EFFECT OF INTRODUCING OZONE PRIOR TO ELEMENTAL CHLORINE FREE BLEACHING OF WHEAT STRAW PULP ON PULP, PAPER AND EFFLUENT PROPERTIES

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 ClO2 delignification (DHT) exhibited higher final pulp brightness. The final brightness of wheat straw pulp reached to 90 % after D0/DHT(EP)D1 bleaching, 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 DHT process than D0 process. Oxygen delignified pulp and DHT process discharged lower COD load.

Download Full-text

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

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2020-0062 ◽

2020 ◽

Vol 35 (4) ◽

pp. 559-568

Author(s):

Sandeep Kumar Tripathi ◽

Nishi Kant Bhardwaj ◽

Himadri Roy Ghatak

Keyword(s):

Optical Properties ◽

Wheat Straw ◽

Oxygen Demand ◽

Elemental Chlorine ◽

Wheat Straw Pulp ◽

Pulp Properties ◽

Organic Halogens ◽

Ecf Bleaching ◽

Adsorbable Organic Halogens

AbstractEffect 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.

Download Full-text

The Effect of Microwave Treatment on the Hydrogen Peroxide Bleaching of Soda-AQ Wheat Straw Pulp

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.236-238.1307 ◽

2011 ◽

Vol 236-238 ◽

pp. 1307-1312

Author(s):

Chao Jun Wu ◽

Chuan Shan Zhao ◽

Jun Li ◽

Ke FU Chen

Keyword(s):

Hydrogen Peroxide ◽

Wheat Straw ◽

Fiber Length ◽

Weighted Average ◽

Microwave Treatment ◽

Arithmetic Average ◽

Peroxide Bleaching ◽

Bleached Pulp ◽

Infra Red ◽

Wheat Straw Pulp

In this paper, the effect of microwave treatment on the hydrogen peroxide bleaching of Soda-AQ wheat-straw pulp was investigated. The results showed that microwave treatment could increase the brightness of the hydrogen peroxide bleached pulp. The fiber coarseness of microwave enhancing peroxide bleached pulp was higher than that of the peroxide bleached pulp. However, the arithmetic average fiber length, the length weighted average fiber length and weight weighted average fiber length of the former was lower than that of the latter. Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD) spectra showed that CrI(%) crystallinity of microwave enhancing peroxide bleached pulp was similar as that of the peroxide bleached pulp but all higher than that of the Soda-AQ wheat-straw pulp. N·O′KI infra-red crystalline index of microwave enhancing peroxide bleached pulp were lower than that of the peroxide bleached pulp. The FTIR spectra of lignin showed that the microwave treatment had some influences on the methoxyl and phenolic group in lignin.

Download Full-text

Xylanase and laccase aided bio-bleaching of wheat straw pulp

The Canadian Journal of Chemical Engineering ◽

10.1002/cjce.21798 ◽

2013 ◽

Vol 92 (1) ◽

pp. 131-138 ◽

Cited By ~ 11

Author(s):

Bhavin S. Dedhia ◽

Mangesh D. Vetal ◽

Virendra K. Rathod ◽

Csoka Levente

Keyword(s):

Wheat Straw ◽

Wheat Straw Pulp

Download Full-text

Study of Selecting Proper Chitosan from Various Chitosan Sample as Paper Strengthening Agent

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.117-119.1421 ◽

2011 ◽

Vol 117-119 ◽

pp. 1421-1424

Author(s):

Yong Sheng Ma ◽

Xian Hui Sun

Keyword(s):

Wheat Straw ◽

Strengthening Effect ◽

Chitosan Sample ◽

Viscosity Range ◽

Wheat Straw Pulp

It is usually reported that chitosan is used as paper strengthening agent. However, it is sorry that the study choosing chitosan which DD (degree of de-acetyl )and viscosity is filtered by experiments is blank. Many chitosan samples of wide viscosity range and wide DD range were tested by their strengthening effect on bleched wheat straw pulp. Then a few sample of chitosan is selected because of their obvious strengthening effect on pulp. This study could be as the foundation of further research of chitosan used as paper strengthening agent.

Download Full-text

Preparation and Properties of Multi-Layer Composite Paperboard

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.774-776.1010 ◽

2013 ◽

Vol 774-776 ◽

pp. 1010-1013

Author(s):

Quan Xiao Liu ◽

Dan Xi Li ◽

Fei Ma ◽

Chang Qing Chen ◽

Jun Yang

Keyword(s):

Wheat Straw ◽

Raw Materials ◽

Pulp Fiber ◽

Paper Pulp ◽

Mechanical Pulp ◽

Physical Strength ◽

Chemical Pulp ◽

Layer Composite ◽

Wheat Straw Pulp ◽

The Cost

In order to study the preparation and property of the multi layer composite paperboard, bleached wheat straw pulp, bleached chemical thermal mechanical pulp and waste newsprint pulp are used as raw materials to making paperboard. The results show that the bonding force between fibers of grasses chemical pulp is strong which can improve the bonding strength between the layers. Bleached wheat straw pulp is used as outer layer and waste news paper pulp is used as inner layer to make composite paperboard has high physical properties. Bleached chemical thermal mechanical pulp fiber is shorter, so paperboard tightness and physical strength reduce, which can be used as the lining of the multi layer composite paperboard to improve the stiffness of the paperboard and reduce the cost.

Download Full-text