Production of Aniline From Ammonolysis of Phenol- 2010-CH-09,61,65,87

Mini project- Production of Aniline from ammonolysis of Phenol PROJECT TITLE:

ANILINE PRODUCTION [By The Ammonolysis Of Phenol] TH

5 SEMESTER

[SECTION A ] SESSION [2010 - 2014]

SUBMITTED TO:

SIR – A – ASIF AKHTAR

SUBMISSION DATE

Nov 21st, 2012

DEPARTMENT OF CHEMICAL ENGINEERING U NIVERSITY OF E NGINEERING & TECHNOLOGY, LAHORE

Mini project- Production of Aniline from ammonolysis of Phenol

If you have knowledge, let others light their candles at it.

Margaret Fuller

Mini project- Production of Aniline from ammonolysis of Phenol CONTENTS GROUP MEMBERS --------------------------------------------------------------------------------------------------------------------------------------- I ABSTRACT ------------------------------------------------------------------------------------------------------------------------------------------------- II PREFACE -------------------------------------------------------------------------------------------------------------------------------------------------- III ANILINE – AN ORGANIC COMPOUND ------------------------------------------------------------------------------------------------------------- 4 [1]

PROPERTIES OF ANILINE

------------------------------------------------------------------------------------------------------------------------------ 4

PRACTICAL APPLICATIONS OF ANILINE ----------------------------------------------------------------------------------------------------------------- 4 PROCESS SELECTION ----------------------------------------------------------------------------------------------------------------------------------- 5 [3]

EXISTING PROCESSES

---------------------------------------------------------------------------------------------------------------------------------- 5

Hydrogenation of Nitrobenzene ------------------------------------------------------------------------------------------------------------- 5 By Ammonolysis of Chlorobenzene --------------------------------------------------------------------------------------------------------- 6 By Ammonolysis Of Benzene ----------------------------------------------------------------------------------------------------------------- 6 [4 ] By Ammonolysis Of Phenol ----------------------------------------------------------------------------------------------------------------- 7 SUMMARY ----------------------------------------------------------------------------------------------------------------------------------------------- 7 ANILINE PRODUCTION – BY THE AMMONOLYSIS OF PHENOL----------------------------------------------------------------------------- 7 CAPACITY SELECTION: ----------------------------------------------------------------------------------------------------------------------------------- 8 [5 ]

Industrial Aspect ------------------------------------------------------------------------------------------------------------------------------ 8 Global Supply And Demand ------------------------------------------------------------------------------------------------------------------- 8 Our Goal ------------------------------------------------------------------------------------------------------------------------------------------- 8 PROCESS DESCRIPTION ---------------------------------------------------------------------------------------------------------------------------------- 9

Fresh Feed: -------------------------------------------------------------------------------------------------------------------------------------- 10 Surge Tank:-------------------------------------------------------------------------------------------------------------------------------------- 10 Chemical Reactor: ----------------------------------------------------------------------------------------------------------------------------- 10 Distillation Column: --------------------------------------------------------------------------------------------------------------------------- 10 Ammonia Recycle: ----------------------------------------------------------------------------------------------------------------------------- 10 Drying column: --------------------------------------------------------------------------------------------------------------------------------- 10 Purification column: -------------------------------------------------------------------------------------------------------------------------- 10 APPENDIX – I -------------------------------------------------------------------------------------------------------------------------------------------- IV REFERENCES ---------------------------------------------------------------------------------------------------------------------------------------------- 1

CONTENTS |


GROUP MEMBERS 2010 – CHEM – 09

[K ] A L I M [U] L L A H 2010 – CHEM – 61

[Z] A I D [M] A S O O D 2010 – CHEM – 65

[A] H M A D [I] J A Z 2010 – CHEM – 87

[S] H I R A Z [D] A U D

GROUP MEMBERS | I


ABSTRACT This report is been written under the supervision of a group of four members. Data included in this literature is authentic and accurate, mostly taken from reliable sources. We would like to thank a number of people who encouraged and helped us in writing and compiling this report including, Seniors from University of Engineering & Technology, Lahore, who enable us to do so. We can assure the reader that this may be our first report of its own kind, because we have put a bit of "heart and soul" into it! Therefore, we hope that you will find this report immensely educative & informative.

AUTHORS

ABSTRACT | II


PREFACE This project simply talks about the “ Production Of Aniline By Ammonolysis Of Phenol ”. We have tried our best to gather as much information as we can and to present our research in the form of completely arranged booklet. As far as its contents are concerned, it includes the necessary introduction to the topic and the basic knowledge about our topic i.e.” Production of Aniline by ammonolysis of Phenol” .The technique which is our topic of concern is a very unique process that is being utilize mostly in middle east and western Europe for the production of Aniline. During completing this assignment it was our intention to cover all major information regarding to our process, its benefits, and its other features. In presenting a good deal of information concerning the topic of this mini project, every group member did different jobs in order to divide the bulk of this assignment. We collectively gathered information from the internet and various books to present the data in the complete form. In the end, we would like to thank again all the people who helped us. We hope that our assignment will prove beneficial to our class mates as well as the others seeking information about the Aniline Production and about this contemporary technique.

PREFACE | III


ANILINE – AN ORGANIC COMPOUND [A brief review]

Aniline, phenyl-amine or amino-benzene is an organic compound with the formula C 6H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the prototypical aromatic amine. Being a precursor to many industrial chemicals, its main use is in the manufacture of precursors to polyurethane. Like most volatile amines, it possesses the somewhat unpleasant odor of rotten fish. It ignites readily, burning with a smoky flame relating it to aromatic compounds. Aniline is colorless, but it slowly oxidizes and revivifies in air, giving a red-brown tint to aged samples.

In commerce, three brands of aniline are distinguished: aniline oil for blue, which is pure aniline; aniline oil for red, a mixture of equimolecular quantities of aniline and ortho- and para-toluidines; and aniline oil for safranine, which contains aniline and ortho-toluidine, and is obtained from the distillate of the fuchsine fusion. [1]

PROPERTIES OF ANILINE Aniline when freshly prepared is a colorless oily liquid. It has a characteristic unpleasant odor and is not poisonous in nature. It is heavier than water and is only slightly soluble. It is soluble in alcohol, ether and benzene. Its color changes to dark brown on standing.

Aniline in solution adsorbs strongly to colloidal organic matter, which effectively increases its solubility and movement into ground water. It is also moderately adsorbed to organic material in the soil; adsorption is dependent upon soil pH (pKa of 4.596). It will slowly volatilize from soil and surface water (vapor pressure 0.67 mm Hg @ 25 C) and is subject to biodegradation. Although rapidly degraded in the atmosphere, aniline can be deposited in the soil by wet and dry deposition, and by adsorption on aerosol particles. Aniline reacts with any free radicals produced by sunlight in the atmosphere.This radical scavenging reactivity has been shown to inhibit the production of Photochemical smog by sunlight. Aniline apparently undergoes direct photolysis and has considerable absorption of wavelengths above 290 nanometers. Photoproducts formed from aniline in the atmosphere include N-methylaniline, N, Ndimethylaniline, Isomeric hydroxyanilines and phenols. The half-life of atmospheric Aniline due to photo degradation has been estimated at 3.3 hours. PRACTICAL APPLICATIONS OF ANILNE Aniline is an important organic compound which is used mainly used in the preparation of other chemicals, industrial as well as on laboratory scale. These applications are given below:   



It is used in the preparation of diazonium compounds which are used in dye industry. Anils (Schiff's bases from aniline) are used as antioxidants in rubber industry. It is used for the manufacture of its some derivatives such as acetamide, sulphanilic acid and sulpha drugs, etc. It is used as an accelerator in vulcanizing rubber. PREFACE | 4

Mini project- Production of Aniline from ammonolysis of Phenol 

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The largest application of aniline is for the preparation of methylene diphenyl di-isocyanate (MDI). Other uses include rubber processing chemicals (9%),herbicides (2%), and dyes and pigments (2%) As additives to rubber, aniline derivatives such as phenylenediamines and diphenylaminesare antioxidants. Illustrative of the drugs prepared from aniline is paracetamol (acetaminophen, Tylenol). The principal use of aniline in the dye industry is as a precursor to indigo, the blue of blue jeans. Aniline is also used at a smaller scale in the production of the intrinsically conducting polymer polyaniline. Aniline is also used to produce medicinal and pharmaceuticals, resins, varnishes, perfumes, shoe blacks, photographic chemicals (hydroquinone), explosives.

PROCESS SELECTION [Choice Of A Prefect Method ]

Combination of steps is known as a process, while A chemical process is a method or mean of somehow changing one or more chemicals or chemical compounds into a useful product. The process selection is also based on the fact that in Pakistan the production of nitrobenzene [important constituent] is very less and hence not abundantly available in the market and hence is expensive similar to the case in Western Europe. But in some countries such as United States of America where nitrobenzene is abundantly available in the market at a very cheap price the first process is mostly used. More than a few methods are there for the production of Aniline. Selection of a particular method depends upon many factors which are characterizing that speci fic area. Like:     

Climatic conditions Cost of Raw Material Government subsidy scheme Capital Cost Payback period etc. [3]

EXISTING PROCESSES Following processes are currently being used all over the world for the production of aniline, depending upon the various factors mentioned above. These processes are:    

Hydrogenation of nitrobenzene Ammonolysis of chlorobenzene By ammonolysis of Benzene Ammonolysis of Phenol

HYDROGENATION OF NITROBENZENE Nitrobenzene is the classical feedstock for Aniline manufacture. Recently less chlorobenzene and Phenol are being used in aniline manufacturing processes in several countries. The reduction of nitrobenzene with iron turnings and water in the presence of small amounts of hydrochloric acid is the oldest form of industrial aniline manufacture. It would certainly have been replaced much earlier by more economical reduction methods if it had not been possible to obtain valuable iron oxide pigments from the resulting iron oxide sludge. However, the increasing demand for aniline has far

PREFACE | 5

Mini project- Production of Aniline from ammonolysis of Phenol surpassed the market for the pigments, so that not only catalytic hydrogenation processes (both liquid- and gas-phase) but also other feed stocks have been used for aniline production. The modern catalytic gas-phase hydrogenation processes for nitrobenzene can be carried out using a fixed-bed or a fluidized-bed reactor.

Rayer and Allied work with nickel sulfide catalysts at 300-475 °C in a fixed bed. The activation of the hydrogenation catalysts with Cu or Cr, and the use of different supports and catalyst sulfurization methods with sulfate, H2S or CS 2 all belong to the expertise of the corresponding firms. The selectivity to aniline is more than 99%. The catalytic activity slowly decreases due to carbon deposition. However, the catalyst can be regenerated with air at 250-350°C and subsequent H2 treatment. Similar processes are operated by Lonza with Cu on pumice, by ICI with Cu, Mn, or Fe catalysts with various modifications involving other metals, and by Sumitomo with a Cu-Cr system. The gas-phase hydrogenation of nitrobenzene with a fluidized-bed catalyst is used in processes from BASF, Cyanamid and Lonza. The BASF catalyst consists of Cu, Cr, Ba, and Zn oxides on a SiO2 support; the Cyanamid catalyst consists of Cu/SiO 2. The hydrogenation is conducted at 270290 °C and 1-5 bar in the presence of a large excess of hydrogen (H 2:nitrobenzene=ca. 9:1). The high heat of reaction is removed by a cooling system which is built into the fluidized bed. The selectivity to aniline is 99.5%; the nitrobenzene conversion is quantitative. The catalyst must be regenerated with air periodically. BY AMMONOLYSIS OF CHLOROBENZENE An alternate manufacturing route for aniline is the ammonolysis of chlorobenzene or of phenol. For example, in the Kanto Electrochemical Co. process, chlorobenzene is ammonolyzed to aniline with aqueous NH3 at 180-220 °C and 60-75 bar in the presence of CuCl and NH 3Cl ("Niewland catalyst")

Aniline can be isolated with 91 % selectivity from the organic phase of the two-phase reaction product. BY AMMONOLYSIS OF BENZENE Du Pont has developed an interesting new manufacturing process for aniline. Benzene and ammonia can be reacted over a NiO/Ni catalyst containing promoters including zirconium oxide at 350°C and 300 bar to give a 97% selectivity to aniline with a benzene conversion of 13%

Since the hydrogen formed in the reaction reduces the NiO part of the catalyst, catalyst regeneration (partial oxidation) is necessary. Despite inexpensive feed stocks, industrial implementation is still thwarted by the low benzene conversion and the necessary catalyst re-oxidation. PREFACE | 6

Mini project- Production of Aniline from ammonolysis of Phenol [4]

BY AMMONOLYSIS OF PHENOL As

an alternative, aniline is also prepared from phenol and ammonia, the phenol being derived from the cumene process. Dow stopped operation of a similar process for aniline in 1966. Phenol can also be subjected to gas-phase ammonolysis with the Halcon/Scientific Design process at 200 bar and 425°C

Al2O3.SiO2 (possible as zeolite) and oxide mixtures of Mg, B, Al, and Ti are used as catalysts; these can be combined with additional co-catalysts such as Ce, V, or W. The catalyst regeneration required previously is not necessary with the newly developed catalyst. With a large excess of NH3, the selectivity to aniline is 87-90% at a phenol conversion of 98%. The byproducts are diphenylamine and carbazole. This process has been operated since 1970 by Mitsui Petrochemical in a plant which has since been expanded to 45 000 tons per year. A second plant with a capacity of 90000 tons per year was started up by US Steel Corp. (now Aristech) in 1982. In 1977, Mitsui Petrochemical started production of m-toluidine by the reaction of m-cresol with ammonia in a 2000 ton-per-year plant, analogous to the phenol ammonolysis. Thus, there is another manufacturing path besides the conventional route (nitration of toluene and hydrogenation of mnitrotoluene). SUMMARY Each process carries its own importance regarding purity, cost, future demands. There are mainly two processes which are mostly applied at the industrial scale for the preparation of aniline.  

By hydrogenation of nitrobenzene By ammonolysis of Phenol

The other two processes are economically not efficient (Their drawbacks are briefly explained above) and hence are mostly not used. But we are interested in the formation of aniline by the ammonolysis of phenol because of the following few reasons & keeping other steps in consideration. 

  

Capital costs of the process are lower than for processes based on the conventional nitrobenzene raw material. Yields are nearly quantitative at high conversions. Efficient and easy separation of phenol from aniline. Phenol as a raw material is cheaper than nitrobenzene.

ANILINE PRODUCTION – BY THE AMMONOLYSIS OF PHENOL [Comprehensive Discussion on The Subject Of Process]

Initiation of a process based on its output i-e desired quality and amount. Quality in terms of its purity has already been discussed in the previous section, while capacity selection is an important criterion which will be discussed here:

PREFACE | 7

Mini project- Production of Aniline from ammonolysis of Phenol CAPACITY SELECTION: Capacity selection is a very important topic in plant design. Capacity selection involves detail market survey about the demand of the product in the market and what will be its trend after few years, in future. Capacity selection to some extent also tells us that how long it will take us to clear our debt as greater the capacity more quickly the debt can be cleared.

The raw materials and intermediates are derived from various organic and inorganic chemicals. The raw materials such as resorcinol, Phenol, benzyl alcohol are not being manufactured in Pakistan, due to economy of scale and lack of feed stocks. Since in Pakistan the petrochemical industries are not established and we know that phenol (which is mainly produced from benzene through Cumene process about 80-85%) so if we are to produce aniline from raw materials such as phenol and ammonia we would have to mostly import phenol. I NDUSTRIAL ASPECT[5] Sardar Chemical Industries Limited imports 2000kg aniline for 2 months for the manufacture of direct dyes, leather dyes etc. suppose our target is to supply them 2000kg aniline/per 2months.According to our rough calculation the monthly requirement of aniline for the production of dyes is 200,000kg/month. GLOBAL SUPPLY A ND DEMAND Global capacity was 4.98m tons/year in 2006, with 1.62m tons/year in Western Europe, 1.38m tons/year in the US, 1.15m tons/year in Asia-Pacific (excluding Japan), 474,000 tons/year in Japan, 316,500 tons/year in Eastern Europe, 70,000 tons/year in Latin America and 64,000 tons/year in Asia/Middle East. Western Europe is the largest consumer, at about 1.32m tons/year, followed by the US at 1.19m tons/year and Asia-Pacific at 717,860 tons/year. Japan, Asia/Middle East and Latin America consume 319,190 tons/year, 98,360 tons/year and 73,130 tons/year, respectively. Global demand in 2006 was 3.95m tons/year. OUR GOAL Besides considering increasing demands of aniline we select the capacity of our plant as 250,000kganiline/month so that we can sell our products to other dyes and rubber producer companies in considering their increasing demands. Also annual increase in usage of aniline is increasing in Pakistan by 6-7% per year. We have selected a very low capacity of our plant because in Pakistan phenol is not readily available due to the lack of establishment of petrochemical industries and we will have to import 40-60% phe nol for fulfilling our requirements. This import will increase its price a bit but still it is a lot cheaper than importing aniline. Our main goal is to supply aniline to the dyes and rubber producing companies in Pakistan.

PREFACE | 8


PROCESS DESCRIPTION PREFACE | 9

Mini project- Production of Aniline from ammonolysis of Phenol Various unit operations including in this process are explained comprehensi vely below.

FRESH FEED: Fresh feed containing phenol and ammonia is pressurized to 260 psig before entering into surge tank. SURGE TANK : It is a special kind of storage reservoir which reduces the fluctuations in temperature and pressure. Feed enters in surge tank at 1000F and 260psig. So it reduces the chances of damaging pipelines and heat exchangers. Then this combined stream enters into heat exchanger in which it exchanges heat with the stream coming from the reactor. Then it is heated to 6700F before entering into chemical reactor. CHEMICAL R EACTOR : An exothermic reaction takes place in between Ammonia and phenol in fixed bed adiabatic reactor.

Conversion of phenol into aniline is 98%. Rest of the phenol is converted into di-phenylamine by this side reaction. C6H5 NH2

+

C6H5OH

→

(C6H5)2 NH

+

H2O

Al2O3.SiO2 (possible as zeolites) and oxide mixtures of Mg, B, Al, and Ti are used as catalysts; these can be combined with additional co-catalysts such as Ce, V, or W. Stream leaving the reactor which contains aniline, di-phenylamine, water and un-reacted ammonia passes through the heat exchanger where it exchanges heat with the stream entering in the reactor. Then this combined stream is cooled further before entering into distillation column. DISTILLATION COLUMN: Stream enters into distillation column at the temperature of 2480F and 220psig. Ammonia is separated from the mixture in distillation column. Two streams leave the distillation column, one is top stream which is ammonia recycle stream while the remaining components are removed from the bottom stream which passes through the hydraulic turbine and then it goes to drying column. AMMONIA R ECYCLE: Conversion of ammonia in the chemical reactor is 87-90%. So rest of the ammonia is recycled overhead through a compressor to surge tank. In compressor recycled ammonia is pressurized from 220psig to 260psig, correspondingly temperature varies from 2480F to 1000F DRYING COLUMN: Drying column is maintained at very low pressure. Water and traces of ammonia are separated from the top of drying column. Bottom stream containing aniline and di-phenylamine moved towards purification column.

PURIFICATION COLUMN: PREFACE | 10

Mini project- Production of Aniline from ammonolysis of Phenol Distillation is carried out in this column where aniline due to its lesser boiling point than di phenylamine. So, aniline which is our actual product is separated from top of purification column while di-phenylamine which is by product leaves the column from bottom. Aniline product formed by this process is 99% pure.

PREFACE | 11


APPENDIX – I

PHYSICAL PROPERTIES OF A NILINE [8] PROPERTY

Molecular Weight Melting point Viscosity at 20 oC

Enthalpy dissociation

VALUE

PROPERTY

93.12 g/gmol -6.15 oC

Boiling Point Density at 20/4 oC

VALUE

184.4 [1 atm] 1.02173

4.4233 – 4.435 cP

Dissociation Constant pKa at 20 oC

4.60

21.7 kJ/mol

Heat of combustion

3389.72 kJ/mol

Specific Heat [20-25] oC

0.518 Jkg-1K -1

Latent heat of vaporization

476.3 J/g

Flash Point [closed cup]

76 oC

Auto ignition

615 oC

Flammable Limits in air (% by Volume)

LEL = 1.3 UEL = 11.0

Vapor Density

3.22

Solubility

3.5 g in 100g water

Odor threshold, ppm

APPENDIX | IV

1.1


REFERENCES [1]

http://www.epa.gov/chemfact/anali-sd.pdf

[2]

http://www.icis.com/Articles/2008/01/07/9089893/chemical-profile-aniline.html

[3]

Kent and Riegel's Handbook Of Industrial Chemist ry And Biotechnology

[4]

http://books.google.com.pk/Synthetic Nitrogen Products: A Practical Guide to the Products and Processes by Gary Maxwell/production of aniline by ammonolysis of phenol.

[5]

http://www.lookchem.com/Chempedia/Chemical-Technology/Organic-ChemicalTechnology/7791.html.

[6]

http://pubs.acs.org/doi/abs/10.1021/cen-v047n014.p044

[7]

http://onlinelibrary.wiley.com/doi/10.1002/0471238961.0114091201130914.a01.pub2/abstract

[8]

http://www.tutorskingdom.com/.../properties-and-uses-of-aniline/ - United States.

A NILINE PRODUCTION – By Ammonolysis of Phenol | 1


R EFERENCES |

Production of Aniline From Ammonolysis of Phenol- 2010-CH-09,61,65,87

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