The retrofit design of distillation-based separation systems

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6119380

Carlberg, N A

A solution strategy for retrofit problems requires a two phase procedure. In order to be comprehensive, the search must include all possible distillation sequences. The first phase characterizes each column's ability towards performing separation tasks in series and parallel. The second phase uses this information in the formulation of a mixed integer nonlinear program (MINLP). Solution of the MINLP provides the optimal distillation sequence under retrofit conditions. In an alternate approach, individual coverage scenarios are generated and optimized. Solution of an integer linear program (ILP) determines the optimal combination of scenarios. Heat integration between condensers and reboilers is an effective means to reduce utility consumption. To explore heat integration possibilities with existing columns requires a two step procedure. Once again, to be comprehensive, the search must include all possible sequences. In the first step, a screening procedure identifies all feasible heat matches of interest. In the second step, the solution of a MINLP indicates the optimal heat integrated sequence. Complex column configurations also have the potential to reduce utility consumption. Insight into complex column heat flow facilitates extension of Underwood's method to columns with side strippers and side enrichers. The same insights show that, even though these configurations are more energy efficient, they require a larger temperature range for operation than analogous simple column sequences. The set of Underwood equations developed for the side stripper and side enricher easily extend to the Petlyuk configuration. Close scrutiny of these equations shows a family of middle component split fractions that give rise to minimum reflux. This analysis is valid for any multicomponent feed mixture with any number of middle components.

• Research Organization: Carnegie-Mellon Univ., Pittsburgh, PA (USA)
• OSTI ID: 6119380
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320303* -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Equipment & Processes
CAPACITY
COMPUTER CODES
CONDENSERS
DESIGN
DISTILLATION EQUIPMENT
ECONOMICS
EFFICIENCY
ENERGY
ENERGY CONSERVATION
ENERGY EFFICIENCY
ENERGY TRANSFER
EQUIPMENT
HEAT
HEAT TRANSFER
INDUSTRIAL PLANTS
M CODES
NUMERICAL SOLUTION
OPTIMIZATION
PROCESS HEAT
PURIFICATION
RETROFITTING
SEPARATION PROCESSES
SPECIFICATIONS
WASTE HEAT UTILIZATION
WASTE PRODUCT UTILIZATION