Addition Of Anthraquinone Research Articles

Enhancing cellulose fiber properties from chromolaena odorata and anana comosus through novel pulping chemical mixtures

The production of cellulose with exceptional properties has led to the modification of chemical pulping methods and the development of newer chemical pulping methods. This study developed mixtures of sodium hydroxide, ethanol, and anthraquinone as new pulping chemicals to produce alpha-cellulose from pineapple leaves and Saim weed stems. The addition of anthraquinone was noticed to influence the pulp yield positively and the FTIR of all the cellulose has the characteristic cellulose bands. Calculated Total crystallinity index (TCI), (Lateral order index) LOI., and Hydrogen bond intensity (HBI) from the FTIR presented PLSHAEC (68.38 %) and SWSHQEC (67.74 %) having high crystallinity. From the XRD, the 2? by all the materials is attributed to cellulose I diffraction, and the crystallinity index aligned with FTIR determined crystallinity. The determined particle average diameter using ImageJ software showed that PLSHQEC 3.00 had the smallest value, followed by 5.17 for PLSHQC, 5.32 for SWSHQEC, and 6.03 for SWSHQEC. From the thermal analysis, the onset of the degradation of all the cellulose occurred at different temperatures: 247.10? (PLSHQC), 253.38? (PLSHQEC), 240.20? (SWSHQC) and 242.58? (SWSHQEC). The increase in yield, higher crystallinity index, and smaller fiber diameter of the cellulose demonstrated anthraquinone as a better additive to produce quality cellulose that would undergo easy chemical modification.

Concentration-response of an anthraquinone-based repellent for raccoons (Procyon lotor)

Wildlife repellents can be part of non-lethal management strategies to reduce the negative impacts of wildlife to property, agricultural production, and human health and safety. Raccoons (Procyon lotor) are associated with negative impacts in all three of these areas. Anthraquinone is a useful avian repellent and its utility as a mammalian repellent is still being explored. Our objective was to evaluate laboratory efficacy of an anthraquinone-based repellent for raccoons using different concentrations. We fed captive raccoons whole corn treated at 0.5%, 1%, 1.5% and 2% anthraquinone and examined their behavioral response related to feeding repellency including consumption and change in duration related to approach, interaction and extended interaction with the feed bowl. Feeding repellency was 26–37% for whole corn treated with 0.5–1.5% anthraquinone and 71% for whole corn treated with 2% anthraquinone. Interaction duration among the treatments varied (p = 0.005) with a longer interaction duration with the food bowl at 2% anthraquinone compared to 0.5% anthraquinone. However, the addition of anthraquinone did not significantly alter behaviors of approach, interaction, or extended interaction between pretreatment and treatment for the raccoons within treatments. The decreases in consumption that we observed warrant development of further research and field evaluation regarding anthraquinone as a deterrent with raccoons or to repel vertebrate competitors from raccoon specific baits.

NOHUT (Cicer arietinum) SAPI KAĞIT HAMURLARININ KARAKTERİZASYONU VE KAĞIT ÜRETİMİNDE DEĞERLENDİRİLMESİ

In this study, the evaluability of chickpea stalks generated after harvest in chickpea production was investigated in pulp and paper production. Besides, paper production was carried out by blending the chickpea stalk fibers with primary and secondary fibers in certain proportions and the effects of chickpea stalk fibers on the paper properties were determined. Modified kraft method was used in the pulping of chickpea stalks and anthraquinone (AQ) was added to the cooking solution as a catalyst. Some chemical, mechanical and optical properties of the pulps produced with the addition of different AQ charges were compared and the optimum results were obtained from the 0.7% AQ added cooking experiment. The yield and viscosity values of the chickpea stalk pulps increased by 12.6% and 34.2%, respectively and the kappa number decreased by 46.7% with the addition of AQ to cooking liquor. Paper production was carried out by blending the fibers obtained from optimum cooking condition with primary and secondary fibers in certain rates and the effects of chickpea stalk fibers on the paper properties were examined. Depending on the amount of chickpea stalk fibers, the mechanical properties of the papers produced with secondary fibers and the optical properties of the papers produced with primary fibers improved. The strength losses that occur during the recycling of waste paper could be reduced by blending the chickpea stalk fibers with secondary fibers and it is possible to produce various paper types such as writing-printing paper by blending the short fiber chickpea stalk fibers and long fibers.

Biorefining of Scots pine using neutral sodium sulphite pulping: investigation of fibre and spent liquor compositions

Neutral sulphite pulping of softwood as a potential biorefinery was investigated, by producing pulps at two main yield levels (55–65% and 75–85%) under various process conditions and by analysing the composition of the resulting fibre fractions and pulping spent liquors. It was found that both delignification rate and selectivity were enhanced by addition of anthraquinone (AQ 0.1% on o.d. wood) whereas delignification was accelerated by higher temperature (180 °C vs. 170 °C) and initial liquor pH (10 vs. 7). The established conditions preserved significant amount of carbohydrates, especially galactoglucomannan, in the fibres at the selected yield levels. At the yield level of 65%, still over 60% of galactoglucomannan was detected in the pulps whereas 50–70% of lignin was removed. In the spent liquors, lignosulphonates as the principal component represented the possible source of by-product in addition to acetic and formic acids.

A sustainable and effective potassium hydroxide pretreatment of wheat straw for the production of fermentable sugars

The development of sustainable and effective pretreatment technology is of critical importance for the conversion of lignocelluloses into bioethanol. In this work, KOH pretreatment of wheat straw with the supplement of anthraquinone (AQ) and sodium lignosulfonate (SLS) was investigated under the relatively mild conditions. The effectiveness of KOH pretreatment was evaluated by enzymatic saccharification. It was found that after the KOH pretreatment with 15% KOH, 0.1% AQ and 2% SLS at 120 °C for 40 min, the final total sugar yields (glucose + xylose + soluble xylan) could reach up to 80%, which was 16% higher as compared to the KOH pretreatment without addition of AQ and SLS under the same conditions. In addition, the spent liquor could be reused twice to maintain a relatively good effectiveness of pretreatment, and it could be used to produce fertilizer due to the high content of potassium.

Comparative material balances and preliminary technical analysis of the pilot scale sugarcane bagasse alkaline pretreatment to 2G ethanol production

Material balance and preliminary technical analyses of pilot scale sugarcane bagasse alkaline pretreatment, using sodium hydroxide with and without anthraquinone (AQ) addition were analyzed and compared to elucidate the carbohydrates and phenolic components flux in the streams.The lowest carbohydrates solubilization rates (9% wt for cellulose and 41% wt for hemicelluloses) were reached for the condition at 130 °C with AQ addition, however the highest lignin solubilization (87% wt) was accomplished for the condition using 170 °C with AQ addition. Preliminary technical analysis was carried out to evaluate the performance of the best pretreatment condition when integrated to a first and second generation ethanol plant, in a biorefinery concept, showing that 83.03 m3/h of ethanol can be produced by this process. Ethanol production (in L/ton biomass) for proposed process is 8.1% lower than the expected for short terms technologies concluding that upgrades on the process, as higher solids concentrations and lignin energy use or, principally, lignin valorization must be performed to allow viability of the process.

Efeito da antraquinona na curva de cozimento kraft para madeira do híbrido Eucalyptus grandis x Eucalyptus urophylla

O presente estudo teve por objetivo avaliar os efeitos da adição da antraquinona em uma curva de cozimento, com diferentes cargas de reagentes, por meio do processo kraft de polpação, para a madeira de híbrido de Eucalyptus grandis x Eucalyptus urophylla, visando inferir sobre os parâmetros do processo. A madeira foi transformada em cavacos e classificada para condução das curvas de cozimento kraft. As cargas aplicadas foram de 10% a 24% de álcali ativo e 25% de sulfidez, com uma carga de antraquinona de 0,05% (sobre a massa seca de madeira). Avaliou-se o rendimento bruto e depurado, o teor de rejeitos, o número kappa (nível de deslignificação) e o álcali ativo residual. Observou-se que a adição da antraquinona não afetou o rendimento bruto do processo, porém aumentou o rendimento depurado através da redução do teor de rejeitos, em especial para as baixas cargas de álcali ativo (10% e 12%). Outro efeito observado foi a redução do número kappa com a adição da antraquinona, o que indica o aumento da taxa de deslignificação da madeira. Esse aumento é reforçado pelo menor álcali ativo residual, o que se subentende maior aproveitamento dos reagentes no processo.

Alkaline Pretreatment Severity Leads to Different Lignin Applications in Sugar Cane Biorefineries

Lignin, a multifunctional major biomass component, has a prominent potential as feedstock to be converted into high value-added products. Lignin is available in high amounts as side streams during cellulosic ethanol production, and within the biorefinery context, it is important to assess its structural characteristics in order to explore its potential to replace some petroleum-based reactants. In this study, some important features were evaluated for different lignins such as lignin purity and the amounts of syringyl (S), guaiacyl (G), and p-hydroxyphenyl (H) units. Four alkaline lignins, generated from a pilot-scale pretreatment of sugar cane bagasse (NaOH 1.5%, 30 min), were evaluated according to the severity of the alkaline pretreatment (130 or 170 °C, with or without the addition of anthraquinone). The different pretreatments produced lignins with different chemical characteristics that can be used for different purposes in sugar cane biorefineries. As the severity of alkaline pretreatment increased...

Effect of Anthraquinone on Alkaline Pretreatment and Enzymatic Kinetics of Sugarcane Bagasse Saccharification: Laboratory and Pilot Scale Approach

A laboratory (2 L) scale alkaline pretreatment with and without anthraquinone addition was performed to evaluate the influence of temperature, alkaline loading, residence time, heating and stirring system on mass yield and solubilization rates of the main components. The best conditions were scaled up to pilot scale (350 L), and enzymatic conversion of structural carbohydrates into sugars for cellulosic ethanol production was analyzed. The tested conditions were 130–170 °C, 0.5–1.5% NaOH, 30–90 min with and without 0.15% w/w of anthraquinone (AQ). The AQ addition did not lead to substantial cellulose preservation in the laboratory scale; however, in the pilot scale the AQ addition resulted in 67.4% and 28.5% of cellulose preservation for reactions at 130 °C, 1.5% NaOH, 30 min (5Pil) and 170 °C 1.5% NaOH, 30 min (7Pil) respectively in relation to those studies without addition. The most efficient heating and agitation system of pilot reactor was probably the determining factor for effective performance. Te...

Sodium sulphite pulping of Scots pine under neutral and mildly alkaline conditions (NS pulping)

Abstract Sodium sulphite pulping of Scots pine chips in the initial pH range of 7.5–9 was investigated at 180°C and 165°C (for 120–240 min), using chemical charges between 25 and 50% and anthraquinone (AQ) charges 0–0.2%. As a result, pulps with yields of 52–73% and kappa numbers of 35–106 were produced. Delignification was accelerated by higher Na2SO3 charges and temperatures, and by AQ addition, whereas the effect of initial pH was negligible. The high pulp yields at a given kappa number were attributable to high retention of hemicelluloses, especially that of galactoglucomannan. The relatively low viscosities of pulps were apparently caused by depolymerisation of cellulose by sulphite. The sulphonic acid groups in the pulps correlated well with the residual lignin content, although some sulphonation of polysaccharides may also be possible. The results indicate that pulping of softwood in buffer-free (without Na2CO3 and/or NaOH) sodium sulphite liquor may result in pulps with tailored characteristics.

The cellulose protection agent used in the oxidation degumming of ramie

In this paper, anthraquinone was used to improve the properties of ramie fiber in oxidation degumming. The chemical components, structure properties, tensile properties of degummed fiber and the character of oxidation degumming solution were tested and analyzed. With the optimal dosage of anthraquinone (2% (o.w.f.)), the content of hemicellulose, the yield of degumming process, polymerization degree and the work of rupture of the degummed fiber were improved by 17.3%, 7%, 2% and 41%, respectively. The oxidation reduction potential (ORP) value of the degumming solution was also tested, with the addition of anthraquinone, and the ORP value decreased by 250 mV, which is of benefit for the properties of fiber.

Oxygen Delignification of Wheat Straw Soda Pulp with Anthraquinone Addition

Oxygen delignification of wheat straw soda pulp with the addition of anthraquinone (AQ) was conducted to evaluate the effects of AQ on pulp quality. The pulp yield, kappa number, intrinsic viscosity, and brightness were selected as the properties to optimize oxygen delignification. The optimal pulp was obtained via grey relational analysis with an alkali charge of 3%, oxygen pressure of 0.5 MPa at 120 °C for 85 min, and with 0.05% AQ. In contrast to conventional oxygen delignification, the addition of AQ produced pulp with a higher yield, and it did not generate other negative impacts on pulp kappa number, viscosity, and brightness. The reaction mechanism of AQ in oxygen delignification was different from that in alkali pulping.

Tobacco residuals as promising lignocellulosic materials for pulp and paper industry

Fiber dimensions, chemical composition, and soda and soda-AQ pulping of tobacco stalks were examined to assess if they were suitable for pulp and paper production. The results showed that the morphological characteristics of tobacco stalks were similar to those of nonwoods and hardwoods. The average values of length, diameter, and cell wall thickness of tobacco stalks fibers were determined as 1.23 mm, 24.31 μm, and 8.93 μm, respectively. The holocellulose and alpha-cellulose in tobacco stalks were lower than those of hardwoods and common nonwoods. In addition, lignin content of tobacco stalks was lower than that of hardwood. The holocelluloses, alpha-cellulose, lignin, and ash contents of tobacco stalks were examined to be 67.79, 39.20, 18.90, and 6.86 wt%, respectively. The optimum cooking conditions for a bleachable pulp of tobacco stalks were found to be as follows: active alkali 25%, temperature 165°C, cooking time 180 min, and 0.2% anthraquinone. Addition of anthraquinone resulted in lower screening rejects and lower kappa number, higher screen yield, and higher brightness. The bleaching of tobacco stalk pulp did not respond very well. The brightness of pulp made by tobacco stalks reached about 73.06% on DED and 78.2% on DEDD bleaching sequences.

Differential behavior between acacia and Japanese larch woods in the formation and decomposition of hexenuronic acid during alkaline cooking

The effects of anthraquinone (AQ) and polysulfide (PS) on the hexenuronic acid (HexA) content of pulp during kraft cooking were studied using Acacia mearnsii (acacia) and Larix leptolepis (Japanese larch) sapwood. In contrast to the results of cooking Japanese larch at an H-factor of 1200, the HexA contents of acacia pulp with a kappa number of 20 at an H-factor of 291 did not differ greatly between the kraft, kraft-AQ, and PS-AQ cooking methods, although the hydroxide ion concentration in the acacia cooking liquor decreased on the addition of AQ or sulfur. To explain this difference, we studied the behavior of the formation and degradation of HexA during alkaline cooking of glucuronoxylan from cotton linter, which was cooked with 1.0 and 2.0 mol/l NaOH. The relationship between HexA content and H-factor during alkaline cooking of glucuronoxylan was clarified. The amount of HexA and its rate of decomposition were higher in the 2.0 mol/l solution than in the 1.0 mol/l solution. At a low H-factor similar to that for hardwood cooking, HexA content increased to a maximum level and then started to decrease at high hydroxide ion concentrations such as 2.0 mol/l, whereas it slowly decreased at low hydroxide concentrations such as 1.0 mol/l. At an H-factor of around 450, the HexA formation/degradation curve for 1.0 mol/l of hydroxide crossed the decomposition curve for 2.0 mol/l of hydroxide. Therefore, it was shown that at a low H-factor, a decrease in hydroxide ion concentration during acacia wood cooking had little effect on the HexA content of pulp.

Effect of additives on fiber yield improvement for kraft pulping of kadam (Anthocephalus chinensis)

Projected decline in future wood resources has prompted researchers to try various additives in existing pulping processes for fiber yield improvement. Many studies have been conducted in the past aimed at improving kraft pulp yield with the use of additives in the cooking liquor. In this study, the effects of anthraquinone (AQ) and 2-methylanthraquinone (MAQ) on the pulp yield of kadam (Anthocephalus chinensis) were investigated. Three different active alkali doses (14%, 16% and 19% as NaOH) along with 0.1% of AQ or MAQ on chips were used to obtain various levels of delignification of the hardwood. Addition of AQ or MAQ to kraft pulping, increased fiber yield (0.5-2.7% on chips) and improved delignification selectivity (lignin vs. carbohydrate removal). Increases in pulp yield due to AQ or MAQ were more significant at lower doses of active alkalis. The viscosities and the physical strength properties of the pulps with kappa numbers 16-19 were comparable to kraft although there was a minor decrease in tensile strength for the kraft/MAQ pulp.

MEA/water/AQ-pulping of wheat straw

Abstract Annual plant pulping is faced with serious challenges. Traditional pulping processes with bleaching in chlorine based sequences and without appropriate chemical recovery system cannot be tolerated anymore. Alternative pulping processes with non-conventional chemicals, such as organic solvents, e.g., monoethanolamine (MEA), might be suited for an environmentally sound process with a closed mill system. Thus, pulping of wheat straw with MEA as the main delignifying agent was investigated in comparison to soda and soda/AQ pulps as references. The main focus was placed on reduction of the cooking temperature in order to avoid heat-induced MEA degradation. The temperature was reduced stepwise from 165°C to 130°C. At 150°C, a sufficient delignification was achieved. MEA was partly substituted by water and the resulting decrease of the delignification rate could be compensated by addition of anthraquinone (AQ). After optimization of the process, a pulp with a kappa number of 17 was obtained at a total yield of 56% based on o.d. straw. This pulp was selected for bleaching. Both, O/Q/OP/DQ/P (“ECF light”) and O/Q/OP/ZQ/P (TCFZ) bleaching were applied. NaOH was substituted by MEA as alkali source in the oxygen delignification stage. Up to 50% delignification rate was achieved under these moderate conditions. In the ECF light bleaching sequence, a brightness of 80% ISO was reached at a kappa number level below 3. In TCFZ bleaching, an even somewhat higher brightness was achieved at a kappa number level below 1. A yield of fully bleached screened pulp of around 50% (based on o.d. straw) was obtained. The strength properties of the MEA pulp were improved after bleaching. ECF bleaching resulted in slightly better pulp strengths than the TCFZ alternative. MEA forms in combination with water and AQ a very selective pulping system providing effective delignification and maintaining extremely high yields. MEA/water/AQ pulping should be regarded as a serious, environmentally friendly alternative to soda or soda/AQ pulping to produce high-quality pulp from wheat straw.

Impact of Kraft Process Modifications on Eucalyptus globulus Pulping Performance and Polysaccharide Retention

The impact of effective alkali (EA) splitting and anthraquinone (AQ) addition on Eucalyptus globulus kraft pulping yield and pulp quality was investigated. AQ addition to kraft pulping enhances the rate of delignification, leading to alkali saving and reducing time at maximum temperature. A 1.9% total yield increase was observed, assigned to the enhancement of both cellulose and xylan retention but also due an increase of rejects content. Contrary to results described in the literature for other woods, the use of an even effective alkali concentration profile throughout the cook of E. globulus did not affect pulp yield or carbohydrate composition of screened pulp. However, EA profiling resulted in a higher pulp viscosity, indicating a lower degradation of cellulose chains along the pulping. Such results were interpreted taking into account the peculiar chemical structure of E. globulus wood components.

Eucalyptus globulus kraft process modifications: Effect on pulping and bleaching performance and papermaking properties of bleached pulps

AbstractBACKGROUND: Increasing the yield of the wood pulping process allows the reduction of specific wood costs. Process modifications with a great impact on pulp yield are the profiling of chemical charges and addition of anthraquinone (AQ). The aim of the present work is to investigate the influence of effective alkali (EA) profiling and addition of anthraquinone on E. globulus kraft pulping performance. The impact of such process modifications on the ECF bleaching process and on the papermaking properties of the resulting bleached pulps is also evaluated.RESULTS: An EA profiling cook may lead to a pulp yield gain, which is more significant as the total EA charge used in the kraft cook increases. AQ addition to kraft pulping leads to a significant yield increase. The ClO2 charge required to fully bleach the pulps is lower for EA profiling and higher for kraft + AQ unbleached pulps. Bleached AQ pulp presents a high beatability due to high pulp xylan retention.CONCLUSION: A low total EA charge is the key parameter for high polysaccharide retention on pulp. AQ addition constitutes a feasible strategy to increase pulp yield. Bleaching performance and papermaking properties of pulps produced with the three different methods may be affected by the kraft pulping modifications. Copyright © 2008 Society of Chemical Industry

Enzymatic degradation of low soluble compounds in monophasic water:solvent reactors. Kinetics and modeling of anthracene degradation by MnP

Polycyclic aromatic hydrocarbons (PAHs) are toxic compounds presenting low water solubility and high hydrophobicity, which greatly hampers their natural biodegradation. The enzymatic degradation of a model compound, anthracene, was evaluated in presence of a miscible solvent for an increased solubility. Manganese peroxidase, a ligninolytic enzyme from white-rot fungi, was used as biocatalyst in a medium containing acetone. The kinetic parameters of the enzymatic degradation of anthracene, obtained from fed-batch experiments, were applied to model the operation of a continuous reactor. Kinetics comprised a Michaelis-Menten equation, modified with an autocatalytic term, assumed to the effect of quinones acting as electron carriers, and a logistic function related to enzyme activity. The continuous reactor has been operated for 108 h, attaining a 90% of anthracene degradation, which demonstrated the feasibility of the system for its application in the removal of poorly soluble compounds. The model of this reactor permitted to predict accurately anthracene degradation in different conditions, such as external addition of anthraquinone and different enzymatic activities.

Assessment of potential approaches to improve Eucalyptus globulus kraft pulping yield

AbstractThe main goal of this work is to study the potential approaches to improve polysaccharides retention during Eucalyptus globulus kraft pulping. The addition of anthraquinone to kraft pulping leads to the highest pulp yield while the addition of urea promotes lower depolymerization of polysaccharides (higher pulp viscosity), but does not have a significant effect on yield. The early interruption of kraft cooking followed by oxygen delignification is a reliable approach to increase pulp yield, particularly when pulping is interrupted at the end of the faster and more selective kinetic regime (bulk phase). Yield loss during oxygen delignification is considerably lower than that incurred in the last phase of kraft pulping. Pulping with OH−/HS− charge profiling, carried out with liquor injection in three different phases leads to a yield increase. However, this increase results from a lower total alkali charge applied when profiling pulping is compared to standard pulping conditions, rather than to alkali profiling. Standard kraft pulping with different active alkali (AA) charges demonstrated that this operational variable is determinant for pulp yield and viscosity. Pulping experiences with lower AA (14%) resulted in a higher and almost constant pulp viscosity and in a higher pulp yield, assigned to improved retention of both cellulose and xylan. During the last stage of pulping, cellulose content decreases, this being mainly responsible for the decrease of pulp yield, while xylan content is almost constant, a feature attributed to the peculiar structure of this E. globulus's hemicellulose. Copyright © 2007 Society of Chemical Industry