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.

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BACKGROUND The clay treatment widely utilized to reduce unsaturated components in aromatic stream has a detrimental effect on catalyst lifetime. Due to the short lifetime of commercial clay, a huge number of studies have been carried out to address this problem over the last decade. This study aims to optimize the temperature for longer serviceability of clay by removal of unsaturated aliphatic components from aromatic streams through the adsorption and catalytic properties of clay. A novel process arrangement is introduced by scheduling the reuse of deactivated clay that is discarded after deactivation. RESULTS Results showed that the suitable range of temperature for olefin removal is 155–205 °C, and the optimum temperature with the lowest operational cost was 185 °C, which is then gradually elevated to 205 °C. CONCLUSION The new process arrangements utilize these results and elevate clay's lifetime by almost 3.5 times, leading to an economical solution on an industrial scale. © 2021 Society of Chemical Industry (SCI).

This is a 'preproof' accepted article for Clay Minerals. This version may be subject to change during the production process.

Membrane-based separation technologies are gaining prominence in energy-efficient separation processes. Smart membranes, which change their physical or chemical characteristics in response to environmental stimuli, are attractive membrane candidates. This review summarizes the recent development and applications of smart membranes based on two-dimensional (2D) materials, mainly focusing on their design, fabrication, and applications in molecular separations. Furthermore, stimuli for triggering smart 2D membranes are classified and explained. Finally, we propose areas for improvement and further development for future studies, such as the issues of complicated fabrication, long term stability in real operating conditions, and responding to different environmental stimuli at the same time.