Process Simulation ReportAnojan Sriskandarajah

Table of Contents

2

Summary

The purpose of this report is to detail a well-run simulation of the conversion of Toluene to Benzene (Toluene Hydrodealkylation) using software called ASPEN Plus, Processing Model V8.6. In addition to this, the report outlines all the reasoning’s to determine whether or not a Toluene Hydrodealkylation plant should be built or not.The document is split into two main sections, as the process is very complex. The first part of the process explains how Toluene is recovered via the reactor; using the design specifications listed, as shown in Appendix A. The second part will model the full process, as shown in Appendix B, using some of the results of part 1 to calculate certain stream and block inputs, and also to provide initial guesses for the full process. Once all the results are compiled from both parts then it is possible to evaluate the process efficiency, the composition of all the product streams and their potential values, the process energy requirements and economic feasibility of the process. (Wang, n.d.)

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Introduction

Toluene (C7H8) is clear, flammable, colourless liquid that has a sweet pungent aroma; it is found to naturally occur in crude oil and is a volatile organic compound (VOC). (U.S. National Library of Medicine, 2015) In industry, Toluene is used as a solvent and added to increase the octane number in gasoline, paint thinners, medicines, dyes, as antifreeze and used in the production of benzene. (United States Environmental Protection Agency, 2016) In the past, especially during World War 2, it was used to make explosives, TNT (Trinitrotoluene). After the war, when TNT was less in demand, it became favourable to convert large quantities of toluene to benzene for use in the manufacture of cyclohexane, a precursor of nylon; chemical used to make plastics and synthetic fibres. (Wang, n.d.)

Chemical reactions involved

The initial reaction that occurs is the thermal conversion of Toluene (C7H8) to Benzene (C6H6) as shown in figure 1. The reaction takes place in the Hydrodealkylation Reactor.

C7H8 + H2 → C6H6 + CH4 (1)

An unavoidable side reaction that occurs in series that produces biphenyl, as seen in figure 2:

2C6H6 → C12H10 + H2 (2)

Conversion of Toluene in the reactor is 75 mol%, with 2 mol% of the benzene present in the initial reaction occurs being converted to biphenyl. This suggests that the reactions have to be specified ‘as in series’. Excess of H2 is supplied to the reactor to ensure the prevention of carbon deposition from occurring and absorb much of the heat of the exothermic Hydrodealkylation reaction. (Wang, n.d.)In addition to this, a purge stream is setup to avoid an expensive separation of methane and hydrogen. The product passes through the flash separator at a temperature of 38oC and a pressure of 33 bars, where it is then sent to a three-column distillation train. It is here where the CH4, H2, C12H10 and C6H6 are recovered and C7H8 is recycled. (Wang, n.d.)

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Part One – Hydrodealkylation Reactor

This part of the process required two design specifications, which are listed below. These specifications were needed to ensure the simulation ran successfully with no errors or warnings. There are two main product streams, the vapour product stream and the liquid product stream. Both of these streams contain:

CH4 – Methane H2 – Hydrogen C12H10 – Biphenyl

C6H6 – Benzene C7H8 – Toluene

Please refer to Appendix A for further detail of the process flow diagram showing this.

Design Specifications (DS)

Labelled as DS-1: The flow rate of the water outlet has a temperature of 50oC and the final cooler prior to the flash separator uses cooling water at 30oC and 3 bar. This is to ensure the regulation of inlet cooling water flow rate is equal to the outlet cooling water.

Labelled as DS-2: Part of the liquid from the flash separator is to be recycled to quench the reactor effluent (vent) to 620oC. The 620oC is used in the controlled regulation of the recycle to quench the flash separator needs to vary the proportion (split fraction) of liquid taken at the splitter for recycle.

Assumptions based on Design Specifications

When conducting this process there are two main issues that arise in part one. The first issue being the unknown value for the split fraction of the splitter (SPLIT) for the stream leaving the mixer (MIXER2) to the heat exchanger (HEATEXC1) at 620oC and secondly, the mass flow rate of the cooling stream for the heat exchanger (HEATEXC2); an input that is normally expected by ASPEN, however, it is an unknown that needs to be determined in the simulation.

Design specifications are needed to allow ASPEN to iteratively assume different values for the unknown variables of the input stream and block. By systematically adjusting an assumed value for the missing input variable, the design specification option fulfils ASPEN's request for a complete set of input data whilst allowing the simulation meet the convergence criterion to produce the desired results.

For example, in DS-1, the cooling water flow-rate entering was assumed to be 20,000 kmol/hr and the cooling water exiting the heat exchanger, had a temperature of 50oC and a tolerance of 0.01. The flow-rates were manipulated from the lower limit and upper limit range of 0 and 50,000. When the simulation ran, it was found that the results of the flow-rates of the cooling water entering into the heat exchanger and cooling water exiting out of the heat exchanger was 12,191.3 kmol/hr.

In DS-2, the split fraction leaving the splitter (SPLIT) as a liquid product was assumed to be 0.5 for stream 6; as two streams exit from the splitter. In addition to this, another assumption was made that stream 10 had a temperature of 620oC with a relevant tolerance of 0.001 – the manipulated lower and

5

upper limits were set between a value from 0 and 1.

Appendix C: Design Specification Results – Table 1

Design Specification 1 (Heat Exchanger 2)This was set up to ensure that the cooling water inlet flow had a temperature and pressure of 300C and 3 bar, was equal to the cooling water out stream flow at 50oC.The heat exchanger (HEATEX2) has an outlet pressure drop of 0.4bar with a constant U of 280W/m2K and the actual flow rate of the cooling water is shown in table 2. A design specification was not essentially needed for this section, if you had stated the cooling water as a utility in the heat exchanger (HEATEX2), then this would have regulated the water flow rates by specifying the parameter as cooling water.

Design Specification 2 (Splitter)To ensure that the temperature of the recycle from the flash separator to the quench (S10) is maintained at 620oC, the split fraction from the ‘SPLIT’ had to be altered to meet this criterion. The initial guess for the ‘SPLIT’ was 0.5, which would mean that the stream entering the pump would have 50% of the liquid leaving as recycle stream and 50% leaving as liquid product stream. As stated earlier the range varies from 0-1 and has a tolerance of 0.0001. From the results in table one, it is noted that the initial value for the split fraction in ‘SPLIT’ is 0.299514823 and that the final value for the ‘SPLIT’ is 0.299514823. Therefore, the split fraction for the liquid product can be calculated to be (1- 0.299514823) = 0.700485177, this value is then calculated by ASPEN and then inputted into the split for the LIQPROD stream.

VARIABLE INITIAL VALUE FINAL VALUE UNITS

DS-1 Manipulated 12191.262 12191.262 kmol/hr

COOLOUT 49.995144 49.995144 °C

DS-2 Manipulated 0.299514823 0.299514823 -

Quench (S10) 620.000234 620.000234 °C

6

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Appendix D: Stream Results Summary – Table 2

LIQUPROD VAPPROD COOLIN COOLOUT

Temperature (°C) 38 38 30 50

Pressure (bar) 33 33 3 3

Vapor Frac 0 1 0 0

Mole Flow (kmol/hr) 170.654 2092.146 12191.262 12191.262

Mass Flow (kg/hr) 13431.516 24575.253 219628.999 219628.999

Volume Flow (cum/hr) 16.006 1626.998 222.045 226.536

Enthalpy (Gcal/hr) 1.498 -23.739 -840.376 -835.312

Mole Flow (kmol/hr)

Methane (CH4) 8.396809 1357.678 - -

Hydrogen (H2) 0.5111025 717.5026 - -

Benzene (C6H6) 120.7553 15.34222 - -

Toluene (C7H8) 39.60259 1.622409 - -

Biphenyl (C12H10) 1.388607 0.000142666 - -

Water (H2O) - - 12191.3 12191.3

Viewing the stream results summary labelled as table 2, the main product streams are said to be the vapour product and liquid product. This is because we are viewing the streams that produce the desired products and that continue on in the process. Both the liquid and vapour product streams have the same temperature and pressure, 38oC and 33bar respectively, but they differ with their mass and molar flow rate. The vapour product stream has a higher molar flow rate and mass flow rate compared to the liquid product. In addition to this, the efficiency of this process can be calculated by using the worked flow rates:[(Product flow rate of LIQPROD stream) / (Feed flow rate of TOLFEED)] x 100=[39.60259/124.40) x 100 = 31.83487942%Therefore, the amount of Toluene used in the process is 100 – 31.83487942 = 68.16512058%The percentage calculated is reasonable, as the toluene conversion factor was set to 75%, as stated in the specification, therefore it can be said that the process efficiency of the Toluene conversion is 90.88682744% accurate.

Calculating Split Ratio

To calculate the ratio split of the component for the vapour stream (VAPPROD) and liquid stream (LIQPROD), both streams need to be taken into consideration. The formula is shown below.

Benzene (C6H6)

= 0.127052146

The vapour product stream consists of 0.127052146 compared to the liquid product meaning that there is a larger composition on Benzene in present in the liquid product stream.

= 0.733324539%

Appendix E: Ratio and Percentage Compositions – Table 3

Components RATIO

VAPOUR : LIQUID

% IN VAPOUR PRODUCT STREAM

% IN LIQUID PRODUCT STREAM

Methane (CH4) 161.6898:1 64.89403703 4.920370457

Hydrogen (H2) 1403.833:1 34.29505398 0.299496349

Benzene (C6H6) 0.127052:1 0.733324539 70.76031034

Toluene ( C7H8) 0.040967:1 0.077547599 23.20636493

Biphenyl (C12H10) 0.000103:1 6.81912x10-6 0.813697306

Water (H2O) - - -

From the table of results, it is evident that the liquid stream produces a higher amount of Benzene and Toluene than the vapour stream. In contrast, to this the vapour stream has a higher amount of methane and hydrogen present in the liquid stream.

Example Calculation of how ratio is derived for Methane (CH4) by using Appendix D information: CH4: The fractional distribution between the vapour product stream and liquid product stream is 1357.678/8.396809=161.6898:1; relative percentage of component in the stream is calculated by dividing the molar flow of the component with the overall mole flow of the stream: (1357.678/2092.146)*100=64.89403703% in VAPPROD stream.

Calculating the Process efficiency

As stated in the reaction, C7H8 + H2 → C6H6 + CH4, the molar reaction stoichiometry is in a ratio of 1:1. Knowing this we can calculate the process efficiency, as stated below:

The is a value of Toluene that hasn’t reacted in the process, if you subtract this value

from 100% we can determine the percentage of Toluene that has reacted, which is 68.16512058%. Given that the conversion factor was 75% for this part of the process for the reaction in the reactor, an overall process efficiency can be calculated by dividing it by 75.

Part Two – Complete Process

In this section of the report, we look at part 2 which overlooks the whole process of Toluene Hydrodealkylation; the process includes three distillation columns, a pump, a splitter, a mixer and a compressor. In the full process, the liquid product stream (LIQPROD) that exits the splitter (SPLIT) is connected to the train of distillation columns. The second splitter (SPLIT2) that was originally connected to the vapour product stream is now used to split the vapour product leaving the flash separator (FLASHSEP); it is split into two different streams, one stream that leaves the system as a purge stream (PURGE) and the other stream (S11) re-entering into the mixer (MIXER3).In addition to the changes above, there is also another change with the liquid product stream (LIQPORD). This passes into the first distillation column (COLUMN1), where the fuel is removed at the top and the bottom product of (COLUMN1) passes into (COLUMN2). In the second distillation column, the component is separated again into two streams where the top distillate is Benzene and the bottom stream enters the third and final distillation column (COLUMN3); where Biphenyl is the major component in the bottom product and the top product is recycled back towards the feed input. Some of the results from part 1 were used as inputs for the full process in part 2.

Calculating the ‘Split Fraction’ for Purge and Stream 11

Molar flow rate of CH4 from the gas recycle feed from part one = 1242.4 kmol/hrMolar flow rate of CH4 from the vapour product stream from part one= 1357.324 kmol/hrUsing both these flow rates we can substitute these values into the equation, therefore we get:

= 0.91533 (5dp)

= 0.08467 (5dp)

The values above determine how much of the vapour product coming out of the flash separator is passed into the gas recycle and purge streams; 91.5% of the vapour product stream (VAPPROD) is sent to gas recycle and the remaining 8.5% is sent to the purge stream.

Calculating the Hydrogen feed need to enter the mixer

H2 molar flow rate in stream 11 (part 2) can be calculated by the H2 molar flow rate in vapour product stream in (part 1) x the Split Fraction of stream 11; as shown numerically below.

Appendix F: Product Streams Results – Table 4

PURGE COLUMN1 FUEL

COLUMN2 BENZENE

COLUMN 3 BIPHENYL

Stream 16 Stream 11 Gas Recycle

Temperature (°C)

37.99979 63.18679 92.65541 200.3847 122.7559 37.99979 56.46116

Pressure (bar) 33 7.3 1.5 1.4 1.4 33 39.2

Vapor Frac 1 1 0 0 0 1 1

Mole Flow (kmol/hr)

177.3265 9.726905 119.0812 1.673574 40.16577 1917.01 1917.01

Mass Flow (kg/hr)

2083.495 200.5674 9305.798 240.4045 3683.839 22523.88 22523.88

Volume Flow (cum/hr)

137.8987 36.76859 11.62649 0.2784158 4.79971 1490.771 1335.328

Enthalpy (Gcal/hr)

-2.012734 -0.1295606 1.659884 0.0569544 0.2840539 -21.7589 -21.47137

Mole Flow (kmol/hr)

Methane (CH4) 115.1116 8.384603 0.0147259 0 0 1244.428 1244.428

Hydrogen (H2) 60.77678 0.5107797 5.30822x10-7

0 0 657.0349 657.0349

Benzene (C6H6) 1.30066 0.8262799 118.7207 8.56853x10-5 1.215941 14.06095 14.06095

Toluene ( C7H8) 0.1374768 0.00522536 0.3454612 0.2847774 38.94983 1.48621 1.48621

Biphenyl (C12H10) 1.2099 x10-5 1.1632 x10-

14

0 1.389014 6.13562x10-7 0.000130798

0.000130798

Water (H2O) - - - - - - -

As seen above, there is an evident pressure drop going through all the distillation columns, a pressure drop of 5.9bar and a temperature increase passing through all the distillation columns too; this may be due to condensate the products at their respected temperatures. The largest mole flow that can be seen for the products (Purge, COLUMN1, COLUMN2, COLUMN3, S16) is the purge stream with a mole flow of 177.3265 kmol/hr; whereas the smallest mole flow is the bi-phenyl stream with a mole flow of 1.673574 kmol/hr. However, COLUMN2 stream that condenses Benzene has the largest mass flow rate for the products, flowing at 9305.798 kg/hr. Whereas COLUMN1 that condenses the fuel has the smallest mass flow rate, flowing at 200.5674 kg/hr. The purge stream comprises of fuel (115.1116 kmol/hr – Methane) and (60.77678 kmol/hr – Hydrogen). During this process both the Methane and Hydrogen are re-used; mainly to assist in the powering up of the furnace of the reboilers in the distillation columns. All of the streams do not contain water due to the fact that the water, cooling water, serves as a cooling reagent for the heat exchanger (HEATEXC2).

Calculating the purity of the products

Purity of Fuel

The amount of purity for the fuel that is produced is 91.37121597%, this purity value is very high which will efficiently contribute to the provision of energy or can be sold in industry for other uses to generate revenue.

Purity of Benzene

The purity percentage of Benzene is also very high, almost to 100%; however, this may also suggest that it may have a great impact on the overall process.

Purity of Bi-Phenyl

Purity of Toluene

In part 2 (the full process) the purity of the desirable product, benzene, is 99.7%. However, in Part 1 the purity of benzene in the liquid product stream is 70.8%. However, by using the three distillation columns to separate the components, the purity of benzene has increased by 28.9% - making it a more viable/desirable product that is needed.

Calculating the Process efficiency

As stated in the reaction, C7H8 + H2 → C6H6 + CH4, the molar reaction stoichiometry is in a ratio of 1:1. Knowing this we can calculate the process efficiency, as stated below:

Calculating the Product Streams Percentage Composition

This is done to ensure that the splitter functioned accordingly and that the relevant composition of the components was present in the relevant streams.

Appendix G: Percentage Composition – Table 5

% In Purge % In Fuel % In Benzene % In Biphenyl % In Stream 16

Methane (CH4) 64.91505782 86.20011196 0.01236626772 - -

Hydrogen (H2) 34.27394101 5.251204777 4.457647387x10-7 - -

Benzene (C6H6) 0.7334831511 8.494788424 99.6972654 0.0511989909 3.027306585

Toluene (C7H8) 0.0775276115 0.05372068505 0.290105575 17.01612238 96.9726959

Biphenyl (C12H10) 6.823007278x10-6 1.195858292x10-13 - 82.99686778 1.52757435x10-6

Water (H2O) - - - - -

Appendix H: Energy Required For the Complete Process – Table 6

MW COMPRESSOR

PUMP 1

PUMP 2

HEACTEXC1

HEATEXC2

SEPARATOR

FURNANCE

REACTOR

COLUMN1

COLUMN2

COLUMN3

TOTAL

(MW)

ELECTRICAL

ENERGY

0.334404316

0.00041939049

0.016529517599999998

0.3509920681

HEAT DUTY

18.0546058721

5.8965613063000006

0 4.1862153831599995

-0.00208600865817

- - - 28.13529655

REBOILER DUTY

- - - - - 0.980251819387

1.85575906954

0.441890436429

3.277901325

Condenser Duty

- - - - - 0.031282685800300004

2.3721768103300005

0.440321693641

2.84378119

Calculating the amount of energy required to run the complete process

Using the information stated in table 6, we can find that the total energy required would be the sum of the following equipment:Separator +Furnace +Reactor +Column1 +Column2 +Column3 +Pump1 +Pump2 +Compressor +Heat Exchanger= 0+4.1862153831599995-0.00208600865817 +0.980251819387 +1.85575906954 +0.441890436429 +0.00041939049 +0.016529517599999998+0.334404316 +5.8965613063000006 =13.70958407MWTotal energy required is 13.71MW to run the full process, note that heat exchanger (HEATEXC1) is not included in the calculations although it does use thermal energy to cool components down; the thermal energy is founded within the process. Therefore it doesn’t require any energy input as both heat exchangers have the cool streams to cool down the hot streams. In addition to this, the negative value for the reactor indicates an exothermic reaction and therefore thermal energy is released rather than consumed.

Calculating Purge and Fuel streams

The amount of energy that can be recycled will also be calculated in this section. The combustion reaction of methane and hydrogen is an exothermic process., therefore the hydrogen and methane that

are released into the Purge and Fuel stream can be burnt to produce thermal energy for the Toluene Hydrodealkylations process.

Total mole flow of CH4 from both product streams of Purge + Fuel:115.1116 + 8.384603 = 123.500603 kmol/hrTotal mole flow of H2 from both product streams of Purge + Fuel:60.77678 + 0.5107797 = 61.2875597 kmol/hr

The equation used to work out the energy released by combustion is Q=mΔH combustion Where, ΔH combustion is the heat of combustion and m= molar flow rateThe ΔH combustion values for hydrogen and methane are found online and used in the following calculations:ΔH combustion value for CH4 is 891 kJ/mol (The Engineering ToolBox, n.d.)ΔH combustion value for H2 is 286 kJ/mol (The Engineering ToolBox, n.d.)

Methane: Q=mΔH combustion therefore 123.500603 [kmol/hr] x 1000 [mol/kmol] x 1/3600 [hr/s] x 891 [kJ/mol] = 30566.39924 kW = 30.566 MW

Hydrogen:Q=mΔH combustion therefore 61.2875597 [kmol/hr] x 1000 [mol/kmol] x 1/3600 [hr/s] x 286 [kJ/mol] = 4868.956132 kW = 4.869 MW

Total = 30.56639924 MW + 4.868956132 MW = 35.43535537 MW (2dp 35.44MW)

Calculating the Surplus Energy in the process

Surplus Energy = Total Burning Energy - Total Energy Required for the Process Surplus energy

= (35.44 – 13.71) MW

= 21.73 MW

Calculating the Economical Costs for the Full Toluene Hydrodealkylation Process

The cost of each component in the process was calculated using the heat duty values, the pumps and compressor were calculated using the work done values. The distillation columns each had a condenser and re-boiler where their prices were based from the table below and research on the most affordable electricity was conducted via the Internet. It was found that Sainsbury’s energy was the cheapest and using their tariff the relevant calculations were done. (UKPower, 2016)All other calculations were done using excel and information from ASPEN and displayed in the table below.

Appendix I: Pricing Table – Table 7, (UKPower, 2016)

Supplier Tariff Average £/kWh (Inc VAT) Annual Standing Charge (Inc VAT)

Sainsbury’s Energy Fixed Price Till May 2017 £0.095688 £108.492

Appendix J: Pricing Table – Table 8, (Wang, 2016)

Service Specification Cost

Cooling Water Inlet temperature = 23oC, maximum allowable return temperature = 40oC £6/1000 m3

High Pressure Steam 41 bar(g) (dry, saturated) £3.5/GJ

Medium Pressure Steam 20 bar(g) (dry, saturated) £3.1/GJ

Low Pressure Steam 6 bar(g) (dry, saturated) £2.5/GJ

Fuel For Furnace Natural Gas 1.3 pence per kWh

Appendix K: Energy and Cost Requirement data for following Components – Table 9

Appendix L: Energy and Cost Requirement data for following Components – Table 10

Appendix M: Pricing and Flow rate values for the following Components – Table 11, (Platts Global, 2016) (Platts Global, 2016) (Hydrogen Energy Systems, 2015)

Component Price (£/kg) Flow rate (kg/hr) Cost (£)

Toluene (Feed) 0.46146 11462.3 £42,315,143.66

Hydrogen (Feed) 3.45 367.096 £10,131,849.60

Benzene (Product) 0.57 9260.2146 £37,855,757.28

Conclusion

Considering all the data and results gathered, this process looks very favourable to build due to the high efficiency for the Toluene Hydrodealkyation Process is being 95.43% efficient and the final product Benzene being 99.70% pure.

It is found that the annual cost to run the plant, from the utility and column table results and including standing charge, costs is £982,002.28 in addition to this the reactant costs for the conversion of Toluene to Benzene were far greater than the product profit, the total revenue from the process was found to be £-14,591,235.98 per annum. Therefore the total loss from the process is -£15,573,238.26 per annum this accounts for the high energy value which is 35.44 MW to run all the components but other factors such as legal costs, maintenance and staff income also need to be revised.

However, looking beyond the negatives, the thermal energy produced from the combustion of hydrogen and methane in the purge and fuel stream (exothermic reaction) if harnessed, can be used to heat some of the process.

The process has an excess energy of 21.73MW; therefore it is considered as a net energy producer. This excess energy could be used in the process, as stated above, rather than being bought from the energy supplier (Cost Effective). In addition to this, the excess energy could be sold to an energy supplier to generate profit and reduce the deficit of the process loss instead of investing in new equipment as they are very efficient; pump is approximately 78% efficient based on ASPEN model.Furthermore, the high purity of benzene is due to the three distillation columns indicating that they are very beneficial for the process; providing a suffice separation of the impurities in the liquid product stream. These by-products that pass out the distillation column due to the side reaction are methane, bi-phenyl and hydrogen; it was calculated above that the latter energy could be re-used or sold in industry.For example, bi-phenyl is used in organic synthesis; food preservatives and heat transfer fluids. (PubChem, 2015) Therefore it could be sold to companies that have a demand for biphenyl, especially since the purity is approximately 83%, which is very favourable to those industries.

Overall, this report would support the construction of the process, as the process is seen to have its benefits outweigh the costs; high process efficiency from the process indicates successful conversion of reactant to product whilst also resolving the by-product issues. Although the process is currently making a loss, further research into pricing and usage will make this process very viable and cost-effective. Considerations must be taken into the the by-products can be sold to other industries at a higher demand due to the purity of the products and also the vast amount of surplus energy left over, which can be sold or re-used. The fact there is surplus energy left over suggests that the process is more than 100% efficient as less energy is consumed that released.

Nomenclature

Name on PFD Actual Name

GASCYLE Gas Recycle

TOLFEED Toluene Feed

LIQPROD Liquid Recycle

HEATEXC1 Heat Exchanger

HEATEXC2 Heat Exchanger

FURNACE Furnace

SEPERATO Flash Separator

VAPROD Vapour Product

LIQUPROD Liquid Product

COOLIN Cooling Water In

COOLOUT Cooling Water Out

COLUMN1 Distillation Column 1

COLUMN2 Distillation Column 2

COLUMN3 Distillation Column 3

COMPRESSOR Compressor

SPLIT1 Splitter 1

SPLIT2 Splitter 2

MIXER1 Mixer 1

MIXER2 Mixer 2

PUMP1 Pump 1

PUMP2 Pump 2

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Wang, J., 2016. Lecture 03: Sensitivity Analysis. [Online] N/A Available at: HYPERLINK "https://vle.aston.ac.uk/bbcswebdav/pid-911073-dt-content-rid-4433353_1/courses/2015_CE2105/CE2105%20Lecture%204.pdf" https://vle.aston.ac.uk/bbcswebdav/pid-911073-dt-content-rid- 4433353_1/courses/2015_CE2105/CE2105%20Lecture%204.pdf [Accessed 05 May 2016].

Wang, J., n.d. Coursework Assignment Brief. [Online] Available at: HYPERLINK "https://vle.aston.ac.uk/bbcswebdav/pid-913634-dt-content-rid-4446500_1/courses/2015_CE2105/CE2105_Coursework%20Assignment_v2_2015-6%281%29.pdf" https://vle.aston.ac.uk/bbcswebdav/pid- 913634-dt-content-rid-4446500_1/courses/2015_CE2105/CE2105_Coursework%20Assignment_v2_2015-6%281%29.pdf [Accessed 05 May 2016].

Appendix

Appendix C: An analysis of Aspens Design Specification resultsDesign Specification Results – Table 1

Appendix D: An analysis of the LIQPROD, VAPPROD, COOLIN and COOLOUT stream results when simulation finished for part one on Aspen.Stream Results Summary – Table 2

LIQUPROD VAPPROD COOLIN COOLOUT

Temperature (°C) 38 38 30 50

Pressure (bar) 33 33 3 3

Vapor Frac 0 1 0 0

Mole Flow (kmol/hr) 170.654 2092.146 12191.262 12191.262

Mass Flow (kg/hr) 13431.516 24575.253 219628.999 219628.999

Volume Flow (cum/hr) 16.006 1626.998 222.045 226.536

Enthalpy (Gcal/hr) 1.498 -23.739 -840.376 -835.312

Mole Flow (kmol/hr)

Methane (CH4) 8.396809 1357.678 - -

Hydrogen (H2) 0.5111025 717.5026 - -

Benzene (C6H6) 120.7553 15.34222 - -

Toluene (C7H8) 39.60259 1.622409 - -

Biphenyl (C12H10) 1.388607 0.000142666 - -

Water (H2O) - - 12191.3 12191.3

Appendix E: An analysis of the ratio split of the component between the VAPPROD and LIQPROD, including percentage of each component in the relative streamRatio and Percentage Compositions – Table 3

VARIABLE INITIAL VALUE FINAL VALUE UNITS

DS-1 Manipulated 12191.262 12191.262 kmol/hr

COOLOUT 49.995144 49.995144 °C

DS-2 Manipulated 0.299514823 0.299514823 -

Quench (S10) 620.000234 620.000234 °C

Components RATIO

VAPOUR : LIQUID

% IN VAPOUR PRODUCT STREAM

% IN LIQUID PRODUCT STREAM

Methane (CH4) 161.6898:1 64.89403703 4.920370457

Hydrogen (H2) 1403.833:1 34.29505398 0.299496349

Benzene (C6H6) 0.127052:1 0.733324539 70.76031034

Toluene ( C7H8) 0.040967:1 0.077547599 23.20636493

Biphenyl (C12H10) 0.000103:1 6.81912x10-6 0.813697306

Water (H2O) - - -

Appendix F: An analysis of PURGE, COLUMN1, COLUMN2, COLUMN3, S16, S11 and GASCYCLE streams results when simulation completed for the full process for part 2. Product Streams Results – Table 4

PURGE COLUMN1 FUEL

COLUMN2 BENZENE

COLUMN 3 BIPHENYL

Stream 16 Stream 11 Gas Recycle

Temperature (°C) 37.99979 63.18679 92.65541 200.3847 122.7559 37.99979 56.46116

Pressure (bar) 33 7.3 1.5 1.4 1.4 33 39.2

Vapor Frac 1 1 0 0 0 1 1

Mole Flow (kmol/hr)

177.3265 9.726905 119.0812 1.673574 40.16577 1917.01 1917.01

Mass Flow (kg/hr) 2083.495 200.5674 9305.798 240.4045 3683.839 22523.88 22523.88

Volume Flow (cum/hr)

137.8987 36.76859 11.62649 0.2784158 4.79971 1490.771 1335.328

Enthalpy (Gcal/hr)

-2.012734 -0.1295606 1.659884 0.0569544 0.2840539 -21.7589 -21.47137

Mole Flow (kmol/hr)

Methane (CH4) 115.1116 8.384603 0.0147259 0 0 1244.428 1244.428

Hydrogen (H2) 60.77678 0.5107797 5.30822x10-7

0 0 657.0349 657.0349

Benzene (C6H6) 1.30066 0.8262799 118.7207 8.56853x10-5 1.215941 14.06095 14.06095

Toluene ( C7H8) 0.1374768 0.00522536 0.3454612 0.2847774 38.94983 1.48621 1.48621

Biphenyl (C12H10) 1.2099 x10-5 1.1632 x10- 0 1.389014 6.13562x10-7 0.00013079 0.000130798

14 8

Water (H2O) - - - - - - -

% In Purge % In Fuel % In Benzene % In Biphenyl % In Stream 16

Methane (CH4) 64.91505782 86.20011196 0.01236626772 - -

Hydrogen (H2) 34.27394101 5.251204777 4.457647387x10-7 - -

Benzene (C6H6) 0.7334831511 8.494788424 99.6972654 0.0511989909 3.027306585

Toluene (C7H8) 0.0775276115 0.05372068505 0.290105575 17.01612238 96.9726959

Biphenyl (C12H10) 6.823007278x10-6 1.195858292x10-13 - 82.99686778 1.52757435x10-6

Water (H2O) - - - - -

Appendix G: An analysis of the percentage composition of each component in the PURGE, FUEL, BENZENE, BIHENYL and S16 streams; products. Percentage Composition – Table 5

Appendix H: An analysis of the full process energy requirements, both electrical and thermal and condenser energies.Energy Required For the Complete Process – Table 6

MW COMPRESSOR

PUMP 1 PUMP 2 HEACTEXC1

HEATEXC2

SEPARATOR

FURNANCE

REACTOR

COLUMN1

COLUMN2

COLUMN3

TOTAL

(MW)

ELECTRICITY

0.334404316

0.00041939049

0.016529517599999998

0.3509920681

HEAT DUTY

18.0546058721

5.8965613063000006

0 4.1862153831599995

-0.00208600865817

- - - 28.13529655

REBOILER DUTY

- - - - - 0.980251819387

1.85575906954

0.441890436429

3.277901325

Condenser Duty

- - - - - 0.031282685800300004

2.3721768103300005

0.440321693641

2.84378119

Appendix I: Pricing based on Sainsbury’s Energy Tariff for electrical and thermal energyPricing Table – Table 7

Supplier Tariff Average £/kWh (Inc VAT)

Annual Standing Charge (Inc VAT)

Sainsbury’s Energy Fixed Price Till May 2017 £0.095688 £108.492

Appendix J: Pricing based on Dr Wang’s lecture 3 on sensitivity analysisPricing Table – Table 8

Service Specification Cost

Cooling Water Inlet temperature = 23oC, maximum allowable return temperature = 40oC

£6/1000 m3

High Pressure Steam 41 bar(g) (dry, saturated) £3.5/GJ

Medium Pressure Steam 20 bar(g) (dry, saturated) £3.1/GJ

Low Pressure Steam 6 bar(g) (dry, saturated) £2.5/GJ

Fuel For Furnace Natural Gas 1.3 pence per kWh

Appendix K: An analysis of the full process energy requirements and its relevant costs on utilityEnergy and Cost Requirement data for following Components – Table 9

Appendix L: An analysis of the full process energy requirements and its relevant costs for the columns Energy and Cost Requirement data for following Components – Table 10

Appendix M: An analysis of the pricing of the reactant and product in this processPricing and Flow rate values for the following Components – Table 11

Component Price (£/kg) Flow rate (kg/hr) Cost (£)

Toluene (Feed) 0.46146 11462.3 £42,315,143.66

Hydrogen (Feed) 3.45 367.096 £10,131,849.60

Benzene (Product) 0.57 9260.2146 £37,855,757.28