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Distillation is undoubtedly the most important unit operation in chemical engineering. During design a significant effort is normally put into steady-state optimization of the column with respect to its size, feed location and reflux ratio. However, operating the column close to this optimal point requires reasonably tight control of the product compositions. This is usually not achieved in industrial practice due to stability problems. Improved strategies for distillation control offer a viable means for significant economic savings as compared to the existing ad hoc techniques. This thesis addresses robust control of distillation columns in the face of model-plant mismatch caused by model uncertainty, nonlinearity and changes in operating conditions. The robust control paradigm, introduced by Doyle and coworkers, is used as the basis for controller design and analysis. An important tool is the Structured Singular Value (SSV) which enables the evaluation of a plant's achievable control performance. This provides a consistent basis for comparing controllers and design alternatives. Achievable performance is also related to other commonly used measures such as the RGA and the condition number.

Distillation is undoubtedly the most important unit operation in chemical engineering. During design a significant effort is normally put into steady-state optimization of the column with respect to its size, feed location and reflux ratio. However, operating the column close to this optimal point requires reasonably tight control of the product compositions. This is usually not achieved in industrial practice due to stability problems. Improved strategies for distillation control offer a viable means for significant economic savings as compared to the existing ad hoc techniques. This thesis addresses robust control of distillation columns in the face of model-plant mismatch caused by model uncertainty, nonlinearity and changes in operating conditions. The robust control paradigm, introduced by Doyle and coworkers, is used as the basis for controller design and analysis. An important tool is the Structured Singular Value (SSV) which enables the evaluation of a plant's achievable control performance. This provides a consistent basis for comparing controllers and design alternatives. Achievable performance is also related to other commonly used measures such as the RGA and the condition number.

Part I: The volumetric behavior of nitrogen dioxide was determined experimentally at temperatures between 100 and 340?F for pressures up to 2000 pounds per square inch. The two-phase data are compared with the results obtained by other investigators. The measurements were made in a stainless steel cell of essentially constant volume, and the experimental apparatus is described.

Part II: The volumetric behavior of nitric oxide was determined experimentally at temperatures between 40 and 220?F for pressures up to 2500 pounds per square inch. The measurements were made in a variable volume container of chrome-nickel stainless steel with mercury as the confining fluid. Reaction between the mercury and the nitric oxide was experienced at temperatures of 280?F and above.

Part III: The volumetric behavior of six mixtures in the binary system nitric oxide - nitrogen dioxide was determined in an essentially constant volume apparatus over a temperature range from 10 to 340?F. The composition range was from 0 to 20 weight percent of nitric oxide, and the maximum pressure obtained was approximately 600 pounds per square inch.

Part I: The volumetric behavior of nitrogen dioxide was determined experimentally at temperatures between 100 and 340?F for pressures up to 2000 pounds per square inch. The two-phase data are compared with the results obtained by other investigators. The measurements were made in a stainless steel cell of essentially constant volume, and the experimental apparatus is described.

Part II: The volumetric behavior of nitric oxide was determined experimentally at temperatures between 40 and 220?F for pressures up to 2500 pounds per square inch. The measurements were made in a variable volume container of chrome-nickel stainless steel with mercury as the confining fluid. Reaction between the mercury and the nitric oxide was experienced at temperatures of 280?F and above.

Part III: The volumetric behavior of six mixtures in the binary system nitric oxide - nitrogen dioxide was determined in an essentially constant volume apparatus over a temperature range from 10 to 340?F. The composition range was from 0 to 20 weight percent of nitric oxide, and the maximum pressure obtained was approximately 600 pounds per square inch.

The reverse osmosis process is that by which reverses the flow of water molecules through a semipermeable membrane, as a result of applying pressure to the solution of higher concentration.

You may then obtain pure water from a high concentration solution through a mechanical method

The reverse osmosis process is that by which reverses the flow of water molecules through a semipermeable membrane, as a result of applying pressure to the solution of higher concentration.

You may then obtain pure water from a high concentration solution through a mechanical method