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Pedram Fatehi - One of the best experts on this subject based on the ideXlab platform.
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Isolating lignin from spent liquor of thermomechanical Pulping Process via adsorption.
Environmental technology, 2020Co-Authors: Farshad Oveissi, Pedram FatehiAbstract:Wood chips are pretreated with steam prior to refining in the thermomechanical Pulping Process. The steam treatment dissolves part of lignin of wood chips in the spent liquor (SL) of this Process, and subsequently the SL is sent to the wastewater system of the Process. However, the lignin of SL can be used in the production of value-added chemicals, but it should first be separated from the SL in order to have a feasible downstream Process. In this study, activated carbon (AC) was considered as an adsorbent to isolate lignin from SL. The results showed that the maximum adsorption of lignin on AC was 166 mg/g under the optimal conditions of pH 5.2, 30 degrees C and 3 h treatment. Furthermore, the separation of lignin from SL was improved from 45% to 60% by having a two-stage adsorption Process at pH 5.2, which also reduced the turbidity and chemical oxygen demand of SL by 39% and 32%, respectively.
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fly ash based adsorbent for treating bleaching effluent of kraft Pulping Process
Separation and Purification Technology, 2018Co-Authors: Pedram FatehiAbstract:Abstract The bleaching operation of a kraft Pulping Process generates a large amount of effluents with high organic loads. The affinity of biomass-based fly ash as a low-cost adsorbent for reducing lignin concentration, chemical oxygen demand (COD) and turbidity of the bleaching effluents prior to a biological treatment Process was studied in this work. The results showed that the optimized conditions for obtaining the maximum removals of lignin (81.6%) and COD (67.9%) were the fly ash dosage of 6 wt% in the effluent and the treatment time of 30 min and temperature of 30 °C. The results also showed that the settling rate of the fly ash in fly ash/effluent suspension systems increased as fly ash dosage increased. Charge neutralization played a key role at a low fly ash dosage (less than 2 wt%) for removing lignocellulosic flocs smaller than 10 µm, while complexion of small flocs to larger ones (with the size of 30–500 µm) occurred at the higher fly ash dosage in the effluent. Coagulation and adsorption were the main phenomena for the removals of COD, lignin and turbidity at a higher fly ash dosage and a prolonged treatment time.
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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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pdadmac as a flocculant for lignosulfonate of nssc Pulping Process
Biotechnology Progress, 2016Co-Authors: Farshad Oveissi, Thomas Sitter, Pedram FatehiAbstract:The spent liquor (SL) of neutral sulfite semi-chemical (NSSC) Pulping Process contains about 8 wt% lignocelluloses that can be extracted and used in the production of value-added materials. In this work, a flocculation Process followed by centrifugation was considered for isolating lignosulfonate and hemicelluloses from SL. It was observed that, by adding 20 mg/g of polydiallyldimethylammuniom chloride (PDADMAC) with 100,000-200,000 g/mol molecular weight to SL, 45% of lignosulfonate and 39% of hemicelluloses were removed at 30°C. The lignocellulose removal was more efficient for the dual flocculation system of low and high molecular weights PDADMAC than for individual PDADMAC systems. Overall, 49% of lignosulfonate, 47% of hemicelluloses and 97% of turbidity were removed from SL from the dual system when 10 mg/g low molecular weight PDADMAC and 10 mg/g high molecular weight PDADMAC were added to the SL at 30°C, subsequently. The thermogravimetric analysis (TGA) of generated flocs showed that all samples had similar thermal behaviour and 13-16 wt% of flocs remained as ash after burning at 700°C in nitrogen. As the flocs are made of lignocellulosic materials and they are thermally stable, they could be used as fillers in paper board production. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:686-691, 2016.
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: Allan Gilbert, Mehdi Dashtban, 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).
Jalel Labidi - One of the best experts on this subject based on the ideXlab platform.
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agricultural palm oil tree residues as raw material for cellulose lignin and hemicelluloses production by ethylene glycol Pulping Process
Chemical Engineering Journal, 2009Co-Authors: Gonzalez M Alriols, Ivan Mondragon, M Blanco, Alvaro Tejado, Jalel LabidiAbstract:Agricultural crop residues (palm oil empty fruit bunches—EFB) were used as raw material for cellulose, lignin and hemicelluloses obtaining following sustainable criteria. An organosolv Pulping Process based on ethylene glycol–water mixtures, which allowed an easy recycling of solvents as well as the recovery of generated by-products, was used to induce delignification. Computer simulations using commercial software (Aspen Plus) were made on the whole Process in order to design the solvents recovery stages and optimise the operation conditions. Laboratory experiments were carried out with the aim of characterizing raw material, black liquors and released by-products. Considerable high proportion of recycled solvents (91 wt% ethylene glycol and 88 wt% water) was reached with the proposed scheme. This resulted in 70 and 80 wt% reduction of fresh solvent input for ethylene glycol and water respectively, thus reducing the environmental impact of the Process. EFB organosolv pulp could be considered an acceptable alternative for producing certain paper qualities with moderate strength requirements while allowing an agricultural residue from a major economic activity (viz. oil palm production) to be exploited.
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Agricultural palm oil tree residues as raw material for cellulose, lignin and hemicelluloses production by ethylene glycol Pulping Process
Chemical Engineering Journal, 2009Co-Authors: M. González Alriols, Ivan Mondragon, M Blanco, Alvaro Tejado, Jalel LabidiAbstract:Agricultural crop residues (palm oil empty fruit bunches-EFB) were used as raw material for cellulose, lignin and hemicelluloses obtaining following sustainable criteria. An organosolv Pulping Process based on ethylene glycol-water mixtures, which allowed an easy recycling of solvents as well as the recovery of generated by-products, was used to induce delignification. Computer simulations using commercial software (Aspen Plus) were made on the whole Process in order to design the solvents recovery stages and optimise the operation conditions. Laboratory experiments were carried out with the aim of characterizing raw material, black liquors and released by-products. Considerable high proportion of recycled solvents (91 wt% ethylene glycol and 88 wt% water) was reached with the proposed scheme. This resulted in 70 and 80 wt% reduction of fresh solvent input for ethylene glycol and water respectively, thus reducing the environmental impact of the Process. EFB organosolv pulp could be considered an acceptable alternative for producing certain paper qualities with moderate strength requirements while allowing an agricultural residue from a major economic activity (viz. oil palm production) to be exploited. © 2008 Elsevier B.V. All rights reserved.
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organosolv Pulping Process simulations
Industrial & Engineering Chemistry Research, 2008Co-Authors: Maria Jesus Gonzalez Gonzalez, Alvaro Tejado, C Pena, Jalel LabidiAbstract:Computer simulations of organosolv Pulping Processes (ethanol−water and ethylene glycol−water mixtures) using commercial simulation software (ASPEN PLUS) have been developed in order to design the Process and to establish its key points (product and byproduct mass flow balances, energy analysis, and solvent recovery degree) as well as to analyze operation conditions. Laboratory experiments, in which a deciduous wood called leucaena (Leucaena leucocephala) was used as raw material, were carried out to obtain input data for the simulation. The proposed Process flow sheets allow the recovery and recycling of a high percentage of used solvents (97 wt % ethanol and 88 wt % ethylene glycol), which represent a reduction of 66 and 59 wt % of fresh solvent input for ethanol and ethylene glycol, respectively.
Shuangfei Wang - One of the best experts on this subject based on the ideXlab platform.
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hydrothermal acid hydrolysis for highly efficient separation of lignin and xylose from pre hydrolysis liquor of kraft Pulping Process
Separation and Purification Technology, 2019Co-Authors: Xue Chen, Tongqi Yuan, Shuangfei WangAbstract:Abstract In this study, the effect of traditional acidification and hydrothermal acid hydrolysis on the separation of lignin and xylose from the pre-hydrolysis liquor (PHL) of kraft Pulping Process was comparatively evaluated. The PHL was acidified at room temperature or hydrothermally treated under acidic conditions to isolate lignin and xylose. As compared with the lignin removal rate of 26.8–32.7% by traditional acidification method, a much higher lignin removal rate of 57.1% was achieved by hydrothermal acid hydrolysis. Meanwhile, the content of xylose in the PHL increased dramatically from 7.91 to 13.91–34.82 g/L after the hydrothermal acid hydrolysis. The hydrophilicity of the obtained lignin gradually increased as evidenced by the decrease of the corresponding water contact angel. Additionally, the thermal stability of the lignin sample increased steadily with the increment of acid dosage. The hydrothermal acid hydrolysis provides an effective approach to fractionate lignin and xylose from PHL.
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Effect of Alkali Hydrogen Peroxide Pre-Extraction on APMP Pulping Process of Pink Sheets Bamboo
Advanced Materials Research, 2011Co-Authors: Xue Ping Song, Hui He, Xue Mei Meng, You Xi Ou, Shuangfei WangAbstract:In this paper, the technique of alkali hydrogen peroxide extracting hemi-cellulose and the effects of pre-extraction on APMP Pulping Process of the Pink Sheets bamboo are investigated. The results show that the yields of pentosan and bamboo chip are optimal under the conditions of the dosage of hydrogen peroxide 1.5%, the reaction temperature 90°C, liquid ratio 1:8, holding time 4h. After pre-extracting the tensile index and folding strength decline, and the burst index is kept and the tear index increases slightly. But there is little loss to the brightness of APMP, and the refining energy is reduced largely after pre-extracted.
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Effect of Hot Water Pre-Extraction on APMP Pulping Process of Pink Sheets Bamboo
Advanced Materials Research, 2011Co-Authors: Xue Ping Song, Hui He, Xue Mei Meng, Shuangfei WangAbstract:In this paper, the technology of pressurized hot water extraction of hemi-cellulose and the effects of the pre-extraction on APMP Pulping Process of the Pink Sheets bamboo are investigated. The results show that the yields of pentosan and bamboo chip are the highest under the conditions of the maximum temperature 170 °C, liquid ratio 1:5, holding time 2h. And the yield of bamboo chip is lowered generally, the color of bamboo is deepened, the pulp strength is degraded, but the refining energy is reduced largely after pre-extraction.
Farshad Oveissi - One of the best experts on this subject based on the ideXlab platform.
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Isolating lignin from spent liquor of thermomechanical Pulping Process via adsorption.
Environmental technology, 2020Co-Authors: Farshad Oveissi, Pedram FatehiAbstract:Wood chips are pretreated with steam prior to refining in the thermomechanical Pulping Process. The steam treatment dissolves part of lignin of wood chips in the spent liquor (SL) of this Process, and subsequently the SL is sent to the wastewater system of the Process. However, the lignin of SL can be used in the production of value-added chemicals, but it should first be separated from the SL in order to have a feasible downstream Process. In this study, activated carbon (AC) was considered as an adsorbent to isolate lignin from SL. The results showed that the maximum adsorption of lignin on AC was 166 mg/g under the optimal conditions of pH 5.2, 30 degrees C and 3 h treatment. Furthermore, the separation of lignin from SL was improved from 45% to 60% by having a two-stage adsorption Process at pH 5.2, which also reduced the turbidity and chemical oxygen demand of SL by 39% and 32%, respectively.
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pdadmac as a flocculant for lignosulfonate of nssc Pulping Process
Biotechnology Progress, 2016Co-Authors: Farshad Oveissi, Thomas Sitter, Pedram FatehiAbstract:The spent liquor (SL) of neutral sulfite semi-chemical (NSSC) Pulping Process contains about 8 wt% lignocelluloses that can be extracted and used in the production of value-added materials. In this work, a flocculation Process followed by centrifugation was considered for isolating lignosulfonate and hemicelluloses from SL. It was observed that, by adding 20 mg/g of polydiallyldimethylammuniom chloride (PDADMAC) with 100,000-200,000 g/mol molecular weight to SL, 45% of lignosulfonate and 39% of hemicelluloses were removed at 30°C. The lignocellulose removal was more efficient for the dual flocculation system of low and high molecular weights PDADMAC than for individual PDADMAC systems. Overall, 49% of lignosulfonate, 47% of hemicelluloses and 97% of turbidity were removed from SL from the dual system when 10 mg/g low molecular weight PDADMAC and 10 mg/g high molecular weight PDADMAC were added to the SL at 30°C, subsequently. The thermogravimetric analysis (TGA) of generated flocs showed that all samples had similar thermal behaviour and 13-16 wt% of flocs remained as ash after burning at 700°C in nitrogen. As the flocs are made of lignocellulosic materials and they are thermally stable, they could be used as fillers in paper board production. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:686-691, 2016.
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isolating lignin from spent liquor of thermomechanical Pulping Process via adsorption
Environmental Technology, 2014Co-Authors: Farshad Oveissi, Pedram FatehiAbstract:Wood chips are pretreated with steam prior to refining in the thermomechanical Pulping Process. The steam treatment dissolves part of lignin of wood chips in the spent liquor (SL) of this Process, and subsequently the SL is sent to the wastewater system of the Process. However, the lignin of SL can be used in the production of value-added chemicals, but it should first be separated from the SL in order to have a feasible downstream Process. In this study, activated carbon (AC) was considered as an adsorbent to isolate lignin from SL. The results showed that the maximum adsorption of lignin on AC was166 mg/g under the optimal conditions of pH 5.2, 30 °C and 3 h treatment. Furthermore, the separation of lignin from SL was improved from 45% to 60% by having a two-stage adsorption Process at pH 5.2, which also reduced the turbidity and chemical oxygen demand of SL by 39% and 32%, respectively.
