Pub Date : 2023-03-01DOI: 10.1515/npprj-2023-frontmatter1
{"title":"Frontmatter","authors":"","doi":"10.1515/npprj-2023-frontmatter1","DOIUrl":"https://doi.org/10.1515/npprj-2023-frontmatter1","url":null,"abstract":"","PeriodicalId":19315,"journal":{"name":"Nordic Pulp & Paper Research Journal","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135074931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. R. Coura, A. Demuner, I. F. Demuner, D. Blank, Maria José Magalhães Firmino, Fernando José Borges Gomes, Ana Márcia Macedo Ladeira Carvalho, Marcelo Moreira Costa, Marcelo Henrique dos Santos
Abstract The biomass deconstructed by kraft process and the lignin dissolved in the black liquor are burned to generate energy in a pulp mill. This study used the black liquor from coffee parchment cooking, a residue from the coffee industry, to isolate kraft technical lignin. The parchment was subjected to the kraft pulping process to obtain pulps of kappa number 60 and 25, and the resulting black liquors were used for lignin extraction. Chemical characterization, elemental analysis and heating value of liquors and lignins were performed, as well as FTIR and Py-CG-MS analysis of lignins. The cooking provided liquors with similar characteristics, with lignin content of 31.67 and 32.63% for kappa 60 and 25 liquors, respectively. The extractions resulted in high purity lignin (92.35% for K#60 lignin and 93.96% for K#25 lignin). The higher heating values were 23.8 and 25.4 MJ/kg for K#25 and K#60 lignins, respectively. FTIR analysis showed characteristic peaks of lignin. Through Py-GC-MS, it was possible to observe the slight predominance of guaiacyl-type lignin, which can be an advantage depending on the application. It is possible to extract lignin from the black liquor obtained from the coffee parchment pulping to generate products with high-added value.
{"title":"Technical kraft lignin from coffee parchment","authors":"M. R. Coura, A. Demuner, I. F. Demuner, D. Blank, Maria José Magalhães Firmino, Fernando José Borges Gomes, Ana Márcia Macedo Ladeira Carvalho, Marcelo Moreira Costa, Marcelo Henrique dos Santos","doi":"10.1515/npprj-2022-0100","DOIUrl":"https://doi.org/10.1515/npprj-2022-0100","url":null,"abstract":"Abstract The biomass deconstructed by kraft process and the lignin dissolved in the black liquor are burned to generate energy in a pulp mill. This study used the black liquor from coffee parchment cooking, a residue from the coffee industry, to isolate kraft technical lignin. The parchment was subjected to the kraft pulping process to obtain pulps of kappa number 60 and 25, and the resulting black liquors were used for lignin extraction. Chemical characterization, elemental analysis and heating value of liquors and lignins were performed, as well as FTIR and Py-CG-MS analysis of lignins. The cooking provided liquors with similar characteristics, with lignin content of 31.67 and 32.63% for kappa 60 and 25 liquors, respectively. The extractions resulted in high purity lignin (92.35% for K#60 lignin and 93.96% for K#25 lignin). The higher heating values were 23.8 and 25.4 MJ/kg for K#25 and K#60 lignins, respectively. FTIR analysis showed characteristic peaks of lignin. Through Py-GC-MS, it was possible to observe the slight predominance of guaiacyl-type lignin, which can be an advantage depending on the application. It is possible to extract lignin from the black liquor obtained from the coffee parchment pulping to generate products with high-added value.","PeriodicalId":19315,"journal":{"name":"Nordic Pulp & Paper Research Journal","volume":"38 1","pages":"229 - 241"},"PeriodicalIF":1.2,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49582343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Mostafizur Rahman, Nur-Al-Sarah Rafsan, Jannatun Nayeem, Razia Sultana Popy, Mohammad Moniruzzaman, M. Sarwar Jahan
Abstract Pulping of rice straw was studied using mild nitric acid in mild conditions. Spent nitric acid was chosen as soil nutrient rather than followed by the liquor recovery. The rice straw was treated with 11.03% nitric acid at 90 °C for 3 h, yielded 53.09% pulp. Nitric acid treated rice straw pulp had high residual lignin and minerals. However, further treatment with 7% potassium hydroxide reduced the residual lignin and produced pulp with kappa number 20.36. The papermaking properties of the nitric acid followed by KOH treated pulp showed better quality than the nitric acid pulp. The spent nitric acid liquor was reused repeatedly, pulp yield decreased and residual lignin content increased in each step of spent nitric acid reusing. The spent nitric acid liquor and potassium hydroxide liquor-mixed together to get a neutral effluent liquor which was rich with potassium, nitrogen and biomass. The nutritional capacity of the effluent liquor was assessed by incubation with control soil. The labile form of organic carbon, nitrogen, potassium phosphorous and iron increased in the incubated soil.
{"title":"Nitric acid-potassium hydroxide fractionation of rice straw: an integrated biorefinery initiative","authors":"M. Mostafizur Rahman, Nur-Al-Sarah Rafsan, Jannatun Nayeem, Razia Sultana Popy, Mohammad Moniruzzaman, M. Sarwar Jahan","doi":"10.1515/npprj-2022-0073","DOIUrl":"https://doi.org/10.1515/npprj-2022-0073","url":null,"abstract":"Abstract Pulping of rice straw was studied using mild nitric acid in mild conditions. Spent nitric acid was chosen as soil nutrient rather than followed by the liquor recovery. The rice straw was treated with 11.03% nitric acid at 90 °C for 3 h, yielded 53.09% pulp. Nitric acid treated rice straw pulp had high residual lignin and minerals. However, further treatment with 7% potassium hydroxide reduced the residual lignin and produced pulp with kappa number 20.36. The papermaking properties of the nitric acid followed by KOH treated pulp showed better quality than the nitric acid pulp. The spent nitric acid liquor was reused repeatedly, pulp yield decreased and residual lignin content increased in each step of spent nitric acid reusing. The spent nitric acid liquor and potassium hydroxide liquor-mixed together to get a neutral effluent liquor which was rich with potassium, nitrogen and biomass. The nutritional capacity of the effluent liquor was assessed by incubation with control soil. The labile form of organic carbon, nitrogen, potassium phosphorous and iron increased in the incubated soil.","PeriodicalId":19315,"journal":{"name":"Nordic Pulp & Paper Research Journal","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135256073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A never-dried (ND) fines-free softwood bleached kraft pulp was converted to air-dried and thermally dried handsheets, which were then disintegrated or sonicated in water under various conditions. These disintegrated or sonicated pulps were converted to handsheets and used to obtain fundamental data on paper recycling. The water-vapor-adsorption isotherms of the pulp and sheet samples after super-critical-point drying showed clear differences between the water volumes adsorbed by the ND pulp, once-dried pulp, and dried sheets at the same relative humidities above 50%. These differences are caused by hornification of the pulp and sheet samples during drying and recycling. Air and thermal drying of wet webs decreased the adsorbed-water-vapor volume by 7%–9% and 14%–18%, respectively, relative to that adsorbed by the original ND pulp. We hypothesize that the decrease in water-vapor-adsorption volume from that of the original ND pulp at relative humidities >50% reflects the degree of irreversible formation of hydroxyl groups in the originally hydrophilic hemicelluloses and crystalline cellulose microfibril surfaces in the pulp and sheet samples during drying and paper recycling. The water-vapor-adsorption isotherms of pulp and sheet samples can be used to quantify the degree of hornification or the amount of irreversible hydrogen bonds formed during paper recycling.
{"title":"Changes in water-vapor-adsorption isotherms of pulp fibers and sheets during paper recycling, including drying of wet webs, and disintegration and sonication of dried sheets in water","authors":"M. Kimura, M. Takeuchi, Akira Isogai","doi":"10.1515/npprj-2022-0098","DOIUrl":"https://doi.org/10.1515/npprj-2022-0098","url":null,"abstract":"Abstract A never-dried (ND) fines-free softwood bleached kraft pulp was converted to air-dried and thermally dried handsheets, which were then disintegrated or sonicated in water under various conditions. These disintegrated or sonicated pulps were converted to handsheets and used to obtain fundamental data on paper recycling. The water-vapor-adsorption isotherms of the pulp and sheet samples after super-critical-point drying showed clear differences between the water volumes adsorbed by the ND pulp, once-dried pulp, and dried sheets at the same relative humidities above 50%. These differences are caused by hornification of the pulp and sheet samples during drying and recycling. Air and thermal drying of wet webs decreased the adsorbed-water-vapor volume by 7%–9% and 14%–18%, respectively, relative to that adsorbed by the original ND pulp. We hypothesize that the decrease in water-vapor-adsorption volume from that of the original ND pulp at relative humidities >50% reflects the degree of irreversible formation of hydroxyl groups in the originally hydrophilic hemicelluloses and crystalline cellulose microfibril surfaces in the pulp and sheet samples during drying and paper recycling. The water-vapor-adsorption isotherms of pulp and sheet samples can be used to quantify the degree of hornification or the amount of irreversible hydrogen bonds formed during paper recycling.","PeriodicalId":19315,"journal":{"name":"Nordic Pulp & Paper Research Journal","volume":"38 1","pages":"301 - 309"},"PeriodicalIF":1.2,"publicationDate":"2023-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47914175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In order to solve the problem of bacterial resistance, increase the antibacterial performance and delay the aging of paper, the berberine modified trimethoprim carboxymethyl cellulose was prepared using trimethoprimethylate carboxymethyl cellulose as raw material and trimethoprimethylate lactate (TMP) as antibacterial modifier by Schiff Base reaction. At the same time, berberine (BBR) was used as graft monomer to prepare a multifunctional protective solution integrating strengthening, antibacterial and good biocompatibility. The optimal process conditions were determined by single factor experiment and response surface method. The structure and properties of the product were characterized by FT-IR, XRD, TG and SEM and the antibacterial properties were evaluated by AGAR disk diffusion method. The results showed that when the mass ratio of dialdehyde carboxymethyl cellulose and modified berberine was 7:15, reaction temperature was 40 °C, and pH was 6.0, the optimum synthetic conditions was obtained. And the minimum inhibitory concentration of the product against Staphylococcus aureus and Escherichia coli were 0.2 mg/mL, minimum diameter of antibacterial zone of 6.7 mm and 7.1 mm, respectively, with good antibacterial effect. This paper lays a foundation for further research on the safe and effective antiquities antibacterial agent, and provides a reference for its further development in paper protection.
{"title":"Response surface methodology optimization and antimicrobial activity of berberine modified trimethoprim carboxymethyl cellulose","authors":"Gui Fu, Zhen Chen, Yingping Qi, Hua Li","doi":"10.1515/npprj-2022-0057","DOIUrl":"https://doi.org/10.1515/npprj-2022-0057","url":null,"abstract":"Abstract In order to solve the problem of bacterial resistance, increase the antibacterial performance and delay the aging of paper, the berberine modified trimethoprim carboxymethyl cellulose was prepared using trimethoprimethylate carboxymethyl cellulose as raw material and trimethoprimethylate lactate (TMP) as antibacterial modifier by Schiff Base reaction. At the same time, berberine (BBR) was used as graft monomer to prepare a multifunctional protective solution integrating strengthening, antibacterial and good biocompatibility. The optimal process conditions were determined by single factor experiment and response surface method. The structure and properties of the product were characterized by FT-IR, XRD, TG and SEM and the antibacterial properties were evaluated by AGAR disk diffusion method. The results showed that when the mass ratio of dialdehyde carboxymethyl cellulose and modified berberine was 7:15, reaction temperature was 40 °C, and pH was 6.0, the optimum synthetic conditions was obtained. And the minimum inhibitory concentration of the product against Staphylococcus aureus and Escherichia coli were 0.2 mg/mL, minimum diameter of antibacterial zone of 6.7 mm and 7.1 mm, respectively, with good antibacterial effect. This paper lays a foundation for further research on the safe and effective antiquities antibacterial agent, and provides a reference for its further development in paper protection.","PeriodicalId":19315,"journal":{"name":"Nordic Pulp & Paper Research Journal","volume":"38 1","pages":"271 - 284"},"PeriodicalIF":1.2,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46678061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In this experiment, we explored how to control the penetration of palmitoyl chloride in the gas grafting of PVOH-coated paper. When calcium carbonate was pre-coated, the gas grafting reaction of the PVOH-coated paper tended to be inhibited. It is believed that palmitoyl chloride is additionally consumed by moisture generated when calcium carbonate neutralizes hydrochloric acid gas, a by-product of the graft reaction, thereby inhibiting the graft reaction and reducing the hydrophobization efficiency by generating unreacted residual free fatty acids. Unlike calcium carbonate, the clay coating layer blocks the penetration of vaporized palmitoyl chloride and improves the gas grafting density of PVOH without moisture generation. The PVOH coating layer, where vaporized palmitoyl chloride penetrates, is thinly processed to avoid unnecessary graft reactions in the thickness direction, and the propagation of palmitoyl chloride in the gas phase is blocked by the clay-coating layer. In previous studies, an excess of 1400 mg/m2 of palmitoyl chloride was required to secure strong hydrophobicity of less than 10 g/m2 of Cobb hot water absorption. However, by pre-coating the clay, only 650 mg/m2 of palmitoyl chloride, which was about a 53% reduction compared to previous studies, was sufficient to perform a strong hydrophobic treatment.
{"title":"Study on manufacturing hot water-resistant PVOH coated paper by gas grafting palmitoyl chloride (II)–Control of palmitoyl chloride penetration by inorganic pigments coating","authors":"K. Lee, J. Choi, Kyoung-Hwa Choi, Jeong-yong Ryu","doi":"10.1515/npprj-2022-0069","DOIUrl":"https://doi.org/10.1515/npprj-2022-0069","url":null,"abstract":"Abstract In this experiment, we explored how to control the penetration of palmitoyl chloride in the gas grafting of PVOH-coated paper. When calcium carbonate was pre-coated, the gas grafting reaction of the PVOH-coated paper tended to be inhibited. It is believed that palmitoyl chloride is additionally consumed by moisture generated when calcium carbonate neutralizes hydrochloric acid gas, a by-product of the graft reaction, thereby inhibiting the graft reaction and reducing the hydrophobization efficiency by generating unreacted residual free fatty acids. Unlike calcium carbonate, the clay coating layer blocks the penetration of vaporized palmitoyl chloride and improves the gas grafting density of PVOH without moisture generation. The PVOH coating layer, where vaporized palmitoyl chloride penetrates, is thinly processed to avoid unnecessary graft reactions in the thickness direction, and the propagation of palmitoyl chloride in the gas phase is blocked by the clay-coating layer. In previous studies, an excess of 1400 mg/m2 of palmitoyl chloride was required to secure strong hydrophobicity of less than 10 g/m2 of Cobb hot water absorption. However, by pre-coating the clay, only 650 mg/m2 of palmitoyl chloride, which was about a 53% reduction compared to previous studies, was sufficient to perform a strong hydrophobic treatment.","PeriodicalId":19315,"journal":{"name":"Nordic Pulp & Paper Research Journal","volume":"49 11","pages":"359 - 366"},"PeriodicalIF":1.2,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41306046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rui Chen, Yi Hou, Jinchao Zhang, Jianxiang Cui, Guang-Yin Li
Abstract Reasonable use and disposal of agricultural and forestry wastes become an urgent focus of attention with the dangers of pollution and squandering. In this paper, palm leaves, a typical kind of cellulose-rich agricultural and forestry waste, were attempted to prepare high-valued porous aerogels with cellulose by a short and mild extraction followed by the process of cross-linking with polyvinyl alcohol (PVA). Scanning electron microscope (SEM), Fourier transform-infrared (FTIR), X-ray diffraction (XRD), Bruno-Emmett-Teller (BET), and thermogravimetric analysis (TGA) were applied to examine their structures, chemical composition, and performance compared with hardwood cellulose aerogels. The results showed that palm leaf cellulose could be extracted friendly under mild extraction of 5% NaOH solution for 7 h, following 10% H2O2 solution for 8 h at 80 °C, which inhibits effectively the alkaline hydrolysis of cellulose with the extraction rate of 35.25%, the cellulose purity of 87.12%, and crystallinity of 69.9%. Compared with hardwood cellulose aerogel, the prepared environmentally friendly and recyclable palm leaf cellulose aerogel is a promising application material with similar ultra-low density, high porosity, specific surface area, thermal stability, and better compression resilience, which provides a new technical direction for the high-value application of agricultural and forestry wastes.
{"title":"Feasibility for the preparation of aerogels with celluloses extracted mildly from waste palm leaves","authors":"Rui Chen, Yi Hou, Jinchao Zhang, Jianxiang Cui, Guang-Yin Li","doi":"10.1515/npprj-2022-0084","DOIUrl":"https://doi.org/10.1515/npprj-2022-0084","url":null,"abstract":"Abstract Reasonable use and disposal of agricultural and forestry wastes become an urgent focus of attention with the dangers of pollution and squandering. In this paper, palm leaves, a typical kind of cellulose-rich agricultural and forestry waste, were attempted to prepare high-valued porous aerogels with cellulose by a short and mild extraction followed by the process of cross-linking with polyvinyl alcohol (PVA). Scanning electron microscope (SEM), Fourier transform-infrared (FTIR), X-ray diffraction (XRD), Bruno-Emmett-Teller (BET), and thermogravimetric analysis (TGA) were applied to examine their structures, chemical composition, and performance compared with hardwood cellulose aerogels. The results showed that palm leaf cellulose could be extracted friendly under mild extraction of 5% NaOH solution for 7 h, following 10% H2O2 solution for 8 h at 80 °C, which inhibits effectively the alkaline hydrolysis of cellulose with the extraction rate of 35.25%, the cellulose purity of 87.12%, and crystallinity of 69.9%. Compared with hardwood cellulose aerogel, the prepared environmentally friendly and recyclable palm leaf cellulose aerogel is a promising application material with similar ultra-low density, high porosity, specific surface area, thermal stability, and better compression resilience, which provides a new technical direction for the high-value application of agricultural and forestry wastes.","PeriodicalId":19315,"journal":{"name":"Nordic Pulp & Paper Research Journal","volume":"38 1","pages":"197 - 207"},"PeriodicalIF":1.2,"publicationDate":"2022-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43911514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Interaction between the microwave heating rate and dielectric properties of agricultural wastes is important in identifying suitable microwave operating conditions. This work focuses on the interaction between microwave heating rate (power intensity) and dielectric properties of selected agricultural wastes, namely castor shell, empty fruit bunch and palm kernel shell. Heating rate was recorded every 30 s for 10 min in a 2.45 GHz microwave at power intensities of 100, 300, 450, 600, 700 and 800 W. All materials tested display an increase in heating rate with increasing power intensity. Castor shell and empty fruit bunch at 800 W, and palm kernel shell at 600 W exhibit high heating rates of 0.134, 0.165, 0.247 °C/s, respectively. For dielectric properties, palm kernel shell series shows a high value of loss tangent compared to the other counterparts, indicating its effectiveness to be heated via microwave.
{"title":"Microwave heating rate and dielectric properties of some agricultural wastes","authors":"Norulaina Alias, M. A. Ahmad Zaini, M. Kamaruddin","doi":"10.1515/npprj-2022-0097","DOIUrl":"https://doi.org/10.1515/npprj-2022-0097","url":null,"abstract":"Abstract Interaction between the microwave heating rate and dielectric properties of agricultural wastes is important in identifying suitable microwave operating conditions. This work focuses on the interaction between microwave heating rate (power intensity) and dielectric properties of selected agricultural wastes, namely castor shell, empty fruit bunch and palm kernel shell. Heating rate was recorded every 30 s for 10 min in a 2.45 GHz microwave at power intensities of 100, 300, 450, 600, 700 and 800 W. All materials tested display an increase in heating rate with increasing power intensity. Castor shell and empty fruit bunch at 800 W, and palm kernel shell at 600 W exhibit high heating rates of 0.134, 0.165, 0.247 °C/s, respectively. For dielectric properties, palm kernel shell series shows a high value of loss tangent compared to the other counterparts, indicating its effectiveness to be heated via microwave.","PeriodicalId":19315,"journal":{"name":"Nordic Pulp & Paper Research Journal","volume":"38 1","pages":"1 - 7"},"PeriodicalIF":1.2,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49001090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stefan Bürgmayr, Joanne Tanner, W. Batchelor, A. Hoadley
Abstract Water system closure in recycled containerboard mills may have reached a technical limit due to the accumulation of organic and inorganic contaminants in the process water. The specific water chemistry characteristics of recycled containerboard mills with restricted water systems were analyzed and a computer model was developed to simulate calcium carbonate solubility in the presence of volatile fatty acids under relevant mill conditions. A strong linear correlation between VFAs and calcium ions was found. The calcium carbonate dissolution mechanism, solubility, and precipitation were investigated. The reaction of VFAs with calcium carbonate results in the formation of bicarbonate and carbonic acid. By binding hydrogen ions, the carbonate has a pH buffering effect. The carbonic acid dissociates into water and CO2. Gaseous CO2 escapes from the water and leads to decarbonization. This mechanism is responsible for the uncoupling of pH from the concentration of VFAs, as well as from the concentration of dissolved calcium ions. The resulting lack of carbonates prevents the precipitation of calcium carbonate. The introduction of CO2 contained in the biogas produced in anaerobic biological water treatment reverses the dissolution mechanism and causes the precipitation of calcium carbonate. Concentrating technologies such as membrane filtration and evaporation may therefore meet the specific requirements for complete water system closure in recycled containerboard mills better than current commonly used biological treatment.
{"title":"CaCO3 solubility in the process water of recycled containerboard mills","authors":"Stefan Bürgmayr, Joanne Tanner, W. Batchelor, A. Hoadley","doi":"10.1515/npprj-2022-0042","DOIUrl":"https://doi.org/10.1515/npprj-2022-0042","url":null,"abstract":"Abstract Water system closure in recycled containerboard mills may have reached a technical limit due to the accumulation of organic and inorganic contaminants in the process water. The specific water chemistry characteristics of recycled containerboard mills with restricted water systems were analyzed and a computer model was developed to simulate calcium carbonate solubility in the presence of volatile fatty acids under relevant mill conditions. A strong linear correlation between VFAs and calcium ions was found. The calcium carbonate dissolution mechanism, solubility, and precipitation were investigated. The reaction of VFAs with calcium carbonate results in the formation of bicarbonate and carbonic acid. By binding hydrogen ions, the carbonate has a pH buffering effect. The carbonic acid dissociates into water and CO2. Gaseous CO2 escapes from the water and leads to decarbonization. This mechanism is responsible for the uncoupling of pH from the concentration of VFAs, as well as from the concentration of dissolved calcium ions. The resulting lack of carbonates prevents the precipitation of calcium carbonate. The introduction of CO2 contained in the biogas produced in anaerobic biological water treatment reverses the dissolution mechanism and causes the precipitation of calcium carbonate. Concentrating technologies such as membrane filtration and evaporation may therefore meet the specific requirements for complete water system closure in recycled containerboard mills better than current commonly used biological treatment.","PeriodicalId":19315,"journal":{"name":"Nordic Pulp & Paper Research Journal","volume":"38 1","pages":"181 - 195"},"PeriodicalIF":1.2,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41774980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The bending properties of cardboard in the machine direction and cross direction were obtained via three-point bending and elastica bending tests using samples of various span lengths. The bending stiffness, moment at the proportional limit, and moment capacity per unit width were determined, and the effects of the testing method and span length were investigated. In the three-point bending test, the bending stiffness often decreased as the span length decreased because of the effect of the low interlaminar shear modulus of cardboard, and this tendency was more pronounced when the length direction of the sample coincided with the machine direction. Such dependence was less obvious in the moment at the proportional limit. In contrast, when the length coincided with the cross direction, the moment capacity of the cardboard often decreased as the span length increased because the large deflection prevented the accurate calculation of the moment capacity by using elementary beam theory. However, in the elastica bending test, both the bending stiffness and moment capacity could be obtained while reducing the effect of the span length. Therefore, to obtain the bending properties of cardboard, the elastica bending test was determined to be more advantageous than the three-point bending test.
{"title":"Bending stiffness and moment capacity of cardboard obtained from three-point and elastica bending tests","authors":"H. Yoshihara, Masahiro Yoshinobu, M. Maruta","doi":"10.1515/npprj-2022-0087","DOIUrl":"https://doi.org/10.1515/npprj-2022-0087","url":null,"abstract":"Abstract The bending properties of cardboard in the machine direction and cross direction were obtained via three-point bending and elastica bending tests using samples of various span lengths. The bending stiffness, moment at the proportional limit, and moment capacity per unit width were determined, and the effects of the testing method and span length were investigated. In the three-point bending test, the bending stiffness often decreased as the span length decreased because of the effect of the low interlaminar shear modulus of cardboard, and this tendency was more pronounced when the length direction of the sample coincided with the machine direction. Such dependence was less obvious in the moment at the proportional limit. In contrast, when the length coincided with the cross direction, the moment capacity of the cardboard often decreased as the span length increased because the large deflection prevented the accurate calculation of the moment capacity by using elementary beam theory. However, in the elastica bending test, both the bending stiffness and moment capacity could be obtained while reducing the effect of the span length. Therefore, to obtain the bending properties of cardboard, the elastica bending test was determined to be more advantageous than the three-point bending test.","PeriodicalId":19315,"journal":{"name":"Nordic Pulp & Paper Research Journal","volume":"38 1","pages":"73 - 85"},"PeriodicalIF":1.2,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45818022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：