화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.59, No.7, 2796-2804, 2020
Detecting and Evaluating Detrimental Factors of Clay's Longevity, Selecting, and Optimizing an Appropriate Adsorbent for Operating Time Elevation in the Separation Process of Trace Olefins from Aromatics
Industrial-scale production of aromatic materials is confronted by the problem of removal of impurities such as olefins. Their removal is an essential requirement in marketability. Catalytic adsorbent clay is the most common material used for the removal of olefins from aromatic streams. The current study is focused on increasing the lifetime of a commercial type of clay by identifying the effective parameters in reducing the adsorbent lifetime. An analysis of 3 years of data from a petrochemical complex showed that water, morpholine, and N-formyl morpholine (NFM) contents in the feed stream are the factors reducing the clay lifetime. Various experiments have been performed to determine the individual impacts of these parameters on the clay lifetime. Reducing the water content from 150 to 70 ppm led to a 20% increase in lifetime, while increasing morpholine content from 55 to 160 ppm and NFM content from 0.55 to 91 ppm resulted in 40 and 75% reduction in lifetime, respectively. Also, six types of conventional commercial adsorbents have been tested to minimize the contents of the above-mentioned components before olefin removal by clay. Among them, silica gel showed the best performance. The optimum weight percentage of silica gel relative to the total loaded clay mass was determined to be 10%, which led to a 2.1-fold increase of clay lifetime if silica gel was loaded into the reactor prior to clay loading.