Synthesis of Methyl Acetate through Esterification Plant Design

ECH 158C Design Project Final Report

TO: Jason White

FROM: Bryan Eglan, Daron Fong, Brett Koehn, and Simar Singh
DATE: May 27, 2016
SUBJECT: Revised Methyl Acetate Plant Design Report

    Attached to this memo is our final conceptual design and economic analysis for the methyl acetate plant project commissioned by Ester Chemicals Corporation (ECC). The purpose of this memo is to outline the revisions and improvements carried out on the previous design report. In the updated report, a distillation column previously used to separate the acetic acid and sulfuric acid in the bottoms of the first column has been removed, and the entire stream is now simply recycled back into the reactor as excess reactants and unconsumed catalyst, thus saving on capital and operating costs. The economic analysis was revised to include an higher, much more realistic capital cost, and a heat exchanger network was designed and analyzed to optimize utility savings. Lastly, improvements to the design report itself include the addition of an abstract, reorganization of tables to better fit the flow of the report, and inclusion of a derivation section discussing our calculation of the reaction kinetics (see Appendix).

    In this final report, the downstream separations train features four distillation columns, which are designed to yield the pure product along with purified excess reagents and unconsumed catalyst that can be recycled back into the reactor. The final figure for Fixed Capital Investment (FCI) including updated cost figures for distillation columns, heat exchangers, and an additional pump total to $18,790,224.78. Additionally, the inclusion of a heat exchanger network reduces utility costs to only $821,234.82
per year, compared with $4,328,802.82 per year in utility costs when not recycling heat using heat exchange. Factoring in all the costs of raw materials, labor, utilities, and other operational costs, the net yearly profit under this configuration will be $28,879,678.06, and the plant will have a net present worth of $145,131,801.10 under an interest rate of 10% and a timespan of 10 years. Lastly, the discounted cash flow rate of return (DCFROR) in the final design is  44.01%, with a before-tax return on investment of 154%.

The updated capital costs are calculated again using appropriate figures in Plant Design and Economics for Chemical Engineers, but a previous mistake in reading the figures was corrected, increasing our previous capital cost estimate to a more realistic number. The final TCI includes the updated cost of distillation columns at $611,922.72, an extra pump at $4,800, and the cost of heat exchangers in the new heat exchanger network at $319,340. Moreover, the distillation column and utility cost modification also accounts for one less distillation column, which previously separated acetic and sulfuric acid in the bottoms stream of the first column. Currently an ideal separator in Aspen is used as a placeholder to separate the sulfuric acid to prevent accumulation in the simulation, but in reality the stream including the catalyst will be recycled.  

Overall, due to the favorable financial values, this venture is deemed to be economically feasible. The considerations and decision points behind our design are included in the report and flowsheet, and we hope that the analysis is satisfactory and show the potential value in further pursuing this project. Let us know if you have any questions about the report.

Design & Economics Report for Methyl Acetate Production Facility

To: Mr. Jason White, Project Manager

Authors: Bryan Eglan, Daron Fong, Brett Koehn, Simar Singh

UC Davis, Chemical Engineering Department

Date Due: May 30, 2016

Table of Contents

---

1. Executive Memo
2. Report
1. Abstract
2. Introduction & Background
3. Discussion
1. Esterification Reactor
2. Product Separations and Recovery
3. Recycle Loop
4. Environmental Impact
5. Safety Considerations
4. Final Design
1. Process Flow Diagram
2. Process Equipment Descriptions
3. Material & Energy Balances
4. Utility Summary
5. Economic Analysis
1. Fixed Capital Investment (FCI) Summary
2. Cost & Economic Evaluation Summary
6. Conclusions & Recommendations
7. References
8. Appendix

Abstract

This report details the conceptual design and study-level economic feasibility analysis of a methyl acetate facility in Bangkok, Thailand, scaled to produce 200 million pounds of 99.5% weight purity product per year. The design features a tubular Plug-Flow reactor with a volume of 106.9 liters, four distillation columns, and a recycle loop for excess reactants along with heat exchange to recycle excess heat. The distillation columns are operated at various pressures (pressure swing) to break azeotropes existing for methyl acetate-methanol and methyl acetate - water mixtures, allowing the product to reach desired purity. Factoring in all the costs of raw materials, labor, utilities, and other operational costs, the net yearly profit under this configuration will be $28,879,678.06, and the plant will have a net present worth of $145,131,801.10
for an interest rate of 10% over a timespan of 10 years, and a discounted cash flow rate of return (DCFROR) of 44.01%. Additionally, the before-tax return on investment is 154%. These favorable economic figures suggest a profitable venture, and thus it is suggested that the plant project should continue to be pursued by Ester Chemicals Corporation.

Introduction & Background

Methyl acetate is a useful and valuable industrial product that can be used as a either a chemical intermediate in the manufacture of acetic anhydride or as a low toxicity solvent in glue, paint, and nail polish remover. Major consumers of methyl acetate include East and Southeast Asian countries, such as China and Thailand, as well as Western Europe and the United States, with Asian markets comprising more than a third of the world’s markets. Due to the large proportion of demand in Asian markets, which also show the largest growth in demand for methyl acetates of 4.4% per year, there are very good prospects for increasing methyl acetate production in Asia. [1] For this report, we have been commissioned by Ester Chemicals Corporation to explore the feasibility and engineering design considerations of building an industrial-scale methyl acetate facility in Bangkok, Thailand to meet this rise in demand.

    Methyl acetate is produced via the esterification reaction of methanol and acetic acid, and can be produced in a variety of reactor types. Because the reaction is an equilibrium reaction, the products must be continually separated away from the reactants to ensure higher conversion values. This design consideration results in certain reactor types such as the batch reactor being less useful, while continuous flow reactors such as Continuously-Stirred Tank Reactors (CSTRs), Plug-flow reactors (PFRs), and other specialty reactors are more appropriate and thus more heavily considered. The advantages of using the more commonly used CSTRs and PFRs is ease of availability and construction, and since they are universally used reactors they are well understood and can be easily modeled in process modeling software like Aspen [2].

A common method of production is use of reactive distillation, which integrates reaction and separations within the column and thus has the advantage of reduced capital costs [3]. Furthermore, the column can be operated as such to allow for a high purity product despite the presence of an azeotrope in methanol/methyl acetate mixtures by simply adding excess acetic acid reagent to react the majority of the methanol prior to the separations step.

Another process that is relevant to our discussion is the use of pervaporation membrane reactors (PVMRs) [4]. A particular benefit to this process is higher conversion of methyl acetate when compared to the reactive distillation, due to the continual removal of water via the permeable membrane. PVMRs can be designed with plug flow reactors, semi-batch reactors, or continuous-stirred reactors, which all are fitted with the permeable membranes. For PVMRs, the conversion is directly correlated to the Damkohler Number, or the ratio of conversion to transport. Similar to reactive distillation, the feed stream will have an excess of acetic acid; the reactants will permeate through the membrane, allowing for the reactants to be directly converted to methyl acetate and water in the reactor.

The design premises requested by Ester Chemicals Corporation are for a facility in Thailand producing 200 million pounds of methyl acetate per year at a weight purity of 99.5%, with 335 days comprising an operational year. To account for future interest and demand and allow for future expansion, the plant’s utility capacity will be oversized by 20%. The reactants to be used are liquid methanol and acetic acid stored at about 60°F and atmospheric pressure, with concentrated sulfuric acid as the inert catalyst. Furthermore, Ester Chemicals Corporation’s affiliate Just-in-Time Laboratories provided us with kinetics data on the esterification reaction in a CSTR; the availability of this data caused CSTR’s to be the natural and most convenient initial choice of reactor.

Ultimately, a tubular plug flow reactor was chosen to maximize conversion over a CSTR while still allowing use of the kinetics data provided by Just-in-Time Labs. Subsequent steps in the process include separations of the water and methyl acetate products along with excess reactants, recycling of excess reactants, and recovery of the final 99.5% pure methyl acetate.

Design Considerations

    Our proposed design consists of a tubular plug-flow reactor with separate input streams for each of the reactants. The PFR was chosen due to the reduced equipment cost in comparison to a Continuously-Stirred Tank Reactor (CSTR) for a similar conversion and product flow rate. Additionally, the multi-tube reactor adds the advantage of increased surface area for heat exchange, as the exothermic reaction will necessitate cooling of the reactor to ensure high conversion.

To size our reactors, the kinetics of the esterification reaction were first replicated based on the 1-liter CSTR experimental reaction data given by Just-in-Time Labs, which analyzed the reaction when catalyzed by 1 pound of sulfuric acid catalyst per 100 pounds acetic acid. The equilibrium reaction rate laws were determined using the flow rate data, and then the activation energy and pre-exponential constants were determined through equilibrium analysis by utilizing a power law model to represent the reaction kinetics (See Appendix Sample Calculations). Upon validating our kinetics in Aspen Plus for a 1-liter CSTR, the design product flow rate of 200 million pounds per year was used to back-calculate the necessary CSTR volume of approximately 25,000 liters. However, based on theoretical volume trends in a Levenspiel plot for our reaction (see Figure A-2, Appendix), it was concluded that total reactor volume and residence time could be reduced by adding CSTRs in series. This trend continues indefinitely for infinite CSTRs in series, upon which the reactor is now able to be modeled as a tubular PFR - thus resulting in the selection of a PFR as the most compact and cost-efficient reactor for our plant.

Based on Just-in-Time’s reaction data at various temperatures and pressures for a 1-liter CSTR, it was observed that higher temperatures and pressure are advantageous for achieving higher conversions, and thus our reactor will operate at the max safe allowable temperature of 300°F and a pressure of 150 psia, keeping the reaction in the liquid phase. A co-current stream of water at 85°F and 65 psig is used to cool the PFR, allowing for small temperature fluctuations from 296°F to 300°F. Using a process control scheme that increases the cooling water flow rate when temperatures increase, the run-away reaction can be prevented. The reactant feed streams are pumped in from their respective storage containers at 60°F and 14.7 psia, and then preheated to the reactor operating condition of 300°F in heaters. The methanol and acetic acid will be preheated in separate heaters to avoid premature reaction, and the concentrated sulfuric acid catalyst can be combined with the acetic acid stream to be heated as well. Due to the high viscosity of concentrated sulfuric acid, a positive displacement pump will be used for the catalyst, while the other two reagents may be pumped in using a standard centrifugal pumps.

Figure 2: Process flow diagram of upstream processing steps, including storage pumps, pre-heating, mixing, and reaction in the PFR.

    Upon completion of the reaction, which is designed to reach a conversion of 67.5%  in the PFR, the components must then be separated to collect our product. A significant design challenge presented by our product mixture, which contains excess acetic acid, methanol, unreacted methyl acetate, along with our products of water and methyl acetate, is the presence of two azeotropes [5]. Importantly, methyl acetate and methanol form an azeotrope at 81.3% by weight methyl acetate at atmospheric pressure, and methyl acetate also forms an azeotrope with water at 95% methyl acetate and atmospheric pressure. This makes it impossible to purify our product to the desired 99.5% purity when simply distilling at atmospheric pressure.

To solve this problem, our conceptual design features five distillation columns operating at varying pressures (pressure swing distillation) which feature recycle loops to maximize the purity and recovery of our product. The first column will separate out the highest boiling point components of sulfuric acid and acetic acid to the bottoms, while the water, methanol, and methyl acetate will move onto the next column. This first column is operated at atmospheric pressure and 245°F; the bottoms stream is then separated in another column at atmospheric pressure and 138 °F into sulfuric acid and acetic acid for recycling purposes.

Figure 3. Process flow diagram for the separations into purified methyl acetate product, recycle streams, and waste.

To purify past the azeotropes, the distillate from column 1 is distilled in a second column at 2 pounds per square inch (less than one-seventh of atmospheric pressure, 14.7 psia). The bottoms stream of this column is fed into a separate column to purify the methanol for recycling, while the distillate containing the methyl acetate is purified at 400 psia to our desired purity in the final column. The varying pressures shifts the azeotrope composition and allows us to reach the final product purity of 99.5% methyl acetate, which is then collected.

    This design includes an auxiliary distillation column beneath column 2 along with the recycled bottoms of column 1, allowing our plant to purify and recycle the excess methanol and acetic acid to save a significant portion of raw material costs, as the recycle streams allow us to save up to 40,813,192 and 83,404,419 pounds of methanol and acetic acid respectively. These streams are simply fed into the mixer prior to the PFR along with the fresh reactants. An ideal separator is used in Aspen to model the recycling of acetic acid and the sulfuric acid catalyst due to input requirements, but is not necessary in physical design.

    This inclusion of a recycle loop is an improvement over our alternative design, which originally did not recycle excess reactants and simply dumped excess reactants and wastewater alike. This original design had the benefits of simpler configuration and less operating costs without the need for the two additional distillation columns; however, upon performing calculations of additional operating cost versus raw material conservation, it was determined that the recycle loop would save as much as $44,475,720 per year. The methanol and acetic acid feed flow rates are decreased to 86,599,644 and 178,544,280 lb/year respectively. Thus, it is evident that the more advantageous design in terms of economics will include the recycle loop, and the final design is shown in our flowsheet in Figure A-1 in the appendix.

Environmental & Safety Considerations

In terms of environmental impact, the production of methyl acetate is considered reasonably safe. Research on the effects of methyl acetate on aquatic life has shown that after 72 hours of exposure, no complications could be observed in algae or various species of fish [6]. Moreover, although there is no data available for exposure impact on terrestrial organisms, approximating the exposure to soil in low concentrations has no effect on wildlife, equating to no risk of bioaccumulation through the food chain. Methyl acetate also has an atmospheric half life of approximately 74-94 days, and thus not expected to contribute to global warming or ozone depletion. Acetic acid and methyl acetate both decompose very quickly in the environment, and thus trace amounts left in wastewater streams can be assumed to have negligible risk in damaging wildlife or ecosystems.

As for the waste management strategy, our plant will utilize a third-party waste disposal service. Due to the relatively non-toxic nature of the waste, which contains mainly excess acetic acid, water, and trace amounts of methanol and methyl acetate, this waste will have negligible impact on the environment and will cost only $3 per 1000 gallons to dispose of. Additionally, the waste stream is designed to exit the bottoms at 126°F; this can be further cooled to 105°F via cooling water to make it safer to dispose.

The product specifications will necessitate the use of pressure swing distillation and a high pressure reactor, and thus vessels with operating pressures well above atmospheric will be designed under safety guidelines dictated by ASME’s Boiler and Pressure Vessel Code. The pressure code applies to any vessel above 6 inches in diameter and operating above 15 psig, which applies to many of the vessels in our design. To follow the code regulations, these vessels will be designed with minimum wall thicknesses relative to diameter and operating pressure as dictated by the Pressure Code guidelines.  

Plant operation necessitates proper instruction and handling and easy access to Materials Safety Data Sheets for all reactants. In the case of skin exposure, methyl acetate can be thoroughly washed off with soap and water, while flushing of the eyes is needed for eye exposure [7]. If inhaled, exposure can be treated with proper ventilation followed by immediate medical attention. Plant operators must wear protective clothing and eyewear to reduce the risk of exposure. Methyl acetate is highly flammable and must be kept away from open flames and heat sources, preferably stored in a refrigerated room. The proper care should be taken to ensure no human injury or accidents will happen in the plant.

Final Design

Process Flow Diagram

    Figure A-1  in the appendix depicts the finalized process flow diagram for the production of methyl acetate via esterification of methanol in acetic acid. The operating temperatures and pressures for the equipment is listed in Table 6 in the appendix. The mass flow rates and compositions of the major streams are summarized in Table 7.

Equipment Tables

    A summary of the necessary equipment along with piping is summarized in Table 1, which includes the cost. Physical specifications for the dimensions of the distillation columns are shown in Table 8.

Material and Energy Balances

    The total mass of material entering the plant is 33,200 lb/hr, and the total mass exiting is 32,978 lb/hr. The percent difference between the mass flows is 0.06%, where slight deviations occur due to mathematical rounding in Aspen Plus. A proposed heat exchanger network is shown in Table 9, containing the heat duty of each stream. This network uses excess heat from various vessels to heat other streams, reducing utility costs by conserving energy. In addition the heaters are operated through electricity while the distillation column reboilers are heated using natural gas. Lastly, the condensers are cooled with cooling water at 85°F or with Freon that is cooled using a vapor compression refrigeration cycle.  

Economic Analysis

    The first economic calculations we completed were the inside battery limits (ISBL). The ISBL includes all of the equipment in our plant such as heaters, pumps, distillation columns and reactors. The cost of this equipment was approximated in Plant Design and Economics for Chemical Engineers, and then the prices were updated from 2002 to current year estimations by using a CE index [8][9]. The PFR can be modeled as a heat exchanger for price calculations; for a ten-tube, 10.69 liter per tube carbon-steel PFR, the capital cost is approximated using cost estimation curves, totaling to $68,660. We found that the four centrifugal pumps (including the extra pump) will cost about $4,800 each, while the positive displacement pump will cost about $725. These values were found from Figures 12-20 and Figure 12-22 respectively. The prices of the heat exchangers ranged from $183,060 to $1450. These costs were determined using the appropriate curves for heat elements and figure 14-16. The prices of the distillation columns were found to be $132,641.86, $329,814, $88,302.33, $61,165.72, and $15,500. The cost of all these pieces equipment was summed up to give an ISBL of $875,864.57. Next the startup, spare parts, service facilities and buildings, waste treatment capital, and site development were calculated as 5%, 1%, 25%, 6%, and 4% of the ISBL respectively. The outside battery limits (OSBL) were calculated by summing the auxiliary equipments, utility, and storage costs. The cost of storage tanks are estimated to be $228,830, $305,010, $30,511, and $122,000 for methanol, acetic acid, sulfuric acid, and methyl acetate respectively. The OSBL was found to be $3,924,080. The fixed capital investment or FCI was found to be $4,799,944.39 by summing the ISBL and OSBL. The maintenance materials, operating supplies, taxes, and insurance were calculated as 2.5%, .6%, and 2% of the FCI. Table 1 depicts a summary of the discussed economics.

Table 1 : Capital Investment Costs for Equipment

Equipment	Cost ($)
Positive Displacement Pump 1	4,800
Positive Displacement Pump 2	4,800
Positive Displacement Pump 3	4,800
Extra Positive Displacement Pump	4,800
Centrifugal Pump	725
Heat Exchanger 1	22,880
Heat Exchanger 2	45,770
Heat Exchanger 3	7,630
Heat Exchanger 4	23,000
Heat Exchanger 5	183,060
Heat Exchanger 6	1,530
Heat Exchanger 7	13,730
Heat Exchanger 8	1,220
Heat Exchanger 9	3,510
Heat Exchanger 10	1,450
Heat Exchanger 11	10,680
Heat Exchanger 12	2,290
Heat Exchanger 13	2,590
Methanol Storage Tank	228,830
Acetic Acid Storage Tank	305,010
Sulfuric Acid Storage Tank	30,511
Methyl Acetate Storage Tank	122,000
PFR	68,660
Distillation Column 1	132,641.86
Distillation Column 2	329,814
Distillation Column 3	88,302.33
Distillation Column 4	61,165.72
Total Bare Module	10,337,266.29
Site Preparation	34,847.58
Service Facilities	740,511.14
Waste Treatment	52,527.37
Direct Permanent Investment	11,164,896.39
Contingency	3,349,468.92
Total Depreciable Capital	14,514,365.30
Start Up	43,559.48
Working Capital	4,232,300
Total Capital Investment	18,790,224.78
Piping	765,244.64

    The total bare module investment (TBM) was found by adding the cost of all equipment, totalling to $10,337,266.29. The direct permanent investment (DPI) was determined by summing the TBM, site preparation, and service facilities, which resulted in a value of $11,164,896.39. The total depreciable capital (TDC) was found by adding a contingency of 30% to the DPI, totaling to $3,349,468.92. The working capital (WC) was found by adding the cost of spare parts, 30 days of manufacturing, and half the cost of storage. The total capital investment (TCI) was found by adding the TDC, startup cost, and WC, which gave us a value of $18,790,224.78.

    The utility cost per year was $789,200. An important reduction in utility cost results from the inclusion of the heat exchanger network, which saves up to $3,039,700 per year when compared with a design without heat exchange. Moreover, the any heat duty that is not satisfied by heat exchange is satisfied using a combination of steam, electric heaters, cooling water, and Freon refrigerant, yielding a remaining utility cost of $32,034 per year. The pumps and heater are powered by electricity at a price of $0.1/kWH. The distillation column reboilers are powered by natural gas, which is supplied at $5 / million BTU. The distillation column condensers are cooled using 81,867 mol/hr cooling water, supplied at 65 degrees Fahrenheit and 85 psia.  A breakdown of these energy requirements can be seen in Table 2. The material cost per year was $77,537,838. A breakdown of these material requirements can be seen in Table 3. The labor cost per year was $305,760. The cost of supervision and laboratory were calculated as 20% and 15% of labor cost, which was $56,280/yr and $42,210/yr respectively.

Table 2: Energy Costs

Equipment	Cost ($/yr)
Positive Displacement Pump 1	4,785
Positive Displacement Pump 2	6,363
Positive Displacement Pump 3	20,829
Centrifugal Pump	57.82
HEN Utilities	789,200

Table 3: Material Costs

Material	Amount (lb/yr)	Cost ($/yr)
Methanol	150,847,820	9,050,869
Acetic Acid	310,993,410	68,418,550
Sulfuric Acid	3,109,934	68,419

Table 4: Operating Costs

Operation	Cost ($/yr)
Operating Labor	305,760
Supervision	56,280
Laboratory	42,210
Maintenance Labor	88,295.15
Operating Supplies	35,318.06
Plant Overhead	295,527.09
Taxes and Insurance	117.726.87
General Expenses	2,200,000
Maintenance Materials	147,158.58

The before-tax return on investment was calculated as annual earnings divided by total capital investment, and yielded a value of 154%. This value may be a higher-end estimate, due to our use of more cost effective capital values based on cost tables in Peters, Timmerhaus and West; thus with more precise capital cost estimates, this figure will most likely drop somewhat; but the value represents a very positive return on investment which bodes well economically. Moreover, the net present worth of the project was calculated to be $145,131,801.10 over the given project life of 10 years, and the Discounted Cash Flow Rate of Return (DCFROR) is 44.01%. This net present worth represents the sum of all future incoming and outgoing cash flows, and as it is a net positive number it represents the overall profitability. The DCFROR also values the project while accounting for the time value of money. Both of these figures show that the venture is very profitable, and make it a very attractive project to continue pursuing.

Figure 4: Economic sensitivity analysis graph; the trendline shows the net present value as a function of the price of methyl acetate, displaying the feasibility of the project at various potential methyl acetate prices should the price fluctuate unexpectedly.

A sensitivity analysis was performed to determine the profitability of producing methyl acetate for a given sale price. Figure 4 assumes constant sale values over a 10 year period, showing that methyl acetate production yields a profit for prices ranging from $0.55 / lb to $0.45 / lb. Despite the slight price fluctuations that may occur, the profitability is stable, and does not affect the viability of pursuing the project.

Conclusions and Recommendations

    Overall, for a project life of 10 years, the Bangkok methyl acetate plant will yield a before tax return on investment (ROI) of 154%, a discounted cash flow rate of return of 44.01%, and a net present value of $148,115,290.95  at a minimum acceptable rate of return of 15%. Due to the favorable economic outlook of these numbers, along with the economic stability of production, it is highly advisable to move forward with the project with the current design.

References

[1]. SRI International. Chemical Industries Newsletter (Mar. 2010): IHS Chemical. Web.

6 Apr. 2016. <https://chemical.ihs.com/nl/Public/2010/1003/1003.html>.

[2]. Tramper, J. (1982, May). Optimal design for continuous stirred tank reactors in

series using Michaelis–Menten kinetics. Retrieved May 09, 2016, from

http://onlinelibrary.wiley.com/doi/10.1002/bit.260240518/full

[3]. Huss, Robert S. "Reactive Distillation for Methyl Acetate Production." Reactive

Distillation for Methyl Acetate Production. Elsevier, Dec. 2003. Web. 07 Apr.

2016.

[4]. Assabumrungrat, Suttichai, and Jitkarun Phongpatthanapanich. "Theoretical Study

on the Synthesis of Methyl Acetate from Methanol and Acetic Acid in

Pervaporation Membrane Reactors: Effect of Continuous-flow Modes." Science

Direct (n.d.): n. pag. Print.

[5]. Berg, L. (1985, September 24). Patent US4543164 - Separation of methyl acetate

from methanol by extractive distillation. Retrieved May 09, 2016, from

http://www.google.com/patents/US4543164

[6]. Institute for Health and Consumer Protection. "Methyl Acetate Summary Risk

Assessment Report." European Chemicals Agency. European Union, 2003. Web. 6 Apr. 2016. <http://echa.europa.eu/documents/10162/45a7eb23-6024-4dee-bdf2-369c83b636df>.

[7]. Methyl Acetate; MSDS No. Q007 [Online]; Mallenckrodt Baker: Phillipsburg, NJ, Apr

30, 2014. http://jtbaker.com/Documents/MSDS/USA/SAP/00004374.PDF

[8] "Chapter 7 Capital Cost Estimation." Chapter 7 Capital Cost Estimation. NMSU

Chemical Engineering, 5 Feb. 2012. Web. 19 Apr. 2016.

<http://www.slideshare.net/jose2424/chapter-7-capital-cost-estimation>.

[9] "CEPCI 2015." Scribd. N.p., n.d. Web. 19 Apr. 2016.

<https://www.scribd.com/doc/277921333/CEPCI-2015>.

[10]. Ahmad, A. A. (2014). ERT 316: REACTION ENGINEERING CHAPTER 2

CONVERSION & REACTOR SIZING Lecturer: Miss Anis Atikah Ahmad Email:

Anisatikah@unimap.edu.myanisatikah@unimap. Retrieved May 09, 2016, from

http://slideplayer.com/slide/3422171/

Appendix

Figure A-1: Complete flowsheet and conceptual design of our upstream and downstream processing steps. The left side includes the upstream storage pumps and reaction train, while the right side contains the separations train and the recycle loop. The final product exits in the PRODUCT stream, while the WASTE stream contains waste and CATREC contains the sulfuric acid catalyst which can be fed back into the reactor or sold.

Sample Calculations

Kinetics Scale-up (see attached MATLAB code for full calculations):

    The scale up calculations start with the design equation for a CSTR, shown below:

FA0X = -rAVCSTR        (Equation 1)

Given the flow rate data (FA0) and conversion  (X) for the trial reactions in Just-in-Time Labs’ reaction data in a 1-liter CSTR, we are able to calculate the reaction rate (-rA) or consumption of the limiting reactant. The rate constant for Trials 2 and 3 is then calculated as follows:

k = -rAcAcB - 1KcCcD            (Equation 2)

Then, using the experimental rate constants k for Trials 2 and 3, the activation energy and exponential prefactor are determined using the following equation:

            k1 k2=A1A2exp(-ERT1+-ERT2)           (Equation 3)

Knowing A and E allows us to calculate a new rate constant k for any temperature, and thus extrapolate the rate of reaction -rA for different reaction temperatures.

Table 6: Distillation Column Specifications

Column Number	Distillate Flow Rate (mol/hr)	Bottoms Flow Rate (mol/hr)	Tray Diameter (ft)	Total Number of Trays	Length of Column (ft)
1	389964.978	79872.345	10.17	25	50
2	236452.453	238351.67	13.78	25	50
3	84839.1449	151613.321	5.09	25	50
4	71743.8526	166607.817	5.52	25	50

Table 7: Stream Specifications

Stream	Flow Rate (mol/hr)	Composition	Temperature (F)	Pressure (psia)
ACOH	22207	Pure Acetic Acid	60	14.7
METHANOL	10771.7	Pure Methanol	60	14.7
H2SO4	221.781	Pure Acetic Acid	60	14.7
MIX	48464.5	52% Acetic Acid 47% Methanol	300	150
PFRPROD	48464.5	20% Acetic Acid 15% Methanol 32% Methyl Acetate 32% Water	300	14.7
DIST2FD	37890.27	4% Acetic Acid 18% Methanol 39% Methyl Acetate 39% Water	137.973	14.7
PSWING	34766.56	17% Methanol 83% Acetic Acid	47.3866	2
PRODUCT	24654.14	99.7% Methyl Acetate	390.206	400
BOTTOMS 1	10574.24	98.7% Acetic Acid 1.3% Sulfuric Acid	244.429	14.7
BOTTOMS 2	13236.13	6% Acetic Acid 30% Methanol 1% Methyl Acetate 63% Water	90.5492	2
WASTE	8059.829	9% Acetic Acid 1% Methanol 90% Water	124.857	2
CATREC	1025	99.8% Sulfuric Acid	244.431	14.7
DISTREC	10112.41	47% Methanol 53% Methyl Acetate	346.815	400
MEOHREC	5716.303	99.8% Methanol	68.0741	2
ACREC	77872.35	99.8% Acetic Acid	244.429	14.7
MIXREC	15484.76	52% Acetic Acid 47% Methanol 1% Sulfuric Acid	300	14.7
PFRCOOL	3251.5	Pure Water	85	60
PFROUT	300	Pure Water	300	60

Table 8: Operating Temperatures and Pressures

Equipment	Operating Pressure (psia)	Operating Temperature (degrees F)
Pump (MeOH)	150	61.7696
Pump(AcOH)	150	61.9312
Pump( H2SO4)	150	62.715
Heater 1	150	300
Heater 2	150	300
Heater 3	150	300
PFR	150	300
Distillation Column 1 Reboiler	14.7	245.595
Distillation Column 1 Condenser	14.7	138.074
Distillation Column 2 Reboiler	2	93.9953
Distillation Column 2 Condenser	2	47.2547
Distillation Column 3 Reboiler	400	389.524
Distillation Column 3 Condenser	400	345.537
Distillation Column 4 Reboiler	14.7	348.454
Distillation Column 4 Condenser	14.7	244.43
Distillation Column 5 Condenser	2	70.3706
Distillation Column 5 Reboiler	2	126.611

Table 9 : Heat Exchange Network