| 1. |
- Baena-Moreno, Francisco, 1992, et al.
(författare)
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Effluents and residues from industrial sites for carbon dioxide capture: a review
- 2023
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Ingår i: Environmental Chemistry Letters. - : Springer Science and Business Media LLC. - 1610-3653 .- 1610-3661. ; 21:1, s. 319-337
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Forskningsöversikt (refereegranskat)abstract
- The adverse effects of climate change calls for the rapid transformation of manufacturing processes to decrease the emissions of carbon dioxide. In particular, a lower carbon footprint can be achieved by capturing carbon dioxide at the site of emission. Here we review the use of industrial effluents, waste and residues to capture carbon dioxide. Waste include steelmaking slag, municipal solid waste incinerator ashes, combustion fly ash, black liquor, paper mill waste, mining waste, cement waste, construction and demolition waste, waste from the organic industry, and flue gas desulfurization gypsum waste. Capture capacities range from 2 to 800 kg of carbon dioxide per ton of waste, depending on processes, waste type and conditions. Cement waste and flue gas desulfurization gypsum waste show the highest capture capacity per ton of waste.
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| 2. |
- Leventaki, Emmanouela, 1996, et al.
(författare)
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Experimental evaluation of black liquor carbonation for carbon dioxide capture
- 2023
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Ingår i: Journal of CO2 Utilization. - 2212-9820. ; 72
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Tidskriftsartikel (refereegranskat)abstract
- Carbon dioxide is one of the main if not the most potent greenhouse gases responsible for climate change. Scientists put great efforts to tackle this problem and carbon dioxide capture seems to be a promising solution. The present study proposes a novel method of carbon dioxide capture using black liquor, a side stream from the paper and pulp industry. Its content in sodium hydroxide makes it an attractive candidate for carbon dioxide capture via carbonation. The black liquor was prepared from oat husks, a non-woody biomass, using the soda-pulping process. To estimate its carbon dioxide absorption capacity, a mixture of nitrogen and carbon dioxide (70:30%) was sparged into a bubble column reactor and computational fluid dynamics simulations of this setup were used to evaluate the mixing process. The formation of carbonate and bicarbonate ions throughout the carbonation process was followed using a Fourier-Transform Infrared (FTIR) probe and a pH meter. The absorption capacity was measured from the weight increase of the reactor. It was found to be around 30 g of carbon dioxide/L of black liquor. The carbonate and bicarbonate species in black liquor before and after carbonation were further characterized with 13C Nuclear Magnetic Resonance (NMR), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and optical microscopy. Using industrial side-streams might enable an economically feasible process without the need for production of virgin absorbents or their recovery. Furthermore, this capturing process, which is performed at atmospheric conditions might reduce the overall energy consumption. The results demonstrated that black liquor could be an attractive absorbent for carbon dioxide, paving the way for a circular and resource-efficient economy.
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| 3. |
- Mucha, Joanna, et al.
(författare)
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Fine root classification matters : nutrient levels in different functional categories, orders and diameters of roots in boreal Pinus sylvestris across a latitudinal gradient
- 2020
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Ingår i: Plant and Soil. - : Springer Science and Business Media LLC. - 0032-079X .- 1573-5036. ; 447:1-2, s. 507-520
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Tidskriftsartikel (refereegranskat)abstract
- Background: Fine roots and their symbionts are the key drivers of processes such as nutrient cycling and belowground productivity. Their function depends on position in a branching hierarchy, with absorptive roots (responsible for resource acquisition), and transport roots. Aim: We examined how the different diameter cutoffs for root classification mirror concentrations of 11 different nutrients, plus Al in functionally different fine roots of Pinus sylvestris based on anatomical/ functional categorization and in relation to their biomass along a latitudinal gradient. Results: The C:N:P ratios for pooled roots ≤2 mm in diameter reflected the nutrient concentrations of transport roots. In contrast, the C:N:P ratios for all absorptive roots was best reflected by nutrient ratios in the 1st root order, and not by those in root <2 mm. These patterns were more clear along decreasing mean annual temperature, despite increasing contribution of absorptive roots in the fine root biomass. Higher biomass fraction of transport roots did not always mirror higher concentration of element accumulated. Narrowing the root diameter cutoffs to 0.5 mm provided more informative data about nutrient concentrations in the absorptive root pool than <2 mm cut-off. Conclusions: By analyzing nutrient concentration using ≤2 mm cut-off it is impossible to properly understand nutritional properties of roots with different functional attributes. Given that the diameter of fine root orders vary considerably even within a single species between stands, the diameter cutoffs for absorptive roots should be based on the characteristics of the studied species, and not on a fixed, universal diameter cutoff.
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| 4. |
- Oleksyn, Jacek, et al.
(författare)
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A fingerprint of climate change across pine forests of Sweden
- 2020
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 23:12, s. 1739-1746
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Tidskriftsartikel (refereegranskat)abstract
- Climate change has likely altered high-latitude forests globally, but direct evidence remains rare. Here we show that throughout a ≈1000-km transect in Scots pine (Pinus sylvestris L.) forests in Sweden, mature trees in ≈2015 had longer needles with shorter lifetimes than did trees in ≈1915. These century-scale shifts in needle traits were detected by sampling needles at 74 sites from 2012 to 2017 along the same transect where needle traits had been assessed at 57 sites in 1914–1915. Climate warming of ≈1 °C all along the transect in the past century has driven this temporal shift in foliage traits known to be physiologically critical to growth and carbon cycling processes. These century-scale changes in Scandinavian Scots pine forests represent a fingerprint of climate change on a fundamental biological element, the leaf, with repercussions for productivity and sensitivity to future climate, which are likely to be mirrored by similar changes for evergreen conifers across the boreal biome.
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| 5. |
- Salam, Muhammad Abdus, 1983, et al.
(författare)
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One-pot reductive liquefaction of sawdust to renewables over MoO x -Al 2 O 3 variants: insight into structure-activity relationships
- 2024
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Ingår i: Sustainable Energy and Fuels. - 2398-4902. ; 8:12, s. 2668-2681
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Tidskriftsartikel (refereegranskat)abstract
- Valorization of forest residual products can offer a vital pathway to derive bio-based chemicals and fuel components. Herein, we report the effective and direct conversion of sawdust biomass over a supported Mo-oxide catalyst that results in a dominant fraction of aliphatic/cyclic alkanes and alkylbenzenes with low residual solids. The reductive liquefaction was conducted in an autoclave reactor using a series of MoOx-Al2O3 variants in the range of 340-400 °C with an initial H2 pressure of 35 bar for 4 h. At 340 °C, a correlation between Mo-loadings and reactivity for depolymerization and hydrodeoxygenation was found optimal for a surface density of 3.2 Mo-atoms per nm2 corresponding to 8 wt% Mo-loading. The liquefied fraction showed high selectivity (∼38%) for the formation of cycloalkanes and alkylbenzenes. At higher temperatures (400 °C) enhanced reactivity over the optimal catalyst showed higher cycloalkane and alkylbenzenes formation (∼57%) at a low biomass-to-catalyst feed mass ratio (3 : 1). At a higher ratio (10 : 1), alkylphenols (∼41%) are the leading product fraction followed by cycloalkanes and alkylbenzenes (∼34%) with a high liquefied monomer bio-oil product yield of 39.4 wt%. Catalyst characterization via XRD, Raman, H2-TPR, and XPS analysis revealed that the origin for this reactivity arises from the Mo species formed and stabilized over the support surface. A well dispersed, octahedral, higher fraction of easily reducible Mo-species (Mo5+) was evident over the optimal catalyst which enables enhanced C-O cleavage facilitating the hydrodeoxygenation reaction. Moreover, the solid residue yield could be reduced to below 5 wt% by optimizing the reaction conditions and particle size of the sawdust.
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| 6. |
- Wojtasz-Mucha, Joanna, et al.
(författare)
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Dissolution of wood components during hot water extraction of birch
- 2021
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Ingår i: Wood Science and Technology. - : Springer Science and Business Media Deutschland GmbH. - 0043-7719 .- 1432-5225. ; 55:3, s. 811-835
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Tidskriftsartikel (refereegranskat)abstract
- Autohydrolysis-based pretreatments enable extraction of hemicellulose from wood tissue prior to the paper pulp cooking processes enabling their further use as platform chemicals and in material applications. In this study, hot water extraction of birch meal was conducted in a small flow-through system. The combination of high surface area of the milled material with increased driving force induced by constant flow of freshwater, together with fast evacuation of extract, enabled a detailed study of the dissolution process. Based on the findings, deeper insight into acidification and autohydrolysis progress was obtained.
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| 7. |
- Wojtasz-Mucha, Joanna, 1989, et al.
(författare)
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Dissolution of wood components during hot water extraction of spruce
- 2023
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Ingår i: Tappi Journal. - 0734-1415. ; 22:5, s. 329-343
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this study was to investigate the autohydrolysis of softwood, which is the main chemical operation in both hot water extraction and steam explosion. Control of the process and monitoring its course were ensured by the careful choice of experimental setup and conditions: a milled spruce material was extracted in a small flow-through reactor to minimize degradation of the dissolved material and to enable analysis of the resulting liquors extracted at selected time points. The obtained liquid and solid fractions were analyzed for sugar composition and acetic acid concentration. The results showed that partially degraded hemicelluloses were extracted; hemicelluloses side chains were cleaved off and detected as monomers, while deacetylation was limited. Chain scissions of cellulose were observed as a result of autohydrolysis.
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| 8. |
- Wojtasz-Mucha, Joanna, 1989, et al.
(författare)
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Dissolution of wood components during hot water extraction of spruce
- 2023
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Ingår i: Tappi Journal. - 0734-1415. ; 22:5, s. 329-343
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to investigate the autohydrolysis of softwood, which is the main chemical operation in both hot water extraction and steam explosion. Control of the process and monitoring its course were ensured by the careful choice of experimental setup and conditions: a milled spruce material was extracted in a small flow-through reactor to minimize degradation of the dissolved material and to enable analysis of the resulting liquors extracted at selected time points. The obtained liquid and solid fractions were analyzed for sugar composition and acetic acid concentration. The results showed that partially degraded hemicelluloses were extracted; hemicelluloses side chains were cleaved off and detected as monomers, while deacetylation was limited. Chain scissions of cellulose were observed as a result of autohydrolysis.
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| 9. |
- Wojtasz-Mucha, Joanna, 1989, et al.
(författare)
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Hydrothermal pretreatment of wood by mild steam explosion and hot water extraction
- 2017
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Ingår i: Bioresource Technology. - : Elsevier. - 0960-8524 .- 1873-2976. ; 241, s. 120-126
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this work was to compare the two most common hydrothermal pre-treatments for wood – mild steam explosion and hot water extraction – both with the prospect of enabling extraction of hemicelluloses and facilitating further processing. Although both involve autohydrolysis of the lignocellulosic tissue, they are performed under different conditions: the most prominent difference is the rapid, disintegrating, discharge employed in the steam explosion opening up the structure. In this comparative study, the emphasis was placed on local composition of the pre-treated wood chips (of industrially relevant size). The results show that short hot water extraction treatments lead to significant variations in the local composition within the wood chips, while steam explosion accomplishes a comparably more even removal of hemicelluloses due to the advective mass transport during the explosion step.
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| 10. |
- Wojtasz-Mucha, Joanna, 1989
(författare)
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Mild Steam Explosion of Wood and Forest Residues in the Perspective of a Materials Biorefinery
- 2019
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main objective of this work was to explore the prospects of using mild steam explosion as a pretreatment step in a forest based material biorefinery. During the steam explosion saturated steam is applied to the biomass at elevated pressure leading to an autohydrolysis of the lignocellulosic tissue, which is followed by a rapid pressure discharge, disintegrating and opening up the structure. As a consequence, the pretreatment enables the extraction of the most sensitive hemicelluloses and facilitates further processing, e.g. enzymatic treatment and chemical pulping. To investigate the effects rendered by the pretreatment, it was performed on two different types of forest biomass: Norway spruce wood chips and forest residues of mixed origin. The focus was on investigating the effects on the chemical structure of the material. In order to gain improved understanding of the fundamental mechanisms behind the pretreatment, the local effects on the composition of the wood tissue pretreated using steam explosion were investigated and compared with those accomplished by hot water extraction. Furthermore, cooking experiments were performed on pretreated forest residues to evaluate how the changes rendered by the pretreatment affect further processing of the material. The effects of the steam explosion were evaluated in terms of compositional analysis, molecular weight distribution and structural changes of extracted material (lignin and hemicelluloses). The results show that, due to the advective mass transport during the explosion step, steam explosion accomplishes a more even removal of hemicelluloses from the pretreated wood chips compared to the hot water extraction. Moreover, the impact of the steam explosion was found to be limited when material of a smaller size, namely refined forest residues, was pretreated.
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