Porous biomaterials such as paper and board have a complex structure that influences their mechan... more Porous biomaterials such as paper and board have a complex structure that influences their mechanical, optical, and transport properties and thereby their performance during manufacturing and end uses. Reconstruction of the three-dimensional (3D) pore spaces in paper was obtained by X-ray computed tomography and used to study the structure and its impact on properties. A set of laboratory-made paper samples of varying freeness was prepared, and the 3D structures of the samples were visualized and characterized. Tomographic reconstruction images were processed using techniques such as anisotropic diffusion, minimum error thresholding, and isolated voxel removal to enhance image quality. The pore structures were analyzed to determine porosity, fiber-pore interfacial surface area, geometric tortuosity, and pore size distributions (using a sphere growing algorithm). These properties were compared with experimental data and were found to be in good agreement. The results from 3D visualiz...
The three dimensional structure of paper materials plays a critical role in the paper manufacturi... more The three dimensional structure of paper materials plays a critical role in the paper manufacturing process especially via its impact on the transport properties for fluids. Dewatering of the wet web, pressing and drying will benefit from knowledge of the relationships ...
This study investigates the use of brewer’s spent grains (BSG), a major waste stream from the bre... more This study investigates the use of brewer’s spent grains (BSG), a major waste stream from the brewing process, for its potential as a carbon source for the fermentative production of polyhydroxyalkanoates (PHAs), biodegradable polyesters. The sugars obtained from hydrolysis of raw and hot water-pretreated BSG were fermented using a recombinant Escherichia coli LSBJ harboring genes for biosynthesis of either homopolymer polyhydroxybutyrate (PHB) or PHB-co-medium chain length copolymer (PHB-co-MCL). The highest biopolymer titers obtained from the BSG hydrolysate were 3.53 g/L and 3.32 g/L for PHB and PHB-co-MCL, respectively, which corresponded to process yields of 0.353 g PHB/g sugar and 0.32 g PHB-co-MCL/g sugar. Titers obtained from the BSG hydrolysate were higher compared to titers from native PHA producers observed in previous works, which was likely due to the metabolic advantages inherent to using a recombinant organism. These results demonstrate both the viability of BSG as a ...
... Rune Holmstad SUNY-ESF, NY Prof. BV Ramarao University of Jyvaskyla Prof. Markku Kataja Amit ... more ... Rune Holmstad SUNY-ESF, NY Prof. BV Ramarao University of Jyvaskyla Prof. Markku Kataja Amit Goel, Mayank Gupta, Lei Wang, Vasa Zhdankin Page 3. Structure Property Relationships in Porous Media Background Fiber properties, mechanical and chemical ...
... Somporn Chaiarrekij, H. Gupta, WS Amato and BV Ramarao ... We gratefully acknowledge the fina... more ... Somporn Chaiarrekij, H. Gupta, WS Amato and BV Ramarao ... We gratefully acknowledge the financial support of Niagara Mohawk Power Corporation, Syracuse NY and the New York State Energy Research and Development Authority (NYSERDA), Albany NY through the ...
... Eng'g. and Mat. Sci., Syracuse Univ., Syracuse, NY, 13244, ETATS-UNIS Résumé / Abstr... more ... Eng'g. and Mat. Sci., Syracuse Univ., Syracuse, NY, 13244, ETATS-UNIS Résumé / Abstract. Au titre de modèle simplifié de la fabrication du papier dans les systèmes statiques tels que la formette British, on a analysé à la fois l'égouttage d'une suspension de fibres à travers un ...
Introduction The three dimensional structure of paper and board plays a critical role in the manu... more Introduction The three dimensional structure of paper and board plays a critical role in the manufacturing process as well as during end-use applications, especially via its impact on fluid transport properties. Characterization of the structural parameters, like porosity, specific surface ...
Filtration of submicrometer aerosols in fibrous beds was considered as a mass transfer process. E... more Filtration of submicrometer aerosols in fibrous beds was considered as a mass transfer process. Earlier experimental data on the single-fiber collection efficiency of aerosols collected in fibrous filters were used to calculate j-factors for mass transfer. A correlation for j-factors as a function of the modified Reynold's number in the bed was developed. Comparison of the j-factors based on both
Industrial Engineering Chemistry Research, May 3, 2012
ABSTRACT Pretreatment of lignocellulosic materials involves the solubilization of hemicelluloses,... more ABSTRACT Pretreatment of lignocellulosic materials involves the solubilization of hemicelluloses, small portions of the lignin, and such components. The hemicellulose solutions are hydrolyzed for downstream fermentation into biofuels or biomaterials. Hydrolyzates produced by pretreatment contain significant colloidal material that is anionically charged. Many of the compounds that are present in the hydrolyzates are inhibitory to fermentation and interfere with downstream separations. The flocculation of this colloidal material makes separations easier by sedimentation and can reduce the fouling tendencies of membranes. It can also reduce the toxicity of the hydrolyzates to fermentation micro-organisms. We studied the dynamics of flocculation of lignocellulosic hydrolyzates with a variety of flocculating agents: electrolytes (alum) and polymers (PEI, pDADMAC, CPAM). It was found that trivalent cations were the most effective suspension destabilizers among the electrolytes, while the cationic polymers could cause flocculation and also redispersion depending on their dosage levels. Flocculation reduced the hydrolyzates’ turbidity from >10000 to under 20. With PEI and pDADMAC, flocculation occurred rapidly when the zeta potential of the colloid was close to zero showing that charge neutralization is the significant destabilizing mechanism. At higher dosages, redispersion occurred indicating that patching is also important in flocculation. Flocculation by PEI was sensitive to pH (from hydrolyzate pH of 3 to 8) with increased dosage necessary at higher pH values. The cationicity of PEI is reduced at higher pH which results in loss of its effectiveness. On the other hand, the zeta potential was largely unaffected with CPAM dosage indicating the dominance of bridging flocculation. Floc sizes ranged up to 3 mm, depending on flocculant dose and pH.
Porous biomaterials such as paper and board have a complex structure that influences their mechan... more Porous biomaterials such as paper and board have a complex structure that influences their mechanical, optical, and transport properties and thereby their performance during manufacturing and end uses. Reconstruction of the three-dimensional (3D) pore spaces in paper was obtained by X-ray computed tomography and used to study the structure and its impact on properties. A set of laboratory-made paper samples of varying freeness was prepared, and the 3D structures of the samples were visualized and characterized. Tomographic reconstruction images were processed using techniques such as anisotropic diffusion, minimum error thresholding, and isolated voxel removal to enhance image quality. The pore structures were analyzed to determine porosity, fiber-pore interfacial surface area, geometric tortuosity, and pore size distributions (using a sphere growing algorithm). These properties were compared with experimental data and were found to be in good agreement. The results from 3D visualiz...
The three dimensional structure of paper materials plays a critical role in the paper manufacturi... more The three dimensional structure of paper materials plays a critical role in the paper manufacturing process especially via its impact on the transport properties for fluids. Dewatering of the wet web, pressing and drying will benefit from knowledge of the relationships ...
This study investigates the use of brewer’s spent grains (BSG), a major waste stream from the bre... more This study investigates the use of brewer’s spent grains (BSG), a major waste stream from the brewing process, for its potential as a carbon source for the fermentative production of polyhydroxyalkanoates (PHAs), biodegradable polyesters. The sugars obtained from hydrolysis of raw and hot water-pretreated BSG were fermented using a recombinant Escherichia coli LSBJ harboring genes for biosynthesis of either homopolymer polyhydroxybutyrate (PHB) or PHB-co-medium chain length copolymer (PHB-co-MCL). The highest biopolymer titers obtained from the BSG hydrolysate were 3.53 g/L and 3.32 g/L for PHB and PHB-co-MCL, respectively, which corresponded to process yields of 0.353 g PHB/g sugar and 0.32 g PHB-co-MCL/g sugar. Titers obtained from the BSG hydrolysate were higher compared to titers from native PHA producers observed in previous works, which was likely due to the metabolic advantages inherent to using a recombinant organism. These results demonstrate both the viability of BSG as a ...
... Rune Holmstad SUNY-ESF, NY Prof. BV Ramarao University of Jyvaskyla Prof. Markku Kataja Amit ... more ... Rune Holmstad SUNY-ESF, NY Prof. BV Ramarao University of Jyvaskyla Prof. Markku Kataja Amit Goel, Mayank Gupta, Lei Wang, Vasa Zhdankin Page 3. Structure Property Relationships in Porous Media Background Fiber properties, mechanical and chemical ...
... Somporn Chaiarrekij, H. Gupta, WS Amato and BV Ramarao ... We gratefully acknowledge the fina... more ... Somporn Chaiarrekij, H. Gupta, WS Amato and BV Ramarao ... We gratefully acknowledge the financial support of Niagara Mohawk Power Corporation, Syracuse NY and the New York State Energy Research and Development Authority (NYSERDA), Albany NY through the ...
... Eng'g. and Mat. Sci., Syracuse Univ., Syracuse, NY, 13244, ETATS-UNIS Résumé / Abstr... more ... Eng'g. and Mat. Sci., Syracuse Univ., Syracuse, NY, 13244, ETATS-UNIS Résumé / Abstract. Au titre de modèle simplifié de la fabrication du papier dans les systèmes statiques tels que la formette British, on a analysé à la fois l'égouttage d'une suspension de fibres à travers un ...
Introduction The three dimensional structure of paper and board plays a critical role in the manu... more Introduction The three dimensional structure of paper and board plays a critical role in the manufacturing process as well as during end-use applications, especially via its impact on fluid transport properties. Characterization of the structural parameters, like porosity, specific surface ...
Filtration of submicrometer aerosols in fibrous beds was considered as a mass transfer process. E... more Filtration of submicrometer aerosols in fibrous beds was considered as a mass transfer process. Earlier experimental data on the single-fiber collection efficiency of aerosols collected in fibrous filters were used to calculate j-factors for mass transfer. A correlation for j-factors as a function of the modified Reynold's number in the bed was developed. Comparison of the j-factors based on both
Industrial Engineering Chemistry Research, May 3, 2012
ABSTRACT Pretreatment of lignocellulosic materials involves the solubilization of hemicelluloses,... more ABSTRACT Pretreatment of lignocellulosic materials involves the solubilization of hemicelluloses, small portions of the lignin, and such components. The hemicellulose solutions are hydrolyzed for downstream fermentation into biofuels or biomaterials. Hydrolyzates produced by pretreatment contain significant colloidal material that is anionically charged. Many of the compounds that are present in the hydrolyzates are inhibitory to fermentation and interfere with downstream separations. The flocculation of this colloidal material makes separations easier by sedimentation and can reduce the fouling tendencies of membranes. It can also reduce the toxicity of the hydrolyzates to fermentation micro-organisms. We studied the dynamics of flocculation of lignocellulosic hydrolyzates with a variety of flocculating agents: electrolytes (alum) and polymers (PEI, pDADMAC, CPAM). It was found that trivalent cations were the most effective suspension destabilizers among the electrolytes, while the cationic polymers could cause flocculation and also redispersion depending on their dosage levels. Flocculation reduced the hydrolyzates’ turbidity from >10000 to under 20. With PEI and pDADMAC, flocculation occurred rapidly when the zeta potential of the colloid was close to zero showing that charge neutralization is the significant destabilizing mechanism. At higher dosages, redispersion occurred indicating that patching is also important in flocculation. Flocculation by PEI was sensitive to pH (from hydrolyzate pH of 3 to 8) with increased dosage necessary at higher pH values. The cationicity of PEI is reduced at higher pH which results in loss of its effectiveness. On the other hand, the zeta potential was largely unaffected with CPAM dosage indicating the dominance of bridging flocculation. Floc sizes ranged up to 3 mm, depending on flocculant dose and pH.
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