sci. Technol., 2008, 42, 5137–5143.
[5] J. Li, J. Hazard. Mater., 2014, 280, 450–457.
[6] W. Vercruysse, Journal of Analytical and Applied Pyrolysis, 2021, 159, 105294.
[7] J. Castro, Polymers, 2020, 12(1483), 1–13.
[8] A. Korus, Fuel Process. Technol., 2019, 185, 106–116.
[9] A. Zuorro, Processes., 2019, 7(3), 126
Activated carbon adsorbers from NADES-extracted brewer’s spent grain and malt dust biomass
No full textKeywords Biomass; valorisation; pyrolysis; adsorption materials; activated carbon
This investigation elaborates on a sustainable two-step valorization method for obtaining specialty bio-chemicals and activated carbon materials from biomass side products of the beer brewing industry. Two specific biomass streams are investigated: Brewer’s spent grain (BSG), a nutrient- and antioxidant-rich side product obtained after the beer brewing process (3.4 million tons per annum in the EU ), and malt dust (MD), an underexplored biomass stream obtained from the barley malting process. As a two-step valorization route, antioxidant phenolic compounds are first hydrothermally extracted from these biomass streams using non-toxic, bio-based natural deep eutectic solvents (NADES), after which the spent biomass is further pyrolyzed and activated to obtain activated carbon (AC) adsorption materials . These biomass-based AC are proposed as a promising tool for separation of phenolic extracts and NADES solvent recuperation.
Dry biomass was extracted using a hydrothermal extraction method at 120°C. Two choline chloride-based NADES solvents (malic acid:choline chloride, glycerol:choline chloride) were evaluated for their efficiency against a ‘conventional’ acetone-water solvent mixture. Filtered extracts were analysed on HPLC for contents of four major phenolic components (caffeic acid, syringaldehyde, p-coumaric acid and ferulic acid). Next, the spent biomass was pyrolyzed at 700 °C, and physically activated using CO2 at 800 °C. The produced AC were then analysed using nitrogen physisorption experiments to obtain their BET (Brunauer–Emmett–Teller) specific surface area, scanning electron microscopy for surface morphology, ultimate (CHNSO) analysis, and thermogravimetric analysis for volatiles and ash content determination. To test the applicability of AC for separation of solutes from NADES solvents, preliminary batch ad- and desorption tests were performed.
Hydrothermal extractions performed with NADES generally offered favourable results for both biomass streams (22.3 µg/g caffeic acid, 4.7 µg/g syringaldehyde, 91.8 µg/g p-coumaric acid and 272.0 µg/g ferulic acid for BSG, 33.5 µg/g caffeic acid, 6.5 µg/g syringaldehyde, 17.2 µg/g p-coumaric acid and 42.3 µg/g ferulic acid for MD). These results are in line with, or exceed the findings of earlier studies . Results also showed that the hydrothermal process using NADES solvent could serve as a valid alternative to extraction methods with classical solvents. Elemental analysis, ICP-OES and FT-IR analysis showed (slight) alterations in the physico-chemical properties of AC obtained from spent biomass. BET surface areas of the produced AC’s reached up to 1658 m2/g for BSG biomass, and up to 1198 m2/g for malt dust, representing an uptick of 16% and 33% over the untreated biomass AC from each stream, respectively.
In conclusion, through the proposed two-step valorisation method of BSG and MD biomass, phenolic anti-oxidant compounds were successfully extracted from BSG and malt dust biomass streams, using green solvents and a novel hydrothermal extraction method. Secondly, the obtained AC’s from spent biomass were characterized with excellent surface areas that exceeded those of untreated biomass. Physisorption tests will be performed to indicate the ad- and desorption capacity of the produced AC.
L. F. Guido. et al. Techniques for Extraction of Brewer’s Spent Grain Polyphenols: a Review. Food and Bioprocess Technology, 10(7), 1192–1209 (2017).
J. Steiner. et al. Brewer’s spent grain: source of value-added polysaccharides for the food industry in reference to the health claims. European Food Research and Technology. 241(3), 303–315 (2015).
J. Li. et al. A comparison of biochars from lignin, cellulose and wood as the sorbent to an aromatic pollutant. Journal of Hazardous Materials. 280, 450–457 (2014).
Y. Cai. et al. Adsorption and Desorption Performance and Mechanism of Tetracycline Hydrochloride by Activated Carbon-Based Adsorbents Derived from Sugar. Molecules. 24 (2019).
K. Dubey. et al. Adsorption-Desorption Process Using Wood-Based Activated Carbon for Recovery of Biosurfactant from Fermented Distillery Wastewater. Biotechnological progress. 21, 860−867 (2008).
A. Zuorro. et al. Water-organic solvent extraction of phenolic antioxidants from brewers’ spent grain. Processes. 7(3), 126 (2019).
McCarthy, A. L. et al. The hydroxycinnamic acid content of barley and brewers’ spent grain (BSG) and the potential to incorporate phenolic extracts of BSG as antioxidants into fruit beverages. Food Chemistry. 141(3), 2567–2574 (2013)
Activated carbon adsorbers from NADES-extracted brewer’s spent grain and malt dust biomass
No full textKeywords Biomass; valorisation; pyrolysis; adsorption materials; activated carbon
This investigation elaborates on a sustainable two-step valorization method for obtaining specialty bio-chemicals and activated carbon materials from biomass side products of the beer brewing industry. Two specific biomass streams are investigated: Brewer’s spent grain (BSG), a nutrient- and antioxidant-rich side product obtained after the beer brewing process (3.4 million tons per annum in the EU ), and malt dust (MD), an underexplored biomass stream obtained from the barley malting process. As a two-step valorization route, antioxidant phenolic compounds are first hydrothermally extracted from these biomass streams using non-toxic, bio-based natural deep eutectic solvents (NADES), after which the spent biomass is further pyrolyzed and activated to obtain activated carbon (AC) adsorption materials . These biomass-based AC are proposed as a promising tool for separation of phenolic extracts and NADES solvent recuperation.
Dry biomass was extracted using a hydrothermal extraction method at 120°C. Two choline chloride-based NADES solvents (malic acid:choline chloride, glycerol:choline chloride) were evaluated for their efficiency against a ‘conventional’ acetone-water solvent mixture. Filtered extracts were analysed on HPLC for contents of four major phenolic components (caffeic acid, syringaldehyde, p-coumaric acid and ferulic acid). Next, the spent biomass was pyrolyzed at 700 °C, and physically activated using CO2 at 800 °C. The produced AC were then analysed using nitrogen physisorption experiments to obtain their BET (Brunauer–Emmett–Teller) specific surface area, scanning electron microscopy for surface morphology, ultimate (CHNSO) analysis, and thermogravimetric analysis for volatiles and ash content determination. To test the applicability of AC for separation of solutes from NADES solvents, preliminary batch ad- and desorption tests were performed.
Hydrothermal extractions performed with NADES generally offered favourable results for both biomass streams (22.3 µg/g caffeic acid, 4.7 µg/g syringaldehyde, 91.8 µg/g p-coumaric acid and 272.0 µg/g ferulic acid for BSG, 33.5 µg/g caffeic acid, 6.5 µg/g syringaldehyde, 17.2 µg/g p-coumaric acid and 42.3 µg/g ferulic acid for MD). These results are in line with, or exceed the findings of earlier studies . Results also showed that the hydrothermal process using NADES solvent could serve as a valid alternative to extraction methods with classical solvents. Elemental analysis, ICP-OES and FT-IR analysis showed (slight) alterations in the physico-chemical properties of AC obtained from spent biomass. BET surface areas of the produced AC’s reached up to 1658 m2/g for BSG biomass, and up to 1198 m2/g for malt dust, representing an uptick of 16% and 33% over the untreated biomass AC from each stream, respectively.
In conclusion, through the proposed two-step valorisation method of BSG and MD biomass, phenolic anti-oxidant compounds were successfully extracted from BSG and malt dust biomass streams, using green solvents and a novel hydrothermal extraction method. Secondly, the obtained AC’s from spent biomass were characterized with excellent surface areas that exceeded those of untreated biomass. Physisorption tests will be performed to indicate the ad- and desorption capacity of the produced AC.
L. F. Guido. et al. Techniques for Extraction of Brewer’s Spent Grain Polyphenols: a Review. Food and Bioprocess Technology, 10(7), 1192–1209 (2017).
J. Steiner. et al. Brewer’s spent grain: source of value-added polysaccharides for the food industry in reference to the health claims. European Food Research and Technology. 241(3), 303–315 (2015).
J. Li. et al. A comparison of biochars from lignin, cellulose and wood as the sorbent to an aromatic pollutant. Journal of Hazardous Materials. 280, 450–457 (2014).
Y. Cai. et al. Adsorption and Desorption Performance and Mechanism of Tetracycline Hydrochloride by Activated Carbon-Based Adsorbents Derived from Sugar. Molecules. 24 (2019).
K. Dubey. et al. Adsorption-Desorption Process Using Wood-Based Activated Carbon for Recovery of Biosurfactant from Fermented Distillery Wastewater. Biotechnological progress. 21, 860−867 (2008).
A. Zuorro. et al. Water-organic solvent extraction of phenolic antioxidants from brewers’ spent grain. Processes. 7(3), 126 (2019).
McCarthy, A. L. et al. The hydroxycinnamic acid content of barley and brewers’ spent grain (BSG) and the potential to incorporate phenolic extracts of BSG as antioxidants into fruit beverages. Food Chemistry. 141(3), 2567–2574 (2013)
Demineralization of common ivy-derived biomass and biochar and its effect on the resulting activated carbon properties
No full textConventional activated carbon (AC) production relies heavily on unsustainable feedstocks (coal or wood from deforestation), which incites the need for alternative biomass-based resources to create sustainable biobased products. However, biomass residue streams generally contain large amounts of impurities (heavy metals, alkali minerals) which limit their industrial applicability. Conventionally occurring problems entail fouling and corrosion of industrial equipment or reductions in the efficiency of the manufactured products, e.g., decreased adsorption capacities of the resulting AC’s. Therefore, novel green demineralization techniques should be studied.
Natural deep eutectic solvents (NADES) are promising green demineralization solvents. Currently, most NADES research focuses on applying these solvents to fractionate (lignocellulosic) biomass, extract valuable bioactive compounds, or replace non-natural deep eutectic solvents in chemical synthesis. A novel lignocellulosic biomass feedstock is common ivy (CI), Hedera helix L. However, its high mineral content, derived from the adsorption of atmospheric fine particulate matter during its growth, limits its applicability in future bio-refinery processes. Therefore, this biomass stream is a prime subject to be examined in a comparative evaluation of the promising green NADES demineralization treatment in lieu of conventional environmentally unfriendly acid treatments.
The investigated NADES was choline chloride-malic acid (CCl:MA). Its demineralization efficiency was compared with conventional demineralization agents: H2O and dilute hydrochloric acid (HCl). Moreover, the preferred washing sequence (before or after pyrolysis) for AC-production was investigated. Demineralization before pyrolysis removed a large fraction of the biomass’s minerals for each of the washing agents: HCl (97.1% removal), CCl:MA (84.7%), and H2O (75.2%). The main difference was attributed to the removal of different Ca-containing species. Demineralization after pyrolysis created highly microporous AC’s. In this case, the solvent performance was ranked: HCl = CCl:MA > H2O. Lastly, the AC’s phosphate removal efficiency showed that biomass washing with either H2O or CCl:MA yields functional AC’s (phosphate adsorption capacities 19.3 and 16.5 mg/g). Ultimately, this investigation demonstrated CCl:MA’s potential as demineralization agent to treat metal-contaminated lignocellulosic biomass in future bio-refinery processes.Research Foundation Flanders: FWO – SB-1S92022N, Travel grant: K179823N
Demineralization of common ivy-derived biomass and biochar and its effect on the resulting activated carbon properties
No full textConventional activated carbon (AC) production relies heavily on unsustainable feedstocks (coal or wood from deforestation), which incites the need for alternative biomass-based resources to create sustainable biobased products. However, biomass residue streams generally contain large amounts of impurities (heavy metals, alkali minerals) which limit their industrial applicability. Conventionally occurring problems entail fouling and corrosion of industrial equipment or reductions in the efficiency of the manufactured products, e.g., decreased adsorption capacities of the resulting AC’s. Therefore, novel green demineralization techniques should be studied.
Natural deep eutectic solvents (NADES) are promising green demineralization solvents. Currently, most NADES research focuses on applying these solvents to fractionate (lignocellulosic) biomass, extract valuable bioactive compounds, or replace non-natural deep eutectic solvents in chemical synthesis. A novel lignocellulosic biomass feedstock is common ivy (CI), Hedera helix L. However, its high mineral content, derived from the adsorption of atmospheric fine particulate matter during its growth, limits its applicability in future bio-refinery processes. Therefore, this biomass stream is a prime subject to be examined in a comparative evaluation of the promising green NADES demineralization treatment in lieu of conventional environmentally unfriendly acid treatments.
The investigated NADES was choline chloride-malic acid (CCl:MA). Its demineralization efficiency was compared with conventional demineralization agents: H2O and dilute hydrochloric acid (HCl). Moreover, the preferred washing sequence (before or after pyrolysis) for AC-production was investigated. Demineralization before pyrolysis removed a large fraction of the biomass’s minerals for each of the washing agents: HCl (97.1% removal), CCl:MA (84.7%), and H2O (75.2%). The main difference was attributed to the removal of different Ca-containing species. Demineralization after pyrolysis created highly microporous AC’s. In this case, the solvent performance was ranked: HCl = CCl:MA > H2O. Lastly, the AC’s phosphate removal efficiency showed that biomass washing with either H2O or CCl:MA yields functional AC’s (phosphate adsorption capacities 19.3 and 16.5 mg/g). Ultimately, this investigation demonstrated CCl:MA’s potential as demineralization agent to treat metal-contaminated lignocellulosic biomass in future bio-refinery processes.Research Foundation Flanders: FWO – SB-1S92022N, Travel grant: K179823N
High-Temperature Hydrothermal Extraction of Phenolic Compounds from Brewer’s Spent Grain and Malt Dust Biomass Using Natural Deep Eutectic Solvents
No full textAligned with the EU Sustainable Development Goals 2030 (EU SDG2030), extensive research is dedicated to enhancing the sustainable use of biomass waste for the extraction of pharmaceutical and nutritional compounds, such as (poly-)phenolic compounds (PC). This study proposes an innovative one-step hydrothermal extraction (HTE) at a high temperature (120 °C), utilizing environmentally friendly acidic natural deep eutectic solvents (NADESs) to replace conventional harmful pre-treatment chemicals and organic solvents. Brewer’s spent grain (BSG) and novel malt dust (MD) biomass sources, both obtained from beer production, were characterized and studied for their potential as PC sources. HTE, paired with mild acidic malic acid/choline chloride (MA) NADES, was compared against conventional (heated and stirred maceration) and modern (microwave-assisted extraction; MAE) state-of-the-art extraction methods. The quantification of key PC in BSG and MD using liquid chromatography (HPLC) indicated that the combination of elevated temperatures and acidic NADES could provide significant improvements in PC extraction yields ranging from 251% (MD-MAC-MA: 29.3 µg/g; MD-HTE-MA: 103 µg/g) to 381% (BSG-MAC-MA: 78 µg/g; BSG-HTE-MA: 375 µg/g). The superior extraction capacity of MA NADES over non-acidic NADES (glycerol/choline chloride) and a traditional organic solvent mixture (acetone/H2O) could be attributed to in situ acid-catalysed pre-treatment facilitating the release of bound PC from lignin–hemicellulose structures. Qualitative 13C-NMR and pyro-GC-MS analysis was used to verify lignin–hemicellulose breakdown during extraction and the impact of high-temperature MA NADES extraction on the lignin–hemicellulose structure. This in situ acid NADES-catalysed high-temperature pre-treatment during PC extraction offers a potential green pre-treatment for use in cascade valorisation strategies (e.g., lignin valorisation), enabling more intensive usage of available biomass waste stream resources.Funding:
This work was funded by BOF UHasselt (BOF20OWB02). Financial support was also provided by Hasselt University and the Research Foundation Flanders (FWO Vlaanderen) via the Hercules project (AUHL/15/2-GOH3816N).
Acknowledgments:
The authors would like to acknowledge Alken-Maes NV for providing the brewer’s spent grain and malt dust samples utilised in this project. The authors would like to acknowledge Jenny Put for support with HPLC-MS analysis and Bernard Noppen for performing py-GC-MS analysi
Demineralization of common ivy-derived biomass and biochar and its effect on the resulting activated carbon properties
No full textThis work was financially supported by Research Foundation Flanders (FWO-SB-1S92022N) . We want to acknowledge Greet Cuyvers and Elsy Thijssen for their support and execution of the ICP-AES analysis
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
