Preparation of Sorbent Loaded with Nano-CuO for Room Temperature to Remove of Hydrogen Sulfide

2013 ◽  
Vol 475-476 ◽  
pp. 1329-1333 ◽  
Author(s):  
Fen Li ◽  
Jin Wei ◽  
Ying Yang ◽  
Guang Hui Yang ◽  
Tao Lei

In this paper, an efficient metal oxide sorbents for the deep removal of H2S were synthesized using equal volume impregnation (EVIM) method. Modified coconut shell charcoal was selected as support to deposite the particles of copper oxide onto the surface. And copper nitrate were selected as the active component precursors in the preparation process of sorbents. Sorption experiments were carried out at room temperature in fixed-bed reactor. The grain size and crystal form of loading metals were characterized by X-ray diffraction (XRD). We investigated the effects of modifier onto coconut shell charcoal, load rate of metal oxide and calcination temperature on the desulfurization activity of the sorbent. Results show that the best modifier for coconut shell charcoal is KOH, which is significantly better than the other modifiers. And the optimum load rate is 20%(wt), the optimum calcination temperature is 300°C. Copper oxide onto the surface of modified coconut shell charcoal proved to be monoclinic nanoparticles with grain size of 18.7nm. Sulfidation test was carried out on the condition of i) the concentration of hydrogen sulfide gas (mixed with nitrogen ) is 1024.2ppm and ii) gas velocity is 20ml/min, iii) 0.1g sample in the middle of the fixed-bed reactor (length: 450 mm, interior diameter: 5 mm) to test. The sample show excellent sulfur removal efficiency and its breakthrough time is up to 287 min on this condition.

Author(s):  
Kotaro Nakamura ◽  
Masashi Tanabe ◽  
Satoru Abe ◽  
Takashi Mawatari ◽  
Takao Nakagaki

Abstract At the Fukushima Daiichi nuclear power plant, zirconium in the fuel rod cladding reacted with water vapor at elevated temperatures due to a loss of cooling water, resulting in the production of a large amount of hydrogen. This hydrogen leaked from the reactor vessel and accumulated in the top of reactor building, eventually leading to an explosion. A hydrogen treatment system that re-oxidizes hydrogen to water vapor is one of the effective methods to prevent such an explosion. A prominent re-oxidation method is via a fixed bed reactor packed with metal oxide pellets. The advantages of this method are its relatively fast oxidation rate without external oxygen/air injection. In this study, experiments and complementary numerical calculations were performed on the hydrogen re-oxidation reaction by metal oxides. The oxidation of hydrogen by copper oxide is modeled by 5 interacting, elementary reactions consisting of 6 chemical species. Experiments were performed using two packed bed set-ups, with measurement of inlet/outlet gas composition and pre/post-analysis of solid composition used to determine constants of the individual reaction rates for numerical calculations. From these reaction constants, the temporal behavior of the outlet gas was predicted.


Author(s):  
Ehsan Kianfar ◽  
Mahmoud Salimi ◽  
Saeed Hajimirzaee ◽  
Behnam Koohestani

Abstract In this research, the catalytic conversion of methanol to gasoline range hydrocarbons has been studied over CuO (5 %)/ZSM-5 and CuO (7 %)/ZSM-5 catalysts prepared via sonochemistry methods. Conversion of methanol to gasoline (MTG) has been carried out in a fixed bed reactor under atmospheric pressure and 400˚C temperature, over copper oxide on the synthesized ZSM-5 catalyst. The samples were characterized by XRD, SEM, TEM, BET, and FTIR techniques; in which good crystallinity and high specific surface area of synthesized zeolite were proved after impregnation of zeolite with copper. The present investigation suggests that the CuO/ZSM-5 catalyst made by sonochemistry method can increase the yield toward hydrocarbon production. It was concluded that impregnation of zeolite with copper oxide can alter the Brønsted/Lewis acid sites ratio and provide new Lewis acid sites over the surface of the ZSM-5. The main products of methanol to gasoline reaction over the catalyst that prepared via sonochemistry method were toluene, xylene, ethylbenzene, ethyl toluene, tetra methylbenzene, diethyl benzene and butylbenzene. The total amount of aromatics in the products was 80 % by using this catalyst. Our results suggest that catalyst synthesized by using sonochemistry shows better production yield toward hydrocarbons by affecting the distribution of active sites on the surface of the ZSM-5.


Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1970 ◽  
Author(s):  
Jayanto Kumar Sarkar ◽  
Qingyue Wang

In the present study, a series of laboratory experiments were conducted to examine the impact of pyrolysis temperature on the outcome yields of waste coconut shells in a fixed bed reactor under varying conditions of pyrolysis temperature, from 400 to 800 °C. The temperature was increased at a stable heating rate of about 10 °C/min, while keeping the sweeping gas (Ar) flow rate constant at about 100 mL/min. The bio-oil was described by Fourier transform infrared spectroscopy (FTIR) investigations and demonstrated to be an exceptionally oxygenated complex mixture. The resulting bio-chars were characterized by elemental analysis and scanning electron microscopy (SEM). The output of bio-char was diminished pointedly, from 33.6% to 28.6%, when the pyrolysis temperature ranged from 400 to 600 °C, respectively. In addition, the bio-chars were carbonized with the expansion of the pyrolysis temperature. Moreover, the remaining bio-char carbons were improved under a stable structure. Experimental results showed that the highest bio-oil yield was acquired at 600 °C, at about 48.7%. The production of gas increased from 15.4 to 18.3 wt.% as the temperature increased from 400 to 800 °C. Additionally, it was observed that temperature played a vital role on the product yield, as well as having a vital effect on the characteristics of waste coconut shell slow-pyrolysis.


2011 ◽  
Vol 347-353 ◽  
pp. 2231-2235 ◽  
Author(s):  
Ping Lan ◽  
Li Hong Lan ◽  
Tao Xie ◽  
An Ping Liao

Catalytic steam reforming of bio-oil is an economically feasible route producing renewable hydrogen. Ni/MgO-La2O3-Al2O3 catalyst was prepared with Ni as active agent, Al2O3 as support and MgO, La2O3 as promoters. The experiments were carried out in a fixed-bed reactor. The content of Ni, calcination temperature, and calcinations time, were investigated with hydrogen yield as index. The optimal preparation conditions were concluded as follows: the Ni content 18%, the calcination temperature 8500C and the calcinations time 6 h.


Author(s):  
Emre Kilic ◽  
Selahattin Yilmaz

H-ZSM5 and H-Ferrierite acidities were modified by chemical liquid deposition using tetraethylorthosilicate (TEOS), silicontetratchloride (SiCl4) and triaminopropyltriethoxysilane (3-APTES). All depositions were carried out at room temperature for deposition times of 0.5 and 1 h. Reaction tests were performed in a tubular quartz fixed bed reactor at 375°C for weight hour space velocities of 22 h-1. Surface area and pore volume of the catalysts were decreased upon modifications. The least modification of acidity was achieved by TEOS. However, SiCl4 and 3-APTES deposition modification strongly decreased the number of Bronsted and Lewis acid sites. As the effect of the modification increased, total acidity of the SiCl4 modified catalyst decreased. The catalysts were tested in isomerization of n-butene. Modification decreased the activity of the catalysts, but improvement in selectivity was observed with TEOS deposition. TEOS deposition increased the selectivity of the catalysts; for synthesized H-ZSM5 from 57.95 to 63.74 percent, for commercial H-ZSM5-C from 26.78 to 32.52 percent, and for H-FER from 63.06 to 81.23 percent. However, modification with SiCl4 and 3-APTES decreased both conversion and selectivity of the parent catalysts.


2015 ◽  
Vol 29 (04) ◽  
pp. 1530002 ◽  
Author(s):  
A. R. Chourasia ◽  
Jacob Stahl

The technique of X-ray photoelectron spectroscopy has been used to investigate the chemical reactivity at the metal/ CuO interfaces. Thin films of the metallic overlayer (0.5 nm, 1.0 nm and 2.0 nm thickness) were deposited on copper oxide substrates at room temperature. In situ characterization of the interfaces has been performed. The 2p core level regions of the metals have been investigated. The spectral features show considerable reactivity at the interfaces. The core level peaks of the metal are observed to be shifted to the high BE energy side with the appearance of satellites. The spectral data confirm the formation of the metallic oxide at the interface. The satellite structure in the copper region is observed to disappear and the spectral features are found to approach those of elemental copper. The room temperature deposition of the metal on copper oxide therefore results in the reduction of copper oxide to elemental copper followed by the oxidation of the metal. The interface is found to consist of a mixture of metal oxide and elemental copper. The 2.0 nm samples were annealed. These samples show the diffusion of copper oxide through the overlayer. The metal reacts with this diffusing oxide to form metallic oxide. The interface is found to consist of a mixture of unreacted metal, the metal oxide, and elemental copper. The amount of the unreacted metal varied between 0% and 40% and can be controlled by the processing conditions. The investigation shows room temperature chemical reactivity at the metal/ CuO interface and provides a new method of preparing sub-nano-oxide films.


RSC Advances ◽  
2021 ◽  
Vol 11 (43) ◽  
pp. 26739-26749
Author(s):  
Nishesh Kumar Gupta ◽  
Jiyeol Bae ◽  
Kwang Soo Kim

In this study, CeO2/Fe2O3, CeO2/Mn2O3, and CeO2/Mn2O3/Fe2O3 nanocomposites were synthesized by the calcination of molten salt solutions.


2021 ◽  
Vol 83 (7) ◽  
pp. 1691-1702
Author(s):  
Yunlong Yang ◽  
Ling Li ◽  
Shuqian Sun ◽  
Ershu Lin ◽  
Jibo Xiao

Abstract In this study, spent mushroom substrates (SMSs) were fermented anaerobically at room temperature to gain liquid SMSs (LSMSs) that were used to remove nitrogen from the piggery wastewater with a low C/N ratio in a sequencing batch reactor (SBR) and solid SMSs (SSMSs) that were utilized to adsorb Pb2+ from Pb2+-containing wastewater in a fixed-bed reactor (FBR). After LSMSs supplement, the removal efficiency of both total nitrogen (TN) and NH+4-N increased from around 50% to 60–80%. High-throughput sequencing results presented an obvious change in microbial diversity, and some functional microorganisms like Zoogloea and Hydrogenophaga predominated to promote nitrogen removal. Pb2+ did not emerge from the effluent until 240 min with the corresponding concentration being less than 3 mg/L when using 30-day SSMSs as adsorbents, and it was demonstrated to be appropriate to use the Thomas model to predict Pb2+ sorption on SSMSs. Although various functional groups played a role in binding ions, the carboxyl group was proved to contribute most to Pb2+ adsorption. These results certified that the anaerobically fermented SMSs are decidedly suitable for wastewater treatment.


2021 ◽  
Vol 920 (1) ◽  
pp. 012002
Author(s):  
R Ahmad ◽  
S M Ahmahdi ◽  
A R Mohamed ◽  
C Z A Abidin ◽  
N N Kasim

Abstract This study describes the influence of torrefied coconut shell (CS) as solid fuel on pyrolysis product yield. The CS were torrefied and then pyrolysed in a fixed-bed reactor at different temperature and reaction time. The raw and torrefied CS were analysed for mass and energy yield, proximate analysis and ultimate analysis. The pyrolysis products yield were compared between raw CS and torrefied CS. The results showed that the properties of torrefied CS in terms of proximate and ultimate analysis were enhanced than raw CS. The calorific value for torrefied CS increased 17.17 MJ/kg to 22.25 MJ/kg. The optimum condition obtained for torrefaction pretreatment was at 275 °C and reaction time of 60 min. The highest bio-oil yield of 45% from pyrolysis process was at temperature and reaction time of 500 °C and 6 min, respectively. Thus, these results indicate torrefied CS was a suitable fuel feedstock to conduct in thermal conversion such as pyrolysis.


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