Designer Solvents for the Extraction of Glycols and Alcohols from

158 Pages·2012·20.62 MB·English

Designer Solvents for the Extraction of
Glycols and Alcohols from Aqueous
Streams

L.Y. Garcia-Chavez
Copyright ® 2012 L.Y. Garcia Chavez
Cover Design by L. Garcia-Chavez

This research was carried out in cooperation with the Institute of
Sustainable Process Technology (ISPT) of the Netherlands.
Designer Solvents for the Extraction of Glycols and Alcohols from
Aqueous Streams
A catalogue record is available from the Eindhoven University of
Technology Library
ISBN: 978-90-386-3316-9
Designer Solvents for the Extraction of
Glycols and Alcohols from Aqueous
Streams

PROEFSCHRIFT

ter verkrijging van de graad van doctor aan de
Technische Universiteit Eindhoven, op gezag van de
rector magnificus, prof.dr.ir. C.J. van Duijn, voor een
commissie aangewezen door het College voor
Promoties in het openbaar te verdedigen
op maandag 21 januari 2013 om 16.00 uur

door

Lesly Yeranui Garcia Chavez

geboren te Morelos, Mexico
Dit proefschrift is goedgekeurd door de promotoren:
prof.dr.ir. A.B. de Haan

Copromotor:
dr.ir. B. Schuur
A mi familia (con un poco de ayuda de mis amigos)
To my family (with a little help of my friends)

Content
Summary I
Chapter 1 Introduction 1
Chapter 2 Glycols Recovery Using Reactive Extraction with 15
Boronic Acid Derivatives
Chapter 3 COSMO-RS Assisted Solvent Screening for liquid- 25
Liquid Extraction of Mono Ethylene Glycol from
Aqueous Streams
Chapter 4 Equilibrium Data for Glycols +Water + Tetraoctyl 47
ammonium 2-Methyl-1 Naphthoate
Chapter 5 Conceptual Process Design and Economic Analysis 81
of Liquid-Liquid Extraction using Ionic Liquids for
the Recovery of Glycols from Aqueous Streams
Chapter 6 Bio-butanol Recovery Using Non-Fluorinated Task 107
Specific Ionic Liquids (TSILs)
Chapter 7 Conclusions and Recommendations 131

List of Publications i
Acknowledgments iii
Curriculum Vitae v

Summary
The separation of polar compounds from aqueous streams is one of the most
energy intensive operations within the chemical industry, because of the formation
of hydrogen bonds that should be broken and the high heat of vaporization of
water. Important bulk chemicals like glycols and alcohols produced from
petrochemical feedstock or renewable sources through fermentation processes are
classified in this category. In this thesis, the recovery of low molecular weight
diols, such as Mono Ethylene Glycol (MEG), 1,2-Propanediol also known as
propylene Glycol (PG) and 2,3-Butanediol (BD) that are particularly difficult to
separate due to their high water affinity and important alcohols like 1-Butanol
(BuOH) were studied. Their recovery by conventional multiple effect distillation is
associated with high energy consumption; therefore liquid-liquid extraction
technology can be a promising alternative since it can be more energy efficient.
However, for conventional solvents the distribution coefficients are generally
insufficient to achieve efficient extraction at low concentrations as encountered in
the chemical synthesis of diols or production through fermentation. For this reason,
the use of novel extraction solvents like reactive extractants or ionic liquids is
needed to improve the glycol distribution coefficient and selectivity.
Boronic acids derivatives were studied as they are known because of their good
ability to form complexes with cis-diols. Naphtalene-2-Boronic Acid (NBA) was
selected as extractant and it was diluted in 1-Ethyl-Hexanol and octanol. Aliquat
336 (N-Methyl-N,N-dioctyloctan-1-ammonium chloride) was applied as
counterion to facilitate the complexation between NBA and MEG. 1-Ethyl-
Hexanol was the better diluent. The partition coefficient of MEG in 1-ethyl-
hexanol was 0.0025, and distributions and selectivities up to 0.026 and 0.089,
respectively (at pH 11, 298K) were observed with NBA and Aliquat 336 in equal
amounts at 0.2 mol/L. This maximum distribution is around 10 times better than
the conventional solvents. Nevertheless further improvements in the distribution
and selectivity towards the glycol are required, which could be provided by
I
advanced solvents like ionic liquids. In Chapter 2, experimental work and
molecular modelling simulation with COSMO-RS were used to support the solvent
screening for (MEG). The ionic liquid design and tailoring to optimize the glycol
distribution coefficient (D) and selectivity (S) was done by employing the sigma
electron profile. As a result, the glycol distribution coefficients improved compare
to the conventional solvents when combining a tetraoctyl ammonium cation of the
IL with a carboxylate, phosphinate and boronate anion. These ILs were tailor made
and evaluated in LLE experiments. They outperformed the other solvents tested
with D up to 0.45, and S up to 3.2 vs D = 0.04 and S = 0.95 for 2-ethyl-
MEG MEG
hexanol for initial feed concentrations of 20% wt MEG.
For the best performing ionic liquid tetraoctyl ammonium 2-methyl-1-napthoate
[TOA MNaph], liquid-liquid equilibrium data were determined and the NRTL and
UNIQUAC thermodynamic models were constructed for the three different
glycols. The results, presented in Chapter 4, show that both models can properly
describe the experimental data. These thermodynamic models were used to
develop conceptual process designs in Aspen Plus ® and compared the different
processes for the production of MEG and PG with two different technologies,
conventional triple effect distillation (MED) and solvent extraction (LLE) using
[TOA MNaph].The results showed that the LLE alternative could provide energy
savings >50% compared to the current state-of-the-art three effect distillation
technology (94% for MEG 20% wt from the petrochemical process and 54% for
PG 10%wt from a fermentation process). Regarding CAPEX, the conventional
technology is always preferable because less equipment is required, while for the
LLE technology the CAPEX is higher due to the solvent cost, the equipment in
solvent recovery section and the additional heat exchangers required for the heat
integration in the process. The purification of PG has the lowest CAPEX because a
lower solvent to feed ratio is required compared to MEG extraction. According to a
total annualized cost analysis at the current crude oil prices, the purification of PG
from a fermentation broth via LLE could be an advantageous technology to replace
MED. For the MEG production we can say that currently the LLE process is not a
suitable option and that a significant increase in crude oil prices should occur
before the use of LLE technology with this IL can become feasible. In Chapter 6,
II