A Report on
Production of Phenol from 99.9% pure Cumene from Naptha cracker
Production of 99.99% pure Bisphenol A from 99.99% pure Phenol
Major Project Report submitted by Virender Pratap Singh Department of Chemical Engineering, IIT Roorkee On November 24, 2014
Table of content Phenol 1. Uses & present status of the product
Page 2
2. Market Prospects
Page 5
3. Available process for the production of product
Page 7
4. Techno-Economic appraisal of alternative processes
Page 10
5. Selection of Technology/Scheme 5.1 Basis of Selection
Page 11
5.2 Details of selected process - Sunoco/UOP Process
Page 11
5.3 Process flow and recent technology advances
Page 12
6. Raw Material 6.1. Sources of raw material
Page 25
6.2 Availability of Cumene
Page 27
6.3 Import Data
Page 27
6.4 Export Data
Page 30
6.5 Prevailing Prices
Page 31
6.6 Government Policies & Import duty
Page 31
BisPhenol A 1. 2. 3. 4. 5.
Uses & present status of the product Market Prospects Available process for the production of product Techno-Economic appraisal of alternative processes Selection of Technology/Scheme
References
1|Page
Page 32 Page 34 Page 35 Page 36 Page 37
Page 46
Phenol 1. Uses & present status of the product The main use of phenol is as a feedstock for phenolic resins, bisphenol A and caprolactam (an intermediate in the production of nylon-6). It is used in the manufacture of many products including insulation materials, adhesives, lacquers, paint, rubber, ink, dyes, illuminating gases, perfumes, soaps and toys. Also used in embalming and research laboratories. It is a product of the decomposition of organic materials, liquid manure, and the atmospheric degradation of benzene. It is found in some commercial disinfectants, antiseptics, lotions and ointments. Phenol is active against a wide range of microorganisms, and there are some medical and pharmaceutical applications including topical anaesthetic and ear drops, sclerosing agent. It is also used in the treatment of ingrown nails in the "nail matrix phenolization method". Another medical application of phenol is its use as a neurolytic agent, applied in order to relieve spasms and chronic pain. It is used in dermatology for chemical face peeling. Phenol is a toxic and corrosive compound often used in DNA extractions -- not exactly the kind of thing you want to eat. A variety of organic compounds, however, contain the same chemical group and structural features that distinguish phenol, and many of these other compounds are beneficial for your health. Compounds in this class are collectively called phenols. Cancer Prevention Some phenolic compounds are believed to be cancer chemopreventives, compounds that may decrease your risk of developing cancer. Epigallocatechin-3 gallate, for example, is a phenolic compound found in green tea and believed to be a cancer chemopreventive. A broad group of phenolic compounds called flavonoids are common in plants; according to a review in the "British Journal of Nutrition," there is evidence to suggest many flavonoids like anthocyanins may have anticancer effects. Antioxidants Many phenolic compounds found in plants may have antioxidant effects, meaning they react with and capture dangerously reactive compounds called free radicals before the 2|Page
radicals can react with other biomolecules and cause serious damage. Flavnoids and tocopherols are two broad classes of phenolic compounds with antioxidant properties. Resveratrol, a phenolic compound found in grape skins and red wine, also has antioxidant effects. Other use are housing construction, fiber, detergents, gazing, coating, sheets and films etc. Apart from various uses phenol is toxic material should be handled carefully. In presence of light or higher temperature decomposition of phenol takes place so should be kept in dark container and away from sunlight. The most important chemical made from phenol is bisphenol A, which is used to make the polycarbonates. Phenol is also catalytically reduced to cyclohexanol, which is used in the manufacture of polyamides 6 and 6,6. Phenol is also used to make a range of thermosetting polymers (resins). It reacts with methanal in the presence of a catalyst to form phenol-methanal resins. Among the other uses of phenol is the production of phenylamine (aniline) needed, for example, for the manufacture of dyes. Antiseptics such as 2,4-and 2,6-dichlorophenols are also made from phenol. Phenolic resins are found in myriad industrial products. Phenolic laminates are made by impregnating one or more layers of a base material such as paper, fiberglass or cotton with phenolic resin and laminating the resin-saturated base material under heat and pressure. The resin fully polymerizes (cures) during this process. The base material choice depends on the intended application of the finished product. Paper phenolics are used in manufacturing electrical components such as punch-through boards and household laminates. Glass phenolics are particularly well suited for use in the high speed bearing market. Phenolic micro-balloons are used for density control. Snooker balls as well as balls from many table-based ball games are also made from phenol formaldehyde resin. The binding agent in normal (organic) brake pads, brake shoes and clutch disks are phenolic resin. Synthetic resin bonded paper, made from phenolic resin and paper, is used to make countertops. Phenolic resins are also used for making exterior plywood commonly known as WBP (Weather & boil proof) Plywood because Phenolic resins have no melting point but only a decomposing point in the temperature zone of 220 degree Celsius & above. Phenolic resin is used as a binder in loudspeaker driver suspension components which are made of cloth.
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4|Page
2. Market Prospects 1.
Phenol Consumption – 7166000 tonnes consumption in 2002
2.
Consumption Growth (%) 1997-2002
2002-2007
2007-2012
2009-2014
2014-19
5.2
4.4
1.7
5.1
2.5
3.
Capacity in 2002 - 7,843000 tonnes
4.
Production in 2010 – 8 million tonnes
5.
Capacity in 2010 – 10.4 million tonnes
Demand: The outlook for the phenol market in 2014 is uncertain, particularly for major derivative Bisphenol A (BPA) which drives global demand. The global demand for phenol has been steadily increasing over the last 10 years. In 2000, global phenol demand stood at 6,072,774 tons, before increasing to 7,934,218 tons in 2010. A significant portion of the increase in demand for phenol was from the Asia-Pacific region, and this is expected to continue in the forecast period. The Asia-Pacific region is expected to account for 51.2% of global phenol demand in 2020. The global demand for phenol will increase to reach 11,576,620 tons by 2020. According to SRI consulting report 2010 global production and consumption of phenol were both around 8.0 million tonnes with global capacity utilization of 77%. Phenol consumption is expected to average growth of 5.1percent per year from 2009 to 2014 and around 2.5% from 2014-19. Phenol is consumed mainly for production of bisphenol A and phenolic resins which accounted for 42% and 28% respectively of total phenol consumption in 2009.
5|Page
Year
Installed Capacity (in x10^3 MT)
Production (in x10^3 MT)
Consumption (in x10^3 MT)
2006-07
-------------------
71.27
137.43
2007-08
-------------------
74.94
175.73
2008-09
-------------------
75.75
165.47
2009-10
-------------------
71.59
171.94
2010-11
-----------------
79.81
202.01
2011-12
77.13
65.93
211.54
2012-13
77.13
59.92
232.24
2013-14
77.13
46.39
258.35
Fig. 2 Yearwise Installed Capacity, Production & Consumption of India
Year
Exports (quantity in MT)
Exports (Value in lakhs)
Imports (quantity in MT)
Imports (Value in lakhs)
2006-07
68754
40552
66158
37795
2007-08
102871
66153
100793
63950
2008-09
92918
46763
89723
43010
2009-10
103071
51907
100351
48638
2010-11
123490
93671
122197
91350
2011-12
146762
111194
145616
109047
2012-13
172758
139980
172323
138952
2013-14
214098
172427
211956
169197
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Fig. 3
Producers
Location
Phenol Capacity (kT/year)
Hindustan Organic Chemicals
Kochi
42
SI Group India Ltd
Navi Mumbai
37
3. Available process for the production of product Significant improvements in the technology for the production of phenol have been made over the past decade. New catalysts and processes have been commercialized for the production of cumene via alkylation of benzene with propylene. Recent process design innovations have been commercialized for the cumene hydroperoxide route that remains the process of choice for the production of phenol. All of this effort has been directed at improving yield, process economics/costs, and process safety for the preparation of phenol as a key intermediate for the growing bis-phenol A and phenolic resins markets. A review of technology offerings by major licensors of these new 7|Page
processes is provided as well as a discussion of key process differences and recent advances. Current state-of-the-art processes for the production of cumene as a feedstock for phenol involve technology offerings from UOP, Badger Licensing (formerly ExxonMobil and the Washington Group) and CDTech based on zeolitic catalysis. For cumene hydroperoxide processing to phenol technology, offerings by UOP/Sunoco (formerly Allied-UOP technology), GE/Lummus, and KBR (Kellogg-Brown & Root formerly BPHercules technology) represent the state-of the-art based on the autocatalytic cumene oxidation and dilute acid cleavage (cumene hydroperoxide decomposition) processing routes. Much of the improvement in these technologies falls along the lines of improved yield and stability for the zeolitic cumene technologies and improved yield, safety, and economy for the phenol technologies. A brief discussion regarding alternative methods of phenol production such as the toluene oxidation route and direct oxidation of benzene to phenol is also presented as shifting economic considerations in the future may
make
these
processes
more
attractive.
A. Sunoco/UOP Phenol process The Sunoco/UOP Phenol process produces high-purity phenol and acetone by the cumene peroxidation route, using oxygen from air. This process features low-pressure oxidation for improved yield and safety, advanced CHP cleavage for high product selectivity, an innovative direct product neutralization process that minimizes product waste, and an improved, low cost product recovery scheme. The result is a very low cumene feed consumption ratio of 1.31 wt. cumene/wt. phenol that is achieved without acetone recycle and without tar cracking. The process also produces an ultra-high product quality at relatively low capital and operating costs. Extensive commercial experience has helped to validate these claims. B. KBR 4th Generation Phenol process KBR 4th Generation Phenol process also claims improvements for the cumene peroxidation route for a process based on high-pressure oxidation technology. These include improved oxidation yield, an advanced cleavage system, elimination of tar cracking, and an efficient energy and waste management system. C. GE/Lummus Process It claims various improvements to the cumene peroxidation process. It is similar to KBR in that it is also based on high-pressure oxidation technology. Improvements include enhanced oxidation reaction rates, an advanced cleavage section using a co-catalyst, elimination of tar cracking, and an improved product recovery scheme. 8|Page
Overall process description/chemistry The main reactions for phenol and acetone production via cumene peroxidation are shown in Fig. 4. Both reactions are highly exothermic. Oxidation of cumene to cumene hydroperoxide (CHP) proceeds via a free-radical mechanism that is essentially autocatalyzed by CHP. The decomposition reaction is catalyzed by strong mineral acid and is highly selective to phenol and acetone. In practice, the many side reactions which take place simultaneously with the above reactions are minimized by optimization of process conditions. Dimethylphenylcarbinol is the main oxidation by-product, and the DMPC/AMS reactions play a significant role in the plant.
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4. Techno-Economic appraisal of alternative processes GE/Lummus claims an improved flow scheme to clean up acids and other activity depressing components present in the recycle cumene stream. This results in enhanced cumene oxidation rates for their high-pressure oxidation technology. However, the process is more likely to have higher yields of these components as a result of the higher operating pressure. This requires greater measures to ensure adequate clean up compared to a more modern low-pressure system that provides higher oxidation yields. Also, the high pressure system is more complex and costly and requires higher air compression costs. With either low-pressure or high-pressure oxidation, the oxidation air strips light acids out of the oxidation products. With Sunoco/UOP low pressure oxidation, the air stripping combined with partitioning of the acids to the condensate in the spent air cumene recovery system and the weakcaustic scrubbing of the recycle cumene is so effective that no other method of acid removal is required. This does not appear to be the case for GE/Lummus high-pressure oxidation. KBR employs a similar high-pressure oxidation technology for the manufacture of phenol. KBR claim to have eliminated the sodium carbonate scrubbing system completely thereby reducing capital and operating costs. The aqueous effluent rate for the oxidation section is also said to be reduced by as much as 75% resulting in off-site treating savings. However, similar to GE/Lummus, higher reactor/compressor section 10 | P a g e
costs and lower yields are likely to more than offset these gains compared to lowpressure technology. GE/Lummus claims improvements in the CHP decomposition technology. The technology employs a cocatalyst CHP cleavage process using a very precise mix of NH3 and H2SO4 to control acidity at the optimal level for maximum yield. However, use of such a pre-neutralized acid mix may greatly reduce reaction rate; resulting in much higher decomposer residence times.
5. Selection of Technology/Scheme 5.1 Basis of Selection Sunoco/UOP Process was chosen based on the benefits mentioned in the technoeconomic appraisal above. 5.2 Details of selected process - Sunoco/UOP Process The major processing steps include: (1) Liquid-phase oxidation of cumene to cumene hydroperoxide [CHP] (2) Concentration of CHP (3) Acid-catalyzed decomposition of concentrated CHP to phenol and acetone (4) Neutralization of acidic decomposition product (5) Fractionation of the neutralized decomposition product for recovery of acetone, phenol, AMS, and residue (6) Recovery of phenol and the effluent wastewater via an extraction process to prepare it for further downstream treatment required to meet effluent quality specifications (7) Hydrogenation of AMS back to cumene for recycling to synthesis; or, optionally, refining of AMS for sale as a product
11 | P a g e
The details of each of these main processing steps are discussed as follows highlighting recent technological advances made by various licensors of phenol technology.
5.3 Process flow and recent technology advances 5.3.1 Oxidation section process flowUsing the Sunoco/UOP process as an example, Fig. 7 shows a typical series flow twooxidation reactor configuration for the low-pressure technology. As many as 5–6 reactors or more reactors can be used in multiple reaction trains depending on the capacity of the unit, location, processing objectives, and to stage the investment over time as capacity increases are needed. The fresh cumene feed is pumped from the oxidation day tank to the combined feed surge drum. Recycle cumene streams from other sections of the plant are combined and flow through the feed pre-wash column, where organic acids are removed by scrubbing with weak caustic and water. The recycle cumene then joins with the fresh cumene feed in the combined feed surge drum. The combined feed is then pumped to oxidizer No. 1.
12 | P a g e
Cumene is also used for various utility-like purposes through the plant. Cumene is sent from the day tank to the phenol recovery section on a batch basis as make-up solvent. It is also used as pump seal flush in the various sections of the plant. The two oxidizers are in series with respect to liquid flow but in parallel with respect to air flow. The oxygen requirement for the oxidizers is supplied from atmospheric air. The air is first filtered and then compressed before going into the oxidizers through a sparger. The heat of reaction in the first oxidizer is balanced by adjusting the temperature of the cool cumene feed, so that no other cooling is required. For large phenol units, it is economical to recover the heat of reaction from the second oxidizer by heat integration with the concentration section. The hot oxidizer circulating liquid stream is used to supply heating to the pre-flash column upper vaporizer. The net oxidate from oxidizer No. 2 (effluent from oxidation section) flows directly to the concentration section. As shown in the flow diagram (Fig. 8) again for the Sunoco/ UOP process, the spent air streams from both oxidizers are combined and routed through a water-cooled condenser, a chilled condenser and an entrainment separator for the maximum removal of hydrocarbon and cumene. From the entrainment separator, the air flows to the charcoal absorbers. Two of the adsorbers are always on line in series flow, while the third one is being regenerated with steam. The cleaned air from the charcoal absorbers is vented to safe atmospheric disposal. A catalytic incinerator is usually not needed to meet emission limits, but one can be provided if regulations stipulate incineration as the emission 13 | P a g e
control method. The cumene collected by the charcoal adsorbers is recovered by desorption with low-pressure steam followed by condensing the steam and decanting the cumene and water phases. The cumene is then recycled to the feed pre-wash column.
Recent advances in oxidation section technology For the Sunoco/UOP technology, recent improvements to the oxidation section include: (1) The use of high-efficiency charcoal adsorption to recover trace products from spent air (2) Use of an emergency water spray installation and elimination of oxidizer rupture disks (3) A reduction in oxygen content of vent gas thus reducing air compressor capacity (4) The elimination of the requirement for caustic scrubbing of fresh feed from zeolitic cumene
unit
(5) Use of a dilute caustic wash tower that replaces the feed wash mixer/settler system (6) The integration of the decanter with the concentration section vacuum system and elimination
of
the
vent
gas
scrubber
(7) The integration of the feed coalescer into the combined feed surge drum and (8) The use of common spares for oxidizer pumps and emergency coolers. All of these improvements serve to reduce capital and operating costs of the process making it one of the most effective phenol processes available
14 | P a g e
5.3.2 Concentration section process flow An example of the typical flow for the concentration section of the process where CHP in the oxidizer reactor effluent is concentrated to a level of 75–85 wt.% prior to decomposition to phenol and acetone is shown for the Sunoco/UOP process in Fig. 9.
The oxidate from the last oxidizer flows to the concentration section to recover unreacted cumene. For large phenol units, it is economical to use a two-column concentration system, in which the heat of reaction from oxidizer No. 2 and very lowpressure steam are used to vaporize cumene in the first (pre-flash) column, reducing the size of the main flash column. The pre-flash drum and flash column operate under vacuum to minimize the temperature necessary to concentrate the CHP. The vacuum is typically generated by an ejector system. Under vacuum in the pre-flash drum, cumene vaporizes in the upper vaporizer using heat from the second oxidizer cooler. Additional cumene vaporizes in the lower vaporizer with heat supplied by very low-pressure steam. Final CHP concentration is achieved in the flash column vaporizer and flash column, both of which operate under deeper vacuum than the pre-flash drum. The preflash drum bottoms stream flows through the flash column vaporizer, where additional cumene vaporizes using heat from low-pressure steam. The CHP content of the flash column overheads is minimized by rectification in the flash column, using either screen trays or packing, whichever is more economical. The flash column overheads, consisting of primarily cumene, is recycled to the oxidation section via the feed pre-wash column. The concentrated CHP collects in the integral receiver/cooler at the bottom of the flash column, where it is cooled to a safe 15 | P a g e
temperature. The CHP concentrate from the flash column bottoms reservoir is then pumped to the decomposition section. A cumene quench tank is also provided in this section for automatic emergency quenching of various strategic sections of the concentration section if necessary to maintain safe operating temperatures in the event of an incipient CHP decomposition excursion. Recent advances in Concentration section technology For the Sunoco/UOP process, recent improvements include: (1) Heat integration with oxidation section (2) A two-stage concentration section consisting of pre-flash and flash column (3) Elimination of overhead receivers (4) Use of a Packinox style exchanger in the flash column condenser (5) Use of power traps instead of level-controlled pumped condensate pots. All of these improvements are claimed to reduce capital costs for the process. 5.3.3 Decomposition section flow The decomposition or cleavage section of the process involves the catalytic decomposition of concentrated CHP in the presence of ppm levels of acid to crude phenol and acetone. The most effective technology for this section is a unique two-step process described in U.S. Patent 4,358,618 by Sifniades/Allied Corporation patented in 1982. The process involves the use of a back mixed reactor section at low temperature/higher contact time for the main CHP decomposition step followed by a plug flow dehydration section at higher temperature/short contact time for conversion of dicumylperoxide (DCP) to AMS. The process represents a breakthrough in AMS yield improvement and with the expiration of the patent in 1999, is currently being used by all licensors as the process of choice for modern high yield phenol technology. An example of the most advanced decomposer technology is the process offered by Sunoco/UOP shown in Fig. 10. It consists of a very simple but elegant drum and loop reactor design where concentrated CHP from the concentration section flows into the decomposer drum, along with a metered amount of water to maintain optimal reaction conditions in the decomposer recycle loop. Sulfuric acid is injected via injection pumps into the loop to provide the catalyst required for the decomposition of CHP to phenol and acetone. A circulation pump is provided to circulate the content of the decomposer. Sulfuric acid is injected into the circulating stream to such an extent that the decomposition of CHP and dehydration of dimethylphenylcarbinol (DMPC), a key byproduct of oxidation reaction, are precisely controlled. The level of unreacted CHP is monitored via calorimeters, to which part of the acid catalyst flow is routed. 16 | P a g e
The effluent from the decomposer is pumped to the dehydrator in which the effluent is heated to a temperature where remaining DMPC is dehydrated and DCP converted to AMS at very high yield. This is a unique advantage of the Sunoco/UOP decomposition technology. The Sunoco/UOP process produces approximately 90% AMS yield from DMPC. This also results in higher phenol yield, thus lower cumene consumption and less residue (e.g., tar) formation.
Recent advances in Decomposition section technology In addition to very high yields across the decomposer section, the Sunoco/UOP technology offers the following recent improvements: (1) The implementation of advanced process control (APC) (2) A reduction in required recycle rate from 100:1 to 25:1 (3) The elimination of water injection tank and pumps (4) Use of acid totes to eliminate the acid tank dependent on unit size and client preference (5) Design of the unit for safe containment in most probable relief situations and elimination of the catch tank. The major advantage of these improvements is reduced capital costs and improved process yields and economics. AMS yields as high as 85–90% across the decomposer section have been demonstrated making the Sunoco/UOP technology one of the most selective offerings in the industry today. 17 | P a g e
5.3.4 Neutralization section process flow The acid catalyst that is added in the decomposition section must be neutralized to prevent yield loss due to side reactions and protect against corrosion in the fractionation section. The Sunoco/UOP Phenol process uses a novel approach for neutralization: the acid catalyst is neutralized by injecting a stoichiometric amount of a diamine which does not need to be removed from the process, as shown in Fig. 11. The main advantages of direct diamine neutralization over conventional systems are: (1) A new/simplified design that is easy to operate and reduces capital cost (2) Process uses soluble salts that reduces reboiler fouling and lowers maintenance costs (3) Does not require water addition for neutralization which in turn lowers wastewater production and reduces distillation utilities.
Recent advances in Neutralization section technology By replacing older ion exchange resin technology with the new direct neutralization process, Sunoco/UOP claim that phenolic wastewater production can be reduced by 45% or more at lower capital cost.
18 | P a g e
5.3.5 Acetone refining section process flow Acetone is a major by-product of the CHP oxidation process for the production of phenol. The overall economics of the process are highly dependent on production of high quality acetone (e.g., 99.7–99.9% purity) for sales in the solvents market and bisphenol A markets. Fig. 12 shows the typical flow scheme for the Sunoco/UOP process. Fractionation feed goes from the fractionation feed tank to the crude acetone column. Water is injected as necessary to the bottom of the crude acetone column to increase the volatility of the acetone and maintain the bottom temperature. The overhead of the column, consisting of acetone, water and some cumene flows to the finished acetone column (FAC). The key impurities removed in the FAC are aldehydes, which have been historically analyzed with the permanganate fading test, and water. More recently, as the product quality demands for acetone have increase, most phenol producers use gas chromatography (GC) as the definitive method for determining aldehyde content. The Permanganate Fading test is simply not effective for aldehydes unless the level is in the range of several hundred ppm or more. Caustic is injected into the FAC column to catalyze the condensation of trace aldehydes. The heavier condensation products are less volatile and leave with the FAC bottoms. High-purity acetone flows by gravity from the FAC side cut near the top of the column to the acetone product day tank. The net bottoms stream of the FAC flows to the FAC bottoms drum where cumene and water are separated. The water goes to the sewer while the cumene is recycled to the oxidation section.
19 | P a g e
Recent advances in Acetone refining section technology Recent improvements for the Sunoco/ UOP process include the use of stabbed-in condensers and elimination of overhead receivers, where appropriate, to save capital cost. 5.3.6 Phenol fractionation and purification process flow Once the crude phenol has been produced, it must be further fractionated to prepare a finished product that is of sufficient purity to meet downstream user specs. An example of the phenol purification is shown in Fig. 13. It is based on Sunoco/UOP technology using AMS hydrogenation as a means of recycling the by-product AMS to maximize phenol production. The bottoms material from the crude acetone column flows to the cumene/AMS column where cumene and AMS are recovered overhead and sent to the cumene caustic wash in the phenol recovery section. A chemical agent is injected into the bottom half of the column for the removal of carbonyl impurities such as acetol (a-hydroxyacetone) and mesityl oxide from the phenol. The bottoms from the column are routed through a chemical treatment reactor which provides residence time for the chemical treatment reactions.
20 | P a g e
The effluent from the chemical treatment reactor flows to the crude phenol column where the heavy components distill to the bottoms and then flow into the residue stripper column for removal as the net residue by-product. This separate residue stripper column section allows the final stripping of phenol from the residue to be conducted at higher vacuum, which allows both the crude phenol column and residue stripper column to be reboiled with medium-pressure steam. Thus, no high-pressure steam is required for the phenol plant! The residue product has flow and combustion properties similar to No. 6 fuel oil, and is typically charged to a dedicated burner a boiler furnace. The crude phenol column has a top pasteurizing section to remove the small amount of light by-products generated during distillation. The main product from the column is taken off as a side cut and flows to IX resin treaters, in which the ion exchange resin catalyzes conversion of methylbenzofurans (MBF) and residual AMS to high-boiling components. MBF and AMS are otherwise difficult to remove by distillation. The effluent from the IX resin treaters goes to the phenol rectifier, where the heavy components along with some phenol are distilled to the bottoms and recycled back to the crude phenol column. The phenol rectifier also has a top pasteurizing section for removal of small amounts of light by-products generated during distillation. Phenol product flows by gravity from the rectifier side cut to storage.
Recent advances in Phenol purification section technology For the Sunoco/UOP process, improvements in the phenol fractionation and purification section included:
21 | P a g e
(1) Replacement of the azeotropic phenol stripper with chemical/resin treating (2) Elimination of the acid neutralizer system (3) Use of stabbed-in condensers and elimination of overhead receivers where appropriate. The main benefit of these changes has been reduced capital/utilities cost while maintaining the already very high overall phenol product quality. Further, equipment sizes and wastewater have been significantly reduced by implementation of the advance Sunoco/UOP Phenol recovery technology shown in Fig. 14.
5.3.7 AMS hydrogenation section flow The Sunoco/UOP Phenol process utilizes AMS hydrogenation technology developed by Huels. The Huels MSHPTM process is a mild hydrogenation process based on a Pd containing catalyst system that operates at moderate pressure. The process achieves nearly complete conversion of AMS with very high selectivity to cumene resulting in a very low overall process cumene/phenol consumption ratio of 1.31 w/w. The simple process shown in Fig. 15 has been demonstrated to operate without significant catalyst deactivation over multiple years of operation. In this section the AMS in the cumene/AMS stream from the phenol recovery section is selectively hydrogenated to cumene by the Huels MSHP process. The fresh cumene/AMS feed is mixed with reactor effluent recycle and hydrogen. The combined feed passes through Hydrogenation Reactor No. 1, where the bulk of the AMS is hydrogenated to cumene. The reaction is highly exothermic. 22 | P a g e
The reactor effluent recycle is cooled before joining with the fresh feed. The net flow goes to Hydrogenation Reactor No. 2 as a finishing reactor to complete conversion of AMS to cumene. Product from the second reactor goes through the product cooler and then to the product separator. Hydrogen flow is once through, with only a slight excess over stoichiometric. The flow rate of feed hydrogen is regulated based on the flow of excess hydrogen and light gases from the product separator. Dissolved gases which come out of solution when the liquid flashes to low pressure are disengaged in the flash drum. The cumene liquid product is then recycled to oxidation.
Recent advances in AMS Hydrogenation section technology Advances in the Sunoco/UOP/Huels AMS hydrogenation technology include: (1) Elimination of the recycle hydrogen compressor (2) Elimination of the hydrogen flash drum and pumps. Both of these improvements save capital cost and utilities. 5.3.8 Tar Cracking Both Sunoco/UOP and KBR claim that tar cracking of heavy ends produced in the phenol process is no longer required due to the improvement in process yield achieved over the last 10 years. KBR claims that phenolic tars have been reduced by as much as 40%. By eliminating tar cracking, phenol product purity has improved so that total organic impurities (including cresols) have been reduced to 50 ppm, according to KBR. Sunoco/UOP, with additional refinements in cumene and phenol fractionation technology, have further reduced this level to about 30 ppm. 5.3.9 Phenol process safety 23 | P a g e
Safety considerations in the production of phenol and acetone from cumene include design and operating criteria for processing the intermediate CHP. CHP decomposes rapidly to phenol and acetone when exposed to strong acids, even at low temperatures. This reaction is highly exothermic and is the second reaction step in the process. At high temperatures, the rate of CHP decomposition catalyzed by weak acids would also
become
significant.
In
addition,
CHP
reacts
with
cumene
to
form
dimethylphenylcarbinol. This reaction occurs to some extent under normal conditions in the oxidation, concentration and decomposition sections, but the rate becomes significant at higher temperatures. At still higher temperatures, CHP also decomposes thermally to form acetophenone and methane. CHP decomposition catalyzed by weak acids and the thermal CHP reactions would only become significant from a safety standpoint in the event that heat cannot be removed. In such a case the increasing temperature from the heat of reaction would result in a higher reaction rate, creating the potential for an uncontrolled reaction. Thus, the availability of heat exchangers, cooling medium, and pumps for cooling CHP mixtures is critical from a safety standpoint. A significant advantage of the Sunoco/UOP low-pressure oxidation technology in addition to high yields is the very mild operating temperature (e.g., typically 82–90 Degree Celcius) required for the process. The lower oxidizer operating temperature translates into a much longer allowable operator response time in the event intervention is required due to an upset to prevent oxidizer temperatures that are high enough to promote CHP thermal decomposition. The intervention response time may be as long as 24 h or more to avoid elevated temperatures and high rates of CHP decomposition in the oxidizers. For high-pressure processes such as KBR and GE/Lummus, the response time is much shorter, on the order of only a few hours, to prevent accelerated CHP thermal decomposition due to the higher initial process temperature (e.g., typically 95–100 8C or more). The Sunoco-UOP Phenol process design and operating criteria are based on an industry accepted 10,000-year probability guideline. Safety provisions include emergency coolers and pumps, reliable power supplies, reliable cooling water supply, and further backup provisions including ability to use firewater as once through cooling water, and the capability to use cool cumene to reduce (quench) temperature. For all cooling services designated as critical, if cooling becomes unavailable, it must be possible to reestablish cooling within 20 h with 99.99% certainty. Analysis has shown that meeting this availability criterion typically requires a cooling water supply system with a minimum of three pumps, with two normally operating and the third in standby; and multiple independent power sources for the pumps and cooling tower fan. For all pumping services designated as critical, if pumping becomes 24 | P a g e
unavailable, it must be possible to re-establish pumping within 20 h with 99.99% certainty. Meeting this criterion typically requires multiple sources of power. Options for multiple independent power sources can include, but are not necessarily limited to, an emergency electric power generator, steam-driven turbine, a direct drive engine, or multiple independent external electric power supplies. While the first three options are less reliable than normal electrical power, the combination of multiple power sources provides a more robust system than a typical single external electrical power supply. For example, if a diesel powered emergency electric power generator is utilized, a probability of 97% is typical. Emergency generators are less reliable than normal electrical power because of the probabilities associated with failure to start, failure to run, and unavailability due to testing and maintenance. Quantitative risk assessment is typically performed to verify the reliability of such systems.
6. Raw Material 6.1. SOURCES OF RAW MATERIAL Cumene peroxidation process is a process involves the liquid phase air oxidation of cumene to cumene peroxide, which in turn is decomposed to phenol and acetone by the action of acid. During the cumene peroxidation process, there are two main raw materials used in this process which are cumene and oxygen. Oxygen is a gas form fluid. Oxygen is colourless gas that can be found in the air. In the air there is 21% of oxygen contains while another 79% is nitrogen gas. Oxygen acts as an oxidizer. Table shown the physical and chemical properties of oxygen as well as cumene. Most important cumene specifications: Purity 99.90 wt-%, min. Benzene 10 wt-ppm, max. Toluene 5 wt-ppm, max. Ethylbenzene 50 wt-ppm, max. n-Propylbenzene 300 wt-ppm, max. Butylbenzenes 100 wt-ppm, max. (for 99.5 wt-% AMS purity)
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PHYSICAL AND CHEMICAL PROPERTIES of CUMENE (TYPICAL) PROPERTY
DATA & INFORMATION
Synonyms
Isopropyl benzene
Chemical Formula
C6H5CH(CH3)2
Physical State at room temperature
Liquid
Odor
Aromatic
Appearance
Colorless liquid
Boiling Point Critical Temperature
152°C -
Melting Point
-------------------------
Specific Gravity
0.86 (Water = 1)
Molar mass
120.00 g/mol
Solubility in water
Negligible solubility in cold water
Vicosity (cSt @ 40°C)
0.7
Vapor Pressure
1.1 kPa (8 mm Hg) (at 20°C)
Volatility
862 g/l VOC (w/v)
Flash point
Closed cup: 36°C (96°F). (Pensky-Martens.)
Additional Properties
Paraffin, Isoparaffin and Cycloparaffin Hydrocarbons Content = <1 Wt.% (ASTM D-1319); Aromatic Hydrocarbon Content = >99 Wt. % (ASTM D1319); Average Density at 60°F = 7.19 lbs./gal. (Calculated via ASTM D-287); Aniline Cloud Point Temperature = 52°F (11°C) (ASTM D611); Kauri-Butanol (KB) Value = 96 (ASTM D-1133); Dry Point Temperature = 307°F (153°C) (ASTM D-86, D-850 or D-1078); Evaporation Rate = 0.5 (n-Butyl acetate = 1.0); Heat Value = 18,670 Btu. per pound
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STABILITY AND REACTIVITY Chemical Stability
Stable.
Hazardous Polymerization
Not expected to occur.
Conditions to Avoid
Keep away from heat, sparks and flame. Forms explosive peroxides with prolonged storage
Materials Incompatibility
Strong acids, alkalies, and oxidizers
Hazardous Decomposition Products
No additional hazardous decomposition products were identified other than the combustion products identified in Section 5 of this MSDS.
6.2 Availability of Cumene Ashland Chemical, Inc. and Chevron Chemical Co. offer cumene in tank car, tank truck, and barge quantities. Cumene is available from various Naptha crackers across India which includes - IOCL Panipat, Hazira of Reliance, IPCL Vadodara, Haldia of Haldia petrochemicals 6.3 Import Data Major importers of cumene in India are Macoma Hardwares Tuff Stone Marketing Pvt Ltd. Chemilab Corporation Schenectady Herdillia Limited Bayer Abs Limited 7th Floor, Abs Towers Old Padra Road BARODA , Gujrat Btp India Private Limited Kences Towers, (Ii Floor) , No.1, Ramakrishna Street,t.nagar, CHENNAI, TAMIL NADU 27 | P a g e
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6.4 Export Data Major Exporters in India are Alok Industries Ltd. 43-b;mittal Tower Nariman Point, MUMBAI. MAHARASHTRA M-tex Exports 505,gagangiri Avenue, Samta Nagar,opp.raymonds, THANE , MAHARASHTRA Chemilab Corporation 55, B. R. B. Basu Road, B- Block, 3rd Floor, Room No. 55, CALCUTTA , WEST BENGAL
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6.5 Prevailing prices
6.6 Govt Policies and Import Duty Import Duty on Cumene Description
Duty (in INR)
Basic Duty
5.00
Education Cess
2.00
Secondary Hiigher Education Cess
1.00
Contravailing Duty (CVD)
12.00
Additional Contravailing Duty
4.00
Additional Cess
0.00
National Calamity Contigent Duty (NCCD)
0.00
Abatement
0.00
Total Duty
22.85
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Bisphenol 1. Uses & Importance Bisphenol is an important building block and its measure use is in the manufacture of polycarbonate plastic and epoxy resins. Other uses include in flame retardants, unsaturated polyester resin and polyacrylate, polyetherimide and polysulphone resin. Some
common
uses
are
mentioned
below
-
Store Sales Receipts Some thermal paper receipts can contain BPA as a component of the heat sensitive coating that allows for inkless printing. This paper technology provides speedy, reliable and cost-effective printing. Packaging & Storage BPA is used to make polycarbonate plastic and polymeric coatings called epoxy resins for food packaging and storage that are essential to enhance the safety of our food supply and contribute to healthy, modern life styles. Medical Polycarbonate plastic is used to make critical components of many medical devices and their housings. Its optical clarity allows direct observation of blood or other fluids to monitor proper flow. Health care providers depend on medical devices and equipment made with BPA for a transparent view within the human body so they can check for the presence of air bubbles or other obstructions during medical procedures. Safety Equipment BPA is regularly used to strengthen products for human health and safety. Products like bike helmets, police shields, reading glasses and bullet-proof glass are all shatter resistant because of BPA. Electronics & Auto BPA is used to make parts of cars, circuit boards, flat screen televisions and smart phones—improving safety and quality of many of the products. Industrial & Business From LED lights to adhesives, find out how BPA is used for industrial and architectural purposes.
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Optical Media ●
Compact Discs
●
CD-ROMs
●
Digital Versatile Discs
●
HD-DVDs
●
Blu-RayDiscs
●
Holography Discs
●
Innovative Data Storage Technology (e.g. Near Field Recording Discs)
●
Forgery-proof holographic shadow pictures in ID cards
Construction: Buildings ●
Sheets for roofing, conservatory glazing
●
Architectural glazing (e.g. sports arenas)
●
Greenhouse glazing
●
Rooflights
●
Cover for solar panels
●
Noise reduction walls for roads and train tracks
●
Car port covers
●
Glazing for bus stop shelters
●
Roadsigns
●
Internal safety shields for stadiums
●
Transparent cabins for ski lifts
●
Housings and fittings for halogen lighting systems
●
Roadsigns
●
Front panels for advertising posters, signboards(e.g. fuel stations)
●
Large advertising displays
●
Dust & water-proof luminaires for streetlights and lamp globes
●
Diffusing reflectors for traffic lights
Others: Safety ●
Safetygoggles
●
Protective visors for welding or handling of hazardous substances
●
Protective visors for motor bikes, snowmobiles
●
Motorbike and cycle helmets
●
Fencing helmets
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●
Safety shields for policemen
●
Guards to protect workers from moving machine parts
2. Market Prospects ·
Demand of bisphenol in India during 2010-11 was 30,000 tonnes per annum
·
Global installed capacity: around 5.2 million tones
·
Global demand around 4.2 million tones
·
Global growth rate in demand 5 to 6percent
·
Polycarbonate resin are the largest and fast growing BPA market, consuming 60percent of the global production.
Epoxy production
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3. Production Methods Various process technologies available for manufacture of bisphenol are: A) Synthesis of Bisphenol-A from phenol and acetone using Organic-Inorganic modified heteropoly acid catalyst BPA is conventionally produced through acid catalyzed condensation reaction between phenol and acetone by using ion-exchange resins promoted by mercapto compounds. Excellent performance is shown by ion-exchange resins in experiments. It has been tested that modified ion-exchange resins like Amberlyst show very good activity for BPA synthesis. Because of thermal instability of resin catalysts, they cannot be used at higher temperatures. The other problem being fouling of resin catalysts in the reactor. Use of inorganic acid catalysts have been tried and found effective.Bisphenol-A is synthesized using an effective design of heteropoly acid catalyst by organic-inorganic dual modification. Dual modification was made by partial Cs ion exchange for lowering acid strength and by immobilization of 2-diethylamino-ethanethiol (DEAT) adjacent to protonic acid sites. Yields near to 94% is achieved on designed catalyst which is equivalent to conventional ion-exchange catalyst (yield 96%). The aim of this study is to develop an effective strategy of catalyst design for BPA synthesis. Ion exchange resins are the preferred catalysts, but these have temperature limitations. B) Synthesis of bisphenols using ion-exchange catalysts Modification of an insoluble strong-acid cation-exchange resin in acid form by partial neutralization with a mercaptoamine yields an improved catalyst for the preparation of bisphenols by condensation of a phenol and a ketone.This invention relates to an improved resin catalyst for the preparation of bisphenols and particularly bisphenol A. More specifically, the improved catalyst is an insoluble strong-acid cation-exchange resin in acid form modified by partial neutralization with a mercapto amine. Sulfur compounds have long been recognized as effective promoters for the acid catalyzed condensation of phenols and ketones to form bisphenols. For example, in US. Patent 2,359,242 Perkins and Bryner describe the use of H 5 in the condensation of phenol with acetone, methyl ethyl ketone, cyclohexanone, and other similar ketones. In US. Patent 2,917,550 Dietzler recommends as a promoter a soluble ionizable sulfur compound such as H S, methyl mercaptan, ethyl mercaptan, or n-octyl mercaptan.Such soluble promoters however introduce subsequent problems in the purification of the bisphenol. Particularly when the bisphenol is used in the synthesis of epoxy and polycarbonate resins, its purity is a critical factor. Extensive processing is often required. Thus the search for improved catalysts, greater process efliciency and enhanced product color, odor and purity continues.Recently Apel, Conte and Bender disclosed in 35 | P a g e
US. Patents 3,049,568 and 3,153,001 a resin catalyst prepared by partial esterification of a substantially anhydrous strong-acid cation-exchange resin with a lower alkyl mercaptoalcohol. By chemically bonding the mercaptan promoter to the insoluble resin by esterification, contamination of the product with the mercaptan is reducedIt has now been discovered that partial neutralization of a strong-acid cation-exchange resin with a C -C alkyl mercaptoamine provides another new and improved resin catalyst for the preparation of bisphenols. As illustrated by the following equation for partial neutralization of a sulfonated aromatic resin with 2-mercaptoethylamine.
C) ZnCl2-modified ion exchange resin as an efficient catalyst for bisphenol-A production A ZnCl2-modified ion exchange resin as the catalyst for bisphenol-A synthesis was prepared by the ion exchange method. Scanning electron microscope (SEM), thermogravimetric analyzer (TGA) and pyridine adsorbed IR were employed to characterize the catalyst. As a result, the modified catalyst showed high acidity and good thermal stability. Zn2+ coordinated with a sulfonic acid group to form a stable active site, which effectively decreased the deactivation caused by the degradation of sulfonic acid. Thus the prepared catalyst exhibited excellent catalytic activity, selectivity and stability compared to the unmodified counterpart.To overcome the shortcomings of ion exchange resins, numerous efforts have been made, including loading thiol groups and/or amine groups by means of reduction, esterification, neutralization or ion exchange method. Takahim and Toshitaka successfully synthesized a modified catalyst with mercapto alkyl amine, which showed a great improvement in the condensation of phenol and acetone. Carvill et al. discovered that 4-(2-mercaptoethyl)-pyridine was a good modified reagent.Ion exchange resins have been used in other reactions, such as esterification, transesterification, oligomerization. Low acid strength is also one of their main drawbacks affecting the reaction efficiency. Some researchers attempted to solve this issue by introducing Lewis acids into the resins. Magnotta and Gates reported that the acidic property of the complex formed by AlCl3–sulfonic acid can be similar to that of the superacid solution of SbF5 + FSO3H. Shi showed that the efficiency of acid-catalyzed transesterification and esterification reactions depend on the subtle balance between Lewis and Brønsted acidities.
4. Techno-Economic appraisal of alternative processes The use of a novel catalyst based on heteropolyacid supported on clay, particularly dodecatungstophosphoric acid (DTP) supported on K-10 clay and its comparison with commercially available resins such as Amberlyst-15, Amberlyst-31 and Amberlyst-XE36 | P a g e
717p shows DTP/K-10 is an efficient and re-usable catalyst which could be employed at higher temperatures. The kinetics of the reaction with DTP/K-10 have shown interesting features among which the formation of intermediate isopropenyl phenol was found to be the rate determining step with the Eley-Rideal type of mechanism.of phenol to acetone are required for a facile progress of the reaction as well as to suppress the side reactions of acetone. Conventionally bisphenol-A is manufactured by the acid catalysed condensation of phenol and acetone. Ion exchange resins are the preferred catalysts, but these have temperature limitations. High molar proportions of phenol to acetone are required for a facile progress of the reaction as well as to suppress the side reactions of acetone. A large number of side-products are generated depending upon reaction conditions and the type of catalyst. An ideal catalyst for this reaction should be moderately acidic and shape selective, whereby lesser quantities of the by-products would be formed. Ion exchange resins have been used in other reactions, such as esterification, transesterification, oligomerization. Low acid strength is also one of their main drawbacks affecting the reaction efficiency. Some researchers attempted to solve this issue by introducing Lewis acids into the resins. It has been proved that the coordination of a Lewis acid with a Brønsted acid can increase its original acidity.Therefore, the design of dual acid catalysts based on resins can be advantageous in the BPA production. In this study, ZnCl2 acting as a Lewis acid was added into cationic ion exchange resins to fabricate a more efficient catalyst. To the best of our knowledge, this is the first resin catalyst for producing BPA that contains both a Brønsted acid and a Lewis acid.
5. Details of selected process REACTION CHEMISTRY The acid catalysed condensation of phenol and acetone in homogeneous medium leads to several products; in particular with strong sulphuric and hydrochloric acids almost 28 products have been identified. Strong acids such as 70% sulphuric acid, hydrochloric acid or sulphonated polystyrene divinylbenzene cation exchange
37 | P a g e
resins are industrially preferred. Fig. 1 shows the reaction scheme. In a strong acid medium, acetone is protonated to a stable carbenium ion as shown by reaction a in Fig. 1. Following steps occur:Reaction b-The carbenium ion adds to the limiting quinonoid structure of phenol to yield a protonated carbinol. Reaction c-The carbinol rearranges to release water and yields protonated isopropenyl phenol. Reaction d- The isopropenylphenol adds to a second phenol molecule to yield bisphenol-A. Several by-products are formed during this reaction and are shown in next fig.
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The major one being the o,p 1 isomer formed by the reaction of p-isopropenyl-phenol with the phenol in the ortho position (reaction f). Other side products are the chroman derivatives formed by the reaction of phenol with mesityl oxide, which itself is a product of self-condensation of acetone followed by dehydration (reaction e, Fig. 2). Out of the 28 products mentioned, those which are formed in relatively larger quantities are 2,2,4trimethyl chromen, 1,1,3-trimethyl-5-indanol, 9,9- dimethylxanthane and dimethyl hydroxy biphenyl. The remaining by products constitute to less than 0.2% of the reaction mixture. It is obvious from Fig. 2 that the formation of byproducts can be suppressed if the self- condensation of acetone followed by dehydration leading to mesityl oxide is avoided. One of the ways would be to employ excess of phenol over acetone in batch experiments or semibatch mode of operation with continuous addition of acetone making the phenol to acetone ratio very high.
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Chemicals and catalysts The preparation of alumina, zirconia, chromia exchanged clays and heteropoly acid supported on clays has been detailed elsewhere [3,11]. Amberlyst-15, Amberlyst-31 and Amberlyst XE-717p were procured from Rohm and Haas (USA). K-10 and Filtrol-24 were purchased from Fluka (Switzerland) and Engelhardt (Germany), respectively.
Preparation of dodecatungstophosphoric acid (dtp) supported on clay (DTP/K-IO) Approximately 10 g of K-10 clay was dried in an oven at 120°C for 1 h of which 8 g were weighed for subsequent experiment. 2 g of dry DTP was also weighed.The HPA was dissolved in 8 ml of dry methanol. This volume of solvent was approximately equal to the pore volume of the catalyst. The solution was added in aliquots of 1 ml each to the clay under constant stirring with a glass rod or kneading it properly. The solution was added at time intervals of 30 sec. Initially and up to the addition of 6 ml of the DTP solution, the clay was in the powdery form but upon subsequent addition the clay formed a paste. Further kneading of the paste for 10 min. yielded a dry free flowing powder. The preformed catalyst was dried in an oven at 120 °C for 1 h and then calcined at 275°C for 3 h.
Reaction procedure All the experiments were carried out in a 100 ml Parr autoclave equipped with a four bladed turbine impeller. The temperature was maintained within i0.5°C of the desired value. The vessel was also equipped with a speed regulator that could maintain the desired speed at + 1% of the set value. Predetermined quantities of reactants and the catalyst were charged into the autoclave and the temperature was raised to the desired value. Once the temperature was attained the initial sample was withdrawn at time=0 and the stirrer was started. Further samples were withdrawn at definite time intervals. A typical experiment consisted of 5.28 g (0.091 gmol) of acetone, 42.77 g (0.451 gmol) of phenol, 1.25 g of catalyst (loading of catalyst, 0.0268 g/cm 3 of the liquid phase). The reaction temperature was maintained at 100°C and 135°C for the ion exchange resins and inorganic catalysts, respectively.
Analysis The samples were analysed in a gas chromatograph (Perkin-Elmer Model 8500) equipped with a flame ionisation detector. A 2 × 0.003 m column packed with 10% OV41 | P a g e
17 supported on chromosorb WHP was used. Calibration curves were prepared by using standard samples and synthetic mixtures in order to quantify the data. Results and discussion 1) Comparison of the activity of the catalysts A maximum of six products were detected in the reaction mixture. The products were identified as 1,1,3-trimethyl-5-indenol, 2,2,4-trimethyl chromen, 9,9- dimethyl xanthane, dimethyl hydroxy biphenyl, o,p-l-bisphenol and bisphenol- A. In the case of Amberlyst31 and Ambedyst-XE-717p only o,p-l-bisphenol and bisphenol-A were formed, whereas in the case of Amberlyst-15, all the by products were formed in large quantities resulting in a lower selectivity to bisphenol-A. Since it was desired to test the efficacy of dodecatungstophosphoric acid supported on K-10, a few experiments were also conducted with the support clay K-10 as well as Filtrol-24 as shown in Table 1. Both K-10 and Filtrol-24 were rather ineffective. As was expected, Lewis acid type catalysts, such as alumina exchanged K-10, zirconia K-10, chromia exchanged K-10 and sulphated zirconia calcined at 650°C did not show any conversion at 135°C after 4 h of reaction The Bronsted acid type catalyst were more effective. Amberlyst-XE-717p is a promoted ion-exchanger where 17% of the acid sites are promoted with an undisclosed molecule [21]. The activity of the catalyst and selectivity for bisphenol-A were very high. The exchange with any sulphur compound reduces the acidity of the catalyst, whereby the yield of bisphenol- A is increased. The main side reactions were of acetone, particularly the formation of mesitylene and its subsequent reactions. The mesitylene reactions are promoted by strong acidic sites. The sulphur compounds selectively poison the strong acidic sites which are responsible for side reactions. The activity and selectivity of Amberlyst-15 are much lower than over DTP/K10 and Amberlyst-31, both of which having similar activities; but the latter being more selective. Amberlyst XE- 717p is more active and selective than both DTP/K-10 and Amberlyst-31.However, Amberlyst-31 and Amberlyst-XE-717p, like any other ion exchanger have very poor thermal stability. They can be used at a maximum temperature of. By contrast, the clay modified catalysts can be used at temperatures as high as 300°C. The lower selectivity of bisphenol-A with DTP/K-10 could be due to its high acidity giving rise to a variety of by-products. If the acidity of the catalyst is controlled by reducing the activity of some of the sites; for instance, by doping with sulphur compounds the formation of byproducts could be lowered. Further, some reactions can occur on the external surface of the catalysts without any shape selectivity. 42 | P a g e
2) Effect of speed of agitation Fig. shows the conversion of acetone at different time intervals. The conversions were found to remain practically the same at speeds beyond 1000 rpm thereby indicating absence of solid-liquid mass transfer resistance. Further reactions were conducted at a speed of 1000 rpm. Since acetone was taken as a limiting reactant it could be concluded that any external resistance to its transfer from the bulk liquid phase to the external surface of the catalyst was absent.
Effect of catalyst loading Fig. shows the plot of initial rate of reaction of acetone (roi , gmol/cm3/s) against catalyst loading (w, g/cm3). It indicates that the rate of reaction increases linearly up to a loading of 2.6z 10 -2 g/cm 3 and thereafter remains constant even though the loading is almost doubled. Since the number of acidic sites available in the reaction medium is proportional to the available intra-particle surface, the initial rate of reaction of acetone should be directly proportional to catalyst loading (mass/volume) if there are no intraparticle diffusion limitations. This indicates the following: • An intra-particle diffusion limitation was set in for the transfer of acetone from the exterior surface of catalyst beyond a solid loading of 2.6x l0 2 g/cm 3, acetone being the limiting reactant (CAo << Cpo). 43 | P a g e
• The side reactions were also significant due to extra available active sites. It clearly demonstrated that mass transfer limitations were set in and not all internal surface area was utilised for the reaction. In fact, the acetone concentration would become zero at a certain distance from the centre of the particle and the reaction would become intra-particle mass transfer controlled. Further experiments were therefore done at catalyst a loading of 2.6 x l0 -2 g/cm 3 in the absence of intra particle resistance.
Effect of temperature Fig. shows plots of conversion of acetone with time at temperatures of 120, 135 and 150°C. The rate of reaction increases as the temperature increases. The conversions at 120°C are linear with respect to time showing zero-order dependence on acetone concentration. The other two lines indicate non-zero order dependence which will be discussed later in the kinetic interpretation.
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Conclusion The reaction of phenol and acetone was studied over different catalysts. DTP/K- 10, Amberlyst-31 and Amberlyst XE-717p were found to be better catalysts. DTP/K-10 is reusable and better as regards its use at higher temperatures. The kinetics was studied with DTP/K-10 as catalyst where the rate determining step is the formation of pisopropenylphenol from chemisorbed acetone and phenol from the liquid phase within pores according to Eley-Rideal mechanism. The catalyst was characterised fully. By taking higher mole ratio of phenol to acetone, a number of byproducts are avoided. The kinetic model was found to fit the data satisfactorily.
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References http://nptel.ac.in/courses/103107082/module7/lecture8/lecture8.pdf http://ac.els-cdn.com/S0926860X04007562/1-s2.0-S0926860X04007562main.pdf?_tid=c5bf66dc-7338-11e4-b6fa00000aacb35e&acdnat=1416765020_591b5a96e1d46785e235961d2b374f14 https://www.citgo.com/CITGOforYourBusiness/MSDS.jsp http://www.infodriveindia.com/indian-importers/cumene-importers.aspx http://www.sify.com/news/naphtha-cracker-project-at-indian-oil-s-panipatcomplex-dedicated-to-nation-news-national-lcpukciehfbsi.html http://mcgroup.co.uk/researches/cumene http://www.icis.com/globalassets/global/icis/pdfs/sample-reports/chemicalscumene.pdf http://www.pib.nic.in/newsite/erelease.aspx?relid=69826 https://www.zauba.com/customs-import-duty/CUMENE/india.html https://www.zauba.com/importanalysis-CUMENE/hs-code-29096000-report.html http://www.seair.co.in/product-import-data/cumene-import-data.aspx www.sciencedirect.com www.wikipedia.com
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