Pulping product yields

Applied chlorine, % o.d. pulp Product yield (%) Total... 

Pulp Manufacture. Sodium sulfite is utilized in neutral semichemical pulping, acid sulfite pulping, high yield sulfite cooling, and some kraft pulping processes (339). Many pulp mills prepare their own sulfite and recycle as much as possible, but use of merchant sodium sulfite by pulp mills is substantial. Much of the by-product sodium sulfite from resorcinol manufacture goes into pulp appHcations as well as a substantial fraction of the lower assay manufactured sodium sulfite. 

In all cases in modern pulp bleaching, elemental chlorine is excluded and only chlorine dioxide is applied to yield elemental chlorine-free pulps (ECF pulps). If any chlorine-containing compound is avoided totally chlorine-free pulps (TCF pulps) are achieved. Concerning the bleaching, Kraft pulp mills have been converted predominantly to elemental chlorine-free (ECF) bleaching. Totally chlorine-free (TCF) bleaching is the method of choice for sulphite mills. Therefore, the extent of TCF bleaching remains at around 5% of the pulp production. 

Kenaf (Hibiscus cannabinus L.) is a plant in the Malvaceae family. It is a wrarm-season annual fiber crop grown in temperate and tropical areas. Kenaf s significant contribution to the supply of raw material for cellulose pulp and other products makes it a potential substitute for wood resomces [1]. Due to its rapid growth, ecological adaptability and production yield, kenaf is considered as the fiber sotnce of the futiu-e [1],... 

In conclusion, a selection of samples was made for each treatment (water, AcOH and SO2) based on the highest yield of extracted wood components in combination with lowest weight loss (i. e., preservation of wood mass for subsequent pulp production). 

Separation of Fatty Acids. Tall oil is a by-product of the pulp and paper manufacturiag process and contains a spectmm of fatty acids, such as palmitic, stearic, oleic, and linoleic acids, and rosia acids, such as abietic acid. The conventional refining process to recover these fatty acids iavolves iatensive distillation under vacuum. This process does not yield high purity fatty acids, and moreover, a significant degradation of fatty acids occurs because of the high process temperatures. These fatty and rosia acids can be separated usiag a UOP Sorbex process (93—99) (Tables 8 and 9). 

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