You must have javascript enabled to view this ebook the following instructions describe how to enable javascript in your browser. Kraft pulp bleaching with hydrogen peroxide and peracetic. Other chemicalpulping processes mainly using acid sulfite and soda are sometimes combined with various chemicalrecovery subprocesses. To complete these processes, the industry requires many different compounds for a variety of tasks. The major differences between these are the chemicals used, the quality of paper produced, and the economy of chemical recovery. Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fiber crops, waste paper, or rags. As noted in t 617 analysis of lime, two forms of lime are used in the pulp and paper industry. Naoh is completely ionized and for every two sodium atoms of na2s, there will be one ohproduced. Sulfate or kraft pulp is one of the chemical pulping processes. Learn answers chapter 6 chemistry with free interactive flashcards. The different processes of chemical pulping include the kraft process, which uses caustic soda and sodium sulfide and is the most common.
Pulp quality is identified by the good strength, bleach ability, high cellulose and hemicellulose content and low lignin content. The pulp and paper industry integrates different manufacturing and chemical processes to prepare a variety of products essential to modern society. The pulping process is an important link in the papermaking industry. In the white liquor, sulfidity is the ratio of na2s to the active alkali. Kraft pulping process is the most used pulping process in the world. Peroxychem is a leading supplier of pulp and paper chemistries, and provides high value, versatile, clean and environmentally friendly bleaching agents that can be used to brighten chemical, mechanical and recycled pulps, as well as offering a wide range of water and waste treatment solutions. Questions and answers for the pulp and paper national. The chemical pulp is produced through the chemical pulping process, while the mechanical pulp is produced through mechanical pulping. Chips from the storage bins are fed into a digester to which chemicals have been added. A method of converting wood chips into paper pulp for use in papermaking accomplished by chemical cooking of the chips, as opposed to mechanical pulping.
An example of this is kraft pulping, in which alkaline processes are. The 4 processes principally used in chemical pulping are kraft, sulfite, neutral sulfite semichemical nssc, and soda. Lai 33 the modification of multistage polysulfide pulping to improve pulping selectivity. The choice of pulping process is determined by the. Chemical pulping article about chemical pulping by the free. This is a linear programming problem that requires a. Kraft pulping process is the dominating pulp manufacturing process in the world.
In contrast, chemical pul ping produces intact fibres chemical mechanical yield fibrewood low 4070% high 9098% cellulose purity high lignin low lignin dissolved remains end uses dissolving pulp low quality high quality paper high volume paper e. Highlights in this paper, the valorisation of tunisian vine stem wastes was investigated. Pulp and paper mills chemical processes semichemical mechanical total kraft sulphite ontario 94 215 30 quebec 10 8241 61. The author to whom the correspondence should be addressed.
Jun 30, 2015 kraft pulping process is the most used pulping process in the world. Unlike kraft pulping, since there is no innate chemical and heat recovery procedure, in sulfite pulping the mixture used called red liquor drains through the bottom of the tank before being treated and. The pulp and paper industry the ecology of industry. Chemical technology is like specialising in some particular area like petroleum,petrochemicals,sugartechnology,paper and pulp technology, paint technology,surfactant technology etc. Of the chemical processes, alkaline pulping the kraft or sulphite process is the most common and is shown in figure 22. Chemical technology of wood, pulp and paper in culture, education and industry conference paper pdf available january 2003 with 1,7 reads how we measure reads. In this process lignin goes into the reactions with the cooking liquor chemicals and split into fragment.
Chemical bonding section 3 short answer answer the following questions in the space provided. Some of the fundamentals of the book are bleaching of bamboo cold, high yield semi chemical pulping of mixture of bamboo and mixed hardwoods, sulphate semi chemical process, kraft green liquor semi chemical process, neutral sulphite semi chemical process, thermo. Discover manufacturers, suppliers, industrial product variants and raise rfqs. Sulfate pulping is a process that was developed in germany in 1879. Olson pulp and paper centre, department of mechanical engineering, university of british columbia mechanical pulping comparison of mechanical and chemical pulps debarking stone groundwood refiner mechanical pulp thermo mechanical pulping tmp. Integration of biorefinery processes into chemical pulp mills. Sep 14, 2016 sulfite pulping proceeds quite similarly to kraft pulping, except it uses different materials in its lignin dissolving chemical mixture. Pdf chemical technology of wood, pulp and paper in culture. Fresh pulping liquor for the kraft process containing naoh, na 2 s, and a variety of impurities. Mechanical pulping has the advantage of converting up to 95 % of the dry weight of the wood input into pulp, but the mechanical action requires a large energy input. Pulping chemical preparation and analysis 156 effective alkali ea. The purpose of pulping is to reduce wood or other fibrous raw material to individual cellulose fibers. Chemical pulping involves dissolving lignin in order to extract the cellulose from the wood fiber.
Kraft sulphate pulping is the most widely used pulping process and. Pulping is done mechanically, thermomechanically, chemically, or with combinations of these treatments. The comparison of physical pulp and papers properties from vine stem with data collected from the literature, we show that this agricultural residue has the potential to be used. This book will tell you, step by step, the research and technology behind the process of obtaining fibres from wood by chemical pulping. Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibers from wood, fiber crops, waste paper, or rags. Contains most of the original inorganic components most in different forms and a high concentration of dissolved organics. The book covers kraft pulp mill technology from fibre line spent liquor black liquor to the recovered active cooking chemical white liquor and energy in the form of steam and electricity. Pulping and bleaching hardcover january 1, 1952 by james p. The chemical reactions in kraft pulping process pulp paper mill. There are two widely recognized processes for producing chemical pulp. To learn why it is important, we have to start from the pulp.
Energy and environmental profile of the us pulp and. Choose from 500 different sets of answers chapter 6 chemistry flashcards on quizlet. Commercial processes are generally classified as mechanical, chemical, or semi. Semichemical pulping products do the same enter beating or go through a bleaching process prior to beating. Mech 450 pulping and papermaking topic 3 mechanical pulping james a. For semichemical pulping, wood preparation and chipping are essentially the same as that for other woodpulping processes. We fully characterized the obtained pulps from this agricultural material. The chemical reactions in kraft pulping process pulp. Chemical composition and pulp characterization of tunisian. This includes newspapers, magazines and even toilet paper.
Chemical pulping part 2,recovery of chemicals and energy. While pulp and paper production residues should be supported as. The effect of acetone concentration on the pineapple leaves pulping was first observed by the turbidity of the spent. Separation of wood fiber for paper pulp by chemical treatment of wood chips to dissolve the lignin that cements the fibers together explanation of chemical pulping. Cho 32 the chemical aspects of sulfiteaq delignification of norway spruce 163 h. Following the successful completion of the transaction, metso paper will be able to deliver all core processes for modern pulp mills, including chemical pulping lines, chemical recovery and power generation for pulp and paper production.
Chapter 6 chemical composition francis howell high school. The chips are steeped and impregnated with inorganic chemical solutions similar to those used for full chemical pulping, but in smaller amounts and with less severe conditions. Volume 6 chemical pulping part 1 fibre chemistry and technology. Ea is the sum of sodium chemicals that will produce ohduring kraft pulping.
This is achieved by breaking the bonds in the lignin macromolecule. Chemical pulp is used for materials that need to be stronger or combined with mechanical pulps to give a product different characteristics. Handbook of pulping and papermaking 2nd edition elsevier. Fiber paper is thin, tough, brittle, and a bit rough. In the 1930s, the process was enhanced with chemical recovery. Within each neshap section, the questions of individual volumes are numbered consecutively.
The pulp samples were handkneaded for one minute and treated in a preheated water bath. Metso paper will be able to deliver all core processes for modern pulp mills, including chemical pulping lines, chemical recovery and. Chemical and pulping ltd with registration in hong kong and the usa, cpl is committed to serving all regions of the world as a provider of energy saving process technologies and equipment. Panu tikka, professor, scitech service oy ltd, espoo, finland volume 6 part 2 of the papermaking science and technology series, published by the finnish paper engineers association. Note, there is a dedicated bleacher for each process. A summary of the negative effects caused by pulp and paper. The chemical composition of vine stems was studied. Dec 31, 2014 sulfate or kraft pulp is one of the chemical pulping processes.
Questions and answers are organized and presented by section of the neshap. Semichemical pulping article about semichemical pulping. The kraft process alone accounts for over 80 percent of the chemical pulp produced in the united states. Pulp paper is not as strong as fiber paper, but it is easier to make, softer, thicker, and preferable for most everyday purposes. Aries chemical provides the products and technical support to optimize pulp and paper manufacturing. This book will tell you, step by step, why research and how technology things are done to obtain fibres from wood by chemical pulping. Pdf on the potential utilisation of sawdust and wood chip screenings. In kraft pulping, the dominant chemical pulping method, wood chips are cooked with chemicals. The companies and products represented worldwide include cabtec international llc pulping technologies as well as other pulp and paper equipment suppliers. Hemp pulp paper can be made without chemicals from the hemp hurd.
From kraft pulping, some products enter the bleaching stage prior to beating while others go directly to beating. The kraft process is the dominant chemical pulping method, with the sulfite process second. Chemicals features indepth and thorough coverage of chemical additives in the pulp and paper industry. Cooking removes lignin breaking up the wood into fibres. The book emphasizes principles and concepts behind papermaking, detailing both the physical and chemical processes. What is the difference between mechanical and chemical pulp. Chemical pulping article about chemical pulping by the. Summary of environmental aspects of kraft chemical recovery. Lignin is the binding material which holds the cellulose fibres together. Chemical pulping recovery of chemicals and energy, 2nd edition book editor. This september 1999 document provides implementation information by supplying answers to frequently asked questions, such as applicability, definitions, various system processes, etc. Technology book 6a chemical pulping fapet oy in cooperation with the.
Casey author see all formats and editions hide other formats and editions. Historically soda pulping was the first successful chemical pulping method. Semichemical pulping wood chips are softened with chemicals and disc refiners are used to mechanically convert chips into fibres eg. They can also be used in the production of kraft pulp, ethanol and chemicals. Pulp and paper pulp is the fibrous mass that results when a pulping process ruptures the bonds in the wood structure that hold the woody cells together. Therefore, it is desirable to have a pulp process that gave the highest delignification efficiency and good quality of cellulose and hemicellulose. Discovering the high potential of pulp and paper production. Energy efficiency of finnish forest industry semantic scholar. Every tenth presented at the 27th international conference of the slovak society of chemical engineering, tatransko matliare, 2226 may 2000. Pulping technology two methods for converting wood to papermaking fibres chemical kraft pulping uses chemical to dissolve lignin from wood to produce nearly pure cellulose fibres 1 ton of tree 0. It discusses use of enzymes green chemicals that can improve. This chapter discusses three different chemical pulping processes. Chemical pulping of waste pineapple leaves fiber for kraft.
The main chemical reactions in the cooking process can be described as. The chips are cooked by heat and pressure in caustic soda and sulphur. The most widely used chemical pulping process in paper making is the sulfate, or kraft, process. The first 3 display the greatest potential for causing air pollution. Pdf chemical technology of wood, pulp and paper in. Some of the fundamentals of the book are bleaching of bamboo cold, high yield semi chemical pulping of mixture of bamboo and mixed hardwoods, sulphate semi chemical process, kraft green liquor semi chemical process, neutral sulphite semi chemical process, thermo mechanical pulps for newsprint, zeta potential. Today this process is most widely used with a production of 7080% of the total pulp. Pulp can be classified mainly into two types by the pulping methods. These smaller pieces can then undergo either chemical pulping or mechanical pulping.
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