Dilute acid catalysed hydrolysis of cellulose – extension to formic acid

68 Pages·2012·1.08 MB·English

by  Kupiainen, Laura

C438etukansi.kesken.fm Page 1 Friday, November 2, 2012 4:09 PM
C OULU 2012
4 C 438
3
8
UNIVERSITY OF OULU P.O.B. 7500 FI-90014 UNIVERSITY OF OULU FINLAND
AACCTTAA
A UUNNIIVVEERRSSIITTAATTIISS OOUULLUUEENNSSIISS
A C T A U N I V E R S I T A T I S O U L U E N S I S C
T
A
CC
S E R I E S E D I T O R S TTEECCHHNNIICCAA
Laura Kupiainen
A
SCIENTIAE RERUM NATURALIUM
L DILUTE ACID CATALYSED
a
B Senior Assistant Jorma Arhippainen u
r
a
HUMANIORA K HYDROLYSIS OF CELLULOSE –
u
CUniversity Lecturer Santeri Palviainen p
i EXTENSION TO FORMIC ACID
a
i
n
TECHNICA
e
n
D Professor Hannu Heusala
MEDICA
E Professor Olli Vuolteenaho
SCIENTIAE RERUM SOCIALIUM
F University Lecturer Hannu Heikkinen
SCRIPTA ACADEMICA
G Director Sinikka Eskelinen
OECONOMICA
Professor Jari Juga
EDITOR IN CHIEF
Professor Olli Vuolteenaho
PUBLICATIONS EDITOR
Publications Editor Kirsti Nurkkala
UNIVERSITY OF OULU GRADUATE SCHOOL;
UNIVERSITY OF OULU,
FACULTY OF TECHNOLOGY,
ISBN 978-952-62-0002-6 (Paperback)
DEPARTMENT OF PROCESS AND ENVIRONMENTAL ENGINEERING,
ISBN 978-952-62-0003-3 (PDF) CHEMICAL PROCESS ENGINEERING LABORATORY
ISSN 0355-3213 (Print)
ISSN 1796-2226 (Online)

ACTA UNIVERSITATIS OULUENSIS
C Technica 438
LAURA KUPIAINEN
DILUTE ACID CATALYSED
HYDROLYSIS OF CELLULOSE –
EXTENSION TO FORMIC ACID
Academic dissertation to be presented with the assent of
the Doctoral Training Committee of Technology and
Natural Sciences of the University of Oulu for public
defence in Kuusamonsali (Auditorium YB210), Linnanmaa,
on 14 December 2012, at 12 noon
UNIVERSITY OF OULU, OULU 2012
Copyright © 2012
Acta Univ. Oul. C 438, 2012
Supervised by
Professor Juha Tanskanen
Doctor Juha Ahola
Reviewed by
Professor Erik Heeres
Docent Arto Laari
ISBN 978-952-62-0002-6 (Paperback)
ISBN 978-952-62-0003-3 (PDF)
ISSN 0355-3213 (Printed)
ISSN 1796-2226 (Online)
Cover Design
Raimo Ahonen
JUVENES PRINT
TAMPERE 2012
Kupiainen, Laura, Dilute acid catalysed hydrolysis of cellulose – extension to
formic acid.
University of Oulu Graduate School; University of Oulu, Faculty of Technology, Department of
Process and Environmental Engineering, Chemical Process Engineering Laboratory, P.O. Box
4300, FI-90014 University of Oulu, Finland
Acta Univ. Oul. C 438, 2012
Oulu, Finland
Abstract
New methods are being sought for the production of chemicals, fuels and energy from renewable
biomass. Lignocellulosic biomass consists mainly of cellulose, hemicellulose and lignin.
Cellulose and hemicellulose can be converted to their building blocks, i.e. sugars, via hydrolysis.
This thesis is focused on glucose production from cellulose by dilute acid hydrolysis. Acid
hydrolysis has the drawback of limited glucose yields, but it has the potential to become a short-
term solution for biochemical production.
During acid hydrolysis, the cellulose chain is split into glucose, which undergoes further
decomposition reactions to hydroxymethylfurfural, levulinic acid, formic acid and by-products
like insoluble humins. The present thesis aims to increase our knowledge on complicated acid-
catalysed hydrolysis of cellulose. Glucose decomposition and cellulose hydrolysis were studied
independently in laboratory experiments. Kinetic modelling was used as a tool to evaluate the
results. The effect of the hydrogen ion on the reactions was evaluated using formic or sulphuric
acid as a catalyst.
This thesis provides new knowledge of cellulose hydrolysis and glucose decomposition in
formic acid, a novel catalyst for high-temperature dilute acid hydrolysis. Glucose yields from
cellulose hydrolysed in formic or in sulphuric acid were comparable, indicating that a weak
organic acid could function as a cellulose hydrolysis catalyst.
Biomass fibres in the form of wheat straw pulp were hydrolysed more selectively to glucose
than a model component, microcrystalline cellulose, using formic acid. Glucose decomposition
took place similarly in formic and sulphuric acid when the temperature dependence of the
hydrogen ion concentration was taken into account, but a significant difference was found between
the reaction rates of cellulose hydrolysis in formic acid and in sulphuric acid. The observations can
be explained by changes in the cellulose hydrolysis mechanism. Thus, it is proposed in this thesis
that side-reactions from cellulose to non-glucose compounds have a more significant role in the
system than has earlier been understood.
Keywords: cellulose hydrolysis, dilute sulphuric acid, formic acid, glucose
decomposition, specific acid catalysis, wheat straw pulp

Kupiainen, Laura, Selluloosan happokatalyyttinen hydrolyysi –
muurahaishappoon pohjautuva tarkastelu.
Oulun yliopiston tutkijakoulu; Oulun yliopisto, Teknillinen tiedekunta, Prosessi- ja
ympäristötekniikan osasto, Kemiallisen prosessitekniikan laboratorio, PL 4300, 90014 Oulun
yliopisto
Acta Univ. Oul. C 438, 2012
Oulu
Tiivistelmä
Uusia menetelmiä etsitään kemikaalien, polttoaineiden ja energian valmistamiseen uusiutuvasta
biomassasta. Eräs biomassa, ns. lignoselluloosa, koostuu pääasiassa selluloosasta, hemiselluloo-
sasta ja ligniinistä. Selluloosa ja hemiselluloosa voidaan muuttaa hydrolyysin avulla niiden
rakennuspalikoikseen eli sokereiksi. Tämä väitöskirja keskittyy glukoosin tuottamiseen selluloo-
sasta laimean happohydrolyysin menetelmällä. Happohydrolyysi kärsii rajoittuneesta glukoosin
saannosta, mutta sillä on potentiaalia tulla lyhyen aikavälin ratkaisuksi biokemikaalien tuotan-
nossa.
Happohydrolyysin aikana selluloosaketju pilkkoutuu glukoosiksi, joka reagoi edelleen hajoa-
misreaktioiden kautta hydroksimetyylifurfuraaliksi, levuliini- ja muurahaishapoiksi ja kiinteäksi
sivutuotteeksi. Tämän tutkimuksen tavoitteena on kasvattaa ymmärrystämme monimutkaisesta
happokatalysoidusta selluloosan hydrolyysistä. Glukoosin hajoamista ja selluloosan hydrolyysiä
tutkittiin erikseen laboratoriokokein. Kineettistä mallinnusta käytettiin työkaluna arvioimaan
tuloksia. Vety-ionien vaikutus reaktioihin arvioitiin käyttämällä muurahais- ja rikkihappoja kata-
lyytteinä.
Tämä väitöskirja antaa uutta tietoa selluloosan hydrolyysistä ja glukoosin hajoamisreaktiois-
ta muurahaishapossa, joka on uusi katalyytti korkean lämpötilan laimean hapon hydrolyysissä.
Glukoosisaannot muurahaishappo-hydrolysoidusta selluloosasta olivat vertailukelpoisia vastaa-
viin rikkihappo-hydrolyysi saantoihin. Tämä viittaa siihen, että heikko orgaaninen happo voisi
toimia selluloosahydrolyysin katalyyttinä.
Kun katalyyttinä käytettiin muurahaishappoa, vehnän oljesta tehdyt kuidut hydrolysoituivat
selektiivisemmin glukoosiksi kuin mallikomponenttina toimineen mikrokiteisen selluloosan.
Kun vetyionikonsentraation lämpötilariippuvuus otettiin huomioon, glukoosi hajosi samalla
tavalla sekä muurahais- että rikkihappokatalyytissä, mutta merkittävä ero havaittiin selluloosa-
hydrolyysin reaktionopeudessa. Havainnot voidaan selittää selluloosahydrolyysin mekanismissa
tapahtuvilla muutoksilla. Väitöskirjassa esitetään, että sivureaktioilla selluloosasta ei-glukoosi-
tuotteiksi on merkittävä vaikutus systeemiin.
Asiasanat: glukoosi, happohydrolyysi, laimea rikkihappo, muurahaishappo, selluloosa,
spesifinen happokatalyysi, vehnän olki sellu

Acknowledgements
This study was conducted in the Department of Process and Environmental
Engineering at the University of Oulu during 2007–2012.
I want to express my gratitude to all the people without whom this thesis
would never have been completed. In particular, I would like to thank my
supervisor Prof. Juha Tanskanen for guiding me into such an interesting research
area and for his feedback during the research process. In addition, I would have
not been able to carry out this work without my supervisor, Dr. Juha Ahola, who
has taught me so much about chemical reaction engineering and who took care of
me during these years.
I would like to thank Chempolis Oy for supplying the raw material and for
the fruitful collaboration. I am also grateful to Ismo Koskenkorva, who performed
numerous HPLC analyses, and Jorma Penttinen, who helped me with the
laboratory equipment. Elisa Wirkkala is acknowledged for her assistance in the
laboratory. Olli Taikina-aho from Centre of Microscopy and Nanotechnology in
University of Oulu is appreciated for performing the XRD measurements.
Prof. Erik Heeres from the University of Groningen and Docent, Dr. Arto
Laari from Lappeenranta University of Technology are also greatly appreciated
for reviewing the manuscript of the thesis. Sue Pearson and Mike Jones from Pelc
Southbank Languages are acknowledged for linguistic corrections.
I am also grateful to the Graduate School of Chemical Engineering (GSCE)
as well as Emil Aaltonen Foundation and Oulu University Apuraharahasto for
their financial support.
Special thanks go to my colleagues in the Chemical Process Engineering
Laboratory. You had to live with me during the ups and downs of my research
process, and guess what, we all have survived now! The innovative discussions –
or one may just say the weird discussions – in our coffee room delighted my
working days. In addition, although she would not appreciate these kinds of literal
thanks, Big Ida is acknowledged for taking me away from the world of pyranose
rings, hydrogen bonds and cellulose chains and making me relaxed and refreshed
after our riding trips.
Finally, my warmest thanks go to my family for supporting and encouraging
me during my studies and research.
Oulu, October 2012 Laura Kupiainen

7
8