Energy and Economic Analysis of Methanol Synthesis Using Reactive Distillation

• Published in: Process integration and optimization for sustainability 2022-06, Vol.6 (2), p.527-541
• Main Authors: Ghosh, Shashwata, Srinivas, Seethamraju
• Format: Article
• Language: English
• Subjects: Conversion; Distillation; Economic analysis; Economics; Economics and Management; Effluents; Energy efficiency; Energy Policy; Energy requirements; Engineering; Exothermic reactions; Gases; Heat exchangers; Heat of reaction; Hydrogenation; Industrial and Production Engineering; Industrial Chemistry/Chemical Engineering; Membrane reactors; Methanol; Operating costs; Original Research Paper; Packed beds; Production costs; Productivity; Raw materials; Reactors; Recycling; Simulation; Slurries; Slurry reactors; Solvents; Sustainable Development; Synthesis gas; Waste Management/Waste Technology
• ISSN: 2509-4238; 2509-4246
• DOI: 10.1007/s41660-022-00228-4

Methanol production using reactive distillation (RD) is compared with the conventional process that uses a packed bed reactor and the three phase process involving a slurry reactor (SR). The RD column design was developed using a new methodology to remove the exothermic heat of reaction and overcome the equilibrium limitations. Both the conventional and RD-based processes are comparable in terms of the reactant conversions and production (~ 487 TPD and ~ 491 TPD, respectively), though the conventional process offers better methanol productivity (25.5 mol/(kg.h) vs. 14.8 mol/(kg.h) in case of RD). The SR based process has the lowest conversions of reactants and methanol production (~ 483 TPD) among the three processes, though its productivity is comparable to the RD based process. Though all the processes were self-sufficient in their energy requirements, the process involving the SR had the highest surplus power production of ~ 1.6 MW. The energy efficiency of both the processes was ~ 80% (syngas to methanol). In terms of the economics, the SR-based process has the lowest NPV and IRR due to higher production costs and low methanol production. The RD-based process has higher capital and operating costs leading to a lower net present value (NPV), internal rate of return (IRR), and greater payback period compared to the conventional PBR process. The RD-based process offered economic feasibility over a limited range in comparison with the conventional process, which exhibited economic viability over a wider range of raw material (syngas) costs and product (methanol) prices.