– **History**:
– Precursor to soda pulping was the paper making process by Matthias Koops in 1801.
– Soda pulping invented in 1851 by Burgess and Watts.
– First mill started in the USA in 1866.
– Patent for recovery of cooking liquors by incineration filed in 1865.
– Many early soda mills converted to kraft mills.
– **Production**:
– 5%-10% of paper production worldwide from agricultural crops.
– Agricultural paper production valued at $5-10 billion.
– Notable crops used are wheat straw and bagasse.
– Bagasse requires less bleaching chemicals than wood pulp.
– Spent reaction chemicals in bagasse mills are combusted for power.
– **As Solution for Silicate Scaling**:
– Grasses, bagasse, bamboo, and some hardwoods contain silicates.
– Silicate scales can be controlled with lime mud or lime kiln ash.
– Silicate removal achieved by lowering pH with CO-containing flue gases.
– No commercial silicate removal system available for kraft process.
– Kraft process can handle small amounts of silicates.
– **See Also**:
– Paper chemicals.
– **References**:
– Ali, Mona; Byrd, Medwick; Jameel, Hasan (2001).
– Ward, James (11 September 2014).
– Biermann, Christpher J. (1996).
– Gullichsen, Johan; Paulapuro, Hannu (2000).
– Scientific American, 1868.
Soda pulping is a chemical process for making wood pulp with sodium hydroxide as the cooking chemical. In the Soda-AQ process, anthraquinone (AQ) may be used as a pulping additive to decrease the carbohydrate degradation. The soda process gives pulp with lower tear strength than other chemical pulping processes (sulfite process and kraft process), but has still limited use for easily pulped materials like straw and some hardwoods.