design of an industrial process for the production …...design of an industrial process for the...

Design of an industrial process for the production of aniline by direct aminationR.T. Driessen, P. Kamphuis, L. Mathijssen, R. Zhang, A.G.J. van der Ham, H. van den

Berg, A.J. Zeeuw

University of Twente, Faculty of Science and Technology, Enschede, The Netherlands,

([email protected]); Huntsman Belgium BVBA, Everberg, Belgium

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mailto:[email protected]

Aniline is a frequently used bulk chemical

Precursor for MDA production

MDA is used for MDI production

2

methylene diphenyl di-isocyanate (MDI)

Aniline

Background – Project boundary – Design – Technical – Economics – Recommendations - Conclusion

4,4-methylenedianiline (MDA)

The current aniline production needs to be improved, due to major drawbacks

Drawbacks: • Low atomic efficiency• Formation of acids• Expensive raw materials

T. Kahl et al., Ullmann’s Encycl. Ind. Chem., (2000)

B. Saha et al., Rev. Environ. Sci. Technol., 43, 840-120 (2011) 3

Conventional chemistry:


The aim of the project is to design a process of direct amination of benzene to aniline

Aniline production by direct amination

benzene

N-compound

Protonatedaniline (75 wt%)

MDI productionMDI

Project boundary

250 kton/year

Requirements:

• Location: Rotterdam• Direct amination of benzene• 250 kt/year• 75 wt% protonated aniline

4


All design alternatives are kept, until sufficient basis for

rejection

Douglas’ method:

Functions unit operations

Development of alternatives

5

J. M. Douglas, Conceptual design of chemical processes. McGraw-Hill (1988)

Van den Berg et al., Direct amination of benzene for aniline production,

CHISA 2014



rejection

Douglas’ method:



5

Start

Background

information

Blackbox

Data

complete?

Feasible?

No

Conceptual

Design

Yes

Feasible?

Yes

No

Detailed

design

No

Preliminary

economic

analysis

Finalization

Feasible?

Yes

No

Economics

Alternative

designsFeasible?

No

Yes

Yes



CHISA 2014



rejection

Douglas’ method:



Main choice

Direct amination with …

1. Hydroxylamine (NH2OH)

2. Ammonia (NH3)

Adverse equilibrium

5

Start

Background

information

Blackbox

Data

complete?

Feasible?

No

Conceptual

Design

Yes

Feasible?

Yes

No

Detailed

design

No

Preliminary

economic

analysis

Finalization

Feasible?

Yes

No

Economics

Alternative

designsFeasible?

No

Yes

Yes



CHISA 2014


The focus of this project is on hydroxylamine

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Reaction conditions:

• T = 70 ˚C, P = 1 bar

• good conversion (68.5%), high selectivity (>99.9%)

•Mn-MCM-41 catalyst

K.M. Parida et al., Appl. Catal., A., 351, 59-67 (2008)

The focus of this project is on hydroxylamine

•Hydroxylamine is however expensive

Hydroxylamine production included in scope

6


Hydroxylamine production

Benzene

N-compoundProtonated aniline

(75 wt%)Aniline production by direct

amination

Project boundary

250 kton/year

NH2OH


• T = 70 ˚C, P = 1 bar

• good conversion (68.5%), high selectivity (>99.9%)

•Mn-MCM-41 catalyst

K.M. Parida et al., Appl. Catal., A., 351, 59-67 (2008)

Chemical reduction of nitric oxide is the most promising route to produce hydroxylamine

• Electrochemical reduction:• T = 27 ˚C, P = 1 bar, ζ = 17.6% , σ = 93%

• Chemical reduction:

• T = 25 ˚C, P = 1 bar, ζ = 77% , σ > 85%

• Proven technology

• Platinum catalyst

K. Otsuka et al., J. Electrochem. Soc., 143, 3491, (1996)

R.E. Benson, et al. J. Am. Chem. Soc., 78, 4202–4205, (1956)

T. Hara et al., Appl. Catal. A Gen., 320, 144-151 (2007) 7


Benzene

N-compoundProtonated aniline

(75 wt%)Aniline production by direct amination

Project boundary

250 kton/year

NH2OH


Due to low availability of nitric oxide, the production of nitric oxide is incorporated in the project boundary


Benzene

N-compound

Protonated aniline (75 wt%)Aniline production by

direct amination

Project boundary

250 kton/year

NH2OHNitric oxide production

NO

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NO: • Greenhouse gas• Only low quantities commercially available


• T = 70 ˚C, P = 1 bar

• η = 99%

• Proven technology in nitric acid production

• 5%-Rh-Pt catalyst

M. Thiemann et al., Ullmann’s Encycl. Ind. Chem., 24, 177-223 (2012)

Proposed process

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Proposed flowsheet

10

Modeled with UniSim R410 (NRTL-PR)

N2O, NO, N2,

H2O, NH3

850 °C, 11.8 bar

Air

407 °C, 12 bar

H+, Cl

-, H2, H2O

20 °C, 11.6 bar

H2O, Cl-, H

+, C6H5NH3

+

35 °C, 9.9 bar

N2O, NO, N2,

H2O, NH3, H+,

Cl-, H2, NH3OH

+

163 °C, 10.5 bar

H+, H2O, Cl

-,

C6H6, C6H5NH3+,

C12H10, H2

165 °C, 10.1 bar

R1 R2

R3

S4

S1

N2O, NO,

N2, NH3

28 °C, 11.6 bar

N2O, NO, N2,

H2O, NH3

35 °C, 11.6 bar

H2O

35 °C, 11.6 bar

H2O, H+,

Cl-, NH3OH

+

70 °C, 10.3 bar

H+

, H2O, Cl

-,

C6H6, C6H5NH3+,

C12H10, H2

35 °C, 9.9 bar

H2

20 °C, 11.6 bar

C6H6, C12H10

70 °C, 10.3 bar

S2

H2O, H+,

Cl-, NH3OH

+

350 °C, 10.3 barNH3

20 °C, 12 bar

NH3, NO, N2,

N2O, H2

35 °C, 10.3 bar

H2

35 °C, 9.9 bar

H2O

35 °C, 12 bar

H2O

188 °C, 12 bar

Purge

S3

(pressure swing

adsorption)

NH3, NO, N2, N2O

33 °C, 1.5 bar

H2

35 °C, 10.1 bar

C6H6, C12H10

35 °C, 9.9 bar

C6H6, C12H10

35 °C, 9.9 bar

Purge

N2O, NO, N2,

H2O, NH3, H+,

Cl-, H2, NH3OH

+

35 °C, 10.3 bar

C6H6, C12H10

35 °C, 10.3 barC6H6

20 °C, 10.3 bar

Air

20 °C, 1 bar

Nitric oxide production


Aniline production


Due to the PSA purge 27% of the atomic nitrogen is lost

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No atomic carbon is lost in the process

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Due to the water purge, 14.1% of atomic hydrogen is lost

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Due to an excess of energy it is possible to produce a considerable amount of steam

Reactor ΔTad (°C)

R1 749

R2 505

R3 84

Steam Q

(MW)

F

(ton/h)

High pressure (40 bar) 40.4 84.7

Medium pressure (10 bar) 22.5

Low pressure (3.5 bar) 1.4

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An overview of the costs and revenues shows that the process is profitable

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72%

11%

5%

4%6% 2%

Variable Production Cost

Fixed Production Cost

General Expenses

Depreciation

Profit

Profit taxes

CAPEX (M$) 460

Return on investment (ROI) (%) 5.5

Payback period (PBP) (years) 8

Profit (M$/year) 26

Profit margin (%) 6

Total revenue = 418 M$/year

Based on:

• Material cost factor

• Hand factor, e.g. piping

• Location

Improving the separation efficiency or conversion in hydroxylamine reactor can reduce the nitric oxide loss

Selectively separate hydrogen and nitric oxide from separator (S2) outlet

Selectively separate nitric oxide from the purge

Choose a different catalyst

Increase conversion

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N2O, NO, N2,

H2O, NH3, H+,

Cl-, H2, NH3OH

+

163 °C, 10.5 bar

R2N2O, NO,

N2, NH3

28 °C, 11.6 bar

H2

20 °C, 11.6 bar

S2

H2O, H+,

Cl-, NH3OH

+

350 °C, 10.3 bar

NH3, NO, N2,

N2O, H2

35 °C, 10.3 bar

S3

(pressure swing

adsorption)

NH3, NO, N2, N2O

33 °C, 1.5 bar

H2

35 °C, 10.1 bar

N2O, NO, N2,

H2O, NH3, H+,

Cl-, H2, NH3OH

+

35 °C, 10.3 bar

to aniline productionfrom nitric oxide

production

Burning ammonia to obtain nitric oxide is not energetically efficient, instead an alternative production route should be investigated

Energetically not favorable

o >28 GJ per tonne NH3 (via Haber-Bosch)

T = 2727 - 3227 ˚C, P = 20 - 30 bars η = 1.5%

N. Cherkasov et al. Chem. Eng. Process, 90, 24-33 (2015)

M. Appl, Ullmann’s Encycl. Ind. Chem., (2011) 17


The process design still has an information gap

Investigate kinetics for reactors for sound reactor design

Detailed engineering of separation steps

More effort on process modelling (e.g. electrolytic thermodynamic model)

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Conclusion

The designed process is technologically feasible, but economically it does not meet

industry guidelines.

Economically:

ROI<20%

Capex: 460 M$

Revenue: 420 M$/year

Technically:

Atomic efficiency (C=100%, N = 72%, H = 86%)

Formation of high quality steam

Proven technologies

Integration with MDI production

Raw materials remain expensive

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