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Pedram Fatehi - One of the best experts on this subject based on the ideXlab platform.
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flocculation of thermomechanical pulping Spent Liquor with polydiallyldimethylammonium chloride
Journal of Environmental Management, 2017Co-Authors: Pedram FatehiAbstract:Abstract Currently, the dissolved lignocelluloses in the Spent Liquor (SL) of a thermomechanical pulping process are treated in wastewater treatment systems and thus they are wasted. In this work, polydiallyldimethylammonium chloride (PDADMAC), with different molecular weights, was used for flocculating lignocelluloses of SL and thus isolating them from SL. Results showed that the maximum removals were 38% via treating SL with 100 mg/L of PDADMAC (with 1045 kg/mol molecular weight) at 25 °C for 30 min. The focused beam reflectance measurement of the flocculation process revealed that the chord length of the flocs with the maximum square weighted counts was increased from 70 to 100 μm and also their maximum square weighted counts was increased from 5 to 25 μm 2 /s. The flocs contained 60.71–74.41 wt% PDADMAC, the balance of lignocelluloses and the heating value of 24–25 MJ/kg. The high molecular PDADMAC generated flocs with more organics and a higher heating value.
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Thermal properties of lignocellulosic precipitates from neutral sulfite semichemical pulping process
Fuel Processing Technology, 2017Co-Authors: Dmitry Tarasov, Mathew Leitch, Pedram FatehiAbstract:Abstract In a neutral sulfite semichemical (NSSC) pulping process, wood chips are pretreated with sodium sulfite and sodium carbonate solution. This pretreatment dissolves a part of hemicellulose and lignin from wood chips. The Spent Liquor (SL) that is produced in the pretreatment process contains a considerable amount of lignosulfonate and hemicelluloses, but SL is generally treated in the wastewater effluent system of the mills (i.e. lignocelluloses are wasted). In this paper, these lignocelluloses were separated from SL with organic solvents, and their thermal properties were determined. The results showed that the precipitates isolated from SL/acetone, SL/ethanol or SL/isopropyl mixtures with the weight ratio of 67/33 had the highest heating values of 18.61, 17.59 and 17.05 MJ/kg, respectively. The precipitates made from mixing acidified SL and solvents had lower heating values than those made from mixing untreated SL and solvents, which is likely due to the relatively high ash content of the precipitates made from mixing acidified SL and solvent. The theoretical and experimental heating values of precipitates were compared in this work. The precipitates displayed lower ignition temperatures compared with other biomass-based solid fuels, implying that the combustion of precipitates would require lower activation energies.
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acidification of prehydrolysis Liquor and Spent Liquor of neutral sulfite semichemical pulping process
Bioresource Technology, 2016Co-Authors: Pedram Fatehi, Mehdi DashtbanAbstract:Abstract Acidification has been commercialized for producing kraft lignin from black Liquor of kraft pulping process. This work intended to evaluate the effectiveness of acidification in extracting lignocelluloses from the Spent Liquor of neutral sulfite semichemical pulping (NSSC) process and from prehydrolysis Liquor (PHL) of kraft-based dissolving pulp production process. The results showed that the NSSC and PHL Spent Liquors had some lignin-carbohydrate complexes (LCC), and that the square weighted counts of particles with a chord length of 50–150 μm in the Spent Liquors were significantly increased as pH dropped to 1.5. Interestingly, the acidification reduced the lignosulfonate/lignin content of NSSC and PHL by 13% or 20%, while dropped their oligosugars content by 75% and 38%, respectively. On a dry basis, the precipitates had more carbon, hydrogen and a high heating value of 18–22 MJ/kg, but less oxygen, than Spent Liquors. The precipitates of PHL could be used as fuel.
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separation of lignosulfonate from Spent Liquor of neutral sulphite semichemical pulping process via surfactant treatment
Separation and Purification Technology, 2015Co-Authors: Germaine Cave, Pedram FatehiAbstract:Abstract The Spent Liquor, SL, of neutral sulphite semi chemical pulping process contains lignosulfonate and hemicelluloses, but it is currently treated in the wastewater treatment of the process. This treatment decomposes the lignosulfonate. However, lignosulfonate can be extracted for a better use, but the extraction process is not an easy task. The main objective of this work was to extract lignosulfonate from SL via treating the SL with surfactant. The results showed that the acidification of SL to pH 1.8 caused 6% lignosulfonate, 53% hemicelluloses, and 7% COD removals from SL. Acidification followed by dodecyltrimethylammonium chloride, DTAC, treatment of SL at the optimal conditions of 22 °C, 1.8 pH and 10 mg/g of DTAC/SL yielded 40% lignosulfonate, 78% hemicelluloses, and 25% COD removals. Model solutions were prepared via dissolving commercial lignosulfonate and xylan in solutions or purifying SL via membrane dialysis in order to investigate the impact of SL components, i.e. hemicelluloses and residual cooking chemicals, on the isolation of lignosulfonate from SL. The model analyses confirmed that the presence of impurities, i.e. residual cooking salts, significantly affected the isolation of lignosulfonate from the SL, but the presence of hemicellulose had a minor effect in extracting lignosulfonate from SL via DTAC treatment. In addition, the elemental analysis confirmed that DTAC and lignosulfonate had a ratio of 0.584 mol/mol in precipitates.
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process for treating Spent Liquor of the tmp process with biomass based fly ash
Industrial & Engineering Chemistry Research, 2015Co-Authors: Farshad Oveissi, Pedram FatehiAbstract:The Spent Liquor (SL) of the thermomechanical pulping (TMP) process has a high effluent load. In this work, biomass-based fly ash was used for adsorbing lignin of SL and thus for reducing the COD and turbidity of SL prior to sending SL to a wastewater treatment system. By treating SL with fly ash in a one-stage adsorption process under the conditions of a fly ash/SL ratio of 55 mg/g and 3 h at 30 °C, 67 mg/g of lignin was adsorbed on fly ash at room temperature. Adjusting the pH of SL had an insignificant influence on the lignin isolation from the system but affected the turbidity of SL. The lignin removal was 68% in a two-stage fly ash adsorption process, while the COD and turbidity removal were 70% and 94%, respectively. On the basis of the results, a process for reducing the effluent load of SL using fly ash was proposed.
Mehdi Dashtban - One of the best experts on this subject based on the ideXlab platform.
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acidification of prehydrolysis Liquor and Spent Liquor of neutral sulfite semichemical pulping process
Bioresource Technology, 2016Co-Authors: Pedram Fatehi, Mehdi DashtbanAbstract:Abstract Acidification has been commercialized for producing kraft lignin from black Liquor of kraft pulping process. This work intended to evaluate the effectiveness of acidification in extracting lignocelluloses from the Spent Liquor of neutral sulfite semichemical pulping (NSSC) process and from prehydrolysis Liquor (PHL) of kraft-based dissolving pulp production process. The results showed that the NSSC and PHL Spent Liquors had some lignin-carbohydrate complexes (LCC), and that the square weighted counts of particles with a chord length of 50–150 μm in the Spent Liquors were significantly increased as pH dropped to 1.5. Interestingly, the acidification reduced the lignosulfonate/lignin content of NSSC and PHL by 13% or 20%, while dropped their oligosugars content by 75% and 38%, respectively. On a dry basis, the precipitates had more carbon, hydrogen and a high heating value of 18–22 MJ/kg, but less oxygen, than Spent Liquors. The precipitates of PHL could be used as fuel.
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a combined adsorption and flocculation process for producing lignocellulosic complexes from Spent Liquors of neutral sulfite semichemical pulping process
Bioresource Technology, 2014Co-Authors: Mehdi Dashtban, Allan Gilbert, Pedram FatehiAbstract:Abstract The Spent Liquor (SL) of a neutral sulfite semichemical pulping process contains lignocelluloses that are currently treated in a waste water system. In this work, an adsorption process using activated carbon (AC) was considered for isolating the lignin and hemicelluloses from SL. The maximum adsorptions of 0.9 g/g lignin and 0.43 g/g of hemicelluloses on AC were achieved under the conditions of 30 °C, pH 7 and 3 h with SL/AC weight ratio of 90. The addition of polydiallyldimethylammonium chloride (PDADMAC) to the SL/AC system significantly improved the adsorption of lignin to 2.5 g/g on AC. The molecular weight of PDADMAC considerably affected the results in that the higher MW PDADMAC led to less lignin, but more hemicelluloses, turbidity and chemical oxygen demand removals from the SL. The thermal analysis also revealed that the higher MW PDADMAC generated precipitates with a lower incineration temperature and heating value.
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separation of lignocelluloses from Spent Liquor of nssc pulping process via adsorption
Journal of Environmental Management, 2014Co-Authors: Mehdi Dashtban, Allan Gilbert, Pedram FatehiAbstract:Abstract Hemicelluloses and lignin present in the Spent Liquor (SL) of neutral sulfite semichemical (NSSC) pulping process can potentially be converted into value-added products such as furfural, hydroxymethylfurfural, levulinic acid, phenols and adhesives. However, the direct conversion of hemicelluloses and lignin of SL into value-added products is uneconomical due to the dilute nature of the SL. To have a feasible downstream process for utilizing lignocelluloses of SL, the lignocelluloses should initially be separated from the SL. In this study, an adsorption process (via applying activated carbon) was considered for isolating the dissolved lignin and hemicelluloses from the SL of an NSSC pulping process. Under the optimal conditions of pH, SL/AC weight ratio, time and temperature of 5.7, 30, 360 min and 30 °C, the maximum lignin and hemicellulose adsorptions were 0.33 and 0.25 g/g on AC. The chemical oxygen demand (COD) and turbidity of the SL were decreased by 11% and 39%, respectively, as a result of lignocellulose adsorption on AC. Also, the incineration behavior of the SL-treated AC was studied with a thermo-gravimetric analysis (TGA).
Haisong Wang - One of the best experts on this subject based on the ideXlab platform.
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tough and multi responsive hydrogel based on the hemicellulose from the Spent Liquor of viscose process
International Journal of Biological Macromolecules, 2016Co-Authors: Yuedong Zhang, Haisong WangAbstract:The hemicellulose isolated from the Spent Liquor of a viscose process was successfully utilized to prepare hydrogels by the graft copolymerization of acrylic acid (AA) with hemicellulose. The hemicellulose and prepared hydrogel were characterized by Fourier-transform infrared (FT-IR), scanning electron microscopy (SEM), and solid-state nuclear magnetic resonance ((13)C NMR). Under the optimum preparation conditions, the highest compressive strength and strain at break of the resultant hydrogel were 105.1±12.9kPa and 34.8%, respectively. Furthermore, the maximum equilibrium swelling degree of prepared hydrogel was 192. Also, the hydrogel could rapidly respond to pH, salt and ethanol. Taken together, the prepared hydrogels had great mechanical and multi-responsive properties. Thus, the prepared hydrogels had a great potential application in drug release, water treatment and cell immobilization. In addition, the utilization of alkaline extracted hemicellulose from the viscose fiber factory has huge market potential and economic benefits.
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tough and multi responsive hydrogel based on the hemicellulose from the Spent Liquor of viscose process
International Journal of Biological Macromolecules, 2016Co-Authors: Jian Du, Guang Yu, Yuedong Zhang, Bin Li, Haisong Wang, Chao Li, Xindong MuAbstract:Abstract The hemicellulose isolated from the Spent Liquor of a viscose process was successfully utilized to prepare hydrogels by the graft copolymerization of acrylic acid (AA) with hemicellulose. The hemicellulose and prepared hydrogel were characterized by Fourier-transform infrared (FT-IR), scanning electron microscopy (SEM), and solid-state nuclear magnetic resonance ( 13 C NMR). Under the optimum preparation conditions, the highest compressive strength and strain at break of the resultant hydrogel were 105.1 ± 12.9 kPa and 34.8%, respectively. Furthermore, the maximum equilibrium swelling degree of prepared hydrogel was 192. Also, the hydrogel could rapidly respond to pH, salt and ethanol. Taken together, the prepared hydrogels had great mechanical and multi-responsive properties. Thus, the prepared hydrogels had a great potential application in drug release, water treatment and cell immobilization. In addition, the utilization of alkaline extracted hemicellulose from the viscose fiber factory has huge market potential and economic benefits.
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effect and characterization of sodium lignosulfonate on alkali pretreatment for enhancing enzymatic saccharification of corn stover
Industrial Crops and Products, 2015Co-Authors: Guang Yu, Bin Li, Huanfei Xu, Xindong Mu, Chunyan Zhang, Paul Deroussel, Haisong WangAbstract:A modified alkali pretreatment (MAP) process was established in both lab-scale and pilot-scale, based on the on-line production and utilization of lignosulfonate for improving enzymatic saccharification of corn stover. Sodium lignosulfonate (SLS) produced by directly sulfonating lignin in Spent Liquor separated from alkali pretreatment was reused in the next cycle of alkali pretreatment. The results showed that, by using 11 wt% NaOH, 2 wt% SLS and 0.1 wt% anthraquinone (AQ) in MAP, delignification rate and final total sugar yields could reach about 78% and 80% respectively, which were about 6% and 9% higher compared to the blank conventional NaOH pretreatment under the same conditions. In addition, sulfonation degree of SLS had linearly impact on the final total sugar yields. (C) 2015 Elsevier B.V. All rights reserved.
Dongjie Yang - One of the best experts on this subject based on the ideXlab platform.
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formation of uniform colloidal spheres based on lignosulfonate a renewable biomass resource recovered from pulping Spent Liquor
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Qianqian Tang, Xueqing Qiu, Mingsong Zhou, Dongjie YangAbstract:Effects of mass ratios on the sodium lignosulfoante (NaLS) and cetyltrimethylammonium bromide (CTAB) mixing system were first investigated by zeta potential and surface tension measurements. Uniform colloidal spheres from the NaLS/CTAB complex were then fabricated via electrostatic and hydrophobic self-assembly and characterized by DLS, TEM, contact angle, elemental analysis, XPS, and FTIR measurements. Results showed the stoichiometric mass ratio (SMR) of the NaLS/CTAB system was 1:2.82, where the hydrophobicity was strongest and preparing colloidal spheres was feasible. Colloidal spheres were formed through gradual aggregation of NaLS/CTAB molecules at SMR, which was induced by continuously adding water into NaLS/CTAB/EtOH solutions. NaLS/CTAB molecules started to form spheres at a critical water content of 58 vol %, and the formation process was completed at a water content of 84 vol % when the initial concentration of NaLS/CTAB in EtOH was 1.0 mg mL–1. The sizes of NaLS/CTAB colloidal spheres could be...
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biorefinery lignosulfonates from sulfite pretreated softwoods as dispersant for graphite
ACS Sustainable Chemistry & Engineering, 2016Co-Authors: Yanlin Qin, Dongjie Yang, Xueqing Qiu, J Y ZhuAbstract:Two biorefinery lignosulfonates (LSs), Ca-LS-DF and Na-LS-LP, were, respectively, isolated from pilot-scale sulfite-pretreated Spent Liquor of lodgepole pine and fermentation residue of Douglas-fir harvest forest residue. The molecular weights of Na-LS-LP and Ca-LS-DF were approximately 9 000 and 11 000 Da, respectively. The two LSs were applied as dispersant for graphite in aqueous suspensions. The dispersion stability was evaluated by a scanning electron microscope and Turbiscan Lab Expert. LS performance in modifying graphite was better than that of a commercial dispersant Reax-85A as indicated by the Turbiscan TSI values, zeta potential of suspension particles, and SEM imaging. The practical importance of this study lies in the fact that the pilot-scale sulfite pretreatments that produced the two LSs also produced excellent bioethanol yields at high titer without detoxification and washing, suggesting the LSs are a true value-added coproduct for high yield biofuel production.
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Biorefinery Lignosulfonates from Sulfite-Pretreated Softwoods as Dispersant for Graphite
2016Co-Authors: Yanlin Qin, Dongjie Yang, Xueqing Qiu, J Y ZhuAbstract:Two biorefinery lignosulfonates (LSs), Ca-LS-DF and Na-LS-LP, were, respectively, isolated from pilot-scale sulfite-pretreated Spent Liquor of lodgepole pine and fermentation residue of Douglas-fir harvest forest residue. The molecular weights of Na-LS-LP and Ca-LS-DF were approximately 9 000 and 11 000 Da, respectively. The two LSs were applied as dispersant for graphite in aqueous suspensions. The dispersion stability was evaluated by a scanning electron microscope and Turbiscan Lab Expert. LS performance in modifying graphite was better than that of a commercial dispersant Reax-85A as indicated by the Turbiscan TSI values, zeta potential of suspension particles, and SEM imaging. The practical importance of this study lies in the fact that the pilot-scale sulfite pretreatments that produced the two LSs also produced excellent bioethanol yields at high titer without detoxification and washing, suggesting the LSs are a true value-added coproduct for high yield biofuel production
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formation of uniform colloidal spheres from lignin a renewable resource recovered from pulping Spent Liquor
Green Chemistry, 2014Co-Authors: Yong Qian, Yonghong Deng, Hao Li, Dongjie YangAbstract:Alkali lignin, recovered from the pulping black Liquor, was chemically modified by acetylating, and then used as a biomass resource to prepare uniform colloidal spheres via self-assembly. The self-assembled structure and colloid formation mechanism of the acetylated lignin (ACL) were investigated by DLS, SLS, TEM, AFM, XPS, FTIR, elemental analysis and contact angle measurements. Results show that ACL colloidal spheres are obtained from gradual hydrophobic aggregation of ACL molecules, induced by continuously adding water into the ACL–THF solution. ACL molecules start to form colloidal spheres at a critical water content of 44 vol% when the initial concentration of ACL in THF is 1.0 mg mL−1, and the colloidization process is completed at a water content of 67 vol%. An excessive amount of water is added into the dispersions to “quench” the structures formed and then the ACL dispersion is treated by rotary evaporation for recycling THF and acquiring colloidal spheres. The ACL colloidal spheres have an of 110 nm with a polydispersity (μ2/Γ2) of 0.022. The average aggregated number ( ) in each colloidal sphere and the average density ( ) are estimated to be 1.0 × 105 and 0.187 g cm−3. Preparation of water-dispersive lignin nanoparticles opens up a green and valuable pathway for value-added utilization of lignin biomass recovered from pulping Spent Liquor, which is of great significance for both the utilization of renewable resources and environmental protection.
Adriaan Van Heiningen - One of the best experts on this subject based on the ideXlab platform.
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study on conditioning of so2 ethanol water Spent Liquor from spruce chips softwood biomass for abe fermentation
Industrial & Engineering Chemistry Research, 2013Co-Authors: Evangelos Sklavounos, Adriaan Van Heiningen, Mikhail IakovlevAbstract:The focus of this study is to develop a process for conditioning Spent Liquor produced by SO2–ethanol–water (SEW) fractionation of spruce chips/softwood biomass for fermentation to butanol, ethanol, and acetone/2-propanol (so-called ABE process) by Clostridia bacteria. This study is an integral part of a project which aims at creating an economic process that can utilize cheap forestry residues such as twigs, cones, treetops, branches, and bark to produce renewable chemicals and liquid fuels. The results of this study suggest that the proposed scheme for conditioning of SEW Spent Liquor from spruce/softwood biomass can be successfully applied to produce chemicals and biofuels by ABE fermentation. Butanol, acetone, and ethanol are produced at a total yield of around 0.25 g/g sugars.
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continuous acetone butanol ethanol fermentation using so2 ethanol water Spent Liquor from spruce
Bioresource Technology, 2011Co-Authors: Shrikant A Survase, Evangelos Sklavounos, German Jurgens, Adriaan Van Heiningen, Tom GranstromAbstract:SO2-ethanol-water (SEW) Spent Liquor from spruce chips was successfully used for batch and continuous production of acetone, butanol and ethanol (ABE). Initially, batch experiments were performed using Spent Liquor to check the suitability for production of ABE. Maximum concentration of total ABE was found to be 8.79 g/l using 4-fold diluted SEW Liquor supplemented with 35 g/l of glucose. The effect of dilution rate on solvent production, productivity and yield was studied in column reactor consisting of immobilized Clostridium acetobutylicum DSM 792 on wood pulp. Total solvent concentration of 12 g/l was obtained at a dilution rate of 0.21 h(-1). The maximum solvent productivity (4.86 g/l h) with yield of 0.27 g/g was obtained at dilution rate of 0.64 h(-1). Further, to increase the solvent yield, the unutilized sugars were subjected to batch fermentation.
