Pulp

Abstract

The article contains sections titled: 1. Chemical Pulp 1.1. Raw Materials 1.2. Processing of Raw Materials 1.2.1. Processing of Wood 1.2.2. Processing of Annual Plants 1.3. Chemical Pulping Processes 1.3.1. Alkaline Pulping Processes 1.3.1.1. Kraft (Sulfate) Pulping 1.3.1.2. Soda Pulping of Annual Plants 1.3.2. Sulfite Process 1.3.2.1. Reactions in Sulfite Pulping 1.3.2.2. The Various Sulfite Processes 1.3.2.3. Multistage Sulfite Processes 1.3.2.4. Anthraquinone‐Catalyzed Sulfite Pulping 1.3.3. Other Pulping Processes 1.3.3.1. Nitric Acid Pulping 1.3.3.2. Pulping with Organic Solvents 1.3.3.3. Pulping with Organic Acids 1.4. Technology of Pulp Production 1.4.1. Pulping 1.4.2. Washing and Screening of Pulp 1.4.3. Pulp Drying 1.5. Waste Liquor Treatment 1.5.1. Recovery of Useful Products from Waste Liquor 1.5.2. Energy Generation from Waste Liquor 1.5.3. Chemicals Recovery 1.6. Pulp Bleaching 1.6.1. Conventional Bleaching 1.6.2. Chlorine‐Reduced and Chlorine‐Free Pulp Bleaching 1.6.3. Technology of Bleaching 1.7. Environmental Aspects of Chemical Pulp Production 1.8. Pulp Properties and Applications 2. Mechanical Pulp 2.1. Introduction 2.1.1. The Raw Material, Wood 2.1.2. Characteristics Required of Mechanical Pulps 2.2. Groundwood 2.2.1. The Grinder Stone 2.2.2. Groundwood Production 2.2.3. Newer Methods of Groundwood Production 2.3. Refiner Mechanical Pulps 2.3.1. Historical Survey 2.3.2. Theory of the Refiner Process 2.3.3. TMP Production 2.3.4. New Methods of Refiner Pulp Production 2.4. Screening of Mechanical Pulps 2.4.1. Purpose of Screening 2.4.2. Mechanical Pulp Screening 2.5. Bleaching of Mechanical Pulps 2.6. Comparison of Mechanical Pulps

Introduction

“…The specific effluent COD and AOX emissions after the biological treatment plant of today's state-of-the-art kraft pulping technology are at a level of about 7 kg adt -1 and <0.1 kg adt -1 , respectively [25]. In order to overcome the problem with the additional recovery of methanol, a new attempt was made to improve the efficiency of alkaline sulfite pulping, AS/AQ, in the absence of methanol [48]. The successful technological improvements in the past, as well as the current developments focusing on new generations of alkaline cooking, clearly signal that kraft pulping will remain the dominant cooking process in the future.…”

Cleave and couple: toward fully sustainable catalytic conversion of lignocellulose to value added building blocks and fuels

“…27-29 A wellestablished example is paper production by various pulping methods. 30,31 These approaches typically result in high quality cellulose, which can be used as such for the production of fibers and paper, or subjected to enzymatic treatment to produce bioethanol, and impressive progress has been made in the catalytic or biocatalytic deconstruction of cellulose for the production of important platform chemicals. However, the lignin originating from these fractionation methods typically suffers from severe structural modification and contains more robust C-C bonds and much less cleavable b-O-4 linkages compared to native lignin and is therefore not ideal for further depolymerization, especially under mild conditions.…”

A study on supercritical water gasification of black liquor conducted in stainless steel and nickel-chromium-molybdenum reactors

“…Rather than first generation biorefinery, organic wastes could be utilized through integration of a biorefinery with industrial processes. For instance, black liquor – the side stream of the pulping process – has very good potential for this purpose: it has 50% of the organic matter present in wood along with a large number of different organic compounds including polysaccharides, carboxylic acids and extractives. In Finland, the utilization of black liquor for energy purposes accounted in 2002 for 46% of the entire energy produced by biofuels and 11% of the total heat and power generation .…”