Elemental Chlorine Free Bleaching Research Articles

Production of high-quality dissolving pulp from eucalyptus wood chips using deep eutectic solvent and elemental chlorine-free bleaching

Deep eutectic solvent (DES) provides promising alternatives to conventional pulping and cellulose purification with significantly lower energy consumption and impacts on the environment. In this work, choline chloride – lactic acid (ChCl-LA DES) pulping of eucalyptus wood chips combined with several ECF bleaching sequences was investigated to produce high-grade dissolving pulps. Initially, the dependency of DES pulping yield and delignification efficiency on the moisture content (MC) of used wood chips was evaluated. The results exhibited the crucial influence of the MC of wood chips on the delignification efficiency of DES pulping. DES pulping under optimized conditions resulted in an unbleached pulp with kappa number of 42, relatively high screened yield 48.1% and viscosity 796 cm3/g, as well as very low hemicellulose content, typically less than 3.8%. Further purification of the obtained pulp using D-Ep-D and OO-D-Ep-D bleaching sequences produces several dissolving pulps characterized by a high viscosity 695 cm3/g and brightness 89.5% ISO, indicating low degradation of cellulose during DES pulping. DES pulping exhibited considerable potential to remove the hemicelluloses from wood chips and produce high-quality dissolving pulps. This could be attained through shorter pulping operations conducted at a lower temperature and a higher screened yield compared to current dissolving pulp production operations.

PULPING AND PAPERMAKING PROPERTIES OF ZARA PLANT

The fast-growing Zara plant (a putative hybrid of Pennisetum purpureum Schumach.) is usually planted for cattle fodder. For the first time, Zara plant was evaluated for its pulping potential based on anatomical, chemical, and morphological characteristics. This plant was characterized by an acceptable amount of α-cellulose (40.32%) and lignin (18.4%), with medium fiber length (1.09 mm). Soda–anthraquinone (AQ) pulping of Zara plant was investigated. Anatomically, stems of Zara plant had porous structure, mainly composed of vascular bundles surrounded by parenchyma tissue. Consequently, they were easier to delignify and defibrate, and a pulp yield of 46.54% was obtained, with kappa number 15.45 under the conditions of 14% alkali charge for 120 min of cooking at 150 °C. Good papermaking properties were observed, the tensile index was 78.9 N.m/g at 43 °SR. The resulting pulps showed good bleachability in elemental chlorine-free (ECF) bleaching sequences (D0(EP)D1). Pulp brightness of 81.5%, with the viscosity of 16.0 mPaS, was obtained, with the consumption of 25 kg ClO2/ton of pulp.

The effect of treating pine regular kraft pulp with peracetic acid before O2-delignification on the consumption of ClO2 in D0ED1 bleaching

Effects of pre-treating pine kraft pulp kappa number 31.5 with peracetic acid (Paa) (0.33% and 0.66% as active oxygen based on oven-dried pulp) before O2-delignification were studied relative to the consumption of chlorine dioxide in a subsequent Elemental Chlorine Free (ECF) bleaching process. The study showed that such pre-treatment is an effective way to extend the delignification of the pine pulp and to reduce the consumption of chlorine dioxide required to bleach the pulp to a brightness of 87%. The reduction in chlorine dioxide required to bleach the pine pulp depended on the amount of Paa used for pre-treatment. Furthermore, the research showed that decreasing the kappa number of the pine pulp to approximately 7.5 units (with Paa pre-treatment and lengthening of O2-delignification process) caused an over-proportional reduction (by approximately 62.5%) in chlorine dioxide consumption to bleach the pulp to 87% brightness.

Use of a Novel Extremophilic Xylanase for an Environmentally Friendly Industrial Bleaching of Kraft Pulps.

Xylanases can boost pulp bleachability in Elemental Chlorine Free (ECF) processes, but their industrial implementation for producing bleached kraft pulps is not straightforward. It requires enzymes to be active and stable at the extreme conditions of alkalinity and high temperature typical of this industrial process; most commercial enzymes are unable to withstand these conditions. In this work, a novel highly thermo and alkaline-tolerant xylanase from Pseudothermotoga thermarum was overproduced in E. coli and tested as a bleaching booster of hardwood kraft pulps to save chlorine dioxide (ClO2) during ECF bleaching. The extremozyme-stage (EXZ) was carried out at 90 °C and pH 10.5 and optimised at lab scale on an industrial oxygen-delignified eucalyptus pulp, enabling us to save 15% ClO2 to reach the mill brightness, and with no detrimental effect on paper properties. Then, the EXZ-assisted bleaching sequence was validated at pilot scale under industrial conditions, achieving 25% ClO2 savings and reducing the generation of organochlorinated compounds (AOX) by 18%, while maintaining pulp quality and papermaking properties. Technology reproducibility was confirmed with another industrial kraft pulp from a mix of hardwoods. The new enzymatic technology constitutes a realistic step towards environmentally friendly production of kraft pulps through industrial integration of biotechnology.

"EFFECTS OF SURFACTANT APPLICATION ON ACACIA HYBRID KRAFT PULP PROPERTIES"

"Acacia hybrid kraft pulping, with the addition of different non-ionic commercial surfactants, as well as its subsequent elemental chlorine free (ECF) bleaching, was studied. The characteristics of bleachable pulps made by conventional kraft and by kraft-surfactant pulping methods were investigated. The results revealed that the type and dosage of the surfactants during the production of Acacia hybrid kraft pulp had no significant influence on the kappa number, screen yield, and reject. On the other hand, the extractive content and brightness of Acacia hybrid bleached kraft pulp were considerably affected by the types and dosages of surfactants used. The addition of 0.1% LAE (linear alcohol ethoxylate) on oven-dried chips lowered the extractive content by 58.20%, whereas 0.125% PEG (polyethylene glycol esters of fatty acids mixed with block copolymer of ethylene oxide with propylene oxide) on oven-dried chips reduced the brightness by 2.78%. Furthermore, the addition of surfactants had no discernible effect on the specks of dirt."

Preparing prehydrolyzed kraft dissolving pulp via phosphotungstic acid prehydrolysis from grape branches

Dissolving pulp was successfully prepared via phosphotungstic acid (PTA) prehydrolysis kraft (PHK) cooking followed by an elemental chlorine-free (ECF) bleaching process from grape branches. The effects of prehydrolysis temperature, reaction time, and PTA concentration that potentially affect the quality of dissolving pulp product on chemical components of pulp were studied via an orthogonal experiment. The structure of lignin was activated during the PTA prehydrolysis phase, and lignin was easily removed during the following cooking process. Thus, relatively mild conditions (140°C, 100 min) can be used in the cooking process. During the prehydrolysis phase, temperature exhibited the most significant influence on the cellulose purity of the obtained pulp fiber, followed by reaction time and PTA concentration. The optimized prehydrolysis conditions were as follows: prehydrolysis temperature, 145°C; reaction time, 75 min; and PTA concentration, 1 wt%. Whether the excessively high prehydrolysis temperature or prolonging the reaction time did not favor the retention of long chain cellulose, the delignification selectivity for the cooking process could not be further improved by excessive PTA loading. Under these prehydrolysis conditions, 94.1% and 29.0% for α-cellulose content and total yield could be achieved after the given cooking and bleaching conditions, respectively. Moreover, the chemical structure and crystal form of cellulose were scarcely changed after PTA prehydrolysis, which could be confirmed by results from Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). PTA prehydrolysis could be considered as an alternative method for preparing PHK dissolving pulp under relatively mild cooking conditions.

Fiber characteristics and chemical composition of three Taxodium ‘Zhongshansa’ woods and pulping evaluation

Taxodium ‘Zhongshansa’ (T. ‘Zhongshansa’) is a hybrid cultivar of the Taxodium Rich. genus. The wood and fiber characteristics and wood chemical compositions of three T. ‘Zhongshansa’ wood specimens were analyzed and compared with their parents, Taxodium mucronatum (T. mucronatum) and Taxodium distichum (T. distichum). It was found that the wood density of the three T. ‘Zhongshansa’ hybrids were slightly lower than the densities of their parents. The average fiber length and length to width ratio of the three samples were similar and greater than their parents. Runkel ratios of the three T. ‘Zhongshansa’ hybrids was smaller than their patents. Compared to the parents, the extractives contents of the three T. ‘Zhongshansa’ hybrids hardly varied, while the lignin content was slightly lower. The result of the kraft cooking and bleaching of T.Z.502 indicated that with a cooking yield of 44.9%, the kappa number of the kraft pulp was 41.8. The T.Z.502 kraft pulp was easier to delignify via oxygen with alkali, and the brightness reached up to 76% ISO after an elemental chlorine free bleaching process. The results provide a reference for the application of T. ‘Zhongshansa’ wood in pulp and paper making in future.

Development of dissolving pulp from Phyllostachys pubescens stem by prehydrolysis soda cooking with 2-methylanthraquinone

Moso bamboo (Phyllostachys pubescens) is a non-wood and non-edible biorefinery resource and is extremely important for the development of dissolving pulp as a material of regenerated cellulose fiber. However, the bamboo contains a high amount of xylan compared to hardwoods. This study aimed at finding suitable conditions for producing dissolving pulp of good quality from the moso bamboo stem using a combination of prehydrolysis non-sulfur alkali cooking and elemental chlorine-free bleaching, and separating a lignin product from the black liquor in the cooking process. Prehydrolysis at 150 °C for 7 h using soda cooking at 160 °C for 3 h with 28% active alkali and 0.06% 2-methylanthraquinone was found to give a good outcome. The xylan content of the pulp was reduced to 4.0%, and further treatment of cold caustic extraction to remove xylan was not required for producing dissolving pulp of good quality, although the pulp yield was approximately 30%. The pulp was then bleached to obtain a dissolving pulp with α-cellulose content of 95.0%, brightness of 89.9%, and viscosity of 8.8 mPa·s. Lignin dissolved in the soda cooking black liquor was easily precipitated by CO2 when employed with 35% of solid concentration and provided a yield of 42%. The precipitation by CO2 followed by purification at pH 2.9 provided a lignin product with weight-average molecular weight, polydispersity, and ash content of 1566, 2.62, and 0.6%, respectively.

Coupling of photocatalysis and biological treatment for elemental chlorine free bleaching wastewater: Application of factorial design methodology

In this study, the visible-light-induced intimately coupled photocatalysis and biodegradation (ICPB) technology was fabricated using the TiO2/bagasse cellulose composite as the carrier and Phanerochaete mixed activated sludge as the biological source. The ICPB degradation effect of elemental chlorine free (ECF) bleaching wastewater was evaluated via the response surface design. Then, the wastewater was characterized, including absorbable organic halogen (AOX), dissolved organic carbon (DOC), chemical oxygen demand (COD), chroma, pH, suspended solids, and the organic compound changes in wastewater were analyzed by fourier transform infrared spectroscopy (FT-IR). Under the optimal conditions of pH 7, carrier filling rate of 5%, aeration rate of 2 L/min, and reaction time of 7 h, the degradation efficiencies of AOX, COD, and DOC were 95%, 91%, and 82%, respectively. The X-ray photoelectron spectroscopy (XPS) results of the ICPB carrier after the reaction were almost identical to those before the reaction. The biomass and its activity on the ICPB system were analyzed by the dominant bacteria during degradation (Curaneotrichosporon, Paenibacillus, Cellulonas, Phanerochaete, Dechlorobacter, Rhodotorula, Sphingobacterium, and Ruminiclostridium), which had a good degradation effect on wastewater. This study affords a novel method for the degradation of ECF bleaching wastewater and a new idea for ICPB technology optimization.

Extraction of Cellulose Acetate from Cajuput (Melaleuca leucadendron) Twigs and Sugarcane (Saccharum officinarum) Bagasse by Environmentally Friendly Approach

This study was carried out to investigate the extraction of cellulose acetate (CA) from cajuput (Melaleuca leucadendron) twigs and sugarcane (Saccharum officinarum) bagasse using an environmentally friendly method. At first, cellulose was extracted from cajuput twigs (CT) and sugarcane bagasse (SB) through prehydrolysis followed by soda (NaOH) pulping and elemental chlorine-free (ECF) bleaching. Later, the extracted cellulose was acetylated using iodine (I) as a catalyst. The obtained CA was characterized by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), thermal gravimetric analysis (TGA), scanning electron microscope (SEM), and X-ray diffraction. FTIR and NMR analysis proved the replacement of free OH (hydroxyl) groups by acetyl groups. The degree of substitution (DS) showed the acetylation capability of cellulose extracted from CT and SB as well. The diameter of CA and its crystallinity index (CrI) were measured by SEM and X-ray diffraction, respectively. The cellulose content was 85.4 and 89.5% for CT and SB, respectively after the pulping and bleaching. The diameter of CA extracted from CT was approximately 10 μm and it was approximately 20 to 30 μm for SB. The CrI of the CA extracted from SB and CT was 75.6 and 60.2, respectively. Furthermore, the thermal gravimetric analysis showed that CA extracted from CT and SB was thermal resistant. Therefore, CT and SB will be potential alternative resources for CA production using the mentioned method.Graphic Abstract

EFFECT OF RECYCLING OF ELEMENTAL CHLORINE FREE BLEACHING EFFLUENT TREATED BY ELECTROCOAGULATION ON PAPER PROPERTIES

This study aimed to determine the effect of recycling elemental chlorine free (ECF) bleaching effluent (D0EpD1 and OD0EpD1) after treatment through electrocoagulation under optimum conditions on paper properties. The effect of pH, current density, time and dose of electrolyte on the reduction of chemical oxygen demand (COD) and color was studied. Maximum decrease in COD and color was found under optimum conditions (i.e., pH 7, treatment time of 30 min, current density of 29.16 mA/cm2, and 1 g/L NaCl). Under these optimum conditions, the reduction in COD and color was of 79.9% and 99.10%, respectively. The reduction in the strength properties of paper, caused by recycling, was found to be insignificant, but a decline of 2.11% for D0EpD1 and of 1.43% for OD0EpD1 in brightness was found. Using the electrocoagulation method to treat the bleaching effluent can prove to have valuable potential towards wastewater utilization, pollution control, and sustainable development of the industry.

Bleaching of bagasse-pulp using short TCF and ECF sequence

Abstract More than 70 % bleached chemical pulp is produced in India through elemental chlorine-free bleaching in which chlorine-based compounds like chlorine dioxide is a dominant chemical which generates chlorinated organic toxins harmful to the environment. Present studies demonstrate short sequence of bleaching combined with acid treatment, followed by pressurized oxygen delignification. It was found that efficiency of oxygen improved by adding hydrogen peroxide as an additive in oxygen delignification with subsequent treatment with ozone or chlorine dioxide as bleaching agents. It was observed that by using additive in ODL process, pulp can achieve 70±1 (%ISO) brightness. Reduction attains in kappa number 65–70 % as compared to 45–50 % in control oxygen delignification stage. Through AOpZ and AOpD bleaching sequences, full brightness achieved 84–85 (%ISO) without considerable loss in mechanical strength properties compared to DEpD sequence. A potential reduction in COD, color, and AOX was 28, 53.3, and 88 % respectively were observed in AOpZ short bleaching sequence compared to DEpD bleaching.

Upcycling strategies for old corrugated containerboard to attain high-performance tissue paper: A viable answer to the packaging waste generation dilemma

This study evaluated the suitability of old corrugated containerboard (OCC) to be upcycled into a high-quality pulp for tissue paper manufacture. The evolution of the physicochemical properties of OCC fibers and their effect on tissue properties were tracked across each stage of two elemental chlorine free (ECF) bleaching sequences. The properties of bleached OCC were compared to those of deinked pulp (DIP), southern bleached softwood kraft (SBSK), and refined OCC unbleached. Both sequences reduced the kappa number from 89 to negligible values and increased brightness from 18.9% to ca. 75% ISO, on average 6.2% ISO units below that of DIP. Overall, bleaching significantly increased tensile index and absorbency rate while having adverse effects on bulk and softness and minor impacts on absorption capacity. The change in properties was correlated to the improved fiber bondability and fiber wettability derived from the lignin removal. Compared to DIP, bleached OCC exhibited a higher tensile index, higher freeness, and similar absorption capacity but lower softness. It also showed higher absorption capacity and similar softness than SBSK but lower freeness at a comparable tensile index. The results indicate that upgraded OCC could be used as an alternative fiber to address the forecasted shortage of high-grade recycled papers in recycled tissue grades or replace virgin fibers in producing virgin tissue grades. In addition, it was determined that refined OCC unbleached could also be suitable for use in tissue grades where high brightness is not an essential product feature.

How do xylanase and hot acid stages differ at enhancing elemental chlorine-free bleaching of hardwood kraft pulp?

Hardwood kraft pulp contains relatively high hexenuronic acid content which increases unnecessary consumption of bleaching chemicals and has negative effects on pulp brightness stability. Hexenuronic acid can be partly removed by an enzyme treatment or a hot acid treatment. The difference between enzyme and hot acid stages on removing hexenuronic acid and enhancing hardwood kraft pulp ECF bleaching has been investigated. A typical hot acid stage removed more than 60% of hexenuronic acid but only saved about 20% of chlorine dioxide to achieve 84% ISO, while xylanase treatment only removed 12% of hexenuronic acid but saved approximately 40% of chlorine dioxide to achieve the same brightness target. In addition to a slight reduction of hexenuronic acid, fiber ultrastructure analysis reveals that enzyme pretreatment removed hemicellulose layer which was originally present on the fiber surface. The removal of “barrier” xylan increases fiber accessibility to bleaching chemicals and decreases the diffusion resistance of delignification during bleaching.

Efeito da extração alcalina na redução do número Kappa no branqueamento ECF

The acid hydrolysis stage (A HT ) used in bleaching sequences of pulp, has as its main objective, the degradation of hexenuronic acids which are present in the pulp and can affect its brightness, reversal of brightness, among others. Despite the benefit of using the acid hydrolysis stage, the pH of this stage is not the most adequate, but when it comes to the degradation of lignin, it is more reactive in alkaline medium. Therefore, the present work sought to study an improvement in the bleaching process by the addition of an alkaline extraction stage after A HT stage, obtaining the best possible use of the chlorine dioxide stage. In this study, oxygen-delignified Kraft pulp from eucalyptus was used. Different ECF (Elemental Chlorine Free) bleaching sequences were performed in the pulp: D 0 (E+P)D 1 , A HT D 0 (E+P)D 1 , A HT /ED 0 (E+P)D 1 and A HT ED 0 (E+P)D 1 .As a result, the inclusion of a simple alkaline stage after the acid hydrolysis indicate a positive effect on the bleaching sequence, with a significant reduction in the consumption of chlorine dioxide. The inclusion of simple alkaline extraction also allowed the reduction of the kappa number and increased brightness, with a reduction of 0.3 points in the average Kappa number and a 1.3% ISO increase in brightness, analyzed after alkaline extraction with hydrogen peroxide of the sequence A HT /ED 0 (E+P)D 1 when compared to the one without simple alkaline extraction.

Improved chlorate production with platinum nanoparticles deposited on fluorinated activated carbon cloth electrodes

Sodium chlorate is one of the main oxidizing agents used in the wood industry due to their capability of use as an elemental chlorine-free (CEF) bleaching. A simple way to produce chlorates is by the electrolysis of an aqueous sodium chloride (NaCl) solution. In the present study activated carbon cloth electrodes (ACC) modified with fluorine and platinum nanoparticles (Pt–F/ACC and Pt/ACC) were used as one of the electrodes. Electrofluorination was used for fluorination of the anodes and polyol method was used for the synthesis of platinum nanoparticles. Chlorate production using a typical solution of 100 ​g/l of sodium chloride (NaCl) and 2 ​g/l sodium chromate (Na 2 Cr 2 O 7 ) and an applied current of 0.540 ​A was studied. Prior to the electrolysis assays, the microstructural properties of the electrodes were characterized by scanning electron microscopy and surface modifications and bonding using infra-red (FTIR) spectroscopy. Electrochemical properties were determined using cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. Interaction between fluorine (F) and platinum (Pt) on the electrode leads to an improvement of the electrocatalytic properties for chlorine evolution as observed from the increase in the current efficiency from 37.5% at 78.5% after 150 ​min of continuous electrolysis using Pt–F/ACC anodes. The results suggest that modified activated carbon material is an attractive and economical alternative as electrodes for chlorate production. • The Cl evolution was improved by Pt nanoparticles on fluorinated activated carbon. • Increasing the substrate’s conductivity increase the kinetics for Cl evolution. • Fluorinated substrate increased the stability of the electrode against oxidation.

Effect of introducing ozone in elemental chlorine free bleaching of pulp on generation of chlorophenolic compounds

Abstract Effect of using ozone before elemental chlorine free (ECF) bleaching of oxygen delignified wheat straw pulp produced following soda-anthraquinone pulping on bleaching effluent and pulp properties was studied. The effluent generated during bleaching of pulp contains high amount of adsorbable organic halogens (AOX), chemical oxygen demand (COD), biochemical oxygen demand (BOD) and highly toxic chlorophenolic compounds. This study is aimed to utilise green chemistry approach during bleaching of one of the abundantly used agro residue wheat straw for improving the quality of bleaching effluent and pulp properties. Introducing ozone stage before ECF bleaching resulted in significant reduction of chloriphenolic compounds like chlorocatechols by 48.9 %, chloroguaiacols by 33.3 %, chlorovanillins by 28.4 % and chlorophenols by 26.7 % in the effluent compared to those of control. Incorporation of ozone before ECF bleaching BOD, COD, AOX and colour were reduced by 40.0 %, 41.1 %, 46.7 % and 57.8 %, respectively, as compared to control. Optical properties like brightness and whiteness of the pulp bleached using ozone were also improved by 2.5 units and 4.0 units, respectively as compared to that with control.

Chlorine dioxide bleaching of nineteen non-wood plant pulps

AbstractBleaching of unbleached and oxygen delignified pulps from nineteen non-wood plants has been evaluated in elemental chlorine free bleaching. Chlorine dioxide charge (kappa factor 0.15, 0.20 and 0.25) and temperature (70 and 85 °C) in the delignification stage (D) were varied. Chlorine dioxide (ClO2) charge and temperature exhibited lower kappa number and higher brightness after alkaline extraction (EP) stage. High temperature ClO2delignification (DHT) exhibited higher final pulp brightness. The final brightness of wheat straw pulp reached to 90 % after D0/DHT(EP)D1bleaching, while banana pseudo stem pulp showed the worst bleachability. Residual hexeneuronic acid contents in final pulp from most of the non-wood plants were lower and exhibited 1–2 % higher pulp brightness in DHTprocess than D0process. Oxygen delignified pulp and DHTprocess discharged lower COD load.

Mass balance and elimination mechanism of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) during the kraft pulping process

Papermaking raw materials are usually digested by NaOH and Na2S solution. The fate of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) during the kraft pulping process is still poorly known. In this study, a comprehensive investigation was conducted on the variation in PCDD/Fs in the kraft pulping section of 3 modern non-wood pulp mills adopting elemental chlorine-free (ECF) bleaching technology. Similar dioxin homologue profiles, dominated by Cl1−3DF and Cl2DD homologues, were observed in the raw materials, black liquors and brown pulps; and the partitioning behaviors of dioxin congeners between black liquor and brown pulp were found to be partly dependent on their octanol-water partitioning coefficients. Dioxin mass flow analysis indicated that the raw materials contributed more than 95 % to the dioxins entering the pulping section. Approximately 7 − 30 % of the input dioxins were exported by black liquor, and the brown pulp carried 44 − 51 % of the input dioxins into the subsequent bleaching section. The kraft pulping process caused a 40 − 48 % reduction in input dioxins. Alkaline hydrolysis and coupling reaction between dioxins and the aromatic fragments of lignin were proposed as two most possible mechanisms for dioxin elimination. In general, modern pulp mills have actually become industrial plants that eliminate environmental dioxins.

Insight into papermaking characteristics of D0EPD1-bleached soda, soda-AQ and kraft pulps of citronella grass (Cymbopogon winterianus Jowitt)

Grasses have emerged as potential alternative raw materials which can replace wood for pulp and paper products. Various species of grasses have been explored previously for pulp and paper production. This study is aimed to investigate pulp and papermaking characteristics of a grass species namely Cymbopogon winterianus Jowitt which is commonly known as citronella grass. This grass was subjected to proximate chemical characterisation; fibre morphology analysis; soda, soda-AQ (soda-anthraquinone), and kraft pulping; elemental chlorine free bleaching using D0EPD1 (D = ClO2 in acidic medium; EP = alkaline extraction with addition of H2O2; 0 and 1 = initial and final stage) sequence; and evaluation of physical strength properties of paper hand sheets. The pulp and paper hand sheets were also examined through SEM (scanning electron microscope) and FTIR (Fourier-transform infrared) spectroscopy to observe the structural and functional group variations. The proximate chemical analysis of citronella grass was found superior in terms of α-cellulose (38.10%), pentosans (22.30%) and alkali solubility (28.20%) while inferior in terms of ash (8.20%), lignin (25.10%) and alcohol benzene solubility (6.31%) with respect to some other grass species used for pulp and papermaking. Fibre length (0.69–0.74 mm) and fibre width (13.8–15.1 μm) were also comparable to other grass species. Brown pulp characteristics such as screened yield (44.67%), brightness (~24 %ISO) and kappa number (~20) revealed superiority of soda-AQ pulping among all the pulping processes while the kraft pulp exhibited the highest brightness (83.05 %ISO) and intrinsic viscosity (17.6 cP) after D0EPD1 bleaching. Tear index, tensile index and burst index of paper hand sheets obtained from bleaching of soda-AQ and kraft pulps were almost similar but higher to that of bleached soda pulp. The citronella grass was found suitable for producing writing and printing grade paper based on processes and optimised parameters described in this study.