Process Development Studies on Itaconic Acid Production from Saw Dust

Abstract

This paper deals with process development studies on wood saccharification using strong sulfuric acid and phosphate rock for producing itaconic acid, in which process studies on recovery of disodium phosphate from the wood hydrolyzate containing phosphoric acid and on itaconic acid fermentation of the refined wood hydrolyzate are involved.
The synthetically prepared sugar mixture solutions simulating several kinds of wood carbohydrate composition and wood hydrolyzate containing phosphoric acid have successfully been proved to give excellent yields of the acid by shake culture.
Ten ppm of 5 valent arsenic compound inhibited Aspergillus terreus K 26 used for this fermentation test but it can be removed by a simple anion exchange operation as pretreatment of the wood hydrolyzate.
For minimizing anion exchange capacity of the wood hydrolyzate, extraction of AcOH by tributyl phosphate and precipitation of salts of inorganic impurities at several steps of pH by neutralizing with Na₂CO₃ were performed.
Purification process involves orthodox procedure described by Waggaman⁽¹⁾ and electrodialysis process for concentrating wood sugar mixture and preliminary refining of phosphoric acid.
Amount of residual arsenic compounds in disodium phosphate crystals, which is allowed by JIS standards, was found less than 0.8 ppm.