One-pot synthesis of C8 aldehydes/alcohols from propylene using eco- friendly hydrotalcite

325 Pages·2009·7.17 MB·English

Development of Green Catalytic Routes for the
Synthesis of Commercially Important Chemicals

Thesis submitted in partial fulfillment of the requirements
For the degree of
Doctor of Philosophy
in
Chemical Engineering

by

Sumeet Kumar Sharma
(Rg. No. D05CH402)

Under the guidance of
Dr. Raksh V. Jasra Prof. Parimal A. Parikh
Former Deputy Director and Head Chemical Engineering Department
Discipline of Inorganic Materials and S.V. National Institute of Technology
Catalysis, Central Salt & Marine Chemicals Surat, Gujarat
Research Institute, Bhavnagar, Gujarat

Chemical Engineering Department
S.V. National Institute of Technology
Surat - 395 007 (Gujarat) INDIA

August 2008
Dedicated to,
My Grand Mother (Amma)

Acknowledgements

It gives an immense pleasure to express my deep sense of gratitude and respect to Dr. Raksh V
Jasra, former Deputy Director and Head, Discipline of Inorganic Materials and Catalysis, Central Salt
and Marine Chemicals Research Institute (CSMCRI) and Prof. Parimal A. Parikh, Professor, Chemical
Engineering Department, S.V. National Institute of Technology (SVNIT), Surat for their invaluable
supervision with persistence, motivation, allowing me to think and work independently, seed
innovations to my work and constant encouragement during the course of my work. Dr. Jasra’s
supportive critics and motivation for the inter–students collaborative work made me feel worthy and
joyful throughout the period of my research. His eternal enthusiasm inspired me to accomplish my goal.
Special thanks go to my Research Progress Committee members for their thoughtful constructive
suggestions to enhance the quality of my research work.
I am also sincerely indebted to Dr. Ram S. Shukla and Dr. Sharad D. Bhatt for making healthy
completive and friendly atmosphere in the High Pressure Laboratory. They have provided me constant
encouragement, valuable suggestions and fruitful discussions related to not only my research work but
also personal matters sometime. The invariable curiosity and fertile discussions from their profound
knowledge made me reach at the present position.
I cannot fail to acknowledge my prodigious gratitude to Dr. Hari C. Bajaj for his kind support,
encouragement and timely help during my research work, especially after resignation of Dr. Jasra from
CSMCRI.
I am thankful to Dr. P.K. Ghosh (Director, CSMCRI), Prof. P.D. Pore (Director, SVNIT) and
Prof. Z.V.P. Murthy for allowing me to carry out theoretical and experimental research work and
extending me all the possible infrastructural facilities in CSMCRI–Bhavnagar and SVNIT–Surat.
Mr. A.H. Lakhanai, Technician, working in the High Pressure Laboratory, deserves for my
exceptional thanks for his constant help in the work related to administration and purchase,
maintenance of the instruments in high pressure lab and procurement of locally available stuffs related
to my research work.
I extend my thankfulness to all my wonderful colleagues in High Pressure Laboratory for their
assistance and friendship. I deeply appreciate the help obtained from my senior Dr. V.K. Srivastava and
colleagues, Munir D. Khokhar, Jinka K. Mohan, Bharat K. Modhera, Asif A. Dabbawala, Mallikarjun
V. Patil, Sudheesh N., C. Murugan, Hasmukh Patel and Kalpesh B. Siddhpuria, at various stages of my
research work, discussions (sometimes hot) related to the nature of observed results in a typical
experimental set–up and completion of inter–students collaborative work. Especial thanks to
Mallikarjun V. Patil and Jinka K. Mohan for discussions related to the mechanistic aspects of the
reactions.
I am extremely grateful to my friends and hostel–mates, Dr. R.K. Nagarale, Binsu R. Nagarale,
Yogesh, Kunal N. Shah, Manoj Agrawal, Harish, Rajendra Patil, Gridhar Joshi with whom I enjoyed a
lot during my stay in Bhavnagar as well as for their moral support in various matters.
I would like to place my respect and deep sense of gratitude to Dr. S.H.R. Abdi, Dr. R.I.
Kureshy, Dr. R.S. Somani, Dr. S. Kannan, Dr. N.H. Khan, Dr. H.M. Modi, Dr. (Mrs.) Beena Tyagi, Dr.
Jugnu Bhatt, Dr. A.B. Panda, Dr. A.B. Boricha, Dr. R.J. Tayade, Dr. A.S. Mehta, Dr. D.B. Shukla and
Mr. Mehul Bhatt for their cooperation, in various ways, whenever I approached them.
I extend my thankfulness to the members from SVNIT, Dr. M. Chakraborty (Asist. Prof.,
Chemical Engineering Department), Mr. Kamal M. Desai (Academic section) and my colleges Alka
Boricha, Paresh Patel and J.U. Kannedy for their time to time invaluable help related to the
departmental documentations (especially Alka Boricha and Paresh Patel) as well as their moral support.
I am thankful to Mr. P.G.M. Pillai, Mr. J.M. Parmar, Mr. B.B. Parmar and. V.C. Zala who were
also contributed in various ways to ensure the successful completion of my doctoral work.
I am also thankful to personnel from Workshop, Mr. J.H. Devmurari, Mr. S.N. Patel, Mr. J.N.
Bhardia and Mr. L.M. Kachhadia. They were always available for maintenance and rectification of the
minute and major problems of the autoclave reactor without which it was difficult to carry out Ph.D.
work in hydroformylation reactions in appropriate time period.
I would also like to acknowledge the important technical assistance of Dr. (Mrs.) P. Bhatt, for
P–XRD analysis, Mr. Vinod Agrawal for FT–IR analysis, Mr. Vinod P. Boricha for FT–NMR analysis,
Prasanth K.P. and Ranjith S. for surface are measurements, Mr. C.K. Chandrakanth for SEM Analysis,
Dr. Jagan Mohan and Harish for TGA Analysis. Without the support of these people, it is impossible to
spread the shining of my research work in the world.
I would like to extend my special thanks to Mr. K. Rajagopalan (AO), R. Kashyap and Y.
Trivadi for their kind support and cooperation during my crucial period in the CSMCRI. I convey my
word of appreciation to R.P. Pillai for his keen interest and cooperation in the matters related to the
CSMCRI research scholar’s hostel, where I had stayed during my research work.
I take this opportunity to express my sincere gratitude to Mr. Pramod Makwana and his team
members, IT Cell for their assistance in various problems related to computer hardwares and softwares.
I wish to express my sincere thanks to Mr. D.H. Khokhar and Mr. I.Y. Iyar for their helps in
various ways for the procurements of chemicals and instruments related to my research work.
I would like to acknowledge Dr. Dharmesh U. Parmar, Dr. Chintan D. Chudasama, Dr. Yogi M.
Badhika, Dr. Manish K. Mishra, Dr. Jince Sebastian, Dr. Surendra Singh, Dr. Irshad Ahmed, Dr. J.
Krishnamurty, Sunil A.P., Praveen K. Surolia, Vishal J. Mayani, Seikh Basha, Kannan K., Achyut
Bhatt, Kunal, Churchil, Jinesh, Kohol Raj, Gyanapraksham, Laxmi, Adarsh for the valuable
discussions, moral support and friendship.
I render my thanks to all the students of Discipline of Inorganic Materials and Catalysis of
CSMCRI for their prompt help and support.
I am grateful to Mr. M.J. Bariyaa for providing me the photo copies of research articles from
the journals and helped me to search the location of journals and books in the institute library. I am also
thankful to Mr. Vinu Solanki and all canteen members for providing me food in the institute premises.
It will be gaffe if I overlook them who had shaped me in early age to reach at the present
position. Among them, at the outset, I am earnestly gratified to my grand mother (Amma) and her
brother (Late Shri V.P. Sharma) who exposed me the world of knowledge in my early age. The highest
gratitude goes to my grand mother, whose constant enthusiasm, hopeful disposition, timely
encouragement, confidence, moral support and deep faith in God has motivated me to persevere and
properly prioritize my life. My deep feelings of gratitude are also goes to my parents and my lovely
brothers and sisters for their unwavering moral support and encouragement in successfully completion
of my research work. My family members only installed in me the values of perseverance, a hard work
ethic, value of common sense and responsibility, which were essential when working under pressure.
Word “thank you” only scratch the surface of my gratitude for my family.
I must be doing injustice if I don’t mention a very special person, my wife Sweta, who has been
my friend, scientific colleague and always beside me in my sunny and rainy days. Her help,
cooperativeness, immensely friendly attitude and compromising nature have made me to learn so many
things from her. I could not have completed my thesis without your love, respect, patience,
appreciation, scientific discussions and faith with your charming presence, which kept my spirits alive.
My special heart felt thanks to my extraordinary graduation teachers, Prof Sanjay H. Amaley
and Vijay Ganorkar from whom I learnt the aroma and taste of chemical reaction engineering
fundamentals and the mantras of success. They have always inspired me and stood by me whenever I
needed them.
I express my sincere thanks to Council of Scientific and Industrial Research (CSIR), India for
providing me financial supports in terms of research scholarship and senior research fellowship.
Last but not least, I would also like to express my sincere thanks to all staff members of
CSMCRI and Chemical Engineering Department, SVNIT–Surat for their cooperation and assistance
directly or indirectly through out the tenure of my research work.

(Sumeet Kumar Sharma)
SRF–CSIR
Abstract
The research work in the present Thesis emphasizes the development of green catalytic
routes for the synthesis of fine and commercially important chemicals using eco–friendly
heterogeneous catalysts via hydroformylation, condensation and isomerization reactions. Chapters
from second to fourth of this thesis are related to the development of multi-functional catalyst to
reduce the multi–steps processes into a single pot for the synthesis of higher carbon chain length
aldehydes/alcohols starting from low carbon number alkene as a reactant. For example, 2–
ethylhexanal and 2–ethylhexanol, which are the commercially important intermediates for the
synthesis of dioctylphthalate (DOP), are synthesized industrially from propylene in three steps
process. The existing commercial processes for the manufacturing of C aldol derivatives have
8
drawbacks like, i) being a multi–step process, ii) use of hazardous liquid base KOH or NaOH in
stoichiometric amount for aldol condensation reaction, iii) involving post synthesis work–up in the
separation of spent KOH or NaOH from product mixture, iv) lower selectivity of product,
corrosion of reactors and storage vessels. Therefore, the main focus was on the replacement of
liquid bases, which are being used in stoichiometric amount, by the eco–friendly heterogeneous
catalyst to carry out all three steps into a single pot by altering the reaction conditions.
The multi-functional [HF/HT] catalyst system was synthesized by the impregnation
(Chapter 2) and intercalation (Chapter 3 and 4) of rhodium complex [HF] onto/into the interlayer
space of hydrotalcite [HT] and its multi–functional potential was evaluated for the single pot
selective synthesis of C aldol derivatives (aldehydes/alcohols) from propylene. The Mg/Al ratio of
8
[HT], amount of [HF] complex and [HT], and reaction temperature showed pronounced effect on
the selectivity of C aldol derivatives. Aldol condensation temperature T played a significant role
8 2
in the formation of 2–ethylhexanol in a single pot. As Mg/Al molar ratio and amount of [HT]
increased, the selectivity of 2–ethylhexanal also increased due to the enhancement in the basicity of
the catalyst. From kinetic experiments, it was observed that the rate of formation of 2–ethylhexanal
is dependent on the rate of aldol condensation which is catalyzed by hydrotalcite present in the
[HF/HT] catalyst.
Other commercial examples are the synthesis of perfumery chemicals such as,
jasminaldehyde by the condensation of heptanal with benzaldehyde; trans–anethole and trans–
isoeugenol by double bond isomerization of methyl chavicol and eugenol, respectively, using
liquid KOH or NaOH in stoichiometric amounts. With increased environmental awareness,
replacement of stoichiometric technologies by atom efficient greener catalytic routes with low
E factor (kg of byproducts generated per kg of desired product) and substitution of toxic and/or
hazardous solvents/reagents with cleaner alternatives is today’s demand. Therefore, it is desirable
to find solid base catalysts which could substitute liquid bases.
The hydrotalcite samples of varied Mg/Al molar ratio were used as catalysts for synthesis
of 2-methypentenal by aldol condensation of propanal (Chapter 5) and jasminaldehyde in solvent
free condensation of 1–heptanal with benzaldehyde (Chapter 6). 97% conversion of propanal with
99% selectivity of 2–methylpentenal was achieved using activated hydrotalcite of Mg/Al molar
ratio 3.5. From the kinetic data for aldol condensation of propanal using activated hydrotalcite
(Mg/Al molar ratio 3.5), the initial rate of reaction was observed to increase on increasing the
amount of catalyst. The activation energy for propanal condensation was calculated by Arrhenius
plot and found to be 58 kJ/mol. The catalyst was recycled upto six cycles without loss in its
activity. The selectivity of jasminaldehyde was observed to increase on increasing the M(II)/Al
molar ratio of as–synthesized as well as activated hydrotalcite. The maximum selectivity of
jasminaldehyde (86%) with 98% conversion of 1–heptanal was observed using as–synthesized
Mg–Al hydrotalcite of Mg/Al molar ratio of 3.5 as a catalyst. The effect of activation of as–
synthesized Mg–Al hydrotalcite samples of varied Mg/Al molar ratio on catalytic activity was
studied and correlated with their basicity as determined from the model test reaction. The rate of
reaction was calculated as 11.6 x 10–4 mol/(g min) at optimum reaction conditions and catalyst
cat
was reused several times for the synthesis of jasminaldehyde..
The regioselective synthesis of trans–anethole from methyl chavicol via double bond
isomerization of methyl chavicol using RuCl (PPh ) and RuCl (AsPh ) .CH OH complexes with
2 3 3 3 3 2 3
detailed kinetics has been studied in Chapter 7. The incorporation of ruthenium in the hydrotalcite
matrix was also carried out for double bond isomerization of perfumery related chemicals such as,
methyl chavicol, eugenol, safrole, allylbenzene, dimethoxy allylbenzene, 3–carene. 98%
conversion of methyl chavicol with 88% selectivity of trans–anethole was observed in 1 h reaction
time. The effect of reaction temperature showed 41% conversion of methyl chavicol and 74%
selectivity of trans–anethole at 100 °C which increased to 98% with 88% selectivity of trans–
anethole on increasing temperature to 210 °C using Ru–Mg–Al as a catalyst. The activity of Ru–
Mg–Al was compared with the various ruthenium impregnated catalysts such as, Ru–HT, Ru–
MgO, Ru–CaO, Ru–SiO and Ru–alumina. The Ru–Mg–Al catalyst was recycled upto fourth cycle
2
without loss of its activity.
Keywords- Hydroformylation; Multi–functional catalyst; Condensation; Isomerization; Carbon
monoxide; Solid base catalyst; Jasminaldehyde.