7 Case study II: n-Butane partial oxidation to maleic anhydride: commercial design
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Gregory S. Patience
Abstract
DuPont applied an iterative design procedure to build a process to partially oxidize n-butane to maleic anhydride in a circulating fluidized bed reactor (CFB). The first step, after generating experimental data in the laboratory, was to develop a flowsheet for a full-scale plant. To address the uncertainties raised in the design of the industrial unit, a pilot plant was built at a scale 100 times smaller than the full scale. In parallel to the detailed design of the commercial unit, the third step dedicated resources to address knowledge gaps remaining after the pilot demonstration. The final step was to support plant operations during the commissioning stages. R&D costs prior to the pilot plant ramped up from 0.5 to 4 million$ year-1 and then jumped to 10 million$ year-1 through pilot plant operation into design and support during commissioning. Many challenges at the pilot plant were resolved in the commercial design (attrition resistance, heat transfer, solids circulation instability, and catalyst cost), while some remained to be resolved (thermal excursions at the oxygen spargers, stripping efficiency, lattice oxygen contribution, kinetics, and hydrodynamics), and others emerged (agglomeration, solids entry from the side, and combustion downstream of the cyclone). Moreover, the engineering uncertainties were compounded by constraints imposed by business team to minimize catalyst inventory that was a major impediment to achieving the economic goals. Due to new uncertainties discovered during the industrial-scale operations and the constraints imposed by business objectives, this process was unsuccessful and after almost 10 years of operation, it was shut down and the metal sold for scrap value.
Abstract
DuPont applied an iterative design procedure to build a process to partially oxidize n-butane to maleic anhydride in a circulating fluidized bed reactor (CFB). The first step, after generating experimental data in the laboratory, was to develop a flowsheet for a full-scale plant. To address the uncertainties raised in the design of the industrial unit, a pilot plant was built at a scale 100 times smaller than the full scale. In parallel to the detailed design of the commercial unit, the third step dedicated resources to address knowledge gaps remaining after the pilot demonstration. The final step was to support plant operations during the commissioning stages. R&D costs prior to the pilot plant ramped up from 0.5 to 4 million$ year-1 and then jumped to 10 million$ year-1 through pilot plant operation into design and support during commissioning. Many challenges at the pilot plant were resolved in the commercial design (attrition resistance, heat transfer, solids circulation instability, and catalyst cost), while some remained to be resolved (thermal excursions at the oxygen spargers, stripping efficiency, lattice oxygen contribution, kinetics, and hydrodynamics), and others emerged (agglomeration, solids entry from the side, and combustion downstream of the cyclone). Moreover, the engineering uncertainties were compounded by constraints imposed by business team to minimize catalyst inventory that was a major impediment to achieving the economic goals. Due to new uncertainties discovered during the industrial-scale operations and the constraints imposed by business objectives, this process was unsuccessful and after almost 10 years of operation, it was shut down and the metal sold for scrap value.
Chapters in this book
- Frontmatter I
- Preface VII
- About the Editors XI
- Contents XIII
- 1 Conventional scale-up method: challenges and opportunities 1
- 2 Iterative scale-up method: concept and basics 21
- 3 Process extrapolation by simulation 57
- 4 Transition from e-pilot to full commercial scale 91
- 5 Life-cycle assessment and technology scale-up 125
- 6 Case study I: n-Butane partial oxidation to maleic anhydride: VPP manufacture 147
- 7 Case study II: n-Butane partial oxidation to maleic anhydride: commercial design 167
- 8 Case study III: Methanol to olefins 191
- 9 Case study IV: Hydropotash from potassium feldspar 221
- 10 Case study V: Lactide production process development 251
- 11 Case study VI: CO2 sequestration in microalgae photobioreactors 279
- 12 Discussion and concluding remarks 305
- Index 327
Chapters in this book
- Frontmatter I
- Preface VII
- About the Editors XI
- Contents XIII
- 1 Conventional scale-up method: challenges and opportunities 1
- 2 Iterative scale-up method: concept and basics 21
- 3 Process extrapolation by simulation 57
- 4 Transition from e-pilot to full commercial scale 91
- 5 Life-cycle assessment and technology scale-up 125
- 6 Case study I: n-Butane partial oxidation to maleic anhydride: VPP manufacture 147
- 7 Case study II: n-Butane partial oxidation to maleic anhydride: commercial design 167
- 8 Case study III: Methanol to olefins 191
- 9 Case study IV: Hydropotash from potassium feldspar 221
- 10 Case study V: Lactide production process development 251
- 11 Case study VI: CO2 sequestration in microalgae photobioreactors 279
- 12 Discussion and concluding remarks 305
- Index 327
