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Semicontinuous Chemical Separation Processes

Semicontinuous chemical separation processes are unsteady-state processes which fall somewhere between traditional batch and traditional continuous processing. Typically, multiple separation steps are combined into one process unit, operating cyclically, but without startup and shutdown stages. For example, a single distillation column tightly integrated with a "middle" vessel (a tank which both feeds to and receives a side-draw from the column) can separate a three component mixture semicontinuously, whereas two distillation columns would be required for traditional continuous processing. Pioneering efforts into semicontinuous separations have demonstrated the economic superiority of the technique at intermediate production rates compared to traditional batch and continuous methods. This is particularly useful for the production of biofuels, where high transportation costs of biomass tend to incentivize the use of a distributed network of small biofuel plants as opposed to a single huge plant. We are currently developing semicontinuous processes for biofuels such as biobutanol and bioDME (dimethyl ether) which can displace petroleum gasoline and diesel. This will not only increase the profitability of renewable fuels but also reduce the total lifecycle environmental impact as well.

Dr. Thomas A. Adams II
Associate Professor
Finding better limit cycles of semicontinuous distillation. 1. Back-stepping design Methodology
Industrial and Engineering Chemistry Research, 58 (36) 16654-16666 (2019)  -  [ Publisher Version ]
Finding better limit cycles in semicontinuous distillation. 2. Extended back-stepping design methodology
Industrial and Engineering Chemistry Research, 58 (36) 16667-16675 (2019)  -  [ Publisher Version ]
Understanding the dynamic behaviour of semicontinuous distillation
Madabhushi, P. B., Edgar Ivan Sanchez Medina, Adams, T. A. II
Computer Aided Chemical Engineering, 43 845-850 (2018)
Side stream control in semicontinuous distillation
Computers & Chemical Engineering, 119 450-464 (2018)  -  [ Publisher Version ]
Subspace Model Identification and Model Predictive Control Based Cost Analysis of a Semicontinuous Distillation Process
Computers & Chemical Engineering, 103 39-57 (2017)  -  [ Publisher Version | Open Access Version (free) ]
Space-Constrained Purification of Dimethyl Ether through Process Intensification using Semicontinuous Dividing Wall Columns
Computers & Chemical Engineering, 105 197-211 (2017)  -  [ Publisher Version | Open Access Version (free) ]
Integrated design and control of semicontinuous distillation systems utilizing mixed integer dynamic optimization
Computers & Chemical Engineering, 89 172-183 (2016)  -  [ Publisher Version | Open Access Version (free) ]
A new process for ternary separations: Semicontinuous distillation without a middle vessel
Chemical Engineering Research and Design, 93 100-112 (2015)  -  [ Publisher Version | Open Access Version (free) ]
Integrated Design and Control of Semicontinuous Processes Using Mixed Integer Nonlinear Dynamic Optimization
Computer Aided Chemical Engineering, 37 1181-1186 (2015)  -  [ Publisher Version ]
Semicontinuous distillation of quaternary mixtures using one distillation column and two integrated middle vessels
Ind Eng Chem Res, 54 (19) 5294-5306 (2015)  -  [ Publisher Version ]