Novel Design of an Integrated Pulp Mill Biorefinery for the ...

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Abstract An integrated gasification process was developed for an Ohio-based kraft pulp mill to produce liquid transportation fuels from biomass and coal. Black liquor byproduct from the pulp mill is co-gasified with coal to generate high quality syngas for further synthesis to dimethyl ether (DME) and/or Fischer-Tropsch fuels. A Texaco gasifier was chosen as the focal point for this design. Whenever possible, energy is recovered throughout to generate heat, steam, and power. Mass and energy balances were performed for individual process components and the entire design. An overall process efficiency of 49% and 53% was achieved for DME and FT-fuels, respectively. 2
Table of Contents List of Figures ................................................................................................................................. 5 List of Tables .................................................................................................................................. 6 1 Introduction .................................................................................................................................. 7 2 Background .................................................................................................................................. 9 2.1 Pulp Mill Background ........................................................................................................... 9 2.1.1 Harvesting and Chipping ............................................................................................... 9 2.1.2 Pulping ......................................................................................................................... 10 2.1.3 Chemical Recovery ...................................................................................................... 12 2.1.4 Extending the Delignification Process ......................................................................... 13 2.1.5 Bleaching ..................................................................................................................... 13 2.1.6 Causticizing and Lime Kiln ......................................................................................... 14 2.1.7 Air Separation Unit ...................................................................................................... 15 2.1.8 Pulp Drying .................................................................................................................. 15 2.2 Black Liquor Gasification to Syngas .................................................................................. 16 2.2.1 Low-Temperature Black Liquor Gasification .............................................................. 17 2.2.2 High-Temperature Black Liquor Gasification ............................................................. 18 2.2.3 Black Liquor Gasifier Recommendation ..................................................................... 20 2.2.3 Coal Gasification Technology ..................................................................................... 20 2.3 Background of DME Synthesis .......................................................................................... 21 2.3.1 Properties of DME ....................................................................................................... 21 2.3.2 Features of DME Synthesis Technologies ................................................................... 22 2.3.3. DME separation and purification ................................................................................ 28 2.3.4 DME Utilization ............................................................................................................... 29 2.4 Fischer-Tropsch synthesis ................................................................................................... 30 2.4.1. Fischer-Tropsch Reactors ........................................................................................... 31 2.4.2. Fischer-Tropsch Catalyst ............................................................................................ 32 2.4.3. Fischer-Tropsch Mechanism ....................................................................................... 34 2.4.4. Fischer-Tropsch Product Selection ............................................................................. 35 2.4.5. Fischer-Tropsch Product Upgrading ........................................................................... 37 2.5 Heat and Power Generation .......................................................................................... 38 3 Process Design ........................................................................................................................... 39 3.1 Pulp Mill ............................................................................................................................. 39 3.1.1 Reference Plant ............................................................................................................ 39 3.1.2 Group Design Modifications ........................................................................................ 42 3.2 Black Liquor and Coal Gasification to Syngas ................................................................... 44 3.2.1 Gasifier Scale and Fuel Yield ...................................................................................... 45 3.2.2 Gasifier Fuel Source .................................................................................................... 46 3.2.3 Gasifier Synthesis Gas Composition ........................................................................... 48 3.2.4 Slag Properties and Chemical Recovery ...................................................................... 49 3.3 Dimethyl Ether Synthesis ................................................................................................... 52 3.3.1 Syngas Clean-up .......................................................................................................... 52 3.3.2 DME synthesis ............................................................................................................. 53 3.3.3 Product separation and purification ............................................................................. 56 3
Page 1: Novel Design of an Integrated Pulp
Page 5 and 6: List of Figures Figure 1: Price of
Page 7 and 8: 1 Introduction The global transport
Page 9 and 10: 2 Background 2.1 Pulp Mill Backgrou
Page 11 and 12: 2.1.2.2 Chemical Pulping The most c
Page 13 and 14: sodium sulfide and sodium carbonate
Page 15 and 16: process described in the section on
Page 17 and 18: 2.2.1 Low-Temperature Black Liquor
Page 19 and 20: Figure 2: Chemrec gasification proc
Page 21 and 22: Table 3: Average syngas composition
Page 23 and 24: DME than that could be obtained fro
Page 25 and 26: U.S. Patent[58] and European Patent
Page 27 and 28: Figure 4: Topsøe gas phase technol
Page 29 and 30: DME Workshop, Japan (Sept. 7, 2000)
Page 31 and 32: 2.4.1. Fischer-Tropsch Reactors The
Page 33 and 34: kpH 2 pCO Cobalt rate = 2 (2.4.1) (
Page 35 and 36: invention of Fischer-Tropsch in the
Page 37 and 38: Table 7: hydrocarbons and associate
Page 39 and 40: 3 Process Design 3.1 Pulp Mill 3.1.
Page 41 and 42: carbonate is fired in a lime kiln t
Page 43 and 44: lost and the pulp that provides tha
Page 45 and 46: Table 16: General operating paramet
Page 47 and 48: Table 19: Ash analysis of Pittsburg
Page 49 and 50: Table 22: Experimental syngas compo
Page 51 and 52: 3.2.5 Process Options and Flexibili
Page 53 and 54:
Nitrogen compounds Nitrogen from th
Page 55 and 56:
3.3.2.3 Reactors A single-step gas
Page 57 and 58:
Table 27: FT-diesel fuel synthesis
Page 59 and 60:
3.5.2 Power Generation Process Desi
Page 61 and 62:
Figure 21: Schematic of biorefinery
Page 63 and 64:
ar) reacts with the fuel in the com
Page 65 and 66:
Figure 25showed the detailed energy
Page 67 and 68:
4. Design Summary The DME design an
Page 69 and 70:
Figure 27: Mass and energy flow of
Page 71 and 72:
References 1. Åhman, M., G. Modig,
Page 73 and 74:
42. R.A. Peascoe, J.R.K., C.R. Hubb
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PerformanceSimulation. 2006, Prince
Page 77 and 78:
Appendix Appendix A MP Steam Demand
Page 79 and 80:
Appendix B: Composite Fuel Blend to
Page 81 and 82:
DME Density = 0.67 kg/L (at 20 °C)
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Air Separation Unit Requirements Ba
Page 85 and 86:
Purge gas: CO conversion is 60%, 40
Page 87 and 88:
Appendix D: FTD Synthesis Two diffe
Page 89 and 90:
Table D.3: The hydrocarbon product
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Figure D.3 Mass and energy balance
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Table D.3 Mass and energy balance o
Page 95 and 96:
Appendix E: Heat and Power Generati
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Energy H2O absorbed MW 46.71 Using
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Combustion 2CO+O2→ 2CO2 + 566 kJ/
Page 101 and 102:
Specific Heat (cp) b kJ/kgK 1.072 E
Page 103 and 104:
Specific Heat of Steam (cp) kJ/kgK
Page 105:
Appendix F: Concept Map 105
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