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The kraft process (also known as kraft pulping or sulfate process) is a process for conversion of wood into wood pulp, which consists of almost pure cellulose fibres, the main component of paper. The kraft process involves treatment of wood chips with a hot mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na 2 S), known as white ...
Mechanical pulping is the process in which wood is separated or defibrated mechanically into pulp for the paper industry. The mechanical pulping processes use wood in the form of logs or chips that are mechanically processes, by grinding stones (from logs) or in refiners (from chips), to separate the fibers.
Recovery boiler is the part of kraft process of pulping where chemicals for white liquor are recovered and reformed from black liquor, which contains lignin from previously processed wood. The black liquor is burned, generating heat, which is usually used in the process of making electricity, much as in a conventional steam power plant. The ...
Chemical pulping processes such as the kraft (or sulfate) process and the sulfite process remove much of the hemicelluloses and lignin. The kraft process does less damage to the cellulose fibers than the sulfite process, thereby producing stronger fibers, but the sulfite process makes pulp that is easier to bleach. The chemical pulping ...
This, along with the ability of the kraft process to accept a wider variety of types of wood and to produce stronger fibres, [13] made the kraft process the dominant pulping process, starting in the 1940s. [2] Global production of wood pulp in 2006 was 175 million tons (160 million tonnes). [14]
Dissolving pulp is mainly produced chemically from pulpwood in a process that has a low yield (30 - 35% of the wood). This makes up of about 85 - 88% of the production. [2] Dissolving pulp is made from the sulfite process or the kraft process with an acid prehydrolysis step to remove hemicelluloses. For the highest quality, it should be derived ...
Heinz announced it is working to develop a new recyclable condiment bottle "made from 100 percent sustainability sourced wood pulp."
This, along with the ability of the kraft process to accept a wider variety of types of wood and produce stronger fibers [4] made the kraft process the dominant pulping process starting in the 1940s. [3] Sulfite pulps now account for less than 10% of the total chemical pulp production [3] and the number of sulfite mills continues to decrease ...