Preparation of Au Supported ZSM-5 Catalysts and its Special Performance in the Catalytic Cracking of Butane Reaction

2014 ◽  
Vol 953-954 ◽  
pp. 1225-1229
Author(s):  
Aisha Nulahong ◽  
Wen Long Mo ◽  
Feng Yun Ma

Au/ZSM-5 was prepared by improved desorption-precipitation (DP) method using urea as precipitant. Au-samples were characterized by TEM, UV-Vis, XRD, pyridine-FTIR, FTIR and the other techniques. The catalytic performance of Au/ZSM-5 catalysts was carried out on the catalytic cracking of butane by mini-scale pulse reactor. Results showed that: 2.0wt% loading Au/ZSM-5 catalyst obtained the best activity that the n-butane conversion rate comes to 58% by weight,60% olefin selectivity and 10% aromatics selectivity; the i-butane conversion rate comes to 53%, 35% olefin selectivity and 15% aromatics selectivity.

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaoliang Liu ◽  
Jing Shi ◽  
Guang Yang ◽  
Jian Zhou ◽  
Chuanming Wang ◽  
...  

AbstractZeolite morphology is crucial in determining their catalytic activity, selectivity and stability, but quantitative descriptors of such a morphology effect are challenging to define. Here we introduce a descriptor that accounts for the morphology effect in the catalytic performances of H-ZSM-5 zeolite for C4 olefin catalytic cracking. A series of H-ZSM-5 zeolites with similar sheet-like morphology but different c-axis lengths were synthesized. We found that the catalytic activity and stability is improved in samples with longer c-axis. Combining time-resolved in-situ FT-IR spectroscopy with molecular dynamics simulations, we show that the difference in catalytic performance can be attributed to the anisotropy of the intracrystalline diffusive propensity of the olefins in different channels. Our descriptor offers mechanistic insight for the design of highly effective zeolite catalysts for olefin cracking.


2005 ◽  
Vol 17 (9) ◽  
pp. 2466-2474 ◽  
Author(s):  
P. Kortunov ◽  
S. Vasenkov ◽  
J. Kärger ◽  
M. Fé Elía ◽  
M. Perez ◽  
...  

2015 ◽  
Vol 44 (12) ◽  
pp. 1697-1699 ◽  
Author(s):  
Subing Fan ◽  
Jiao Zhou ◽  
Junmin Lv ◽  
Min Liu ◽  
Hantao Huang ◽  
...  

2021 ◽  
Author(s):  
Qingsong Zuo ◽  
Xiaomei Yang ◽  
Bin Zhang ◽  
Qingwu Guan ◽  
Zhuang Shen ◽  
...  

Abstract Improving the flow field uniformity of catalytic converter can promote the catalytic conversion of NO to NO2. Firstly, the physical and mathematical models of improved catalytic converter are established, and its accuracy is verified by experiments. Then, the NO catalytic performance of standard and improved catalytic converters is compared, and the influences of structural parameters on its performance are investigated. The results showed that: (1) The gas uniformity, pressure drop and NO conversion rate of the improved catalytic converter are increased by 0.0643, 6.78% and 7.0% respectively. (2) As the cell density combination is 700 cpsi/600 cpsi, NO conversion rate reaches the highest, 73.7%, and the gas uniformity is 0.9821. (3) When the tapered height is 20 mm, NO conversion rate reaches the highest, 72.4%, the gas uniformity is 0.9744. (4) When the high cell density radius is 20 mm, NO conversion rate reaches the highest, 72.1%, the gas uniformity is 0.9783. (5) When the tapered end face radius is 20 mm, NO conversion rate reaches the highest, 72.0%, the gas uniformity is 0.9784. The results will provide a very important reference value for improving NO catalytic and reducing vehicle emission.


Teknik ◽  
2021 ◽  
Vol 42 (2) ◽  
pp. 218-225
Author(s):  
Rahma Amalia ◽  
Teguh Riyanto ◽  
Istadi Istadi

This work discusses the treated spent Residue Fluid Catalytic Cracking (RFCC) catalysts using sulfuric or citric acids to examine the impact of acid treatment on the catalyst physicochemical properties and structural characteristics. The catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), and Brunauer−Emmett−Teller-Barrett−Joyner−Halenda (BET-BJH) methods. The catalytsts were performed in a continuous fixed-bed reactor for catalytic cracking of palm oil. Changes of the catalyst characteristics and catalytic performance testing of the catalyst after the acid treatment for palm oil cracking process were discussed. It was found that the acid treatment on the spent RFCC catalyst can increase the surface area and pore volume of catalysts as well as the crystallinity. The closed pores in the spent RFCC are opened by acid treatment by eliminating heavy metals. Concerning to the catalytic performance, the acid-treated catalysts had better performance than the non-treated catalyst, which could increase selectivity of the kerosene-diesel range fraction from 47.89% to 55.41%. It was interested, since the non-treated catalyst could not produce gasoline fraction, while the acid-treated catalsysts could produce gasoline fraction at selectivity range of 0.57 – 0.84%. It was suggested that both sulfuric or citric acids treatment could increase the cracking performance of spent RFCC catalyst by shifting the product to lower hydrocarbons.


Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 155 ◽  
Author(s):  
Zhenheng Diao ◽  
Lushi Cheng ◽  
Xu Hou ◽  
Di Rong ◽  
Yanli Lu ◽  
...  

Hierarchical HZSM-5 membranes were prepared on the inner wall of stainless steel tubes, using amphiphilic organosilane (TPOAC) and mesitylene (TMB) as a meso-porogen and a swelling agent, respectively. The mesoporosity of the HZSM-5 membranes were tailored via formulating the TPOAC/Tetraethylorthosilicate (TPOAC/TEOS) ratio and TMB/TPOAC ratio, in synthesis gel, and the prepared membranes were systematically characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), N2 adsorption–desorption, N2 permeation, inductively coupled plasma (ICP), in situ fourier transform infrared (FT-IR), ammonia temperature-programmed desorption (NH3-TPD), etc. It was found that the increase of the TPOAC/TEOS ratio promoted a specific surface area and diffusivity of the HZSM-5 membranes, as well as decreased acidity; the increase of the TMB/TPOAC ratios led to an enlargement of the mesopore size and diffusivity of the membranes, but with constant acid properties. The catalytic performance of the prepared HZSM-5 membranes was tested using the catalytic cracking of supercritical n-dodecane (500 °C, 4 MPa) as a model reaction. The hierarchical membrane with the TPOAC/TEOS ratio of 0.1 and TMB/TPOAC ratio of 2, exhibited superior catalytic performances with the highest activity of up to 13% improvement and the lowest deactivation rate (nearly a half), compared with the microporous HZSM-5 membrane, due to the benefits of suitable acidity, together with enhanced diffusivity of n-dodecane and cracking products.


NANO ◽  
2012 ◽  
Vol 07 (05) ◽  
pp. 1250034 ◽  
Author(s):  
O. A. FOUAD ◽  
M. S. EL-SHALL

Copper, nickel and cobalt metals and oxides needle-like shape nanoclusters have been synthesized successfully by chemical reduction in solution without using a surfactant. XRD analyses showed that copper and nickel metals could be synthesized in a short time period by a microwave irradiation (MWI) — assisted step wise reduction of metal ions in basic solution using hydrazine as a reducing agent whereas cobalt was mainly precipitated in the form of either hydroxide or oxide. TEM images showed that the size of needle-like shape nanoclusters varying from about 5 nm to few hundred nanometers length. On the other hand, copper and cobalt showed high catalytic activity toward CO oxidation than that of nickel. The mechanism of catalytic oxidation reactions over unsupported metals and oxides are also discussed.


2013 ◽  
Vol 634-638 ◽  
pp. 628-631
Author(s):  
Yun Hui Long ◽  
Jun Ming Guo ◽  
Du Shu Huang ◽  
Gui Yang Liu

The catalytic synthesis of ethyl acetate from ethanol and acetic acid using Ti2SnC in liquid phase under the atmospheric pressure was studied. The influences of some factors such as catalyst usage, initial reactant molar ratio, reaction temperature and reaction time on acetic acid conversion rate of this reaction system were investigated. The acetic acid conversion rate of 88.12% is achieved while the molar ratio of alcohol and acid is 1:3.6, the amount of catalyst is 0.2000 g, the reaction temperature is 80 °C and the reaction time is 30min. The catalyst Ti2SnC is the ideal catalyst for synthesis of ethyl acetate for good catalytic performance, non-corrosive to equipment, easily separated from product and used repeatedly.


1979 ◽  
Vol 90 (4) ◽  
pp. 680-691 ◽  
Author(s):  
Jan Komor ◽  
Jürg Müller

ABSTRACT The temporal relation between alterations in serum aldosterone and in the conversion of labelled corticosterone to aldosterone by incubated adrenal tissue was studied in conscious rats receiving long-term infusions of KCl, ACTH or angiotensin II. When potassium-deficient rats were given KCl, a marked increase in serum aldosterone was observed only after 12 h, i.e. at a time when the conversion of corticosterone to aldosterone had become normal. After 24 h of ACTH infusion into sodiumand potassium-replete rats the serum aldosterone was markedly elevated, whereas the conversion of corticosterone to aldosterone was significantly decreased. After 48 h of continued ACTH infusion the serum aldosterone returned to normal and there was a further decrease in the conversion rate. A 24-h angiotensin II infusion into sodium- and potassium-replete rats induced significant increases in both the serum aldosterone and the conversion. After 48 h of continued angiotensin infusion the serum aldosterone returned to normal while the conversion and the blood pressure remained elevated. These results indicate that the activity of the enzymes involved in the final steps of aldosterone biosynthesis may become ratelimiting for the secretion of aldosterone during potassium deficiency and during prolonged ACTH treatment. On the other hand, the observed transiency of aldosterone stimulation by exogenous angiotensin II was not due to a suppression of the final steps of aldosterone biosynthesis and remains unexplained.


Sign in / Sign up

Export Citation Format

Share Document