Dimethyl Ether Production

University of TN-ChattanoogaENCH 4290-Intro to ChemE Design

Submitted By: Aziz Albatattah, Alwabari Abdulmohsen, Marquita Beard & Alston Casseday

Outline• Introduction• Objective• Design Constraints• Assumptions• CHEMCAD Design• Sizing• Costing• Conclusion & Questions

What is Dimethyl Ether?

• A clean burning, diesel alternative• Inexpensive• Able to meet strict emissions standards• Used in transportation, agriculture and construction

industries• Can be produced from bio or natural gases

Objective

• Design a production process to produce 50,000 metric tons of 99.5 wt% dimethyl ether using 99 mol% methanol.

• Plant operating hours: 8,375 hours per year

Constraints

• Feed Stream: 25 degrees Celsius and 100 kPa• 80% single pass conversion @ reactor & 100% overall

conversion• Pressure Drops:

• Heat Exchangers: 35 kPa• Mixing Points: 10 kPa• Reactor: 50 kPa• Distillation Columns: 15 kPa

Initial Assumptions

• 50,000 metric tons of DME in 8,375 hours = 129.8 kilomoles per hour

• 259.6 kmol/hr methanol required to produce 129.8 kmol/hr DME

• Pure methanol recycle stream• The reactor feed enters at 250 degrees Celsius.

Block Flow Diagram of DME Production

Separator Feed Prep

Methanol

Reactor

Separator Feed Prep

Storage

Wastewater Treatment

Separator

Separator

DME 99.5wt%129.8 kmol/hr

80% Conversion Methanol

99 mol%259.6 kmol/hr

Process Flow Diagram of DME Production

1

2

35

6

8

97

17

10

3

1112

P-1 01 A/B H-1 01

R-1 01

E-1 01

cw

P-1 02 A/B

cw

T-1 01

lps

cw

E-1 02

cw

T-1 02

lps

P-1 03 A/B

1

2

6

7

13

14

4

5

8 9 10

1112 15 16

18

Figure 1: Process F low Diagram of the Production o f Dimethyl Ether

Design• 1 Storage Tank• 3 Pumps• 1 Fired Heater• 1 Reactor• 2 Distillation Columns (Each w/ 2 Heat Exchangers & 1 Reflux

Pump)• 2 Heat Exchangers• 1 Recycle Stream

Stream PropertiesStream No. 1 10 18 17Stream Name Temp C 25.0 44.98 51.04 111.60 Pres kPa 100.0 1010.00 1045.00 155.00Enth MJ/h -64666 -26673 -17850 -38258Vapor mole frac. 0.00 0.00 0.00 0.00 Total kmol/h 269.70 132.55 74.11 137.16 Total kg/h 8575.80 6097.18 2249.41 2479.41 Total std L m3/h 10.69 9.06 2.84 2.84 Total std V m3/h 6044.96 2971.08 1661.10 3074.19 Flow rates in kg/hDimethyl Ether 0.00 6075.31 78.28 0.00Methanol 8491.13 21.88 2071.03 19.49 Water 84.67 0.0002 140.10 2459.42

Heat Exchangers E-101 E-102 E-103 E-104 E-105 E-106Type S&T S&T Kettle S&T S&T KettleArea(m2) 45.8 41.6Duty (MJ/h) -15718 -1454 4046 -3149 -4444 4690

Temp.(oC) 343 (Tmax) 79 (Tmax) 153 45 51 112Pres. (kPa) 950 (max) 105 (max) 1060 1010 105 155Phase V to L V to L L to V V to L V to L L to VMOC SS CS CS CS CS CSVessels/Tower/Reactors V-101 R-101 T-101 T-102 V-102 V-103Temp.(oC) 31 343 153 112 45 51Pres. (kPa) 1045 1000 1060 155 1010 105Orientation Horiz. Vertical Vertical Vertical Horiz. Horiz.MOC CS SS CS CS CS CS

Height/Length (m) 9 15 8.54 9.76 17.5 11.79Diameter (m) 10 5 0.76 0.76 5.85 3.93Internals s.p. Sized for 2X 14 Valve 16 Valve

Catalyst Vol. Trays TraysTray MOC CS CS CS CS

P-101 P-102 P-103 P-104 P-105(A/B) (A/B) (A/B) (A/B) (A/B)

Flow (kg/h) 8576 10866 2289 2214 1409Fluid Density (kg/m3) 786 654 768 622 768Power (shaft) (kW) 2.86 0.554 0.778

P-101 P-102 P-103 P-104 P-105(A/B) (A/B) (A/B) (A/B) (A/B)

Type/Drive Centrif./ Centrif./ Centrif./ Centrif./ Centrif./Electric Electric Electric Electric Electric

Effi ciency (Fluid 1 1 1 1 1Power/Shaft Power)

MOC CS CS CS CS CSTemp. (in) (oC) 25 77 51 45 51Press. (in) (kPa) 100 915 105 1010 105Pres. (out) (kPa) 1045 1035 1045 1010 105

Pumps/Compressors

Pumps/Compressors

Shell

Size

Equipment Summary

SizingMethanol Storage Tank:

Volume-519 m3

Height-9 m Diameter-10 m

Reactor: Catalyst Volume-5.89 m3

Reactor Volume-11.78 m3

Height-15 m Diameter-5 m

Sizing

• Heat Exchangers:• E-101: 45.8 m2

• E-102: 41.6 m2

• Pump Power:• P-101 A/B- 2.86 kW• P-102 A/B-0.554 kW• P-103 A/B-0.778 kW

Sizing• Distillation Column 1, T-101:

• 14 CS valve trays• Height-8.54 m• Diameter-0.76 m

• Distillation Column 2, T-102:• 16 CS valve trays• Height-9.76 m• Diameter-0.76 m

Economic Information Calculated From Given Information

Revenue From Sales $ 42,944,796 material

CRM (Raw Materials Costs) $ 20,110,251 material

CUT (Cost of Utilities) $ 1,510,000 COM

CWT (Waste Treatment Costs) $ 747,544 material

COL (Cost of Operating Labor) $ 758,030 custom

Factors Used in Calculation of Cost of Manufacturing (COMd)

Comd = 0.18*FCIL + 2.76*COL + 1.23*(CUT + CWT + CRM)

Multiplying factor for FCIL 0.18

Multiplying factor for COL 2.76

Facotrs for CUT, CWT, and CRM 1.23

COMd $ 30,387,551

NPVProject 1

0 1 2 3 4 5 6 7 8 9 10Revenue (42,944,796)$ (42,944,796)$ (42,944,796)$ (42,944,796)$ (42,944,796)$ (42,944,796)$ (42,944,796)$ (42,944,796)$ (42,944,796)$ (42,944,796)$ Cost of Manufacturing 30,387,551$ 30,387,551$ 30,387,551$ 30,387,551$ 30,387,551$ 30,387,551$ 30,387,551$ 30,387,551$ 30,387,551$ 30,387,551$ Depreciation 313,207$ 313,207$ 313,207$ 313,207$ 313,207$ 313,207$ 313,207$ 313,207$ 313,207$ 313,207$ Net Income before tax (12,244,038)$ (12,244,038)$ (12,244,038)$ (12,244,038)$ (12,244,038)$ (12,244,038)$ (12,244,038)$ (12,244,038)$ (12,244,038)$ (12,244,038)$ Tax @ 35% 4,285,413$ 4,285,413$ 4,285,413$ 4,285,413$ 4,285,413$ 4,285,413$ 4,285,413$ 4,285,413$ 4,285,413$ 4,285,413$ Income after tax (7,958,624)$ (7,958,624)$ (7,958,624)$ (7,958,624)$ (7,958,624)$ (7,958,624)$ (7,958,624)$ (7,958,624)$ (7,958,624)$ (7,958,624)$ Depreciation (313,207)$ (313,207)$ (313,207)$ (313,207)$ (313,207)$ (313,207)$ (313,207)$ (313,207)$ (313,207)$ (313,207)$ Cash Flow 3,132,074$ (8,271,832)$ (8,271,832)$ (8,271,832)$ (8,271,832)$ (8,271,832)$ (8,271,832)$ (8,271,832)$ (8,271,832)$ (8,271,832)$ (8,271,832)$ Discounted Cash Flow ($37,174,326)NPV (34,042,252)$

Cummulative Cash Flow 3,132,074$ (5,139,758)$ (13,411,590)$ (21,683,422)$ (29,955,253)$ (38,227,085)$ (46,498,917)$ (54,770,749)$ (63,042,581)$ (71,314,413)$ (79,586,244)$ Internal Hurdle Rate 18%

Conclusion

• Based off the NPV spreadsheet there is never a breakeven point

• The discounted cash flow over ten years is - $37, 000, 000

References

Bondiera, J., and C. Naccache. “Kinetics of Methanol Dehydration in Dealuminated H-Mordenite: Model with Acid and Base Active Centres.” Applied Catalysis 69 (1991): 139-148.

“DME Basics.” Oberion Fuels. http://www.oberonfuels.com/technology/dme-basics-2/ (accessed

November 30, 2015).