The importance of measuring diffusion coefficients in reactor design and simulation

Area of Science:

• Chemical Engineering
• Reaction Engineering
• Transport Phenomena

Background:

• Sorbitol production from glucose via catalytic hydrogenation is a key industrial process.
• Process development requires understanding fluid dynamics, temperature, and diffusion coefficients.
• Accurate diffusion data is essential for optimizing sorbitol yield and reactor design.

Purpose of the Study:

• To experimentally determine diffusion coefficients for the glucose-sorbitol system.
• To evaluate the accuracy of predictive models (Wilke-Chang, Hayduk and Minhas) for diffusion coefficients.
• To investigate the impact of diffusion coefficients on reactor performance simulations.

Main Methods:

• Experimental determination of diffusion coefficients at varying temperatures (25-65 °C) and concentrations.
• Estimation of diffusion coefficients using established correlations (Wilke-Chang, Hayduk and Minhas).
• Reactor simulations under laminar flow conditions using both experimental and correlated diffusion data.

Main Results:

• Experimental diffusion coefficients were obtained for the glucose-sorbitol system.
• Wilke-Chang and Hayduk and Minhas correlations showed good agreement at 25-45 °C but overestimated experimental values at 65 °C.
• Simulations indicated different glucose conversion profiles along the reactor axis based on experimental versus correlated diffusion coefficients.

Conclusions:

• Experimental diffusion coefficient data is vital for accurate sorbitol production process modeling.
• Predictive correlations may require temperature-specific adjustments for reliable application.
• Accurate transport property data significantly influences predicted reactor performance and optimization strategies.