Chemical News

Saturday, July 5, 2008

Flooding Control Saves Big Energy in Distillation

Distillation is a low thermal efficiency unit operation that currently accounts for 40% of the processing energy consumed in refining and chemical processes. In spite of its high-energy requirements, distillation is often chosen over other separation processes because of its low initial capital investments, flexibility, and ability to yield high purity products. This high level of energy consumption and widespread utilization makes distillation column operation an extremely attractive area for optimization.

The Flooding predictor is an advanced process control strategy that utilizes a patented pattern recognition system to identify pre-flood conditions in distillation, absorption, and stripping columns. The application of a Flooding Predictor could greatly increase the stability and energy efficiency in distillation column operation.

Other benefits include lower implementation and maintenance costs and the unique ability to distinguish between different flooding mechanisms within the same tower (e.g., liquid and jet flooding). When potential flood conditions are avoided, column stability increases and column throughput can be increased. Widespread utilization of flooding predictors could save 2.4 trillion Btu of feedstock energy, 7 trillion Btu of heat/steam energy, and 0.11MMTCE/year in carbon emissions by 2020

A series of DOE-funded distillation tests in an 18-inch distillation column at the University of Texas at Austin proved the initial feasibility of using a pattern recognition methodology to permit stable column operation up to the incipient flood point of a tray or packed column operating at total reflux. The new project tasks are outlined below.

• Pilot plant demonstration
• Dynamic model development
• Commercial scale validation
• Commercialization

Feasible commercialization paths include partnering with an industry leader of the technology, partnering with an established process control company, licensing the technology to a technology vendor, or direct licensing to the end user.
Source: DOE