Treatment of NBKP with Cellulase to Reduce the Refining Energy Consumption in Production of Grease Proof Paper

2011 ◽  
Vol 236-238 ◽  
pp. 1379-1384
Author(s):  
Jun Liu ◽  
Hui Ren Hu
Keyword(s):  
Energy Consumption ◽  
Energy Requirement ◽  
Fiber Surface ◽  
Orthogonal Test ◽  
Manufacturing Cost ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Binding Domains ◽  
Tear Index ◽  
Cellulose Binding

Refining is an energy-intensive papermaking process where energy consumption contributes about 18% of the total manufacturing cost. Through the application of cellulases before refining, mills can reduce their energy requirement for refining of pulps and realize the aim of energy consumption. In the present study, two kinds of cellulase within or wothout the cellulose binding domains (CBDs) were used to treat the pulp aimed at reducing the refining energy consumption in production of grease proof paper. In order to compare and evaluate these effects on reducing the pulp refining energy consumption, these two cellulases were compared based on their effects on Schopper-Riegler freeness (°SR), fiber morphology and paper properties ( tensile index, tear index). Orthogonal test was used to examine the interaction of enzyme dosages and contact time on the beatability of the pulp. Results showed that the cellulase of Refinase M (within the CBDs) was excellent in reducing the refining energy consumption, when pretreated with 0.02% of Refinase M about 18.5% of the refining energy can be saved, and the properties of paper were not affected obviously. Moreover, results showed that the existence of CBDs in cellulases play a significant role in reducing the energy consumption. Examination of the fiber surface by SEM show notable improvement in fibrillation.

Influences of Bleached Softwood Pulp Pretreated with Endo-Cellulase on Fiber Surface Properties and Aggregation Structure

2011 ◽  
Vol 391-392 ◽  
pp. 692-696
Author(s):  
Min Du ◽  
Xin Ping Li ◽  
Wu Guang Li
Keyword(s):  
Energy Consumption ◽  
Fiber Surface ◽  
Paper Sheet ◽  
Paper Properties ◽  
Enzymatic Pretreatment ◽  
Wetting Properties ◽  
Tear Index ◽  
Softwood Pulp ◽  
Aggregation Structure ◽  
Refining Performance

The influences of endo-cellulase pretreatment of bleached softwood pulp before refining was investigated in this paper. Refining energy consumption, paper properties, wetting properties, electric charge and aggregation structure of fiber were investigated. The results showed that pretreated with endo-cellulase at the dosage of 0.4ECG/g before refining could increase the refining degree by 53.09%, and it would reduce refining energy consumption significantly. At this dosage, the tensile index of the paper sheet increased while the tear index of paper sheet decreased slightly. Additionally, enzymatic pretreatment could raise fiber surface wettability, lower the absolute value of Zeta potential and decrease the crystallinity of fiber, which was help to improve refining performance.

Enzyme-assisted pulp refining: an energy saving approach

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Amit Kumar ◽  
Chhotu Ram ◽  
Adebabay Tazeb
Keyword(s):  
Energy Consumption ◽  
Paper Industry ◽  
Electrical Power ◽  
Manufacturing Cost ◽  
Paper Properties ◽  
Paper Making ◽  
Paper Manufacturing ◽  
Cost Of Energy ◽  
Refining Time ◽  
Electrical Power Consumption

AbstractEnergy conservation has become an essential step in pulp and paper industry due to diminishing fossil reserves and high cost of energy. Refining is a mechanical treatment of pulp that modifies the structure of the fibres in order to achieve desired paper-making properties. However, it consumes considerable amount of energy. The electrical power consumption has a direct impact on paper manufacturing cost. Therefore, there is a requirement to minimize the energy cost. Enzyme-assisted refining is the environment friendly option that reduces the energy consumption for papermaking. Enzyme-assisted refining is defined as mechanical refining after pretreatment of pulp with enzymes such as cellulases and hemicellulases. It not only reduces the energy consumption but also improves the quality of finished paper. Enzymes improve the beatability of pulp at same refining degree (°SR) and desired paper properties can be achieved at decreased refining time. The selection of suitable enzyme, optimization of enzyme dose and appropriate reaction time are the key factors for energy reduction and pulp quality improvement during enzyme-assisted refining.

scholarly journals BIODEINKING SORTED WHITE LEDGER (SWL) MENGGUNAKAN SELULASE (BIODEINKING SORTED WHITE LEDGER (SWL) BY CELLULASE)

2017 ◽  
Vol 7 (02) ◽  
pp. 49
Author(s):  
Chandra Apriana Purwita ◽  
Sonny Kurnia Wirawan
Keyword(s):  
Optical Properties ◽  
Enzymatic Degradation ◽  
Fiber Surface ◽  
Dry Weight ◽  
Optimum Dose ◽  
Fiber Morphology ◽  
Tear Index

Biodeinking is a process of separating ink on the fiber surface by enzymes. This research was conducted to study and optimize biodeinking condition of sorted white ledger (SWL) by cellulase. Commercial cellulase (Sigma Aldrich, Singapore) at a dose of 0.25; 0.5; 0.75; 1; 2 U/g dry weight pulp was applied to the deinking of SWL and compared with blank. The deinked pulp was then analyzed for the fiber morphology and made laboratory hand sheets for the characterization of physical and optical properties. Based on the experiment, at the optimum dose of cellulase 0.75 IU/g dry weight pulp was obtained a maximum increasement of ISO brightness by 4.7 points and a decreasement of ERIC by 34.45%. The use of celulase on the biodeinking was not affecting the fibers length and diameter so the tensile and tear index of deinked pulp unchanged. Loss of fines by enzymatic degradation causes the tear index decreased by 8.70 % and porosity increased. The increasement of coarseness resulted in the decreasement of pulp opacity.ABSTRAKBiodeinking merupakan proses pemisahan tinta pada permukaan serat menggunakan enzim. Penelitian ini dilakukan untuk mempelajari dan memperoleh kondisi optimum biodeinking sorted white ledger (SWL) menggunakan selulase. Selulase komersial (Sigma Aldrich, Singapura) dengan dosis 0,25; 0,5; 0,75; 1; 2 U/g kering pulp diaplikasikan pada deinking SWL dan dibandingkan terhadap blanko. Pulp deinked yang diperoleh kemudian dilakukan analisis morfologi serat dan dibuat lembaran tangan laboratorium untuk karakterisasi sifat fisik dan optik. Berdasarkan percobaan, pada dosis optimum selulase 0,75 IU/g kering pulp diperoleh kenaikan derajat cerah ISO maksimum sebesar 4,7 poin dan penurunan ERIC 34,45%. Analisis morfologi serat menunjukkan penggunaan selulase pada proses biodeinking tidak berpengaruh terhadap panjang dan diameter serat sehingga indeks tarik dan retak pulp deinked tidak berubah. Kehilangan fines karena degradasi enzimatik menyebabkan indeks sobek turun sebesar 8,70% dan porositas naik. Naiknya nilai coarseness menyebabkan meningkatnya opasitas pulp deinked.

Using cationic polyvinyl alcohol (C-PVA) to improve the strength of wood-free papers containing high-yield pulp (HYP)

Holzforschung ◽  
2010 ◽  
Vol 64 (5) ◽  
Author(s):  
Xin Liu ◽  
Pedram Fatehi ◽  
Yonghao Ni ◽  
Huining Xiao
Keyword(s):  
Polyvinyl Alcohol ◽  
Apparent Density ◽  
Fiber Surface ◽  
Strength Properties ◽  
High Yield ◽  
Kraft Pulps ◽  
Paper Properties ◽  
Atomic Force ◽  
Tear Index ◽  
Afm Analysis

AbstractHigh-yield pulp (HYP) is gaining increasing interest in wood-free papers, because it can improve the bulk, formation, and opacity of papers. However, one of the challenges for the papermakers is the strength of papers when a large amount of HYP is replaced with hardwood kraft pulp. In this work, we explored the potential of using cationic-modified polyvinyl alcohol (C-PVA) in increasing the strength properties of HYP. Also, C-PVA was applied to the paper-sheets made of softwood/hardwood bleached kraft pulps (SBKP/HBKP) and HYP under various conditions, and the corresponding paper properties were evaluated. It was observed that C-PVA increased the strength properties of these paper-sheets, and the results obtained from using C-PVA were only slightly less effective than those obtained from using cationic starch (C-starch). Furthermore, the addition of C-PVA to HYP, and subsequently mixing with the blend of SBKP/HBKP (option no. 1) improved the tensile and burst indices, light scattering coefficient and apparent density of paper-sheets more significantly than did the addition of C-PVA directly to the mixed furnish of SBKP/HBKP/HYP (option no. 2). Additionally, atomic force microscope (AFM) analysis showed that the attraction force, developed between the AFM-tip and the fiber surface, was changed by the C-PVA modification. The tensile and burst indices of paper-sheets were improved by adding 10 mg g-1C-PVA and substituting 30% of HYP for HBKP, whereas the tear index, apparent density, PPS-roughness, and brightness decreased.

SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

1977 ◽  
Vol 35 ◽  
pp. 308-309
Author(s):  
K. W. Robinson
Keyword(s):  
Tension Wood ◽  
Wood Fiber ◽  
Strength Properties ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Pure Cellulose ◽  
Short Rotation ◽  
Hardwood Trees ◽  
Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

scholarly journals Multi-Objective Energy Management and Charging Strategy for Electric Bus Fleets in Cities Using Various ECO Strategies

2021 ◽  
Vol 13 (14) ◽  
pp. 7865
Author(s):  
Mohammed Mahedi Hasan ◽  
Nikos Avramis ◽  
Mikaela Ranta ◽  
Andoni Saez-de-Ibarra ◽  
Mohamed El Baghdadi ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Thermal Management ◽  
Energy Management ◽  
Management Strategy ◽  
Energy Requirement ◽  
Optimization Technique ◽  
Total Cost ◽  
Multi Objective ◽  
Battery Capacity ◽  
Eco Features

The paper presents use case simulations of fleets of electric buses in two cities in Europe, one with a warm Mediterranean climate and the other with a Northern European (cool temperate) climate, to compare the different climatic effects of the thermal management strategy and charging management strategy. Two bus routes are selected in each city, and the effects of their speed, elevation, and passenger profiles on the energy and thermal management strategy of vehicles are evaluated. A multi-objective optimization technique, the improved Simple Optimization technique, and a “brute-force” Monte Carlo technique were employed to determine the optimal number of chargers and charging power to minimize the total cost of operation of the fleet and the impact on the grid, while ensuring that all the buses in the fleet are able to realize their trips throughout the day and keeping the battery SoC within the constraints designated by the manufacturer. A mix of four different types of buses with different battery capacities and electric motor specifications constitute the bus fleet, and the effects that they have on charging priority are evaluated. Finally, different energy management strategies, including economy (ECO) features, such as ECO-comfort, ECO-driving, and ECO-charging, and their effects on the overall optimization are investigated. The single bus results indicate that 12 m buses have a significant battery capacity, allowing for multiple trips within their designated routes, while 18 m buses only have the battery capacity to allow for one or two trips. The fleet results for Barcelona city indicate an energy requirement of 4.42 GWh per year for a fleet of 36 buses, while for Gothenburg, the energy requirement is 5 GWh per year for a fleet of 20 buses. The higher energy requirement in Gothenburg can be attributed to the higher average velocities of the bus routes in Gothenburg, compared to those of the bus routes in Barcelona city. However, applying ECO-features can reduce the energy consumption by 15% in Barcelona city and by 40% in Gothenburg. The significant reduction in Gothenburg is due to the more effective application of the ECO-driving and ECO-charging strategies. The application of ECO-charging also reduces the average grid load by more than 10%, while shifting the charging towards non-peak hours. Finally, the optimization process results in a reduction of the total fleet energy consumption of up to 30% in Barcelona city, while in Gothenburg, the total cost of ownership of the fleet is reduced by 9%.

scholarly journals A Fundamental Study on the Development of New Energy Performance Index in Office Buildings

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2064
Author(s):  
Jin-Hee Kim ◽  
Seong-Koo Son ◽  
Gyeong-Seok Choi ◽  
Young-Tag Kim ◽  
Sung-Bum Kim ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Requirement ◽  
Energy Performance ◽  
Office Buildings ◽  
Light Transmittance ◽  
Wall Structure ◽  
Fundamental Study ◽  
Future Studies ◽  
U Value ◽  
The Impact

Recently, there have been significant concerns regarding excessive energy use in office buildings with a large window-to-wall ratio (WWR) because of the curtain wall structure. However, prior research has confirmed that the impact of the window area on energy consumption varies depending on building size. A newly proposed window-to-floor ratio (WFR) correlates better with energy consumption in the building. In this paper, we derived the correlation by analyzing a simulation using EnergyPlus, and the results are as follows. In the case of small buildings, the results of this study showed that the WWR and energy requirement increase proportionally, and the smaller the size is, the higher the energy sensitivity will be. However, results also confirmed that this correlation was not established for buildings approximately 3600 m2 or larger. Nevertheless, from analyzing the correlation between the WFR and the energy requirements, it could be deduced that energy required increased proportionally when the WFR was 0.1 or higher. On the other hand, the correlation between WWR, U-value, solar heat gain coefficient (SHGC), and material property values of windows had little effect on energy when the WWR was 20%, and the highest effect was seen at a WWR of 100%. Further, with an SHGC below 0.3, the energy requirement decreased with an increasing WWR, regardless of U-value. In addition, we confirmed the need for in-depth research on the impact of the windows’ U-value, SHGC, and WWR, and this will be verified through future studies. In future studies on window performance, U-value, SHGC, visible light transmittance (VLT), wall U-value as sensitivity variables, and correlation between WFR and building size will be examined.

Action Mechanism of the Improvement of Printability for Eucalypt Bleached Kraft Pulp Pretreated by Cellulase

2013 ◽  
Vol 779-780 ◽  
pp. 294-301
Author(s):  
Wan You Tang ◽  
Li Chen ◽  
Zheng Jian Zhang
Keyword(s):  
Tensile Strength ◽  
Fiber Length ◽  
Kraft Pulp ◽  
Pulp Fiber ◽  
Fiber Morphology ◽  
Strength Index ◽  
Bleached Kraft Pulp ◽  
Tear Index ◽  
Pulp Sample ◽  
The Mean

Enzymatic refining of eucalypt bleached kraft pulp with the cellulase NOV476 was studied. The effects of this cellulase on the physical properties of pulp, fiber morphology and fiber appearance of the eucalypt bleached kraft pulp in different application conditions were discussed. The results show that, with the increase in the amount of enzyme, tensile strength index, burst index and TEA index of paper are increased and then decreased; elongation and tear index of paper have been declining, Zeeil tensile strength index has been an upward trend. Without beating the pulp sample, gradually increases as the amount of enzyme, the average fiber length and the average fiber width are gradually reduced, while mean kink index substantially constant. Number of vessels in fiber overall reduced tendency reaches a minimum in the amount of enzyme 0.5μ/g, the phenomenon is most obvious. In the same conditions of beating time, gradually increases as the amount of enzyme, the average fiber length is gradually reduced, an average fiber width is gradually increased, the mean kink index reaches a maximum in the amount of enzyme is 0.5μ/g. Number of vessels in fiber overall reduced trend.

scholarly journals Copper and Lead Ions Removal by Electrocoagulation: Process Performance and Implications for Energy Consumption

2021 ◽  
Vol 10 (3) ◽  
pp. 415-424
Author(s):  
Aji Prasetyaningrum ◽  
Dessy Ariyanti ◽  
Widayat Widayat ◽  
Bakti Jos
Keyword(s):  
Heavy Metals ◽  
Energy Consumption ◽  
Removal Efficiency ◽  
Current Density ◽  
High Current Density ◽  
Energy Requirement ◽  
Lead Ions ◽  
Initial Concentration ◽  
Electroplating Wastewater ◽  
Electrocoagulation Process

Electroplating wastewater contains high amount of heavy metals that can cause serious problems to humans and the environment. Therefore, it is necessary to remove heavy metals from electroplating wastewater. The aim of this research was to examine the electrocoagulation (EC) process for removing the copper (Cu) and lead (Pb) ions from wastewater using aluminum electrodes. It also analyzes the removal efficiency and energy requirement rate of the EC method for heavy metals removal from wastewater. Regarding this matter, the operational parameters of the EC process were varied, including time (20−40 min), current density (40−80 A/m2), pH (3−11), and initial concentration of heavy metals. The concentration of heavy metals ions was analyzed using the atomic absorption spectroscopy (AAS) method. The results showed that the concentration of lead and copper ions decreased with the increase in EC time. The current density was observed as a notable parameter. High current density has an effect on increasing energy consumption. On the other hand, the performance of the electrocoagulation process decreased at low pH. The higher initial concentration of heavy metals resulted in higher removal efficiency than the lower concentration. The removal efficiency of copper and lead ions was 89.88% and 98.76%, respectively, at 40 min with electrocoagulation treatment of 80 A/m2 current density and pH 9. At this condition, the specific amounts of dissolved electrodes were 0.2201 kg/m3, and the energy consumption was 21.6 kWh/m3. The kinetic study showed that the removal of the ions follows the first-order model.

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