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Many new technologies are being developed, but several important barriers must be overcome before process intensification is widely adopted.
THE TERM "PROCESS INTENSIFICATION" refers to technologies that replace large, expensive, energy-intensive equipment or processes with ones that are smaller, less costly and more efficient, or that combine multiple operations into fewer devices (or a single apparatus). This article summarizes the status of process intensification efforts in the chemical industry, outlines the motivations for considering process intensification solutions and the barriers to their acceptance, and makes recommendations for accelerating the adoption of process intensification technologies in the chemical industry (1, 2).
Early process intensification developments
Process intensification dates back to the late 1970s, when ICI first pioneered the concept as a way to reduce the capital cost of a production system. ICI developed HiGee technology, which employs rotating equipment as a replacement for much larger separation systems. HiGee subjects a two-phase system (liquid/liquid or liquid/vapor) to high centrifugal forces, which greatly accelerates mass transfer and collapses many theoretical trays into a relatively small volume - allowing large distillation columns to be replaced with much smaller equipment (3). The ownership of the technology changed hands through the years. The first known example of its commercial use was reported in 1997 by Shengli Oil Field in China, where 1.5-m-dia. rotating strippers replaced 30-m-high vacuum towers for the deaeration of water (4). In 2001, Dow Chemical Co. used HiGee as a rotating packed-bed reactor in its hypochlorous acid process (5).
Earlier examples of what is now regarded as process intensification exist. However, they have been relatively few and not well publicized. (Some were commercialized even before the concept of process intensification had been considered.)
One such technology is Eastman Chemical Co.'s process for the esterification of methanol to methyl acetate in a tower reactor with a liquid-phase catalyst, which integrates distillation and reaction into a single vessel. It was installed at the Kingsport, TN, facility in the late 1970s (6). Another example is static mixers, which combine mixing and transport of fluids through pipelines, first patented by Shell and later commercialized by Sulzer and others.
Reactive distillation is an early type of process intensification. An early assignment of one of the authors (JVP) was to analyze commercial operating...