Carbonization properties of carbonaceous substances oxidized by air blowing—I

Mochida, Isao; Inaba, Toshiaki; Korai, Yozo; Fujitsu, Hiroshi; Takeshita, Kenjiro

doi:10.1016/0008-6223(83)90237-3

Cited by 24 publications

(13 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the DTG curve, the peak observed in the temperature range 676-955 K was attributed to the reaction between n-butylamine and its protonated form, as shown in Eq. (4): The presence of butene, ammonia and diamine as decomposition products on nbutylamine over acid zeolite catalysts was demonstrated by infrared spectroscopy [12], proton nuclear magnetic ressonance [13] and mass spectrometry [14]. It was suggested that the formation of diamines should occur in the bulk of the Ca/NaY zeolite.…”

Section: Ch3(ch2)anh~'---o-zeol --> Nh 3 + Ch3ch2chch 2 + Ho-zeol (3)mentioning

confidence: 98%

Determination of Ca/NaY zeolite acidity by TG and DSC

Araújo

Fernandes

1997

Journal of Thermal Analysis

View full text Add to dashboard Cite

The acid properties of the Ca/NaY zeolite were investigated by means of n-butylamine desorption and thermal decomposition, using both thermogravimetry (TG) and differential scanning calorimetry (DSC). The total acidity of the zeolite was calculated from the TG data, while DSC was used with the Borchardt-Daniels kinetic model to determine the relative acid strength of the catalyst, given in J per acid site. The enthalpies of these processes are proportional to the acid site strength in each specific temperature range.

show abstract

Section: Ch3(ch2)anh~'---o-zeol --> Nh 3 + Ch3ch2chch 2 + Ho-zeol (3)mentioning

confidence: 98%

Determination of Ca/NaY zeolite acidity by TG and DSC

Araújo

Fernandes

1997

Journal of Thermal Analysis

View full text Add to dashboard Cite

show abstract

“…Among these candidates, modified mordenite is a particularly effective catalyst for the selective synthesis of MMA and DMA (2)(3)(4), and the large-scale industrial production of methylamines using mordenite was introduced in 1986 by Nitto Chemical Co. (5). Nevertheless, the reasons why mordenite is effective for selective MMA and DMA synthesis are not thoroughly clear.…”

Section: Note the Role Of Eight-membered Rings Of Mordenite In Methanmentioning

confidence: 99%

The Role of Eight-Membered Rings of Mordenite in Methanol Amination

Kiyoura

Ishikawa

Phala

1997

Journal of Catalysis

View full text Add to dashboard Cite

“…If one excludes that the formation of DME takes place on weaker acid sites (silanol groups) on the external surface (which can be excluded on basis of parallel experiments with silica containing a high concentration of silanol groups), the following reaction routes are plausible. (i) Protonated methanol, which is formed from methanol sorbed on (methyl)ammonium ions as proposed for the formation of surface bound methylamines, reacts with MeOH to form DME (17,28). (ii) Chemisorbed amines react with MeOH to form DME similar to the formation of methylamines via the methyl-scavenging mechanism.…”

Section: Formation Of Dimethyl Ethermentioning

confidence: 99%

“…To enhance the selectivity of acidic catalysts toward monomethylamine (MMA), and dimethylamine (DMA), several molecular sieves were tested. Among them, small pore zeolites (e.g., RHO, ZK-5, and erionite) and mordenites were reported to be the most promising ones (16)(17)(18)(19)(20)(21)(22)(23). Substantial improvement was achieved through variation of zeolite morphology and acidity (18,19).…”

Section: Introductionmentioning

confidence: 99%

Selectivity Enhancement in Methylamine Synthesis via Postsynthesis Modification of Brønsted Acidic Mordenite

Grundling

Eder‐Mirth

Lercher

1996

Journal of Catalysis

View full text Add to dashboard Cite

Methylamine synthesis from methanol and ammonia over parent and modified Brønsted acidic mordenites is studied by in situ infrared spectroscopy and kinetic analysis to elucidate the role of elementary steps for activity and selectivity. In situ infrared spectroscopy reveals that all methylammonium ions are formed in the micropores of these catalysts. The formation of the chemisorbed methylamines, however, is not rate determining. Transient response experiments indicate that the desorption of these methylamines aided by adsorbing ammonia and/or the scavenging of methyl groups with ammonia constitutes the rate determining step. For a given catalyst, the selectivity strongly depends on the methanol conversion and the ammonia to methanol ratio of the feed. Upon modification of mordenite with tetraethoxysilane, the selectivity to the lower methylated amines is strongly enhanced. The transport limitations of the bulkier products, formed in high concentration in the pores, are concluded to cause the enhanced selectivity toward mono-and dimethylamine over the modified catalyst. Since a decrease in activity compared to the parent sample was not observed, it seems that the methyl-scavenging mechanism plays an important role over these catalysts.

show abstract

Carbonization properties of carbonaceous substances oxidized by air blowing—I

Cited by 24 publications

References 17 publications

Determination of Ca/NaY zeolite acidity by TG and DSC

Determination of Ca/NaY zeolite acidity by TG and DSC

The Role of Eight-Membered Rings of Mordenite in Methanol Amination

Selectivity Enhancement in Methylamine Synthesis via Postsynthesis Modification of Brønsted Acidic Mordenite

Contact Info

Product

Resources

About