Generation of environmentally enhanced products: Clean technology for paper chemicals

The modification of existing chemical manufacturing processes to selectively remove unwanted chemicals in products, offers a realistic approach to novel clean technologies. Adjunct biotechnological processing offers a means to achieve the manufacture of new environmentally enhanced products (EEPs). This paper describes the development and implementation of a bioprocess for the manufacture of an enhanced paper chemical. The process was integrated into existing manufacturing plants involved in the production of neutral curing poly(aminoamide) chemicals which are used commercially to impart wet-strength to paper products such as tissues and towels (e.g. Kymene(R) wet-strength resins). A consequence of the epichlorohydrin chemistry involved in the polymer's manufacture, haloalcohols (predominantly, 1,3-dichloropropan-2-ol (DCP) and 1-chloropropanediol (3-CPD)) contaminate the product. The objective was to reduce the concentration of the two haloalcohols in Kymene(R)-SLX wet-strength resins (c. 8000 ppm db) without affecting the performance of the product. A two-membered bacterial consortium was used in an aerobic stirred tank bioreactor system which was capable of rapidly reducing the concentrations of DCP and CPD in an aqueous solution of the wet-strength resin to less than 1 ppm and 5 ppm respectively. A 3000 dm(3) bioreactor was integrated into two established manufacturing plants, generating a reliable and predictable process to enhance the value of the neutral curing wet-strength chemical.