(98c) Pyrolysis Gas Sampling

PYROLOYSIS GAS SAMPLING

        Steve Smith                             David Tamez                                                                  Duane King

Owner – President                   Analyzer Engineer                                                          Analyzer Engineer

Smith Analytical, LLC                Saudi Aramco                                                                  Formerly with LyondellBasell

       Seabrook, Texas                       Dhahran, Saudi Arabia  Houston, Texas   

Keywords

PYROLOYSIS GAS SAMPLING, ETHYLENE CRACKING FURNACE, SAMPLE DISCRIMIATION, REFLUX SAMPLER, DISTILLATION SAMPLE PROBE

Abstract

Over the past four decades, significant advances in gas chromatography and on-line analytical techniques have been made for measuring ethylene cracking furnace effluents. While gas chromatographs remain the analyzer of choice when making an ethylene cracking furnace yield measurement, there have been very few quantified improvements in the primary sampling device used in the measurement of pyrolysis gas. The measurement of pyrolysis gas presents the Analyzer Engineer with number of obstacles if the analyzer is to deliver analytical results Operations or the Unit Engineer can depend upon. With most primary sampling designs currently on the market and in use at ethylene production facilities all over the world, the affect ambient temperature has on this analytical system and the resulting data is seldom understood. The implications of having a cracking furnace on advance control and using analytical data that is subject to ambient temperature drift can result in additional fuel cost or incorrect operational adjustments to the furnace due to inaccurate analytical data. The Smith Analytical Model 1221 Distillation Probe has been extensively tested in the United States and Saudi Arabia to provide a stable, conditioned gas for the analytical method of choice. Use of the distillation probe has proven to eliminate any correlation between ambient temperatures up to 130F (55C) thus providing more reliable analytical data to operations, while at the same time improving cracking furnace control.