Optimization of a Laccase-Mediator Stage for TCF Bleaching of Flax Pulp

SummaryFlax pulp obtained by anthraquinone-soda pulping, resulting in a kappa number of 11.1, a viscosity of 950 ml/g and 36.7% ISO brightness, was bleached in a totally chlorine-free sequence using the enzyme laccase from the fungusPycnoporus cinnabarinusand 1-hydroxybenzotriazole (HBT) as redox mediator (stage L), followed by a hydrogen peroxide stage (P). The laccase treatment was optimized using a three-variable sequential statistical plan over the following ranges: 1–20 U/g o.d.p. (oven-dried pulp) laccase dose, 0.5–7.5% o.d.p. HBT dose and 1–24 h reaction time. The influence of these variables on several pulp properties after the P stage of the LP sequence was examined. The models defined from the results obtained predicted variations in ISO brightness, viscosity and kappa number of 57.6–74.8%,590–955 ml/g and 0–6.2, respectively. The variables most strongly influencing these pulp properties were found to be the reaction time and the enzyme dose. A compromise was adopted as regards the operating conditions in order to ensure optimum results. The study was completed by conducting a biobleaching assay in a pressurized reactor (590 kPa) to assess the effect of oxygen pressure. The high pressure level resulted in improved pulp properties by the laccase-mediator system.

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Biobleaching of Pulp with Dioxygen in the Laccase-Mediator System. Part 1. Kinetics of Delignification

Holzforschung ◽

10.1515/hf.2000.066 ◽

2000 ◽

Vol 54 (4) ◽

pp. 390-396 ◽

Cited By ~ 11

Author(s):

Mikhail Balakshin ◽

Chen-Loung Chen ◽

Josef S. Gratzl ◽

Adrianna G. Kirkman ◽

Harald Jakob

Keyword(s):

Reaction Time ◽

Kappa Number ◽

Acetate Buffer Solution ◽

Alkaline Extraction ◽

Residual Lignin ◽

Rate Law ◽

Order Rate ◽

Mediator System ◽

Laccase Mediator System ◽

Kinetics Of

SummaryKinetics of pine kraft-AQ pulp delignification with the laccase-mediator system (LMS) and the effects of variable factors on the delignification were studied. The delignification was conducted in acetate buffer solution at pH 4.5 and at 40°C under atmospheric pressure. Only a part of the residual lignin could be removed in one-stage processes. Kinetics of kappa number reduction follows a pseudo-second order rate law with pulp consistency of 10 %, mediator charge of 0.1 mmole HOBT/g pulp and laccase charage of 10 UCorioluslaccase/g pulp. Kinetics of dioxygen uptake follows a pseudo-first order rate law up to first 8 hours of the reaction and a pseudo-zero order rate law at the reaction time of 8–24 hours. The amounts of dioxygen consumed per removal of one C9-unit equivalent of residual lignin is rather high, 1.5–2.5 mole, and increases with increasing reaction time. Experimental data show that side reactions between the Laccase-Mediator System and products of oxidative degradation of lignin strongly inhibit the delignification either by chemical or physical means or both. Removal of the degraded lignin fragments by alkaline extraction effectively restores the delignification of pulp with LMS. A four-stage process consisting of consecutive treatment of pulp with dioxygen-laccase-HOBT (LMS) followed by alkaline extraction (E), (LMS-E)4, decreased kappa number of a pine kraft-AQ pulp from 21.8 to less than 5. On the basis of the kinetic data, the mechanism of the pulp delignification with LMS is discussed.

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The Effect of Soda Pulping Variables on Pulp Properties of Coir Fiber

Acta Chimica Asiana ◽

10.29303/aca.v3i2.47 ◽

2020 ◽

Vol 3 (2) ◽

pp. 170

Author(s):

Maria Ulfa ◽

Koriatul Isnaini

Keyword(s):

Kappa Number ◽

Pulp Yield ◽

Cellulose Content ◽

Coir Fiber ◽

Residual Lignin ◽

Coir Fibers ◽

Soda Pulping ◽

Pulp Properties ◽

High Alkali ◽

Potential Use

Abstract The potential use of coir fiber for pulping and papermaking has been investigated. This research aimed to study effects of pulping processing variables (temperature, pulping time, and alkali charge/solvent pulping) on the properties of pulp (residual lignin, alpha cellulose, kappa number and pulp yield) from coir fiber. For this purpose, the coir fibers were cooked using alkali charge (10 to 20% oven dried, as NaOH), pulping time from 60 to 120 min and temperature from 65 to 180oC. Results indicated that alkali charge and pulping time gave more impact on the properties of pulp than temperature. Pulping at high temperature, long pulping time, and high alkali charge resulted in decreasing of lignin, pulp yield, and kappa number but instead on alpha cellulose content. Keywords: coir, soda pulping, lignin

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Does the kappa number method accurately reflect lignin content in nonwood pulps?

TAPPI Journal ◽

10.32964/tj17.11.611 ◽

2018 ◽

Vol 17 (11) ◽

pp. 611-617

Author(s):

Sabrina Burkhardt

Keyword(s):

Lignin Content ◽

Paper Industry ◽

Pulp And Paper Industry ◽

Original Data ◽

Kappa Number ◽

Klason Lignin ◽

Organic Functional Groups ◽

Pulp Properties ◽

Wood Pulps ◽

Hexenuronic Acid

The traditional kappa number method was developed in 1960 as a way to more quickly determine the level of lignin remaining in a completed or in-progress pulp. A significantly faster approach than the Klason lignin procedure, the kappa number method is based on the reaction of a strong oxidizing agent (KMnO4) with lignin and small amounts of other organic functional groups present in the pulp, such as hexenuronic acid. While the usefulness of the kappa number for providing information about bleaching requirements and pulp properties has arguably transformed the pulp and paper industry, it has been mostly developed for kraft, sulfite, and soda wood pulps. Nonwood species have a different chemical makeup than hardwood or softwood sources. These chemical differ-ences can influence kappa and Klason measurements on the pulp and lead to wide ranges of error. Both original data from Sustainable Fiber Technologies’ sulfur and chlorine-free pulping process and kappa and Klason data from various nonwood pulp literature sources will be presented to challenge the assumption that the kappa number accurately represents lignin content in nonwood pulps.

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Enzymatic Transesterification of Waste Frying Oil from Local Restaurants in East Colombia Using a Combined Lipase System

Applied Sciences ◽

10.3390/app10103566 ◽

2020 ◽

Vol 10 (10) ◽

pp. 3566

Author(s):

Mary Angélica Ferreira Vela ◽

Juan C. Acevedo-Páez ◽

Nestor Urbina-Suárez ◽

Yeily Adriana Rangel Basto ◽

Ángel Darío González-Delgado

Keyword(s):

Reaction Time ◽

Methyl Esters ◽

Enzyme Concentration ◽

Operating Conditions ◽

Frying Oil ◽

Biodiesel Production ◽

Optimum Operating ◽

Waste Frying Oil ◽

Production Chain ◽

Enzymatic Transesterification

The search for innovation and biotechnological strategies in the biodiesel production chain have become a topic of interest for scientific community owing the importance of renewable energy sources. This work aimed to implement an enzymatic transesterification process to obtain biodiesel from waste frying oil (WFO). The transesterification was performed by varying reaction times (8 h, 12 h and 16 h), enzyme concentrations of lipase XX 25 split (14%, 16% and 18%), pH of reaction media (6, 7 and 8) and reaction temperature (35, 38 and 40 °C) with a fixed alcohol–oil molar ratio of 3:1. The optimum operating conditions were selected to quantify the amount of fatty acid methyl esters (FAMEs) generated. The highest biodiesel production was reached with an enzyme concentration of 14%, reaction time of 8 h, pH of 7 and temperature of 38 °C. It was estimated a FAMEs production of 42.86% for the selected experiment; however, best physicochemical characteristics of biodiesel were achieved with an enzyme concentration of 16% and reaction time of 8 h. Results suggested that enzymatic transesterification process was favorable because the amount of methyl esters obtained was similar to the content of fatty acids in the WFO.

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Potassium hydroxide pulping of four non-woods

Bangladesh Journal of Scientific and Industrial Research ◽

10.3329/bjsir.v53i1.35903 ◽

2018 ◽

Vol 53 (1) ◽

pp. 1-6 ◽

Cited By ~ 5

Author(s):

S Sutradhar ◽

M Sarkar ◽

J Nayeem ◽

M Sarwar Jahan ◽

C Tian

Keyword(s):

Wheat Straw ◽

Potassium Hydroxide ◽

Raw Materials ◽

Kappa Number ◽

Pulp Yield ◽

Optimum Conditions ◽

Corchorus Capsularis ◽

Sesbania Bispinosa ◽

Soda Pulping ◽

Good Substitute

Four non-woods such as, dhaincha (Sesbania bispinosa), jute stick (Corchorus capsularis), wheat straw (Triticum aestivum) and corn stalks (Zea mays) were cooked by potassium hydroxide (KOH) at the optimum conditions of soda pulping. Dhaincha, wheat straw and corn stalks were delignified to kappa number 19.4, 13.6 and 19, respectively, while jute stick was not delignified sufficiently (kappa number 32.5). All these four raw materials maintained good yield in KOH process. Dhaincha produced the highest pulp yield (50.5%) and wheat straw had the lowest pulp yield (44.7). All pulps were bleached by D0EpD1 bleaching sequences in identical bleaching conditions. Final pulp brightness reached to above 80% ISO except jute stick pulp. Jute stick pulp reached to 74.9% brightness only after the consumption of 30 kg ClO2/ ton of pulp. The overall bleaching yields were 92.6%, 88.4%, 90.1 and 90.8% for dhaincha, jute stick, wheat straw and corn stalks pulps, respectively. The oSR of these four non-wood bleached pulps was above 20, consequently improved papermaking in the unrefined state. Beating rapidly increased papermaking properties, as for example, the tensile index of dhaincha pulps increased from 49 N.m/g in the unrefined pulp to 90 N.m/g in the beaten 50 oSR. It can be seen that KOH is a good substitute to soda process for non-wood.Bangladesh J. Sci. Ind. Res.53(1), 1-6, 2018

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Process Analysis of PMMA Dental Resins Scraps Depolimerization: Optimization of Reaction Time and Temperature

10.20944/preprints202110.0097.v1 ◽

2021 ◽

Author(s):

Paulo Bisi dos Santos Jr. ◽

Haroldo Jorge da Silva Ribeiro ◽

Armando Costa Ferreira ◽

Caio Campos Ferreira ◽

Lucas Pinto Bernar ◽

...

Keyword(s):

Refractive Index ◽

Reaction Time ◽

Liquid Phase ◽

Kinematic Viscosity ◽

Process Analysis ◽

Operating Conditions ◽

Optimum Operating ◽

Dental Resins ◽

Liquid Products ◽

The Cross

In this work, the cross-linked PMMA-based dental resins scraps were submitted to pyrolysis to recover MMA (Methylmethacrylate). The thermal degradation of cross-linked PMMA-based dental resins scraps was analyzed by TG/DTG to guide the operating conditions in pilot scale. The pyrolysis experiments carried out in a reactor of 143L, at 345, 405, and 420°C, 1.0 atmosphere. The reaction liquid products obtained at 345°C, physicochemical characterized for density, kinematic viscosity, and refractive index. The chemical composition of liquid products obtained at 345°C, 30, 40, 50, 60, 70, 80, and 110 minutes, at 405°C, 50, 70, and 130 minutes, and at 420°C, 40, 50, 80, 100, 110, and 130 minutes determined by GC-MS. The experiments show that liquid phase yields were 55.50%, 48.73%, and 48.20% (wt.), at 345, 405, and 420°C, respectively, showing a smooth sigmoid behavior, decreasing with increasing temperature, while that of gas phase were 31.69%, 36.60%, and 40.13% (wt.), respectively, increasing with temperature. The liquid products density, kinematic viscosity, and refractive index obtained at 30, 40, 50, 60, 70, 80, and 110 minutes, varied between 0.9227 and 0.9380 g/mL, 0.566 and 0.588 mm2/s, and 1.401 and 1.414, respectively, showing percentage deviations between 0.74 and 2.36%, 7.40 and 10.86%, and 0.00 and 0.92%, respectively, compared to standard values for density, kinematic viscosity, and refractive index of pure MMA at 20 °C. The GC-MS identified in the reaction liquid products at 345, 405, and 420°C, 1.0 atm, esters of carboxylic acids, alcohols, ketones, and aromatics, showing concentrations of MMA between 83.454 and 98.975% (area.). For all the depolymerization experiments, the concentrations of MMA in the liquid phase, between 30 and 80 minutes, reach purities above 98% (area.), decreasing drastically with increasing reaction time after 100 minutes, thus making it possible to depolymerize the cross-linked PMMA-based dental resins scraps by pyrolysis to recover MMA. The optimum operating conditions to achieve high MMA concentrations, as well as elevated yields of liquid reaction products were 345 °C and 80 minutes.

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Removal of COD and SO42− from Oil Refinery Wastewater Using a Photo-Catalytic System—Comparing TiO2 and Zeolite Efficiencies

Water ◽

10.3390/w12010214 ◽

2020 ◽

Vol 12 (1) ◽

pp. 214 ◽

Cited By ~ 8

Author(s):

Emmanuel K. Tetteh ◽

Elorm Obotey Ezugbe ◽

Sudesh Rathilal ◽

Dennis Asante-Sackey

Keyword(s):

Reaction Time ◽

Catalytic System ◽

Uv Light ◽

Operating Conditions ◽

Oil Refinery ◽

Interactive Effects ◽

Refinery Wastewater ◽

Mixing Rate ◽

Water And Wastewater Treatment ◽

Oil Refinery Wastewater

Advanced oxidation processes (AOPs) have many prospects in water and wastewater treatment. In recent years, AOPs are gaining attention as having potentials for the removal of different ranges of contaminants from industrial wastewater towards water reclamation. In this study, the treatability efficiencies of two photo-catalysts (TiO2 and zeolite) were compared on the basis of the removal of chemical oxygen demand (COD) and SO42− from oil refinery wastewater (ORW) using photo-catalytic system. The effects of three operating parameters: catalyst dosage (0.5–1.5 g/L), reaction time (15–45 min), mixing rate (30–90 rpm) and their interactive effects on the removal of the aforementioned contaminants were studied using the Box–Behnken design (BBD) of response surface methodology (RSM). Statistical models were developed and used to optimize the operating conditions. An 18 W UV light was incident on the system to excite the catalysts to trigger a reaction that led to the degradation and subsequent removal of contaminants. The results obtained showed that for almost the same desirability (92% for zeolite and 91% for TiO2), TiO2 exhibited more efficiency in terms of mixing rate and reaction time requirements. At the 95% confidence level, the model’s predicted results were in good agreement with experimental data obtained.

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Preparation and Characterization of Cu-Mn-Ce@γ-Al2O3 to Catalyze Ozonation in Coal Chemical Wastewater-Biotreated Effluent

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16081439 ◽

2019 ◽

Vol 16 (8) ◽

pp. 1439

Author(s):

Yue Teng ◽

Ke Yao ◽

Wenbin Song ◽

Yongjun Sun ◽

Haoliang Liu ◽

...

Keyword(s):

Reaction Time ◽

Calcination Temperature ◽

Catalytic Performance ◽

Catalytic Ozonation ◽

Operating Conditions ◽

Operating Parameters ◽

Incipient Wetness Impregnation ◽

X Ray Diffraction ◽

Calcination Time ◽

Catalyst Dosage

Cu-Mn-Ce@γ-Al2O3 was prepared by incipient wetness impregnation and used to catalyze ozonation in a coal chemical wastewater-biotreated effluent. The preparation factors that considerably affected the catalytic performance of Cu-Mn-Ce@γ-Al2O3, specifically metal oxide loading percentage, calcination temperature, and calcination time, were examined. The catalyst was characterized by scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and Brunauer-Emmett-Teller analysis. The optimal catalytic ozonation operating parameters, such as ozone dosage, catalyst dosage, pH, and reaction time, were also investigated. Results showed that an optimized catalyst consisted of 17.0% CuO, 3.0% MnO2, and 2.0% CeO2 (wt.%). The optimal calcination temperature and calcination time were 600 °C and 5 h. The optimal catalytic ozonation operating parameters, including ozone dosage, catalyst dosage, pH, and reaction time, were 7, 80.0 mg/L, 20.0 mg/L, 7 and 50 min, respectively. The COD removal of biotreated effluent increased to 61% under these optimal operating conditions. Meanwhile, ozonation alone resulted in only 20% removal. This work proposes the use of easily available Cu-Mn-Ce@γ-Al2O3 catalyst and might drive the advancement of catalytic ozonation for chemical wastewater purification.

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Taguchi Approach and ANOVA in Optimization of the Dissolution of Colemanite in CO2 and SO2- Water Systems

Current Physical Chemistry ◽

10.2174/1877946809666191016145837 ◽

2020 ◽

Vol 10 (2) ◽

pp. 88-97

Author(s):

Zafer Ekinci ◽

Esref Kurdal ◽

Meltem Kizilca Coruh

Keyword(s):

Particle Size ◽

Reaction Time ◽

Reaction Temperature ◽

Gas Flow ◽

Operating Conditions ◽

Optimum Operating ◽

Process Conditions ◽

Liquid Ratio ◽

Positive Effects ◽

Controllable Factors

Background: Turkey is approximately 72% of the world’s boron sources. Colemanite, tincal, ulexite and pandermite are among the most significant in Turkey. Boron compounds and minerals are widely used in many industrial fields. Objective: The main purpose of this study was to investigate the control of impurities in the boric acid production process using colemanite by carrying out the reaction with a mixture of CO2 and SO2 - water, and determining the appropriate process conditions to develop a new process as an alternative to the use of sulfuric acid. Due to worrying environmental problems, intensive studies are being carried out globally to reduce the amount of CO2 and SO2 gases released to the atmosphere. Methods: The Taguchi method is an experimental design method that minimizes the product and process variability by selecting the most appropriate combination of the levels of controllable factors compared to uncontrollable factors. Results: It was evaluated the effects of parameters such as reaction temperature, solid-to liquid ratio, SO2/CO2 gas flow rate, particle size, stirring speed and reaction time. The optimum conditions determined to be reaction temperature of 45°C; a solid–liquid ratio of 0.083 g.mL−1; an SO2/CO2 ratio of 2/2 mL.s−1; a particle size of -0.354+0 .210 mm; a mixing speed of 750 rpm and a reaction time of 20 min. Conclusion: Under optimum operating conditions, 96.8% of colemanite was dissolved. It is thought that the industrial application of this study will have positive effects on the greenhouse effect by contributing to the reduction of CO2 and SO2 emissions that cause global warming.

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Application of Diethylene Triamine Penta Methylene Phosphonic Acid in Bamboo Pulping

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.3331 ◽

2012 ◽

Vol 550-553 ◽

pp. 3331-3334

Author(s):

Hong Xia Gao

Keyword(s):

Phosphonic Acid ◽

Kappa Number ◽

Diethylene Triamine ◽

Bamboo Pulp ◽

Kraft Cooking ◽

Pulp Properties

The effect of Diethylene Triamine Penta Methylene Phosphonic Acid in bamboo kraft cooking was studied. The results show that the bamboo pulp properties are optimal when DTPMPA dosage is 0.4%. The optimal properties are as follows: the kappa number is 16.4, brightness is 37.8%, and the screened yield is 41.9%.

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