Estimating Vent Emissions From a Distillation Column: An Alternative to Stac Testing

摘要

This technical paper points out the cost-effectiveness and data manageability of material balance over the epidemic use of stack testing in the chemical industry. An example is drawn from a Title V emissions inventory prepared for an interntional manufacturer of pharmaceuticals and fuel additives. This example case focuses on the use of mass balance to estimate noncondensibles generated by a typical large-scale distillation column. Distillation fundamentals are reviewed, including discussion of relative volatility, x-y and McCabe-Thiele diagrams, and basic sieve tray mechanics. A seemingly complex set of energy and material balance equations is simplified by the application of constant molar overflow. The example case concludes with a calculation of column noncondensibles, and the paper closes with a review of the material balance approach, including its strengths, limitations, and applicability to other unit operations.