(313a) Design and Control of Processes Producing Derivatives of Furfural: Furan, Furfuryl Alcohol and 2-Methyfuran

Furfural is an important platform for second-generation, lignocellulosic biomass utilization, and about 60-70 percent of furfural produced worldwide is converted to furfuryl alcohol (Hoydonckx et al., 2000; Zeitsch, 2000). In this work, a process for the sustainable simultaneous manufacture of furfural alcohol (FAL) and 2-methylfuran (2-MF) is designed and optimized. Energy consumption is reduced by employing a feed-effluent heat exchanger and employing a 3-phase distillate receiver at the top of the distillation column and refluxing only the organic phase. Control studies suggest that a simple decentralized control structure without controller parameter scheduling can reject disturbances including changes in the production rate and feed composition and can also transition smoothly between product distributions.

Furan is also one of the major products produced from furfural, and it is an important starting material in chemical synthesis. Therefore in this work the design of a process to produce furan from furfural is also considered. The process design is based on one presented by Zeitsch (2000). The fresh furfural feed stream enters an absorption tower to recover furan vapor from the carbon monoxide product stream. The liquid out stream from the absorption tower is fed to the reboiler of a reactive distillation column. The reaction occurs only in the reboiler. At the top of the column, a condenser is cooled to minus 30 degree Celsius to recover most of the furan as a liquid. The liquid product stream from the reactive distillation column contains a significant amount of carbon monoxide. It enters a short stripping column in order to separate furan and carbon monoxide. As the temperature is increased, the solubility decreases, so furan nearly free of carbon monoxide can be collected from the sump. The vapor streams from the top of the reactive column and the top of the stripping column are combined and fed to the absorption tower in order to remove furan from the carbon monoxide. For this process also, key design variables are identified and adjusted to determine the optimal design. Control studies also suggest that this process can also be effectively controlled with a decentralized PID control structure.

References

1. Hoydonckx, H. E.; Van Rhijn, W. M.; Van Rhijn, W.; De Vos, D. E.; Jacobs, P. A., Furfural and Derivatives. In Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH Verlag GmbH & Co. KGaA: 2000.
2. Zeitsch, K. J., The Chemistry and Technology of Furfural and its Many By-Products; Elsevier: London, 281; pp156-158, 2000