Chemical Pulp Research Articles

Preparation and Quality Evaluation of Functional Persimmon (Diospyros kaki) Juice for Diabetic Patients.

Abstract
 Persimmon (Diospyros kaki) a delicious fruit belongs to Rahmanaceae family. It is a climacteric fruit which is successfully grown in all regions of the world. Persimmon a perishable fruit which is consumed in both fresh and processed forms. It is a rich source of essential nutrients and bioactive compounds such as protein, vitamins, minerals, tannin, flavonoids and carotenoids. The current study was planned to investigate the antidiabetic potential of low calorie persimmon juice under different intervals of time. For this objective persimmon pulp was separated from peel and then it was analyzed for quality parameters. After chemical analysis persimmon pulp revealed that crude protein, crude fat, crude fiber, total phenolic, microbiological contents, calcium, and magnesium were 0.56±0.05%, 0.16±0.02%, 3.85±0.05, 12.41±0.39GAE/g, 4.60±0.26log10 CFU/g, 7.5±0.02mg, 156.5±0.11mg and 8.83±0.03mg, respectively. Persimmon juice was prepared by adding various levels of persimmon pulp. The results showed that the persimmon juice contained a lot of antidiabetic activity. It is concluded that low calorie persimmon juice would be appropriate choice for diabetic patients.
 Keywords: Persimmon fruit composition; bioactive compounds; persimmon juice; antidiabetic potential.

Valorisation of Underutilized Grass Fibre (Stem) as a Potential Material for Paper Production.

An integrated and feasible approach was proposed using the underutilized grass fibre (stem) derived from Napier grass and sugarcane for paper production in this study. To enhance paper strength, pre-hydrolysis and beating techniques have been used to improve the chemical pulps and mechanical pulping process, respectively. Napier grass and sugarcane are promising non-wood sources for pulp production, owing to their high cellulose and low lignin and extractive content. With the additional mild alkaline pre-treatment to the mechanical pulping process, the lignin content was greatly reduced. The results reveal that the mechanical pulping with alkaline pre-treatment may indeed potentially replace the most prevalent pulping process (chemical pulping). As evidenced by the paper strength properties, mechanical pulping is far more suitable for grass-type biomass, particularly Napier grass, which had a folding endurance capability five times greater than chemical pulping. Furthermore, the remaining high hemicellulose content from mechanical pulping contributed to a high pulp yield, while also facilitating the fibrillation on the sugarcane's laboratory paper handsheet. The findings also demonstrated that the additional beating process from chemical pulping causes the fibres to be drawn toward each other, resulting in a more robust fibre network that contributes to good paper strength. Consequently, this work sheds new light on the development of advanced paper derived from grass fibre.

Spectroscopic Investigations for the Dating of Paper from the Nineteenth Century.

The knowledge of the detailed material composition of paper can help art historians, archivist, librarians, paper historians, and conservators to determine the possible age of a document or a work of art. The dating of paper by the identification of specific paper components is especially applicable to paper from the 19th century. In this era, many changes in the paper production technology occurred and new raw materials were introduced in relatively short time intervals. ATR-IR and Raman spectroscopic measurements were used to analyze the chemical composition and structure of papers from the 19th century. The infrared spectra showed the general material composition of the papers. More specific information on the different paper components and their distribution in the paper were obtained by Raman microscopic measurements. The resulting Raman images visualize the detailed chemical structure of the papers including all components such as paper fibers, filler pigments, sizing agents, and color pigments. Special emphasis was made on the spectroscopic identification of different paper fiber types, like straw, esparto, and sulphite and sulfate chemical wood pulp, which were introduced to paper production during the second half of the 19th century. It could be shown that the specific spectral differences in the Raman spectra of the different paper fiber types are related to different amounts of hemicellulose xylan compounds on or in the cellulose fibers.

Thermodynamic analysis of a cogeneration system in pulp and paper industry under singular and hybrid operating modes

In the present study, a thermodynamic analysis of a cogeneration system in a pulp and paper industry under different operating modes i.e., singular and hybrid with a variable ambient temperature is conducted according to actual operating data. For singular operating mode, the power boiler is only employed using natural gas while for hybrid operating mode, the power boiler with the recovery boiler is employed using natural gas and black liquor as main fuels, respectively. The results show that for hybrid operating mode in comparison with the singular one, the thermal efficiency of turbine and condenser is enhanced by 1.36 and 7.7%, respectively while it is reduced by 2.8% for the power boiler. In addition, the overall thermal efficiency under singular and hybrid operating modes is 87.4 and 53.7%, respectively. For hybrid operating mode, the exergy destruction of power boiler decreases by almost 10% compared with that for the singular operating mode. Also, at hybrid operating mode, the soda is recovered with a mass flow rate of 33 tons/hour that is required for the cooking process in the chemical pulp section and additionally the consumption of natural gas in the power boiler is reduced by 11.8%.

Utilization of palm fiber as papermaking materials: Microscopic structure and chemical pulping

The microscopic structure and pulping properties of palm fiber were explored. Soda cooking and sulfate cooking were conducted and compared in terms of physical strength of the obtained pulps. Sulfate pulp showed better performance than soda pulp, as indicated by the 23% higher tensile index, 49% higher tear index, and 36% higher burst index. To further elevate physical strength, long fibered pulp (LFP), namely commercial softwood sulfate pulp, was mixed with sulfate pulp of palm fiber at levels from 20% to 50%. At the blend level of 50%, tensile index of 52.13 N•m/g, tear index of 15.63 mN•m2/g, and burst index of 3.42 kPa•m2/g were attained. The lignin in spent liquor from pulping was isolated and characterized. Soda lignin of palm fiber was mainly composed of guaiacyl and syringyl units, and showed weight-average molecular weight of 3616 g/mol.

Internal bonding microstructures characterisation between plant nanocellulose and concrete mortar mixtures for indoor Radon-222 gas emanation reduction

• CNF crystallinity index fosters by high frequency ultrasonication. • Great CNF dissemination enhances mechanical strength of the composite brick. • CNF significantly impact internal porosity nanonization of the composite brick. • Tiniest internal porosity observed on 40 mL kenaf CNF composite brick. • Lowest 222 Rn concentration emanated from 40 mL oil palm CNF composite brick. Radon-222 ( 222 Rn) is a natural radioactive gas produced by the radium-226 ( 226 Ra) decay process, which is part of the uranium-238 ( 238 U) decay series. 222 Rn gas can penetrate into the respiratory system during the inhalation process and have an indirect effect on lung tissues due to energetic alpha particles. Brick is a common building material that consists of rock, water, and sand. It is the most prevalent source of 222 Rn gas emanation to humans in an indoor building environment. To reduce indoor 222 Rn gas emanation, kenaf and oil palm cellulose nanofibrils (CNF) were mixed into bricks in certain ratios and acted as liquid fillers. CNFs were produced by using chemical pulping, bleaching, and ultrasonic techniques. Ten composite bricks with different ratios of CNF and one control brick were fabricated by following Malaysia Standard (MS 7.6:1972). The characterization of CNF was done using Fourier Transformed Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). The Brunauer-Emmett-Teller (BET) was used to analyse the internal porosity and surface area of the fabricated bricks. 222 Rn concentrations in the bricks and humidity inside the prototype Perspex box were recorded using the Radon Sentinel Monitor Model 1030. The surface areas for control brick, 40 mL kenaf, and oil palm CNF composite bricks are 3.4473 m 2 /g, 4.449 m 2 /g, and 4.9025 m 2 /g, respectively. Meanwhile, pore sizes for control brick, 40 mL kenaf and oil palm CNF composite bricks are 2.92 nm, 0.347 nm and 2.27 nm, respectively. The highest 222 Rn concentration was measured in control brick, which is 3.77 pCi/L, followed by 40 mL kenaf CNF brick and 40 mL oil palm CNF brick, with readings of 1.4 pCi/L and 0.93 pCi/L. The incorporation of CNFs has the ability to reduce 222 Rn emissions while increasing the physical strength of the bricks.

ANOTHER VIEW ON HIV/AIDS TESTING AT THE WORKPLACE PFG Building Glass (Pty) Ltd v Chemical Engineering Pulp Paper Wood & Allied Workers Union (2003) 24 ILJ 974 (LC)

In the third of a trilogy of cases (the first two being Joy Mining Machinery (A division of Harnischfeger (SA) (Pty) (Ltd) v NUMSA (2002) 23 ILJ 391 (LC) and Irvin and Johnson Ltd v Trawler and Line Fishing Union (2003) 24 ILJ 565 (LC)) interpreting the boundaries of section 7(2) of the Employment Equity Act 55 of 1998 (hereinafter referred to as “EEA”), the Labour Court in PFG Building Glass (Pty) Ltd v Chemical Engineering Pulp Paper Wood & Allied Workers Union ((2003) 24 ILJ 974 (LC)) (hereinafter referred to as “PFG Building Glass (Pty) Ltd v CEPPWAWU) has yet again approached the issue of HIV/Aids testing at the workplace from a different perspective.In this case the applicant sought a declarator pronouncing that authorisation for the anonymous and voluntary testing of employees for HIV/Aids at the workplace was unnecessary, as such testing does not fall within the scope of section 7(2) of the EEA. Section 7(2) of the EEA expressly prohibits the testing of an employee to establish HIV/Aids status, unless such testing is “determined to be justifiable by the labour court …” A similar order was sought and granted in the earlier decision of Rogers AJ in Irvin and Johnson Ltd v Trawler and Line Fishing Union (supra) on different grounds. Unlike Rogers AJ in Irvin and Johnson Ltd v Trawler and Line Fishing Union (supra), Pillay J in PFG Building Glass (Pty) Ltd v CEPPWAWU (supra) chose to interpret this provision on the grounds identified by section 3 of the EEA, being “compliance with the Constitution, so as to give effect to its purpose, taking into account any relevant code of good practice … and compliance with international law obligations …”

Biodegradation of alkali-O2 oxidized lignins used as dispersants

Large quantities of lignin are produced as by-streams via chemical pulping and emerging biorefinery processes. These lignins are typically water-insoluble; however, they can be converted into a water-soluble form by chemical modifications. A novel LigniOx technology solubilizes lignin using alkali-O2 oxidation. The product can be used for bio-based dispersants. This study evaluated the biodegradability of alkali-O2 oxidized kraft, organosolv, and hydrolysis lignin. The oxidized lignins exhibited higher biodegradation in soil and in aquatic environments in comparison to a commercial kraft lignin and a commercial lignosulfonate. In soil, the biodegradabilities of oxidized lignins were 19 to 44%, whereas the reference lignins exhibited only 5 to 12% conversion to CO2. Biodegradation of the oxidized lignins and references in the aquatic environment increased in a similar order as in the soil environment, although the degradation in each sample was slightly smaller than in the soil. The improved biodegradability of the oxidized lignins was due to the altered chemical structure of lignin. Compared to the untreated lignin, the oxidized lignin contained structures formed in aromatic ring opening reactions, making the lignin more accessible to microbial degradation. In addition, the oxidized lignin contained carbon originating from small organic compounds, which are easily biodegradable.

Developing an Efficient Processing System Treatment for the High Concentration of Eucalyptus Chemical Mechanical Pulp Wastewater.

The current wastewater treatment method shows low efficiency in treating wastewater with high concentrations of chemical mechanical pulp (CMP). Therefore, a chlorine dioxide Pretreatment Anaerobic Treatment (DPAT) was developed and applied to treat the CMP wastewater to obtain higher efficiency, obtaining the following results: The biodegradability of CMP wastewater improved after chlorine dioxide pretreatment. The COD of wastewater treated with chlorine dioxide was reduced from 5634 mg/L to 660 mg/L. The removal rate for chemical oxygen demand (COD) was 88.29%, 29.13% higher than the common anaerobic treatment. The reasons for the high efficiency of the DPAT treatment were that chlorine dioxide pretreatment removed the toxic substances in the original wastewater and thereby promoted the proliferation and growth of the anaerobe. The results show that pretreatment with chlorine dioxide can effectively enhance the biodegradability of high-concentration CMP wastewater. Therefore, DPAT treatment of high-concentration CMP wastewater is beneficial to environmental protection.

Replacement of hydrated lime by lime mud-residue from the cellulose industry in multiple-use mortars production

The pulp and paper industry increases every year in Brazil, providing an important country position in international market due to its production volume. However, because of this increasing, a large volume of wastes is generated. One of them is a lime mud, resulting from the Kraft chemical pulping production process. Thus, the aim of this study was to evaluate the replacement of hydrated lime by lime mud on laying and coating mortars production, in order to verify its feasibility for possible application in civil construction industry. The 100% hydrated lime replacement mortar reached a 28-day compressive strength of 5.84 MPa. Finally, the results obtained in the experimental program showed that the 100% hydrated lime replacement mortar by lime mud meets the normative requirements for multiple-use mortars.

The effect of the strain rate on the longitudinal modulus of cellulosic fibres

The longitudinal stiffness of cellulosic fibres plays an important role in the mechanical performance of many products these fibres are used for. Especially, the fibres’ viscoelastic properties are having an influence on the product performance.In this work, tensile testing at different strain rates was performed on single fibres to investigate the rate dependence of their moduli. Four different fibre types were tested: chemi-thermomechanical softwood pulp (CTMP), bleached chemical softwood pulp (CP), unbleached softwood kraft pulp (UKP), and viscose (VIS). For each fibre sample, ten strain rates ranging from 0.113% s−1 to 800% s−1 were applied. The rate-dependent modulus E_{r} of each fibre at each strain rate was calculated by linearly fitting the stress–strain curves. By obtaining the values of the normalized modulus, a slope value per decade was calculated to quantify the rate dependence. To exclude possible plastic and relaxation effects, two additional experiments were used: a force-controlled loading–unloading experiment and a reverse rate protocol.All cellulosic fibres tested exhibited rate-dependent behaviour with a log-linear relationship between loading rate and modulus. For each tenfold increase in loading rate we found an increase in modulus up to nearly 20%—depending on the fibre type. Viscose fibres exhibit the highest rate dependence, whereas chemical softwood pulp fibres exhibit the lowest.

Dynamic Causal Relationships among Import Price, Import Quantity, and Ocean Freight Rate Index in the Chemical Pulp Market

This study investigates the dynamic causal relationships among import price, import quantity, and ocean freight rate index in the chemical pulp market. The Johansen cointegration test was applied to determine the cointegration among the three time series variables in this study, demonstrating their long run equilibrium relationship. Results of the vector error correction model (VECM) indicated that the pulp import quantity has an error correction mechanism that leads to convergence toward the long run equilibrium level or steady state. Furthermore, the Granger causality test results revealed a unidirectional causal relationship between the ocean freight rate index and quantity of wood pulp imported, implying that ocean freight rates influence the quantity of wood pulp imported. Moreover, the results of impulse response analysis revealed that an increase in ocean freight rate index shock has a notably negative impact on pulp import quantity, leading to the general decrease in import quantity in both the short and long run.

Improving the degree of polymerization of cellulose nanofibers by largely preserving native structure of wood fibers

The degree of polymerization (DP) of cellulose plays an essential role in unlocking the superior mechanical potential of wood cellulose nanofibrils (CNFs). However, severe degradation of cellulose chains during the chemical pulping is a big challenge to obtain CNFs with high DP. In this work, we tend to improve the DP of wood CNFs by significantly preserving the native structure of wood fibers in an industrial method. Wood sticks are first pretreated with hydrothermal treatment to partially remove hemicellulose, thus leading to an increased porous structure that facilitates the penetration of cooking liquid and lignin removal during delignification, and dilute-alkali-sulfate pulping is then employed to obtain wood fibers with highest viscosity average DP (DPV) of nearly 2400. After that, the as-prepared wood fibers with high DP are separated into CNFs with highest average DPV of 1333. Finally, we demonstrate the potential application of wood CNFs with improved DPV in the fabrication of strong and tough isotropic films and macrofibers.

Optimal operation of the evaporator and combustion air distribution system in a pulp mill to maximize biomass recycling and energy efficiency

In the pulping process, the recovery boiler produces “green” steam without the use of fossil fuels as it burns the biomass (black liquor). However, because the black liquor concentration generated during the woodchip cooking is not suitable for combustion, it is concentrated using an evaporator that uses a large amount of steam energy for evaporation. The concentrated black liquor is sprayed to burn in a recovery boiler furnace, and combustion air is simultaneously supplied through an air distribution system. Biomass concentration and combustion air distribution should be optimized to realize sustainable cleaner production by maximizing biomass recycling and energy efficiency. In this study, the optimal operating conditions of the evaporator and combustion air distribution system in a pulp mill were determined simultaneously for biomass recycling and energy efficiency maximization. First, a process model was developed by integrating an evaporator and a recovery boiler furnace with an air distribution system. Using this model, the energy consumption of the evaporator, energy generation in the recovery boiler, and amount of recycled pulping chemicals were predicted for profit and cost estimation. Second, a mathematical model was developed to derive the optimal operating conditions. In this model, the net profit was calculated by subtracting the steam cost in the evaporation process from the profit of steam production and recovered pulping chemicals. Finally, the optimal biomass concentration and combustion air distribution were determined to maximize the net profit. As a result, the derived optimal operating conditions increased the annual power generation by 7,491 MWh/y and the amount of recovered pulping chemicals by 68,602 t/y. In addition, the net profit increased by 11.82%, and the annual CO2 emissions decreased from 2,504 to 1,361 tons, making the pulping process more sustainable. The findings of this study promote cleaner production in the pulping process by substituting fossil fuels with biomass and maximizing energy efficiency.

Evaluating process of auto-hydrolysis prior to kraft pulping on production of chemical pulp for end used paper-grade products

The objective of this work is to systematically evaluate the performance of the hydrolysis-based kraft pulping process and associated pulp and black liquor characteristics. Acacia wood chips were auto-hydrolyzed under various severities, then the hydrolyzed wood chips were kraft pulping. The results indicated that the yield of pulp significantly dropped with intensifying the auto-hydrolysis severity. Meanwhile, the removal rate of pentosan reached 98.6% in the screened pulp at the P-factor of 1 000. The fiber length, fines and fiber crimp of the screened pulp were not affected by the auto-hydrolysis treatment. Auto-hydrolyzed pulps deteriorated fibrillation and beating response of the pulp in a refining process. However, fiber length and fines changed obviously after beating treatment. After auto-hydrolysis, the tensile index of the paper matrices decreased, some particle substances were found on the surface of the pulp fiber, and the solid and organic content of the black liquor were improved.

Evaluating process of auto-hydrolysis prior to kraft pulping on production of chemical pulp for end used paper-grade products

The objective of this work is to systematically evaluate the performance of the hydrolysis-based kraft pulping process and associated pulp and black liquor characteristics. Acacia wood chips were auto-hydrolyzed under various severities, then the hydrolyzed wood chips were kraft pulping. The results indicated that the yield of pulp significantly dropped with intensifying the auto-hydrolysis severity. Meanwhile, the removal rate of pentosan reached 98.6% in the screened pulp at the P-factor of 1 000. The fiber length, fines and fiber crimp of the screened pulp were not affected by the auto-hydrolysis treatment. Auto-hydrolyzed pulps deteriorated fibrillation and beating response of the pulp in a refining process. However, fiber length and fines changed obviously after beating treatment. After auto-hydrolysis, the tensile index of the paper matrices decreased, some particle substances were found on the surface of the pulp fiber, and the solid and organic content of the black liquor were improved.

Energy Optimization in a Paper Mill Enabled by a Three-Site Energy Cooperation

Although there are opportunities to reduce electrical energy demand in unit processes of mechanical pulp-based paper and paperboard production, this may not be financially beneficial. This is generally because energy optimization opportunities connected to reduced refiner electricity demand in mechanical pulping systems also results in less steam available for the drying of the paper. As modern high consistency refiner systems produce approximately one ton of steam for each MWh of electricity when producing one ton of pulp, a reduction in electric energy demand leads to increased fuel demand in steam boilers to compensate for the steam shortage. In this study, we investigated what the financial and environmental situation would look like if we were to expand the system border from a paper mill to a larger system consisting of a mechanical pulp-based paper or paperboard mill, a district heating system with an incineration boiler and a chemical pulp mill. Mechanical pulp production has a wood to product yield of >90%, a high electric energy demand to separate woodchips to pulp and is a net producer of heat and steam while chemical pulp-based production has a wood to product yield of 50%, a low electric energy demand and is a net heat and electricity producer due to the combustion of dissolved wood polymers. The aim of this research is to create useful and robust models of how to use excess heat from certain industry sites to cover the steam shortage in other industry sites by means of utilizing and optimizing the district heating systems connecting these sites. For this purpose, we used a simulation tool which dynamically allows us to evaluate different scenarios. Our results shows that there is great potential to reduce both carbon dioxide emissions and production costs for industry sites and society by means of these tools.

Considerations in managing wastewater odor at pulp and paper operations

Many pulp and paper mills are, at least periodically, faced with the release of odors that can migrate offsite and be considered a nuisance by nearby residents. At chemical pulp mills, perceptible odors associated with reduced sulfur compounds (RSCs) are common, many of which are highly perceptible owing to their low odor thresholds. As releases of RSCs and other odorous substances from production processes are progressively controlled, the proportional contribution from wastewater treatment systems to areal odors can increase. This review paper summarizes important fundamentals of odor generation, source identification, and control. Common odorous substances are identified, and mechanisms for their generation are summarized. Approaches for measuring odorous substances are detailed to enable more effective management, and various odor control strategies are discussed.

Chemical and Kraft Pulping Properties of Young Eucalypt Trees Affected by Physiological Disorders

This study evaluated how Eucalyptus physiological disorder (EPD) affects wood quality and pulping performance. Although research advances have been made in forest management and tree improvement programs for eucalypt plantations, some areas of Brazil are still subject to abiotic stress, mainly due to atypical climatic patterns. Tree growth is affected by abiotic stress, and this can change the wood properties, which influence the pulping process. The Eucalyptus trees used in this study were three-and-a-half-year-old hybrid clones. In order to evaluate the impact of physiological growth disorder on the wood, trees were selected with higher and lower levels of symptoms caused by EPD. First, the density, chemical composition, and variables of the pulping process of each of these woods were compared. The higher levels EPD symptoms resulted in poorer wood quality for pulping. To reduce the negative impact of the pulping process, reference woodchip samples from the industrial process were mixed with these wood samples and evaluated again. The results show that EPD negatively affected the wood quality required for pulp production when trees from higher stress conditions formed wood with more extractives (60% greater) and 9% more of lignin content. Thus, the amount of reagent used was increased and the pulp yield decreased. One solution to minimize the problem is to combine the woodchips from higher EPD trees and stands (20%) with non-EPD-affected chips (80%). Thus, it appears that affected wood requires special management attention in the context of pulp production.

Effects of different levels of nanocellulose and chemical pulp on the optical and mechanical properties of money paper made with bottom combers pulp

Simultaneous effects of using cellulose nanocellulose and chemical pulp in paper money were studied with bottom combers cotton pulp. The bottom combers pulp and chemical pulp were prepared in a factory that produced durable paper, and their products were transferred to the laboratory. The nanocellulose was prepared by Nano Novin Polymer Co. and was consumed at 4 levels, i.e., 0%, 0.3%, 0.6%, and 0.9%. After commixing the pulp with the nanocellulose at the identified percentages, handsheets of 90 g∙m-2 papers were produced. The results showed that by increasing the amount of nanocellulose, up to 0.9%, the tensile strength index, burst strength index, tear strength index, and folding endurance increased 22.7%, 38.9%, 7.7%, and 348%, respectively, when compared with the control sample. Enhancement via nanocellulose up to 0.9% increased the surface smoothness up to 7.9% compared with the control sample, while the air resistance and Cobb decreased 69% and 7.9% in comparison with control sample, respectively. By increasing the nanocellulose content up to 0.9% the opacity increased 0.7%; moreover, the brightness and whitening decreased 3.5% and 10.6, respectively. The scanning electron microscopy results indicated that enhancement via nanocellulose decreased the air resistance.