Recovery of biomass-derived valuable compounds using chromatographic and membrane separations
Hellstén, Sanna (2013-12-12)
Väitöskirja
Hellstén, Sanna
12.12.2013
Lappeenranta University of Technology
Acta Universitatis Lappeenrantaensis
Julkaisun pysyvä osoite on
https://urn.fi/URN:ISBN:978-952-265-529-5
https://urn.fi/URN:ISBN:978-952-265-529-5
Tiivistelmä
Utilization of biomass-based raw materials for the production of chemicals and materials is
gaining an increasing interest. Due to the complex nature of biomass, a major challenge in its
refining is the development of efficient fractionation and purification processes.
Preparative chromatography and membrane filtration are selective, energy-efficient separation
techniques which offer a great potential for biorefinery applications. Both of these techniques
have been widely studied. On the other hand, only few process concepts that combine the two
methods have been presented in the literature. The aim of this thesis was to find the possible
synergetic effects provided by combining chromatographic and membrane separations, with a
particular interest in biorefinery separation processes. Such knowledge could be used in the
development of new, more efficient separation processes for isolating valuable compounds
from complex feed solutions that are typical for the biorefinery environment.
Separation techniques can be combined in various ways, from simple sequential coupling
arrangements to fully-integrated hybrid processes. In this work, different types of combined
separation processes as well as conventional chromatographic separation processes were
studied for separating small molecules such as sugars and acids from biomass hydrolysates
and spent pulping liquors.
The combination of chromatographic and membrane separation was found capable of
recovering high-purity products from complex solutions. For example, hydroxy acids of black
liquor were successfully recovered using a novel multistep process based on ultrafiltration and
size-exclusion chromatography. Unlike any other separation process earlier suggested for this
challenging separation task, the new process concept does not require acidification pretreatment,
and thus it could be more readily integrated into a pulp-mill biorefinery.
In addition to the combined separation processes, steady-state recycling chromatography,
which has earlier been studied for small-scale separations of high-value compounds only, was
found a promising process alternative for biorefinery applications. In comparison to
conventional batch chromatography, recycling chromatography provided higher product
purity, increased the production rate and reduced the chemical consumption in the separation
of monosaccharides from biomass hydrolysates. In addition, a significant further
improvement in the process performance was obtained when a membrane filtration unit was
integrated with recycling chromatography.
In the light of the results of this work, separation processes based on combining membrane
and chromatographic separations could be effectively applied for different biorefinery applications. The main challenge remains in the development of inexpensive separation
materials which are resistant towards harsh process conditions and fouling.
gaining an increasing interest. Due to the complex nature of biomass, a major challenge in its
refining is the development of efficient fractionation and purification processes.
Preparative chromatography and membrane filtration are selective, energy-efficient separation
techniques which offer a great potential for biorefinery applications. Both of these techniques
have been widely studied. On the other hand, only few process concepts that combine the two
methods have been presented in the literature. The aim of this thesis was to find the possible
synergetic effects provided by combining chromatographic and membrane separations, with a
particular interest in biorefinery separation processes. Such knowledge could be used in the
development of new, more efficient separation processes for isolating valuable compounds
from complex feed solutions that are typical for the biorefinery environment.
Separation techniques can be combined in various ways, from simple sequential coupling
arrangements to fully-integrated hybrid processes. In this work, different types of combined
separation processes as well as conventional chromatographic separation processes were
studied for separating small molecules such as sugars and acids from biomass hydrolysates
and spent pulping liquors.
The combination of chromatographic and membrane separation was found capable of
recovering high-purity products from complex solutions. For example, hydroxy acids of black
liquor were successfully recovered using a novel multistep process based on ultrafiltration and
size-exclusion chromatography. Unlike any other separation process earlier suggested for this
challenging separation task, the new process concept does not require acidification pretreatment,
and thus it could be more readily integrated into a pulp-mill biorefinery.
In addition to the combined separation processes, steady-state recycling chromatography,
which has earlier been studied for small-scale separations of high-value compounds only, was
found a promising process alternative for biorefinery applications. In comparison to
conventional batch chromatography, recycling chromatography provided higher product
purity, increased the production rate and reduced the chemical consumption in the separation
of monosaccharides from biomass hydrolysates. In addition, a significant further
improvement in the process performance was obtained when a membrane filtration unit was
integrated with recycling chromatography.
In the light of the results of this work, separation processes based on combining membrane
and chromatographic separations could be effectively applied for different biorefinery applications. The main challenge remains in the development of inexpensive separation
materials which are resistant towards harsh process conditions and fouling.
Kokoelmat
- Väitöskirjat [1037]