Characterization and optimization of SAPO-34 catalysts synthesized by mixed templates in MTO reaction

Abstract

"> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>The effects of templating on the catalytic performance of SAPO-34 catalyst</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>have been investigated in conversion of methanol to olefins. SAPO-34</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>catalysts were synthesized using a different combination of morphine,</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>tetraethyl ammonium hydroxide (TEAOH) and triethylamine (TEA) as</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>structure-directing agents during synthesis of gel with nominal composition</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>as 1Al</em><span style="font-size: 6pt; color: #000000; font-style: normal; font-variant: normal;"><em>2</em><span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>O</em><span style="font-size: 6pt; color: #000000; font-style: normal; font-variant: normal;"><em>3</em><span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>:1P</em><span style="font-size: 6pt; color: #000000; font-style: normal; font-variant: normal;"><em>2</em><span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>O</em><span style="font-size: 6pt; color: #000000; font-style: normal; font-variant: normal;"><em>5</em><span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>:0.4SiO</em><span style="font-size: 6pt; color: #000000; font-style: normal; font-variant: normal;"><em>2</em><span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>:2yTEAOH:2xTEA:2(1-(x+y))morpholine:70H</em><span style="font-size: 6pt; color: #000000; font-style: normal; font-variant: normal;"><em>2</em><span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>O.</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>The different SAPO-34 samples were characterized by XRD, SEM, FTIR,</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>BET, EDX and TPD techniques. Increasing TEAOH in synthesis gel led to</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>decreasing mean crystal size. The catalytic performance of the synthesized</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>catalysts was tested in MTO reaction at 410</em><span style="font-family: Symbol; font-size: 12pt; color: #000000; font-style: normal; font-variant: normal;"><span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>C and a feed WHSV of 6.5 1/h.</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>The catalyst synthesized by combination of tri-templates exhibited highest</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>light olefins yield in 100% methanol conversion. The optimum values</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>(X=0.17, Y=0.34) were obtained by central composite design and response</em> <span style="font-size: 11pt; color: #000000; font-style: normal; font-variant: normal;"><em>surface contour plots.</em></span></span></span></span></span></span></span></span></span></span></span></span></span><br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" /></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>