Kiyoshi Naito

Operation of a bench-scale ideal heat integrated distillation column (HIDiC): an experimental study

Abstract Experimental study of an ideal heat integrated distillation column (HIDiC) is introduced in this work. It is found that the ideal HIDiC can be operated very smoothly, with no special difficulties compared with its conventional counterparts. The higher energy efficiency of the ideal HIDiC is confirmed by the bench-scale experiments. Reflux-free and/or reboil-free operations of the ideal HIDiC are also demonstrated to be feasible by the experiments.

Parameter analysis and optimization of ideal heat integrated distillation columns

Abstract Parametric analysis is performed for ideal heat integrated distillation columns (HIDiC) and comparative studies are made with conventional distillation columns. Implications of process design and operation variables are clarified and heuristics are provided for the effective process design. A generalized process configuration is suggested, which is demonstrated to have both higher energy efficiency and higher flexibilities than its original configuration. Simulation studies are conducted and the obtained results confirm the conclusion.

A New Configuration of Ideal Heat Integrated Distillation Columns (HIDiC)

Abstract A new configuration for ideal heat integrated distillation columns (HIDiC) is proposed by further heat integration between its overhead product and feed. This modification makes the ideal HIDiC more self-support and imposes fewer constraints to the environment. The added heat integration is different in nature from the one between the rectifying and the stripping sections. The latter is self-regulating, while the former is not. Open-loop integrating process is produced by the added heat integration, which makes the process more difficult to control than before. It is therefore extremely important to explore the interaction and tradeoff between process design and operation. Simulation studies are conducted to evaluate the process operation feasibility and it is found that the process can be well controlled through manipulations of pressure difference between the rectifying and the stripping sections and feed thermal condition.

Evaluating control structures for a general heat integrated distillation column (general HIDiC)

Abstract The assessment of control configurations for a general HIDiC (an ideal heat integrated distillation column incorporated with a overhead condenser and bottom reboiler structure) is addressed in this work. It is found that the double ratio control configuration, (L/D, V/B) is still the best one among all the possibilities. Moreover, the pressure difference between the rectifying and the stripping sections and the feed thermal condition are expected to be consistent manipulative variables for the control of the general HIDiC. The control configuration, (pr-ps, q), appears to be a feasible one for the process operation. The performances of the general HIDiC can be substantially improved by employing efficient multivarible control algorithms.

Producing electric power by wet oxidation of biomass ethanol

A new process for producing electric power through wet oxidation of biomass ethanol is proposed in this work. The process configuration is introduced and its energy efficiency is evaluated by using a simple process model. The advantages and disadvantages of the process are also indicated.