Flexibility assessment of a biorefinery distillation train: Optimal design under uncertain conditions

Abstract Multicomponent mixtures can be separated into their single components by mean of different distillation system configurations. The typical distillation train design procedure consists of the assessment of the optimal columns configuration according to the economic and operational aspects. However, this optimal design is strictly related to the operating conditions, i.e. perturbations, when present, can seriously compromise the operation profitability. In these cases a flexibility analysis could be of critical importance to assess the operating conditions range of better performance for different system configurations. This is the typical case of biorefineries where the floating nature of the feedstock causes composition disturbances downstream the fermenter across the year’s seasons. A brand new ABE/W mixture separation case study has been set up; this mixture derives from an upstream microbial conversion process and the successful recovery of at least biobutanol and acetone is crucial for the return on the investments. This paper then compares the possible distillation train configurations from a flexibility point of view. The analysis is focused in particular in highlighting the differences, if present, between the economic optimal solution and flexibility optimal configuration that could not be the same, causing this way a very profitable design to be much less performant under perturbated conditions. Furthermore, a detailed analysis correlating the complex thermodynamics to the operation under uncertain conditions is thoroughly discussed. The proposed design procedure allowed to highlight the differences between weak and strong flexibility constraints and resulted in a dedicated “additional costs vs. flexibility” trend useful to improve the decision making.

[1]  J. Prausnitz,et al.  LOCAL COMPOSITIONS IN THERMODYNAMIC EXCESS FUNCTIONS FOR LIQUID MIXTURES , 1968 .

[2]  Efstratios N. Pistikopoulos,et al.  A novel flexibility analysis approach for processes with stochastic parameters , 1990 .

[3]  Christopher L. E. Swartz,et al.  The Optimal Design of a Distillation System for the Flexible Polygeneration of Dimethyl Ether and Methanol Under Uncertainty , 2018, Front. Energy Res..

[4]  Ana M. Eliceche,et al.  Flexibility analysis leads to a sizing strategy in distillation columns , 1996 .

[5]  Ignacio E. Grossmann,et al.  An index for operational flexibility in chemical process design. Part I: Formulation and theory , 1985 .

[6]  Ho-mu Lin,et al.  Multiphase equilibria for binary and ternary mixtures containing propionic acid, n-butanol, butyl propionate, and water , 2004 .

[7]  Sigurd Skogestad,et al.  Dividing wall columns for heterogeneous azeotropic distillation , 2015 .

[8]  Juan Gabriel Segovia-Hernández,et al.  Multiobjective Optimal Acetone–Butanol–Ethanol Separation Systems Using Liquid–Liquid Extraction-Assisted Divided Wall Columns , 2017 .

[9]  Flavio Manenti,et al.  Flexibility analysis of a distillation column: Indexes comparison and economic assessment , 2019, Comput. Chem. Eng..

[10]  Koichi Iwakabe,et al.  Estimation of isobaric vapor–liquid–liquid equilibria for partially miscible mixture of ternary system , 2005 .

[11]  Thomas A. Adams,et al.  Design of dividing wall columns for butanol recovery in a thermochemical biomass to butanol process , 2015 .

[12]  Ignacio E. Grossmann,et al.  Generalized Disjunctive Programming Model for the Optimal Synthesis of Thermally Linked Distillation Columns , 2001 .

[13]  F. B. Petlyuk,et al.  Distillation Theory and Its Application to Optimal Design of Separation Units: Index , 2004 .

[14]  Mohit Tawarmalani,et al.  A systematic method to synthesize all dividing wall columns for n -component separation-Part I , 2018 .

[15]  J. K. Maund.  Process plant estimating evaluation and control: by Kenneth M. Guthrie, published by the Craftsman Book Co. (U.S.A.), 1974, price $ 25 , 1976 .

[16]  Manfred Morari,et al.  Design of resilient processing plants—VIII. A resilience index for heat exchanger networks , 1985 .

[17]  Thomas A. Adams,et al.  Techno-economic comparison of Acetone-Butanol-Ethanol fermentation using various extractants , 2018 .

[18]  S. J. Benz,et al.  Optimal synthesis of flexible heat-integrated distillation trains , 1992 .

[19]  G. Towler,et al.  Chapter 7 – Capital Cost Estimating , 2012 .

[20]  Anton A. Kiss,et al.  Novel applications of dividing-wall column technology to biofuel production processes. , 2013 .

[21]  Riitta L. Keiski,et al.  Challenges in biobutanol production: How to improve the efficiency? , 2011 .

[22]  Herbert Freundlich,et al.  Anomalous Diffusion of Quinone in Salt Solutions. , 1939 .

[23]  F. A. H. Schreinemakers.  Dampfdrucke ternärer Gemische , 1901 .

[24]  William C. Cole,et al.  Planning, estimating, and control of chemical construction projects , 1995 .

[25]  F. Petlyuk.  Thermodynamically Optimal Method for Separating Multicomponent Mixtures , 1965 .

[26]  Chi Wai Hui,et al.  Process Flexibility for Multivariable Systems , 2008 .

[27]  C. L. Gabriel,et al.  Development of the Butyl-Acetonic Fermentation Industry , 1930 .

[28]  William L. Luyben,et al.  Control of the Heterogeneous Azeotropic n-Butanol/Water Distillation System , 2008 .

[29]  Gael D. Ulrich,et al.  A Guide to Chemical Engineering Process Design and Economics , 1984 .