Production of Propylene from Ethanol Over ZSM-5 Zeolites

Japan), colloidal silica (SiO2 30.5 wt%, Na2O 0.4 w t % , H2O 69.1 w t % , C a t a l o i d S I -30, J G C Catalysts and Chemicals Ltd., Japan), and 1,6-diamino- TON type zeolites with different SiO2/Al2O3 ratios (57, 81, 112, and 140) were synthesized using 1,6-diaminohexane, n-butyl alcohol, and 1-ethylpyridinium bromide as structure-directing agents, and the catalytic performance of protonated forms for conversion of ethanol into light olefins such as ethylene, propylene, and butenes was investigated. Although the yields of light olefins were dependent on the SiO2/Al2O3 ratios of the HTON type zeolites and the reaction conditions such as temperature and contact time, the relatively high propylene yield of ca. 25 C-% was obtained. HTONs with higher SiO2/Al2O3 ratios exhibited longer catalyst life. These results strongly indicate that TON type zeolite with 10-membered rings (0.46 nm 0.57 nm) and only straight channels has high potential for the production of propylene from ethanol. The catalytic performance of HTON type zeolite was slightly improved by strontium modification.

Section: Ethanol Conversion Over Hton Modifiedmentioning

confidence: 99%

Conversion of Ethanol into Propylene over TON Type Zeolite

Tsunoji

Furumoto

Ide

et al. 2013

“…Furthermore, to improve the selectivity for propylene from ethanol, ZSM-5 zeolites have been modified with metals such as zirconium or titanium and phosphorus 14), 16) . In this study, we investigated the reaction mechanism and the characteristics of the active sites for ethanol conversion to propylene over ZSM-5 catalysts by evaluating the relationship between product distribution and contact time.…”

Section: Introductionmentioning

confidence: 99%

Conversion of Bioethanol to Propylene over ZSM-5 Zeolites

Takahashi

Fujitani

2018

Self Cite

The ethanol conversion reaction was systematically investigated over ZSM-5 zeolite catalysts with various Si/Al2 ratios (73, 128, 176, 207) using different contact times and reaction temperatures. The reaction yielded similar product distributions over all catalysts at different contact times, indicating that the product distribution has no relationship with the Si/Al2 ratio. Catalytic activity was proportional to the number of Brønsted acid sites. The mechanism of ethanol conversion was independent of the Si/Al2 ratio and propylene was directly produced via ethylene. Mechanistic analysis of the initial stage of the reaction suggested that ethylene was transformed to a carbene, which was a transient intermediate in the direct production of propylene. ZSM-5 zeolite was modified with phosphorus to improve propylene selectivity. Phosphorus-modified ZSM-5 catalysts showed enhanced selectivity for propylene production and good catalytic stability.

“…Bio-based ethylene and EG can in turn be used to produce polyethylene and polyethylene terephthalate. Propylene, which is the second largest platform chemical after ethylene, is also an important target to be produced from bioethanol 4) . As shown in Table 1, bioethanol that is to be blended with gasoline should contain more than 99.5 % (v/v) alcohol.…”

Section: Introductionmentioning

confidence: 99%

Chemical Analysis of Impurities in Diverse Bioethanol Samples

Habe

Shinbo

Yamamoto

et al. 2013

Bioethanol has recently become an important resource for chemical industries. The chemical compositions of 17 different types of bioethanol were investigated with a focus on impurities that could affect catalytic performances in the downstream chemical processes. Lignocellulosic ethanol contained higher concentrations and a greater variety of organic impurities compared to sugar-or starch-derived bioethanol. Twenty-nine impurities were identified in lignocellulosic ethanol, whereas 16 impurities were in sugar-or starch-derived bioethanol. Lignocellulosic ethanol contained high concentrations of acetic acid, acetaldehyde, methanol, and furan-related compounds such as furfural. In contrast, with the exception of molasses-derived bioethanol obtained by crude distillation, the concentrations of these components were lower in sugar-or starch-derived bioethanol samples. Lignocellulosic ethanol contained dimethyl disulfide and thiazole, whereas the only organosulfur compounds found in sugar-or starch-derived bioethanol were dimethyl sulfide and dimethyl sulfoxide. These sulfur-containing impurities can cause catalyst deactivation in the bioethanol transformation processes. In lignocellulosic ethanol, more than 0.1 mg/mL of Si was detected.