Dual reactor system

Advanced Photon Source (APS), 26 412 Advanced Photo System (APS), 19 266 Advanced power reactors, 17 594—595 Advanced SclairTech dual-reactor system, 20 197... 

Figure 6.9 Schematic representation of the dual reactor system proposed for hydrogen generation by giucose APR (adapted from Ref. [281]).

Jeon, Y. J. and Kim, S. K. (2000). Continuous production of chitooligosaccharides using a dual reactor system. Process Biochem. 35, 623-632. 

If the indicator reaction is also enzyme catalyzed, then two methods may be used for the conversion of primary reaction product into the detected species. The first involves the use of a second reactor column containing immobilized indicator enzyme between the primary column and the detector, in a dual-reactor system. The second, and more common approach, employs a single reactor containing coimmobilized primary and indicator enzymes. For linear conversion of primary product, it must be remembered that the quantity of indicator enzyme present must be sufficient to for the complete conversion of all primary product, so that an excess of immobilized indicator enzyme must be present. 

Continuous stirred-tank reactors (CSTRs) have been routinely employed for producer gas fermentations. A two-stage reactor system has also been used to maximize ethanol production and minimize the formation of byproducts. Carbon monoxide and hydrogen conversions of 90% and 70%, respectively, were observed in the first reactor, while they were about 70% and 10% in the second reactor. High ethanol-to-acetate ratios were achieved by the use of such a dual reactor system. Bubble colunms are also commonly used for industrial fermentations. A comparative study was performed between a CSTR and a bubble column reactor for CO fermentation using Peptostreptococcus productus. Higher conversion rates of CO were observed with the bubble column without the use of any additional agitation. Producer gas fermentation with packed bubble colunms and trickle bed reactors has also been studied. The trickle bed reactor has a low pressure drop and liquid hold-up, and the conversion rates were the highest compared to CSTRs and bubble columns. 

The continuous production of COS was found to be feasible with combination of a column reactor packed with immobilized chitosanase and UF membrane system, and this system was developed by Jeon and Kim (2000b), named as dual reactor system (Figure 5.2). In this system, production of COSs may be performed in two steps. In the first step, chitosan is partially hydrolyzed by the immobilized chitosanase prepacked in the column reactor and the product is supplied to the UF membrane system for the production of COS. As expected, the viscosity of partially hydrolyzed chitosan was low thereby it does not create fouling problems under controlled conditions, and continuous production of COSs was achieved. This method ensures a greater productivity per unit enzyme, ability to control molecular weight distribution and more efficient continuous production process compared to those of conventional methods. Therefore, this method is commonly used to produce different molecular size COSs to study their bioactivities. 

FIGURE 5.2 Schematic diagram of the dual reactor system developed for continuous production of COSs. (From Jeon, Y.J. and Kim, S.K., Proc. Biochem., 35, 623, 2000b. With permission.)... 

The halogenated phenol, e.g., pentafluorophenol, CsFsOH, pmnits the substitution of a portiOTi of the expcmsive MAO with inexpensive Al(alkyl)3. This co-catalyst is most frequently used with an organometallics having >1 PI ligand. The copolymerization of C2 with Ca.jo may be carried out at T = 30-280 °C and P = 14-22 MPa in a dual-reactor system... 

Both processes can produce unimodal and bimodal molecular weight distributions. Currently, bimodal MWDs may have to be produced in dual reactor systems. They are energy intensive and require more capital and increase the control complexity. Some licensors claim now to achieve similar product quality with a single reactor by using a dual site catalyst with bimodal capability. 

Rangaswamy, V. and Ramakrishna, S.V. (2008) Lactic add production by Lactobacillus delbrueckii in a dual reactor system using packed bed biofilm reactor. Lett Appl Microbiol 46, 661-666. 

---