Manufacturing Of Acrylic Acid

Production of Acrylic Acid

Report submitted in partial fulfillment of the requirement for the degree of

B.Tech In Chemical Engineering Under the supervision of

Prof. Uttam Kumar Mandal By

Nikhil Kumar Tanwar To

University School of Chemical Technology GGSIPU, Dwarka Sector 16-C, Delhi 110078

November 2019

Certificate

This is to certify that Report entitled “Production Of Acrylic Acid ” which is submitted by Nikhil Kumar Tanwar in the partial fulfillment of the requirement for the award of degree B.Tech in Chemical Engineering to USCT, GGSIP University, Dwarka, New Delhi is a record of the candidate own work carried out by him under my supervision. The matter embodied in this report is original and has not been submitted for the award of any other degree.

Date Supervisor Prof. Mandal

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Uttam

Kumar

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Acknowledgement I would like to express my special thanks of gratitude to my mentor Prof U.K. Mandal for providing me an opportunity to work on the project and guiding me all through my project. I take this opportunity to express my sincere gratitude towards my mentor Prof. U.K. Mandal, Dean USCT for providing me the right path and motivation throughout his busy schedule and helping by sharing his knowledge. His way of working is a source of inspiration for thousands of students like us. His guidance, constant encouragement and careful monitoring throughout the project are so great that even most profound gratitude is not enough.

Nikhil Kumar Tanwar 01816101416

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Content Certificate Acknowledgement Content List of figure List of table Abstract Notations Unit

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Chapter 1:Intorduction 1 1.1 Acrylic Acid uses 1 1.2 Market Size and Demand 1 1.2.1 Major suppliers of Acrylic acid in India and abroad 2

Chapter 2:Detailed Literature View of Various Process 3 2.1 Acrylic Acid by Dehydration and Oxidation of Glycerol 3 2.2 Acrylic Acid from ethylene 4 2.3 Acrylic Acid from propylene

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2.4

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Acrylic acid from propaneoxidation

2.5Acrylic acid from LacticAcid

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Chapter 3:Economical viability and process description

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iv 3.1 Analyzing the Economic Viability of the Processes

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3.2 Process Flow Chart for production of acrylic acid fromethylene

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3.2.1 ProcessParameters

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Refrences

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List of Figures Figure

Figure Caption

Number

Page Number

Figure.1.1

Demand and supply gap in India

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Figure.1.2

Market size of Acrylic acid in India

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Figure.2.1

Production of Acrylic Acid from glycerol

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Figure.2.2

Production of Acrylic Acid from ethylene

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Figure.3.2

Process flow chat of production of acrylic

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acid

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List of Tables Table

Title

Page

Number Table.3.1

Economical analysis all different processes

Number 7

Table.3.2.1

Flow rate parameter

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Table.3.2.2

Reactor Parameter

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Abstract

This report provides as complete analysis of an alternate method of production of Acrylic acid and advantages of the method over others. Covers all the aspect of the setting up a new production plant my report gives an idea about the needs and the profitability aspects of the setup of Acrylic acid using ethylene and why this process is economical over the other methods of production of Acrylic acid .this includes various process parameters along with their flow charts gives the rough estimation of the production capacity of the plant.

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Notations KTPA – kilo tonnes per year SAPs-super absorbent polymers

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Units Quantity

Unit

production

MM lb/ year

Molarity Normality

Molar (M) Normal (N)

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Chapter 1 INTRODUCTION

1.1

Acrylic Acid uses

Acrylic acid (CH2=CHCOOH) is the simplest unsaturated carboxylic acid and exist as a colorless liquid with pungent smell at standard temperature and pressure (T= 298k, P= 1atm). Acrylic acid finds applications in varied industries due to its varying degree of durability, tackiness & hardness. Crude Acrylic acid is (1): 

Used as a monomer in superabsorbent polymers(SAPs)that have applications in baby diapers , sanitary napkins, soaker pads for food packaging, etc.

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Used to produce acrylates that have applications in masonry and industrial coatings, floor polishes, wood paints, tablets coating, etc.

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Used to make acrylic glass which is an alternative to glass in green house.

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Used as monomer in production of detergents.

1.2 Market size and Demand The demand of acrylic acid is constantly increasing due to growth in demand for SAPs, and growth in water-based adhesives market and real estate industry but our country relies on foreign suppliers. The demand supply gap is increasing very rapidly and is expected to reach 260 kiltonnesper annum(KTPA) by 2020 (Figure 1.1).The Indian market for acrylic acid seems very lucrative as evident from data as shown below (Figure 1.2) (2)

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Figure 1.1:-Demand and supply gap in India(in KTPA)(2) By this we can conclude that setting up a plant producing acrylic acid in not tough due to very low competition present in our country. We sell it at lower prices then the foreign supplier due to low transport cost and other things. Mumbai and Gujarat are best locations for setting up of plant dur availability of labour, government support, flourishing economy, and easy availability of raw materials, and power. Companies like Delta Chemsol, Meru Chem Private limited, Madhu Chemicals, Viraj industries etc.(3) are the main importers and suppliers of acrylic acid. 1.2.1 Major producers of acrylic acid in India and outside India A.B Enterprises(Mumbai), Triveni Interchem Pvt. Ltd. (vapi), A.S. Chemicals (Hyderabad), Alpha Chemika (Mumbai)(4). Amongst foreign players , USA and China are leading exporters.

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Figure 1.2:-Market size of acrylic acid in India (in INR)(2)

Chapter 2 Detailed Literature review about various processes In this Chapter we discuss in detail about the various process for production of with flow diagrams

2.1 Acrylic Acid

by Sequential Dehydration and Oxidation of

Glycerol The production of Acrylic acid using the technique of dehydrogenation –oxidation of glycerol is a very attractive approach. This is mainly because the raw material , glycerol, is available in sufficient amount as the byproduct of the biodiesel production process. Biodiesel is as fast growing industry and so is the production of glycerothat has increased by10 times in the last deacde from 1Million to 10 million tones. This has lead to a drop in the price of glycerol by nearly 60% in the Last ten year (5). First step is dehydration of glycerol in acrolein Dehydration:C3H5(OH)3C3H4O +2H2O Glycerol Acrolien +2Water (5) 3 Next step is oxidation of acrolein in acrylic acid & major byproducts are acetaldehyde & acetic acid.

Oxidation:C3H4O +0.5O2C2H3COOH +H2O Acrolein+0.5OxygenAcrylic acid +water (5) This reaction is carried by using two different types of packed bed catalyst in a single fixed bed reactor because of higher yield (75%)as compared to single packed bed catalyst where the yield is just 25% . For the dehydration of Cs2.5H0.5PW12O40 supported on Nb2O5 (CsPW-Nb) is used as a catalyst and for oxidation step, vanadium-molybdenum mixed oxides supported on silicon carbide (VMo-SiC) is used. Acetol and water which are the byproducts of the dehydration step do not have any negative impact on the subsequent oxidation step. Also, there is no deactivation of any catalysts and both of them can be completely regenerated by coke burning at 500oC . The reaction is carried out at an optimum temperature of 300 oC and ambient pressure because although increasing the temperature increases the conversion but trade off is decrease in selectivity.

Air(O2) Acrylic acid Ace tol Glycerol Water Glycerol Figure 2.1 - production of acrylic acid by glycerol

2.2 Acrylic Acid from ethylene 4

Acrylic acid can be manufactured from ethylene in a three step process namely oxidation of ethylene ,

Carbonylation of ethylene oxide, and acid catalyzed rearrangement of βpropiolactone. Cost of raw material, ethylene, the biggest contributor in the total cost of production. In the first step, ethylene is oxidized to ethylene oxide with highly pure oxygen so as to minimize the reaction volume. This reaction is carried out in vapour phase in a tabular reactor. Silver is used as a catalyst on α-aluminium support. Impurities of Cs and Re are added to the catalyst in order to increase the selectivity of ethylene oxide to 80-90%. The reaction is carried out at a temperature of 240-290 oC and a pressure of 15-25 bar. Since the reaction is highly exothermic, heat removal is a major requirement for maintaining high selectivity. After the purification it is possible to obtain a product stream of 99.5% purity. Oxidation:C2H4 + 0.5 O2 C2H4O Ethylene + CO β-Propiolactone(6) In the second step, ethylene oxide is carbonylated to produce β-propiolactone in the presence of [Co(CO)4] as the catalyst and thiamine propiolactone is toxic and thus cannot be isolated. The reaction is carried out in liquid phase under isobaric conditions (pressure of CO is kept constant) and temperatureof 240oC. Carbonylation:C2H4O +CO  C3H4O2 Ethylene oxide +COβ-Propiolactone(6) In the last step, β-propiolactone undergoes rearrangement to from acrylic acid in the presence of phosphoric acid as catalyst and mono methyl ether hydroquinone(MEHQ) as inhibitor to prevent the product from polymerizing. Small amount of water is added to catalyst to increase its viscosity and maintain phase as liquid . reaction is carried in vaccum at high temperature to achieve per pass conversion of 0.97 and the overall conversion of 0.995.(6) Rearrangement:

C3H4O2C2H3COOH 5 β-propiolactoneAcrylic Acid

ethylene

ethylene oxide

Acrylic acid

O2 Ethylene

CO

Figure 2.2- production of Acrylic acid by ethylene

2.3 Acrylic Acid from propylene Production of acrylic acid through the catalytic partial oxidation of propyleneis another economically viable aaproach. Propylene of acrylic acid takes place by two stages selective oxidation of propylene into acrylic acid where acrolein is as fast acting intermediate. The oxidation reaction is carried in the temperature range of 3100-3500c and is highly exothermic. It takes place in fixed bed reactor using mixed oxide of arsenic ,tantalum and molybedenum as catalyst.200MM lb/year glacial-gradd acrylic acid can be produced using this technique. This process design is technologically advanced in terms of high production yield ,catalysis of unsaturated acid from saturated hydrocarbon and optimization of process component. The process value as it is low cost and enviournmentally responsible and has high purity. Major side reaction are formation of acetic acid through activated propylene or acrolein and oxidation of hydrocarbon to give carbon dioxide. Side reaction can be minimized by maintaining the temperature at desired level by removing the reaction heat(7). Oxidation: C3H6 + O2 C3H4O + H2O Propylene + Oxygen  Acrolein + Water Oxidation: C3H4O + 0.5O2 C2H3COOH Acrolein + Oxygen Acrylic Acid

2.4 Acrylic acid from propaneoxidation Acrylic acid can be manufactured from propane in an attractive way. This is mainly because propane is very less expensive than propylene. In this method, propane is catalytically oxy-dehydrogenated to form a mixture of propylene and propane. Then the mixture of propylene and propane are used to produce crude acrylic acid by using the two stage propylene oxidation process as discussed above. (9) 6

2.5Acrylic acid from LacticAcid Acrylic acid can be produced by the vapour phase dehydration of lactic acid. This method of

production of acrylic acid is highly desirable as it is produced from a bioderivative, which is a renewable source of energy. Various catalysts like sodium dihydrogen phosphate (NaH 2PO4), silica/alumina, Ca3(PO4)2 supported onsilicaare used for dehydration of lactic acid. Calcium sulphate with cupric sulphate and phosphate are added as promoter and CO 2 as the carrier gas in order to increase the selectivity of acrylic aid to 60-70%. The reaction is carried out a temperature of 325400°C. When the reaction temperature increases from 325°C to 400°C, there is a drastic change in the conversion of lactic acid i.e. from 60% to 100%. (8) Lactic acid + NaH2PO4 Acrylic Acid

Chapter 3 Economical viability and Process Description 3.1 Analyzing the Economic Viability of the Processes In this section, we’ll discuss the economic viability of the processesthat were discussed in the previous section. Out of the three major processes discussed, we need to shortlist one by eliminating the rest. Process 5 is eliminated owing to the very high reaction temperatures (~400 oC), which leads 7 to high operation cost. Also, in this reaction, non-volatile oligomers of lactic acid are formed which poison the catalyst (11). Suppressing their formation requires high dilution rates thus this reaction is difficult to scale to industrial levels.Process 3 & 4 are essentially the same except for the way

propylene is obtained. Hence we use a common analysis for both. Here, we are assuming air to be used for the supply of oxygen. Thus, air being a cheap raw material; we are ignoring its cost in the calculation of our EP values(6). In process 1, selectivity (S) of acrylic acid is 95% and rest 5% is mainly acetol, which is a byproduct in this process, and for process 3, selectivity of acrylic acid is 60% and 40% is for the byproduct i.e. acetic acid (7).In process 2, the first step i.e. oxidation of ethylene is considered to be reversible process.The same has been included in EP calculation (5). We assume 100% overall conversion in each of these reactions. Cost of streams involved in each process is shown in Table 3.1(www.indiamart.com).

Raw Material (R1) Price/Kg Price/mol Raw Material (R2) Price/Kg Price/mol Product (P) Price/Kg Price/mol Byproduct (BP) Price/Kg Price/mol General Equation Economic Potential Viability

Process 1 Glycerol

Process 2 Ethylene

Process 3 & 4 Propylene

Rs. 70 Rs. 6.477

Rs. 52.75 Rs.1.884 Carbon Monoxide

Rs. 52.833 Rs. 2.222

Acrylic Acid Rs. 150 Rs. 10.815 Acetol Rs. 150 Rs. 11.1 S*P + (1-S)*BP–R1

Rs. 14.601 Rs. 0.41 Acrylic Acid Rs. 150 Rs. 10.815

P - R1 - R2

0.95*10.815 + 0.05*11.1 – 1*10.815 – 1*1.884- 1*0.41 1*6.477 = 4.352 = 8.521 Low High Table 3.1: Economic Analysis of all different processes

Acrylic Acid Rs. 150 Rs. 10.815 Acetic Acid Rs. 34 Rs. 2.04 S*P + (1-S)*BP – R1 0.6*10.815 + 0.4*2.04 – 1*2.222 = 5.083 Medium

From the Economic Potential (EP) values, it is clear that the process 1, that is, production of acrylic acid by sequential dehydration and oxidation of glycerol, is less viable as compared to the other options. So, it is less preferred due to its low viability. However, we need to conduct a more detailed analysis for choosing between Process 2 (acrylicacid production from ethylene)and Process 3 (acrylic acid production from propylene) since the EP values are almost same. For this, we need to focus on the ease of availability of the raw materials, which can be analyzed on the basis of the production rates of thesematerials. The ration of production rates of ethylene and propylene is almost same till 2006 but post that, the production rates of propylene began to fall down while that of ethylene began to shoot up. This can be attributed to the increasing availability of inexpensive shale gas-based ethane. 8 ethane came into existence, ethylene production is projected to Moreover, as new crackers for pure increase further while propylene production is projected to staylow.(10)

3.2 Process Flow Chart for production of acrylic acid fromethylene The detailed process flowchart is given in Figure 3.2.Stream 1 (ethylene) and stream 2 (air for oxygen)are mixed and heated to reaction temperature and pressure.The mixed stream is fed to microchannel reactor because of its advantages over tubular reactor. The advantages include the fact that it has a larger surface to volume ratio (S/V)which leads to an effective heat management and decreases downstream downstream volume and vessel sizing.Also, if an explosion occurs (due to high pressure) microchannels can withstand it easily. Since ethylene (Boiling Point - 103 oC) and ethylene oxide (Boiling Point 10.7oC) caneasilybe separated, we place a distillation column after first reactor only and send the recycle stream from top to the mixer. This is in accordance with the general heuristics for separation as addition of CO (Boiling Point -191.5 oC) to Reactor 2 (R-2) would have increased the separationcost for the two recycle streams (ethylene and CO). Distillate ethylene epoxide is then fed to a CSTR reactor (R-2) along with pure stream of Carbon Monoxide for effective mixing of CO. We use CSTR over tubular reactor because the liquid phase catalyzed reaction has higher yield in CSTR for first order reactions. The product stream from the reactor R-2 is fed todistillation column D-2that is kept at low pressure to maintain the reboiler temperature. β-propiolactane being the heavy key leaves asbottom product and unreacted CO and ethylene epoxide, which come out astop products are recycled back to the reactor R-2.β-propiolactanebeing toxic is not isolated and for that Reactor 2 is closely coupled with the Reactor 3, which is a packed bed reactor (R-3) where rearrangement reaction takes place in presence ofacid catalyst (phosphoric acid). Product stream is entirely in vapor phase which is then flashed to remove the liquid. Flashed liquid products are then recycled back to the reactor and the vapor of acrylic acid are then fed to the series of distillation column for the further purification.

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Figure 3.2Process flow chart for acrylic acid production

3.2.1 ProcessParameters

As concluded in the previous discussion, we’ll go ahead with production of acrylic acid from ethylene. This reaction takes place in three steps – oxidation, carbonylation and rearrangement. The C first step is oxidation of ethylene, first order reaction with reaction constant (k) at 250 oC is

k250oc=8.91 * 10-4 /sec and Ea = 52.129 kJ/mol 250 C (12). This can be used to calculate k value at any other temperature. Using Vant Hoff’s equation [ln (k 2/k1) = Ea/R * (1/T1-1/T2)], the value of k at 285oC is k285o = 1.89 * 10-3 /sec. Here, we assume the reaction to be reversible. The temperature is maintained at 250oC and pressure at 20 bar and per pass conversionat12%,whichlietowardsthelowerendofthe permissible limit even though the rate constant increases with temperature. Apart from the fact that it is easier and more viable to maintain lower temperature and pressure, this choice is also based on the observation that increasing temperature and per pass conversion leads to decreased selectivity. Thus, ethylene is recycled and ethylene oxide is separated to 99.5% purity to push the reaction in the forward direction. The reactor type and conditions for all the steps have been specified in the table below (6). Here, the rate expression is written in general form since values of other rate constants could not be found in literature

Reaction Oxidation Carbonylatio n Rearrangeme nt

Reactor Type Microchann el CSTR

Temperatur e 250°C

Pressur e 20 bar

Order of reaction First

Rate expression

175 oC

30 bar

Zero

k f[Ethylene] - kb[Ethylene Oxide] k’

Packed bed

170 oC

0.133 bar

First

k'’ [Propiolactone]

Table 3.2.1: Reactor Parameters(6)

The parameters for different streams 10 for the 3 reactors have been specified in Figure 3.2.1. This data is extracted from literature since conducting the experiment at such a large scale is outside the scope of this course. Figure 3.2.2. includes most of the parameters, which will be required while conducting mass and energy balance in Report 5. Any additional information that might be required will be

included later on with proper justification. (13) Stream Ethylene Oxygen Ethylene oxide + CO Propiolactone

Flow T P H Rate (oC (bar) (kJ/kg ) (kg/hr) ) 8126 67 20 1920 6699 67 20 38.5 6614 80 12 -2574

16918 37.7 0.13 -4556 3 Table 3.2.2: Flow rates Parameters(13)

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References [1] Acrylic Acid Production and ManufacturingProcess, November, 2007 [2] Establishment of Acrylic Acid manufacturing inIndia, Govt. of Gujarat, January, 2017 [3] Chemicals and Petrochemicals, Government ofGujarat, Jan, 2017 [4] Acrylic Acids manufacturers, suppliers and exporters: tradeIndia.com [5] Rong Liu, Tiefeng Wang; “Production of Acrylic Acid by Sequential Dehydration & Oxidation

of Glycerol”, May, 2014 [6] Patricia Campos, Minsik Jun; “Production of Acrylic Acid from Ethylene”, April,2014 [7] W.E. Campbell, E.L. Mc Daniel; “Oxidation of Propylene to Acrylic Acid”, April,1970 [8] Vidhya C. Ghantani; “Catalytic dehydration of lactic acid to acrylic acid using calcium

hydroxyapatite catalysts”, Feb, 2013 [9] Acrylic Acid Production by Propane Oxidation, IHS Markit,2003 [10] Jeffrey S. Plotkin, “The Propylene Gap: How can it be filled?”, September, 2015 [11] G. Terrade, Jan van Krieken, Bastiaan J. V. Verkuijl, and Elisabeth Bouwman, “Catalytic

Cracking of Lactide and Poly (Lactic Acid) to Acrylic Acid at Low Temperatures”, April,2017 [12] Robert E. Kenson and M. Lapki; “Kinetics and Mechanism of Ethylene Oxidation”, June,1969 [13] Erin W. Dunn, Jessica R Lamb, “Carbonylation of Ethylene Oxide to β- Propiolactone: A facile

route to Poly(3- Hydroxypropionate) and Acrylic acid”, Nov, 2016

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