A Green Approach

2013 ◽  
Vol 1 ◽  
pp. 194308921350702
Author(s):  
Madhavi Madeti ◽  
Sharad V. Lande ◽  
Kalpana G ◽  
R. K. Mewada ◽  
R. V. Jasra

We have attempted a green alternative to reuse the spent fluid catalytic cracking (FCC) catalyst that is used in petroleum refining industry for the upgradation and purification of various petroleum streams and residues. The spent FCC zeolite–based catalyst modified by enhancing the acidic properties by incorporating Zn and In metals in the matrix. The various prepared catalysts were systematically characterized by X-ray powder diffraction and Brunauer–Emmett–Teller (BET; adsorption isotherm) surface area. The acidity of the materials was studied by temperature-programmed desorption of ammonia (NH3-TPD). The well-characterized catalysts were applied for liquid phase benzylation of o-xylene using benzyl chloride.

2018 ◽  
Vol 18 (12) ◽  
pp. 8437-8446
Author(s):  
Maojiong Cao ◽  
Youyong Su ◽  
Bing Xue ◽  
Yuxiang Yang ◽  
Xiangnong Liu

In the research, zeolite socony mobil-5 (ZSM-5) catalyst was prepared by hydrothermal method and characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), NH3-temperature programmed desorption (NH3-TPD) and Brunauer- Emmett-Teller (BET). The catalytic products from Jatropha carcass L. oil were analyzed by gas chromatography-mass spectrometer (GC-MS). The effects of crystallization time and crystallization temperature on catalytic cracking performance of ZSM-5 were investigated. According to the results, the catalytic cracking performance of ZSM-5 was closely associated with its pore structure. When the crystallization time was 60 h and the crystallization temperature was 170 °C, ZSM-5 with optimal catalytic cracking performance was synthesized. Catalyzed by the optimal ZSM-5, Jatropha carcass L. oil showed the liquid conversion rate of 26.60% and the acid value of 1.24 mg KOH·g−1. The main catalytic products from Jatropha carcass L. oil included benzene (10.02%), methylbenzene (20.52%), o-xylene (14.45%) and p-xylene (6.59%).


2005 ◽  
Vol 879 ◽  
Author(s):  
Scott K. Stanley ◽  
John G. Ekerdt

AbstractGe is deposited on HfO2 surfaces by chemical vapor deposition (CVD) with GeH4. 0.7-1.0 ML GeHx (x = 0-3) is deposited by thermally cracking GeH4 on a hot tungsten filament. Ge oxidation and bonding are studied at 300-1000 K with X-ray photoelectron spectroscopy (XPS). Ge, GeH, GeO, and GeO2 desorption are measured with temperature programmed desorption (TPD) at 400-1000 K. Ge initially reacts with the dielectric forming an oxide layer followed by Ge deposition and formation of nanocrystals in CVD at 870 K. 0.7-1.0 ML GeHx deposited by cracking rapidly forms a contacting oxide layer on HfO2 that is stable from 300-800 K. Ge is fully removed from the HfO2 surface after annealing to 1000 K. These results help explain the stability of Ge nanocrystals in contact with HfO2.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2289
Author(s):  
Haihui Fu ◽  
Yan Chen ◽  
Tingting Liu ◽  
Xuemei Zhu ◽  
Yufei Yang ◽  
...  

Fluid catalytic cracking (FCC) spent catalysts are the most common catalysts produced by the petroleum refining industry in China. The National Hazardous Waste List (2016 edition) lists FCC spent catalysts as hazardous waste, but this listing is very controversial in the petroleum refining industry. This study collects samples of waste catalysts from seven domestic catalytic cracking units without antimony-based passivation agents and identifies their hazardous characteristics. FCC spent catalysts do not have the characteristics of flammability, corrosiveness, reactivity, or infectivity. Based on our analysis of the components and production process of the FCC spent catalysts, we focused on the hazardous characteristic of toxicity. Our results show that the leaching toxicity of the heavy metal pollutants nickel, copper, lead, and zinc in the FCC spent catalyst samples did not exceed the hazardous waste identification standards. Assuming that the standards for antimony and vanadium leachate are 100 times higher than that of the surface water and groundwater environmental quality standards, the leaching concentration of antimony and vanadium in the FCC spent catalyst of the G set of installations exceeds the standard, which may affect the environmental quality of surface water or groundwater. The quantities of toxic substances in all spent FCC catalysts, except those from G2, does not exceed the standard. The acute toxicity of FCC spent catalysts in all installations does not exceed the standard. Therefore, we exclude “waste catalysts from catalytic cracking units without antimony-based passivating agent passivation nickel agent” from the “National Hazardous Waste List.”


Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 391
Author(s):  
Lu Liu ◽  
Xiaofei Philip Ye

The feasibility of fabricating better solid acid catalysts using nonthermal plasma (NTP) technology for biobased acrolein production is demonstrated. NTP discharge exposure was integrated in catalyst fabrication in air or argon atmosphere. The fabricated catalysts were characterized by Brunauer–Emmett–Teller surface area analysis, temperature-programmed desorption of ammonia, X-ray powder diffraction and Fourier-transform infrared spectroscopy of pyridine adsorption, in comparison to regularly prepared catalysts as a control. Further, kinetic results collected via glycerol dehydration experiments were compared, and improvement in acrolein selectivity was displayed when the catalyst was fabricated in the argon NTP, but not in the air NTP. Possible mechanisms for the improvement were also discussed.


ChemCatChem ◽  
2015 ◽  
Vol 7 (22) ◽  
pp. 3674-3682 ◽  
Author(s):  
Sam Kalirai ◽  
Ulrike Boesenberg ◽  
Gerald Falkenberg ◽  
Florian Meirer ◽  
Bert M. Weckhuysen

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.


2015 ◽  
Vol 25 (3) ◽  
pp. 25-34 ◽  
Author(s):  
Laura Alicia Ramírez Llamas ◽  
Araceli Jacobo Azuara ◽  
J. Merced Martínez Rosales

In this paper, layered double hydroxides (LDH) were synthesized and characterized using techniques of Physisorption of Nitrogen, Infrared, Temperature Programmed Desorption, X-Ray Diffraction, TGA and Immersion Microcalorimetry, in order to determine the basic properties of the adsorbent. The methyl orange (MO) is used as a dye and as a result, it is frequently found in effluents from textile industries. The dye adsorption isotherms on LDH were studied as function of pH and temperature. The maximum adsorption capacity of methyl orange on LDH was carried out at pH 5, and the minimum adsorption capacity at pH 11, being 40.2 mg/g and 22.1 mg/g, respectively. Furthermore, the suitable temperature to promote the adsorption of methyl orange on LDH was at 25 °C, as at 35 °C shows a significant decrease. 


Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 357 ◽  
Author(s):  
Huang ◽  
Li ◽  
Qiu ◽  
Chen ◽  
Cheng ◽  
...  

In the present study, a series of CeO2/TiO2 catalysts were fabricated by dry ball milling method in the absence and presence of organic assistants, and their catalytic performances for the selective catalytic reduction (SCR) of NO by NH3 were investigated. It was found that the addition of organic assistants in the ball milling process and the calcining ambience exerted a significant influence on the catalytic performances of CeO2/TiO2 catalysts. The nitrogen sorption isotherm measurement (BET), powder X-ray diffraction (XRD), Raman spectra, high-resolution transmission electron microscopy (HR-TEM), hydrogen temperature-programmed reduction (H2-TPR), ammonia temperature-programmed desorption (NH3-TPD), sulfur dioxide temperature-programmed desorption (SO2-TPD), thermogravimetric analysis (TG), Fourier transform infrared (FT-IR) and X-ray photoelectron spectra (XPS) characterizations showed that the introduction of citric acid in the ball milling process could significantly change the decomposition process of the precursor mixture, which can lead to improved dispersion and reducibility of cerium species, surface acidity as well as the surface microstructure, all which were responsible for the high low temperature activity of CeTi-C-N in an NH3-SCR reaction. In contrast, the addition of sucrose in the milling process showed an inhibitory effect on the catalytic performance of CeO2/TiO2 catalyst in an NH3-SCR reaction, possibly due to the decrease of the crystallinity of the TiO2 support and the carbon residue covering the active sites.


2019 ◽  
Vol 9 (24) ◽  
pp. 6977-6992 ◽  
Author(s):  
Qandeel Almas ◽  
Muhammad Awais Naeem ◽  
Maria Auxiliadora S. Baldanza ◽  
Jessica Solomon ◽  
Jeffery C. Kenvin ◽  
...  

Transformations of an industrial zeolite-based fluid catalytic cracking (FCC) catalyst and its coke deposits during regeneration following FCC reactions of a representative refinery stream are investigated.


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