Water purification conversion rates

There exist two major conversion methods, biochemical and thermochemical, of wood into useful chemicals and liquid fuel. En matic saccahfication is one of the biochemical conversion method whereas acid-, base-, and metal-catalyzed hydrolyses are the themiochemical conversion method, However, the hydrolysis reaction does not proceed at a sufficiently high reaction rate. In addition, corrosion of the reactor may occur in the latter and it requires purification process of the waste water-... 

Kim MG, Lee SB (1996) Penicillin acylase-catalyzed synthesis of P-lactam antibiotics in water-methanol mixtures effect of cosolvent content and chemical nature of substrate on reaction rates and yields. J Mol Catal B Enzym 1 201-211 Kohsaka M, Domain AL (1976) Conversion of penicDlin N to cephalosporin(s) by ceU-free extracts of Cephalosporium acremonium. Biochem Biophys Res Commun 70(2) 465-473 Koreishi M, Tani K, Ise Y et al. (2007) Enzymatic synthesis of P-lactam antibiotics and /V-fatty-acylated amino compounds by the acyl transfer reaction catalyzed by peniciUin V acylase from Streptomyces mobaraensis. Biosci Biotechnol Biochem 71(6) 1582-1586 Kupka JY, Shen, YQ, Wolfe S et al. (1983) Partial purification and properties of the alpha-ketoglutarate-linked ring expansion enzyme of beta-lactam biosynthesis of Cephalosporium acremonium. FEMS Microbiol Lett 16 1-6... 

The process, first disclosed in 1968, was commercialized in 1973. Yields in this process were very high (99%) and ease of operation was excellent. The major difficulty encountered was with catalyst precipitation during product removal. To minimize the problematic catalyst precipitation and to stabilize the catalyst, 10-15% water was included in the reaction mixture and the catalyst -product separation was conducted as an adiabatic flash. The inclusion of large amounts of water and the restriction to an adiabatic flash meant that the conversion was limited by product removal, not the reaction rate, and that there were large recycle streams of acetic acid and water. Additional minor difficulties were the cogeneration of traces of acetaldehyde which ultimately lead to propionic acid and iodine containing impurities. While the propionic acid was removable by distillation (with a dedicated unit of operation), the iodine has proven more problematic. It was important to remove essentially all the iodine (to < 40 ppb) during purification since iodine is a poison for the Pd/Au catalyst used in vinyl acetate production. 

Figure 6.29. Conversion of substrate in the liquid phase (Cs,l) measure of purification effect in waste water treatment versus mass loading rate per unit mass in case of CSTR and CPFR operation Compared are systems operating with one common sedimentation tank (SED), exhibiting only a small difference in conversion, and systems with separated SED, called contact stabilization or sludge-reaeration, in which case the CPFR is superior to the CSTR. (Adapted from F. Moser, 1977.)...

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