Increasing the propylene production in the MTP process through thermal coupling with naphtha reforming process

This paper presents the thermal coupling of the naphtha reforming process with methanol to propylene (MTP) process. In this integrated configuration, the required heat of the endothermic naphtha reforming process is provided by MTP which is an exothermic process. Therefore, intermediate heaters of conventional naphtha reforming (CNR), which were used to adjust the feed temperature of the reactors, were eliminated. The temperature of the MTP reactor increases slightly by transferring its heat to the naphtha reforming reactor; hence, the produced heat in the MTP reactor is controlled to prevent hotspot formation on catalysts. Furthermore, the MTP process is cooled inherently without extra equipment. MTP and naphtha reforming processes were considered to occur in fixed-bed reactors with axial co-current feed streams. The MTP reactor feed streams are parallel while the naphtha reforming feed streams are in series. Results show that in the MTP process, produced propylene and consumed methyl ether in the three parallel reactors are 878 kmol/h and 0.034 kmol/h, respectively. Also, the molar flow rate of aromatics in naphtha reforming is 112 kmol/h. The propylene yield in thermally coupled reactors is 10% more than the conventional one.