Synthesis of SAPO-34 catalysts via sonochemically prepared method and its catalytic performance in methanol conversion to light olefins

Rana Ahmadova,Uwe Rodemerc,Evgenii Kondratenko,Hikmet Ibragimov

doi:10.1007/s13203-018-0193-x

Abstract

Methanol-to-olefin (MTO) reaction was investigated over sonochemically (SAPO-34-U40, SAPO-34-U70, SAPO-34-U100) and hydrothermally (SAPO-34-HT) prepared nanocatalysts. The catalytic performance of prepared samples was investigated over all samples at 450 °C and over SAPO-34-U40 at 350–450 °C temperature range. The higher yield ~ 97 wt% (31.4 wt% C2=, 49.4 wt% C3= and 16.1 wt% sumC4=) of light olefins was obtained at 375 °C on SAPO-34-U40. Physico-chemical properties of catalysts were characterized by XRD, SEM, BET, ICP techniques. XRD analysis showed suitable crystalline structure and SEM images confirmed perfect crystallinity of sonochemically prepared samples. BET analysis indicated remarkable surface area of SAPO-34-U40. The amount of carbon deposits and character of coke was determined by TPO analysis. The higher amount of coke was determined over SAPO-34-HT in comparison to another’s at 450 °C. The character of coke deposited over SAPO-34-U40 was similar for 375–425 °C temperatures.

Highlights

Light olefins such as ethylene and propylene are widely used as raw materials for large-scale production of various polymers, fibers, resins and solvents
All catalysts are in cubic form, and average crystallite size calculated for SAPO-34-hydrothermal method (HT), SAPO-34-U40, SAPO-34-U70 and SAPO-34-U100 are 45, 27, 27.9 and 28.2 nm, respectively
It can be concluded that in comparison to hydrothermal method, ultrasound irradiation of gel leads to obtaining of lower average crystallite size

Summary

Introduction

Light olefins such as ethylene and propylene are widely used as raw materials for large-scale production of various polymers, fibers, resins and solvents. Owing to the rapid development of the world economy, there is increased demand for ethylene and for propylene. Methanol-to-olefin (MTO) process has attracted attention as a potential indirect route for the production of light olefins, because methanol is commercially produced from synthesis gas generated from natural gas and/or coal [1]. Silicoaluminophosphate molecular sieve, especially SAPO-34 catalyst is one of the best candidates for the process of obtaining light olefins from methanol. Because of Department of “Chemistry and Technology of Oil and Gas”, Institute of Petrochemical Processes named after Yu.G.Mamedaliev, Azerbaijan National Academy of Sciences, Khojaly Ave. 30, 1025 Baku, Azerbaijan In this case, preparing of catalysts which are more resistance to coke formation is one of the main problems [4,5,6]

Methods

Results

Conclusion