Abstract
In the interest of lowering the contents of organic sulfur and nitrogen compounds in the feed, the pressure in the reaction zone in the hydrotreating unit was raised to 4.6-4.8 MPa (gauge). During startup and during the operation period of the unit, the concentration of hydrogen-rich gas (HRG) circulating in the reactor section was held constant 80-92% by volume). The feed to the unit was a 200-340 C cut. The temperature in the reaction zone was held at 340 C which made it possible to accelerate the sulfiding process and to stabilize the operation of the catalyst. Over the course of the 19-month working cycle, the temperature in the reaction zone was gradually brought up to 365 C. It is shown that the critical condition for extending the operating cycle of the sieves is a high degree of feedstock treatment to remove organic sulfur compounds (down to 0.01% by weight.) The primary source of a decrease in capacity of the molecular sieves is the absence of desorption of feed from the sieve surface during certain emergency shutdowns. Thorough desorption by ammonia or other desorbents having a high desorption capacity, for a reduction of the temperature from 380 C to 250more » C, prevents coking of molecular sieves during such shutdowns.« less
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call