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Pratima Bajpai Green Chemistry and Sustainability in Pulp and Paper Industry Green Chemistry and Sustainability in Pulp and Paper Industry Pratima Bajpai Green Chemistry and Sustainability in Pulp and Paper Industry Pratima Bajpai C-103 Thapar Centre for Industrial R&D Consultant (Pulp and Paper) Patiala , India ISBN 978-3-319-18743-3 ISBN 978-3-319-18744-0 (eBook) DOI 10.1007/978-3-319-18744-0 Library of Congress Control Number: 2015942906 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2015 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifi cally the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfi lms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specifi c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Printed on acid-free paper Springer International Publishing AG Switzerland is part of Springer Science+Business Media ( www. springer.com ) Pref ace Rising raw material prices, increasing waste disposal costs and expanding legislation are the major drivers behind the rise of sustainable technologies. Producers around the world are forced to evaluate their production processes and to search for alterna- tive technologies with lower environmental impact. A comprehensive technology mapping can help producers to compare sustainable technologies and to select via- ble alternatives. With increasing regulatory pressure and growing market demand for better prod- ucts, the pulp and paper industry faces many challenges and must fi nd new ways to improve environmental and process performance and reduce operating costs. There has been a growing demand in the pulp and paper industry to adopt waste minimiza- tion strategies in order to create a minimum impact mill. A minimum impact mill does not strictly mean a zero-discharge mill, but rather one which either has no discharge or whose effl uent discharge has a minimum or no impact on the environ- ment. The goal of minimum impact mills is to minimize natural resource consump- tion (wood, water, energy) and minimize the quantity and maximize the quality of releases to air, water and land taking into account economic aspects and working environments. The minimum impact mill makes optimal use of its raw materials; reduces air emissions, water usage, and waste generation; and is a net producer of electricity. The vision of minimum impact manufacturing has captured the imagina- tions of industry leaders and the environmental community alike. This book gives updated information on minimum impact mill technologies which can meet the environmental challenges of the pulp and paper industry and describes some of the newest twenty fi rst-century fi bre lines. Patiala, India Pratima Bajpai v Contents 1 General Background ................................................................................. 1 References ................................................................................................... 8 2 Basic Overview of Pulp and Paper Manufacturing Process ................. 11 2.1 Raw Material Preparation ................................................................ 14 2.2 Pulping ............................................................................................. 15 2.2.1 Chemical Pulping ................................................................. 15 2.2.2 Mechanical Pulping .............................................................. 17 2.2.3 Semi-chemical Pulping ........................................................ 18 2.2.4 Secondary Fibre Pulping ...................................................... 19 2.2.5 Dissolving Kraft and Sulphite Pulping Processes ................ 20 2.2.6 Non-wood Pulping ............................................................... 20 2.3 Pulp Washing .................................................................................... 21 2.4 Pulp Screening, Cleaning and Fractionation .................................... 23 2.5 Bleaching.......................................................................................... 23 2.6 Chemical Recovery .......................................................................... 26 2.6.1 Black Liquor Concentration ................................................. 26 2.6.2 Recovery Furnace ................................................................. 26 2.6.3 Causticizing and Calcining .................................................. 27 2.7 Stock Preparation and Papermaking ................................................ 27 References ................................................................................................... 37 3 Environmental Consequences of Pulp and Paper Manufacture ........... 41 3.1 Water Pollution ................................................................................. 46 3.2 Atmospheric Pollution ..................................................................... 51 3.3 Sludge and Solid Waste .................................................................... 56 References ................................................................................................... 59 4 Minimum Impact Mill Technologies ........................................................ 65 4.1 Emission Reduced Wood Handling .................................................. 66 4.2 Dry Debarking .................................................................................. 69 4.3 High Yield Pulping ........................................................................... 71 vii viii Contents 4.4 Extended or Modifi ed Cooking ........................................................ 73 4.4.1 Batch Cooking .................................................................... 74 4.4.2 Continuous Cooking........................................................... 76 4.4.3 Modifying Kraft Pulping with Additives ........................... 80 4.5 Effi cient Brownstock Washing/Improved Pulp Washing ................. 84 4.6 Oxygen Delignifi cation .................................................................... 87 4.7 Ozone Bleaching of Chemical Pulps................................................ 96 4.8 Ozone for High Yield Pulping .......................................................... 106 4.9 Elemental Chlorine-Free Bleaching (ECF) Bleaching ..................... 108 4.9.1 Modifi ed ECF Sequences ................................................... 116 4.10 Totally Chlorine-Free (TCF) Bleaching ........................................... 119 4.11 Fortifi cation of Extraction Stages with Oxygen and Hydrogen Peroxide .................................................................... 126 4.12 Removal of Hexenuronic Acids ....................................................... 128 4.12.1 Hot Acid Stage (Ahot) or Combined Hot Acid and Chlorine Dioxide Stage (AD)hot ................. 129 4.12.2 High Temperature Chlorine Dioxide Stage (DHT) ............ 131 4.13 Liquor Loss Management ................................................................ 132 4.14 Condensate Stripping and Recovery ................................................ 134 4.15 Reduction of Sulphur Oxides and Nitrogen Oxides Emissions ....... 139 4.16 Electrostatic Precipitators................................................................. 142 4.17 Installation of Scrubbers on Recovery Boiler .................................. 146 4.18 Increase in the Dry Solids Content of Black Liquor ........................ 148 4.19 Incineration of Odorous Gases in the Lime Kiln ............................. 151 4.20 Installation of Low NOx Technology in Auxiliary Boilers and the Lime Kiln ............................................ 154 4.21 Selective Non-Catalytic Reduction on Bark Boilers ........................ 156 4.22 Over Fire Air Technique on Recovery Boilers ................................. 160 4.23 Installation of Improved Washing and Filtration of Lime Mud in Recausticizing ................................. 161 4.24 Technologies That can Help Achieve Practical Minimum Energy Consumption ....................................................... 163 4.24.1 Impulse Technology for Dewatering of Paper.................... 163 4.24.2 Energy Effi cient Thermo-Mechanical Pulping (TMP) Processes ................................................... 165 4.24.3 New Energy Effi cient Bleached Chemi-Thermo Mechanical Pulping Processes ........................................... 166 4.24.4 Use of Enzymes During the Refi ning of TMP ................... 167 4.24.5 Condebelt Process .............................................................. 168 4.24.6 High Consistency Forming................................................. 170 4.24.7 Black Liquor and Hog Fuel Gasifi cation ..........................

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