Modelling the Solubility of the 20 Proteinogenic Amino Acids with Experimentally Derived ...

268 Pages·2017·11.75 MB·English

by  Nathan Bowden

Modelling the Solubility of the 20 Proteinogenic Amino
Acids with Experimentally Derived Saturation Data

Nathan A. Bowden
Thesis committee

Promotor
Prof. Dr. J.P.M. Sanders
Emeritus chair of Biobased Chemistry
Wageningen University & Research

Co-promotor
Dr. ir. M.E. Bruins
Senior Researcher at Wageningen Food & Biobased Research
Wageningen University & Research

Other members
Dr.ir. M.L.F. Giuseppin, Avebe
Prof. Dr. Ir. J van der Gucht, Wageningen University & Research
Dr. ir. A.E.M. Janssen, Wageningen University & Research
Dr. A. Plijter-Schuddemat, Cereal & Food Expertise

This research was conducted under the auspices of the Graduate School Food Technology
Agrobiotechnology Nutrition and Health Science
Modelling the Solubility of the 20 Proteinogenic Amino
Acids with Experimentally Derived Saturation Data

Nathan A. Bowden

Thesis
submitted in fulfilment of the requirements for the degree of doctor at Wageningen University by the
authority of the Rector Magnificus, Prof. Dr. A.P.J. Mol, In the presence of the Thesis Committee
appointed by the Academic Board to be defended in public on Wednesday, 16 May, 2018 at 4 P.M. in the
Aula
Nathan A. Bowden
Modelling the Solubility of the 20 Proteinogenic Amino Acids with Experimentally Derived Saturation
Data, 261 pages.

Ph.D. thesis, Wageningen University, Wageningen, the Netherlands (2018)
With references, with summary in English

ISBN 978-94-6343-861-2
DOI 10.18174/446739
Contents
Chapter 1 Introduction .................................................................................................................................. 1

Chapter 2 Solid-liquid phase equilibria and thermodynamic properties of mixtures of 20 α-amino acids in
a model system of industrial residues ......................................................................................................... 19

Chapter 3 Solubility of the proteinogenic α-amino acids in water, ethanol and ethanol-water mixtures ... 49

Chapter 4 The effects of ethanol on the solubility of the proteinogenic α-amino acids in mixtures .......... 79

Chapter 5 Modelling the effects of ethanol on the solubility of the proteinogentic amino acids with the
NRTL, Gude and Jouyban-Acree models ................................................................................................. 129

Chapter 6 Molecular-thermodynamic Correlation of Solubility Data for 20 Amino Acids in Water, in
Ethanol and in Water-Ethanol Mixtures ................................................................................................... 165

Chapter 7 Fractional precipitation of amino acids from agro-industrial residues using ethanol .............. 197

Chapter 8 General Discussion ................................................................................................................... 223

Summary ................................................................................................................................................... 253

Chapter 1
Introduction: Amino Acids in the Bio-based Economy

1
1.1 Introduction to the Bio-based Economy
Until recently, the human species depended solely on the use of biological and renewal
materials for food, fuel and along with mineral resources all the products that were used in our
daily lives. The shift to non-renewable resources for energy and products was made about 250
years ago with coal during the industrial revolution [1]. Today, coal, along with other non-
renewable resources serve as the basis of our energy and many of the products that we use (e.g.
plastic).
While the use of petroleum has many benefits, there are a few side effects that make their
wide-use unattractive. First, the use of non-renewable fuels contributes to the enhancement of the
natural greenhouse effect that we have on Earth. This leads to raising global temperatures and
negative impacts on human lives, global ecosystems and the planet [2]. Second, as the non-
renewable reservoirs that are most easily accessible are used up, we must go to extreme locations
to get to new reservoirs. Extracting petroleum from these extreme locations has led in the last
few years to several global-scale disasters, the incidence of which will only increase if we
continue. Third, the extraction of non-renewable fuels is itself a contaminating process for
ecosystems and techniques such as hydraulic fracturing (also known as “fracking”) has been
shown to contaminate both surface and groundwater reservoirs [3]. Fourth, due to the geographic
imbalance in the location of the petroleum reserves, there have been political and economic
developments that many believe have contributed to tensions between human settlements [4].
Fifth, fluctuating oil prices will slow down investments [5].
An alternative to the petroleum-based economy could be to initiate a paradigm shift back
to a bio-economy. In the bio-economy, many of the products and energy that we rely on would
come from biological material.

1.1.1 Bio-based value pyramid
The use of biological materials can be illustrated using the value pyramid [6, 7]. Shown
in Figure 1.1, the bio-based value pyramid shows that the value of the biological material that is
used is determined by its application. At the bottom of the pyramid, the application has its lowest
value but also demands the largest amount of biological material to produce it. Also at this level,
the most fossil fuel is replaced, having the greatest impact on greenhouse emission reduction. As
2
the applications move up the pyramid, the higher the value of the application and also the less
amount of biological material is used.

Figure 1.1: The bio-based value pyramid. At the top, the products are the most valuable and less biomass
is used. At the bottom the products are less valuable and more biomass is used (8)

At the bottom of the pyramid are the applications of fuel, fire, electricity, heat and
biofuels. Here, any biological material can be used. Processes to transform the biological
material into energy resources include pyrolysis, gasification among others.
The step second from the bottom of the bio-based value pyramid are performance
materials, fermentation, commodity chemicals and fertilizer. Less biological material is needed
for this and the value of the products created are worth more. However, the impact in replacing
non-renewable resources is also lower. Examples of biological materials that can be used for in
these processes include cellulosic, hemi-cellulosic, other carbohydrates and protein-rich sources.
Processes that are useful here include but are not limited to steam-explosion and fermentation
technologies.
Applications on the step second from the top of the bio-based value pyramid include
products such as food for humans and feed for animals. Similar material and processes can be
used here, as in the step below it in the bio-based value pyramid. Present food chains are far from
efficient and this helps to close the waste and residues associated with this.
3
The top position in the bio-based value pyramid is for pharmacy and fine chemicals. Here
the values of the products are the highest and the amount of biological material that is used is the
least. However, only certain biological molecules can be used in these applications. These
include, peptides, proteins, amino acids, their derivatives and other secondary metabolites.

1.1.2 The potential for amino acids in bio-based products
Amino acids are a potential feedstock for the production of nitrogen containing
pharmaceuticals and fine chemicals. An example of this is the chemical 1,2-ethanediamine that is
used as a corrosion inhibitor, an anti-scaling agent and in lubricants [8]. 1,2-Ethanediamine is
made by adding ammonia to ethanolamine. Currently, ethanolamine is produced by the oxidative
conversion of ethylene to ethylene oxide. Then, the ethylene oxide is then converted to
ethanolamine with the addition of ammonia. However, another route would be to convert an
amino acid, such as L-serine, to ethanolamine directly [9]. This route would require one less step
in the production of 1,2-ethanediamine and is energetically more efficient, as shown in Figure
1.2.

Figure 1.2: Production of 1,2-ethanediamine [9-11]. On the top is the petrochemical route. On the bottom
is the bio-based route. The petrochemical route takes more energy to produce (57 GJ) than the bio-based
route (44.5 GJ).

4