Isomerization glucose

Reactor design for glucose isomerization ia the United States has been documented (75). The diameter of the reactor is normally between 0.6 and 1.5 m. Typical bed height is 2—5 m. The ratio between the bed height and diameter of a reactor should be at least 3 1 to ensure good flow distribution. Plants that produce more than 1000 t of HECS per day, based on dry matter, use at least 20 separate reactors. 

Generally, the scale of commercial processes (i.e., with the exception of potable ethanol or glucose isomerate) is modest, and for enzymes it is very low, only a few kg/day. 

The glucose moiety can be isomerized to fructose by the well-established glucose isomerization process to yield a galactose-glucose-fructose syrup with increased sweetness. Another possible variation would involve the isomerization of lactose to lactulose (galactose-fructose) which can be hydrolysed to galactose and fructose by some / -galactosidases. 

Glucose isomerase was initially isolated and identified in 1953 as a xylose isomerase (Hochester and Watson). Four years later the glucose isomerizing capability of xylose isomerase from Pseudomonas liydrophilki was discovered although arsenate was required to enhance the reaction. This enzyme was thus impractical for food production (Marshall and Kooi). 

Glucose Isomerization. Enzymatic isomerization of glucose to fructose provides a real alternative to sugar (sucrose) derived from sugarcane or sugarbeets. The commercial product obtained is known as high fructose com syrup (HFCS). Two grades of the syrup have become established on the world market, HFCS-42 and HFCS-55, which contain 42 and 55% fructose on dry substance basis. These products account for over one-third of the caloric sweetener market in the United States. 

Glucose isomerization with high-purity product recovery... 

Fig. 7.14. Operation of a simulated moving-bed reactor for glucose isomerization using steady-state reaction stages...

Tegge, G., Development and Prospects of Sweeteners Obtained by Glucose Isomerization, in International Sweetener Report No. I, H. Ahlfeld (Ed.), pp. 3-8, F.O. Licht, GmbH., Ratezeburg, Germany, Dec. 1978. 

Sarex (1) [Saccharide extraction] A version of the Sorbex process, for separating fructose from mixtures of fructose and glucose. The usual feed is com syrup. The adsorbent is either a proprietary zeolite or an ion-exchange resin. Unlike all the other Sorbex processes, the solvent is water. The process depends on the tendency of calcium and magnesium ions to complex with fructose. The patents describe several methods for minimizing the dissolution of silica from the zeolite. The process is intended for use with a glucose isomerization unit, so that the sole product from com syrup is fructose. Invented by UOP in 1976 by 2003, five plants had been licensed. 

TMBR, SMBR -equilibrium transport A B Linear Validated for glucose isomerization Hashimoto et al. (1993b)... 

Figure 9.6 Experimental set-up of the three-section reactive SMB process for glucose isomerization.

In this chapter we have advocated the use of online model-based optimization for the automatic control of SMB plants. This approach has the advantage that the process is automatically operated at its economic optimum while meeting all relevant constraints on purities and flow rates. Application to a pilot-plant-scale reactive SMB process for glucose isomerization showed that implementation at a real plant is feasible - the requirements for additional hardware are moderate (a high-level PC and online concentration measurements in the recycle line). The experiments confirmed the excellent properties of the proposed control scheme. The scheme is extremely versatile, and the cost function and constraints can easily be adapted to any specific separation task. 

SMB bioreactor for high fructose syrup by glucose isomerization Maximization of productivity of fructose and minimizing desorbent used. NSGA-II-JG Both operation and design of the SMB bioreactor were optimized. Zhang et al. (2004)... 

All ruthenium catalysts showed a high selectivity to D-sorbitol (>98%). The main by-product at total conversion was D-mannitol (maximum 2%), formed because a fraction of D-glucose isomerized into D-fructose, which was subsequently hydrogenated into D-sorbitol and D-mannitol. The catalytic hydrogenation... 

One remark still needs to be made. Most experiments were performed at a constant flow rate through the fixed bed and the decrease in the fraction of glucose isomerized was observed as a function of time. In the foregoing discussion we referred to the half life of the initial flow velocity at constant relative conversion and this is definitely different from the relative conversion half life at constant flow rate. In general the half life of the latter property is considerably longer than that of the former. The present model furthermore predicts that the half life of the relative conversion at constant flow rate is dependent on the initial glucose concentration and the initial relative conversion. On inspection of equation (17) it is clear that the half life of the initial flow velocity at constant relative conversion is equal to the half life of the property In ((CgO " / -sE -s ) con-... 

Toumi, A. and Engell, S. (2004) Optimization-based control of a reactive simulated moving bed process for glucose isomerization. Chem Eng. Sci., 59, 3777-3792. 

Figure 7.47 Experimental control result for glucose isomerization (Toumi and Engell, 2004).

Glucose isomerase (actually xylose isomerase) is undoubtedly the most important and successful application of enzyme technology. Glucose isomerization by glucose isomerase was developed in the late 1960s but it was not until the mid-1970s when the process acquired industrial significance as a consequence of the... 

Ospina S, Lopez-Munguia A, Gonzalez R et al. (1992) Characterization and use of a penicillin acylase biocatalyst. J Chem Technol Biotechnol 53 205-214 Ospina S, Barzana E, Ramirez O et al. (1996) Effect of pH in the synthesis of ampicilfinby penicillin acylase. Enzyme Microb Technol 19 462-469 Palazzi E, Converti A (2001) Evaluation of diffusional resistances in the process of glucose isomerization to fructose by immobilized glucose isomerase. Enzyme Microb Technol 28 246-252 Pan JL, Syu MJ (2004) A thermal study on the use of immobilized penidllin G acylase in the formation of 7-amino-3-deacetoxy cephalosporanic acid from cephalosporin G. J Chem Technol Biotechnol 79(10) 1050-1056... 

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