Design and control of a process to produce furfuryl alcohol

https://doi.org/10.1016/j.jtice.2015.01.001Get rights and content

Highlights

  • A process to produce furfural alcohol is developed.

  • Reaction occurs in the gas phase.

  • A single distillation column can produce high-purity product.

  • A proposed control structure can effectively reject disturbances.

Abstract

The design and control of a process to produce furfuryl alcohol is reported. Furfural is hydrogenated to furfuryl alcohol in a gas phase packed bed reactor with high selectivity and conversion. The product alcohol is separated from unreacted furfural and byproducts water and 2-methyl furan in a single low-pressure distillation column. Catalyst dilution is employed to increase the area available for heat transfer in the reactor. Control studies indicate that single-point temperature control of the distillation column is adequate to maintain product purity and avoid excessive loss of valuable material from the top of the column. A reactor effluent composition controller cascaded onto a reactor temperature controller can compensate for catalyst deactivation by raising the reactor temperature.

Introduction

Furfuryl alcohol (FOL) is an industrial chemical used primarily in binders for foundry sands in the production of cores and molds in metalworking [1]. Furfuryl alcohol can be produced by hydrogenation of furfural (FAL) in the gas phase over a copper chromite catalyst. Furfural itself can be produced sustainably from agricultural wastes such as corn cobs, bagasse, etc. Thus furfuryl alcohol and other furfural derivatives can be considered to be environmentally friendly, sustainable chemicals.

Conceptual flowsheets for the furfural alcohol process with vapor phase reaction have been published [1], [2], however no detailed modeling studies of this process are available in the literature to our knowledge. That is the purpose of this contribution. Section 2 of this article describes the assumptions employed in the modeling. Section 3 reports the results of the steady-state design and optimization. Section 4 reports the results of the dynamic modeling and control. Finally, conclusions are drawn in Section 5.

Section snippets

Reactions and kinetics

The desired reaction is the hydrogenation of furfural: Furfural + H2 → Furfuryl alchohol

Further hydrogenation of furfuryl alcohol produces the undesired byproduct 2-methyl furan: Furfuryl alcohol + H2 → 2-methyl furan + H2O

Although the desired reaction is theoretically reversible, the equilibrium constant permits conversion greater than 99% at standard operating conditions and therefore many of the kinetic models published in the literature approximate the reaction as irreversible. Several

Process design and optimization

The process flowsheet is shown in Fig. 2. Because high conversion and high yield of the desired product can be achieved in the reactor, the design of the reactor and separation system do not affect each other significantly and therefore they can be designed separately. Therefore they are discussed separately in this section.

Process dynamics and control

Dynamic simulations were conducted in Aspen Dynamics to test the operability and control of the proposed process. Fig. 7 shows the proposed control structure. The recycle flow rate of hydrogen is manipulated to maintain the desired ratio of hydrogen to furfural at the reactor inlet, and the fresh feed of hydrogen is manipulated to maintain the pressure in the hydrogen recycle line. A reactor effluent composition controller is used to maintain the desired conversion in the reactor by adjusting

Conclusions

The design and control of a process to produce furfuryl alcohol has been studied. Simulations indicate that the process is capable of producing furfuryl alcohol with the desired purity. The total annual cost of a process to produce 50 kmol/h of furfural alcohol is $831,000/year. Control studies indicate that the process can be controlled and can reject disturbances while maintaining the desired product purity at all times. The process can be utilized in the production of valuable chemicals from

Acknowledgments

This research was funded by the National Science Council Taiwan under grant (102-2622-E-011-006-CC1).

References (24)

  • GowdaA.S. et al.

    Hydrogenation and hydrogenolysis of furfural and furfuryl alcohol catalyzed by ruthenium(II) bis(diimine) complexes

    Appl Organomet Chem

    (2012)
  • HaoX.Y. et al.

    Copper-containing MCM-48 catalyst for the selective hydrogenation of furfural to furfuryl alcohol

    Chin J Catal

    (2005)
  • Cited by (0)

    View full text