VAPOR-PHASE CATALYTIC CONVERSION OF ETHANOL INTO 1,3-BUTADIENE ON Cr-Ba/MCM-41 CATALYSTS

Abstract

-Al-MCM-41, 16%Ba/Al-MCM-41 and 1.4%Cr-16%Ba/Al-MCM-41 were used as catalysts in the vapor-phase catalytic conversion of ethanol. Physical-chemical properties of the catalysts and the effect of barium and chromium on the Al-MCM-41 activity and 1,3-butadiene yield were studied. The catalysts were characterized by X-ray diffraction (XRD), N 2 physisorption (BET method), CO 2 chemisorption and Fourier transform infrared spectroscopy (FT-IR). When ethanol was completely converted on Al-MCM-41 and 16%Ba/Al-MCM-41, the reaction products showed a high selectivity for ethylene (90-98%). However, on the 1.4%Cr-16%Ba/Al-MCM-41 catalyst, a greater number of reaction products were obtained such as ethylene, acetaldehyde, diethyl ether and 1,3-butadiene. The maximum 1,3-butadiene yield obtained from ethanol reaction was 25% at 723 K and W/F EtOH = 15 g h mol -1 . The latter result was obtained in a single step and without addition of reaction promoters (e.g., acetaldehyde, crotonaldehyde, hydrogen) in the feed stream to the reactor.

Introduction of organic/inorganic Fe3O4@MCM‐41@Zr‐piperazine magnetite nanocatalyst for the promotion of the synthesis of tetrahydro‐4H‐chromene and pyrano[2,3‐d]pyrimidinone derivatives

“…The nitrogen adsorption/desorption isotherms of Fe 3 O 4 @MCM‐41@Zr‐MNPs before and after modification with piperazine are shown in Figure . The isotherms correspond to type IV (in the IUPAC classification), which is typical of mesoporous materials, and further confirm that the piperazine was loaded into the pore channels of the MCM‐41 support. The Brunauer‐Emmet‐Teller (BET) surface areas, total pore volume and Barret‐Joyne‐Halendu (BJH) pore diameter were 597.42 m 2 .g −1 , 0.3912 cm 3 .g −1 , and 2.6196 nm, respectively.…”

Recent Breakthroughs in the Conversion of Ethanol to Butadiene

“…Incidentally, the use of an incorrect support resulted in undesired properties. In particular, MCM-41 was shown to be a poor support, as it structural integrity was repeatedly compromised by post-synthetic modifications, once as silica source for an MgO-SiO 2 catalyst, another time as an acidic support for Cr 2 O 3 and BaO 2 [7,40]. In both case, the ordered mesoporous structure of the silicate was lost.…”

“…Another aspect that will grow in importance is the too-often ignored time-on-stream stability of the catalytic materials. Currently, it is believed the coke deposition is the principal source of deactivation [36,40,50,54]. As the performances of the catalysts improve, growing attention will be devoted to minimizing this phenomenon.…”

Influence of Aluminum Addition in the Framework of MCM-41 Mesoporous Molecular Sieve Synthesized by Non-Hydrothermal Method in an Alkali-Free System

“…Purely siliceous MCM-41 and Al-containing samples with Si/Al molar ratios of 50 and 15 named Al-MCM-41(50) and Al-MCM-41(15), respectively, were synthesized according to the procedure described previously 20 . …”