scholarly journals THERMOCATALYTIC DEGRADATION OF POLYPROPYLENE IN PRESENCE OF ALUMINUM SILICATES

2020 ◽  
Vol 63 (6) ◽  
pp. 85-89
Author(s):  
Lyubov V. Furda ◽  
Dmitry E. Smalchenko ◽  
Evgeny N. Titov ◽  
Olga E. Lebedeva
Keyword(s):  
Aluminum Content ◽  
Sol Gel ◽  
Fixed Bed ◽  
Textural Properties ◽  
Fixed Bed Reactor ◽  
Alternative Source ◽  
Catalyst Composition ◽  
Developed Surface ◽  
Liquid Products ◽  
Thermocatalytic Conversion

The process of thermocatalytic conversion of polypropylene into liquid hydrocarbons using amorphous aluminum silicates with aluminum content of 1.6-12.9 wt.% as catalysts was studied. The aluminum silicates were synthesized by sol-gel method using hydrolysis of tetraethoxysilane in a presence of aluminum salt at pH=9. All samples possessed acidic sites with pKa value of 3.46-5.00 and had a developed surface. Textural properties of the aluminum silicates were determined. Thermocatalytic conversion of polypropylene was carried out in a flow fixed-bed reactor with a fixed layer of the mixture of the catalyst and the reagent at a mass ratio of polymer : catalyst of 3 : 1 in argon atmosphere with a gradual rise of temperature in the range of 300 – 450 ºС. The sample of silica, which did not contain aluminum, was demonstrated to be inactive in polypropylene degradation, while other catalysts provided conversion of polypropylene into liquid products. The highest yield of liquid products was 80% for a catalyst with an aluminum content of 8.1 wt.%. According to the results of GLC saturated hydrocarbons were identified among the products for all samples. The effect of the concentration of acidic centers on the chemical and fractional composition of the target products was shown. For the studied aluminum silicates with the same pKa values, an increase in the aluminum content favored the formation of a lighter hydrocarbon fraction. For the catalyst with the highest aluminum content the n-alkanes of С5-С10 composition were identified. These products were closest to gasoline oil fraction. This provides a possibility to consider secondary polyolefins as an alternative source of motor fuels. An influence of catalyst composition on maximal temperature of polyethylene degradation was determined by differential thermal analysis.

scholarly journals Valuable Chemicals Derived from Pyrolysis Liquid Products of Spirulina platensis Residue

2019 ◽  
Vol 19 (3) ◽  
pp. 703 ◽  
Author(s):  
Siti Jamilatun ◽  
Budhijanto Budhijanto ◽  
Rochmadi Rochmadi ◽  
Avido Yuliestyan ◽  
Arief Budiman
Keyword(s):  
Polyaromatic Hydrocarbons ◽  
Food Additives ◽  
Fixed Bed ◽  
Liquid Product ◽  
Fixed Bed Reactor ◽  
Water Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Human Needs ◽  
Liquid Products ◽  
Interesting Alternative

With a motto of preserving nature, the use of renewable resources for the fulfillment of human needs has been seen echoing these days. In response, microalgae, a water-living microorganism, is perceived as an interesting alternative due to its easy-to-cultivate nature. One of the microalgae, which possess the potential for being the future source of energy, food, and health, is Spirulina plantesis. Aiming to identify valuable chemicals possibly derived from it, catalytic and non-catalytic pyrolysis process of the residue of S. plantesis microalgae has been firstly carried out in a fixed-bed reactor over the various temperature of 300, 400, 500, 550 and 600 °C. The resulting vapor was condensed so that the liquid product consisting of the top product (oil phase) and the bottom product (water phase) can be separated. The composition of each product was then analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). In the oil phase yield, the increase of aliphatic and polyaromatic hydrocarbons (PAHs) and the decrease of the oxygenated have been observed along with the increase of pyrolysis temperature, which might be useful for fuel application. Interestingly, their water phase composition also presents some potential chemicals, able to be used as antioxidants, vitamins and food additives.

Analysis of Gaseous and Liquid Products from Pressurized Pyrolysis of Flax Straw in a Fixed Bed Reactor

2010 ◽  
Vol 49 (10) ◽  
pp. 4627-4632 ◽  
Author(s):  
Mohammad Shahed Hasan Khan Tushar ◽  
Nader Mahinpey ◽  
Pulikesi Murugan ◽  
Thilakavathi Mani
Keyword(s):  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Liquid Products ◽  
Flax Straw

Enhanced Catalytic Conversion of Camelina Oil to Hydrocarbon Fuels Over Ni-MCM-41 Catalysts

2020 ◽  
Vol 12 (2) ◽  
pp. 304-311 ◽  
Author(s):  
Gaofeng Xu ◽  
Chengxinzhuo Jia ◽  
Zhengjun Shi ◽  
Ruijuan Liang ◽  
Chunhua Wu ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Crystalline Structure ◽  
Catalytic Cracking ◽  
Fixed Bed ◽  
Hydrocarbon Fuels ◽  
Fixed Bed Reactor ◽  
Ex Situ ◽  
Camelina Oil ◽  
Liquid Products ◽  
Mcm 41

The ex-situ catalytic cracking of camelina oil using nickel loaded MCM-41 as catalyst at 450 °C in fixed bed reactor was studied. Results revealed that the yield, selectivity and chemical composition of the liquid products was improved by nickel loaded MCM-41 without affecting the crystalline structure of MCM-41. Moreover, the loaded nickel onto MCM-41 facilitated the cyclization, alkylation, aromatization, deoxygenation, isomerization and cracking reactions.

Simulation Studies of Steam Reforming of Methane using Ni-Al2O3 Catalysts

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Giane Gonçalves Lenzi ◽  
Ervin Kaminski Lenzi ◽  
Cláudio Vilas Boas Fávero ◽  
Marcelo Kaminski Lenzi ◽  
Regina Maria Matos Jorge ◽  
...  
Keyword(s):  
Sol Gel ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Co2 Production ◽  
Simulation Studies ◽  
One Dimensional ◽  
Wgs Reaction ◽  
Different Characteristics ◽  
Water Gas ◽  
Al2o3 Catalyst

This paper reports the results of reforming methane into synthesis gas using industrial Ni-Al2O3 catalyst (75% NiO wt.) and Ni-Al2O3 produced by the sol gel method (8% Ni wt.). A mathematical investigation on the performance of a one-dimensional model of catalytic conventional fixed-bed reactor was developed and implemented for the process. The results indicated that the industrial catalyst favored the water gas shift (WGS) reaction increasing CO2 production. However in temperatures of 773 and 973 K the yield (H2/CH4,reacted) was more efficient for the sol-gel catalyst. This result is possibly due to the different characteristics as specific surface area and temperature reduction. The model validation for the adjustment parameters U and a1 was more efficient for temperature profiles (2% error) than for mole fraction (10% error).

Synthesis of CeO2 Supported BaCoO3 Perovskites for Chemical-Looping Methane Reforming to Syngas and Hydrogen

2017 ◽  
Author(s):  
Haoran Ding ◽  
Yongqing Xu ◽  
Linyi Xiang ◽  
Qiyao Wang ◽  
Cheng Shen ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Fixed Bed ◽  
Gas Production ◽  
Fixed Bed Reactor ◽  
Methane Reforming ◽  
Chemical Looping ◽  
X Ray ◽  
Syngas Production ◽  
Fuel Reactor

In order to reduce the hotspots in partial oxidation of methane, CeO2 supported BaCoO3 perogvskite-type oxides were synthesized using a sol-gel method and applied in chemical-looping steam methane reforming (CL-SMR). The synthesized BaCoO3-CeO2 was characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). XRD and XPS results suggested that the obtained BaCoO3 was pure crystalline perovskite, its crystalline structure and lattice oxygen could regenerate after calcining. The reactivity of perovskite-type oxides in CL-SMR was evaluated using a fixed-bed reactor. Gas production rates and H2/CO ratios showed that the optimal reaction temperature was about 860 °C and the properly reaction time in fuel reactor was about 180s when Weight Hourly Space Velocity (WHSV) was 23.57 h−1. The syngas production in fuel reactor were 265.11 ml/g, hydrogen production in reforming reactor were 82.53 ml/g. (CSPE)

scholarly journals Pengaruh kondisi operasi pada kinerja reaksi dekomposisi katalitik metana dalam reaktor gauze

2018 ◽  
Vol 9 (2) ◽  
pp. 69
Author(s):  
Widodo W Purwanto ◽  
Yuswan Muharam ◽  
Dwi Yulianti
Keyword(s):  
Stainless Steel ◽  
Methane Conversion ◽  
Sol Gel ◽  
Fixed Bed ◽  
Dip Coating ◽  
Space Time ◽  
Methane Decomposition ◽  
Fixed Bed Reactor ◽  
Feed Ratio ◽  
Operation Conditions

Methane decomposition is an alternative way to produce high quality carbon nanotubes (CNTs) and hydrogen simultaneously. The use of gauze reactor for methane decomposition had proven in solving pressure drop problem in fixed bed reactor. This experiment was carried out to study the effects of operation conditions (space time, temperature, and feed ratio) to gauze rector performance. Ni-Cu-Al catalyst which is prepared by sol-gel method with atomic ratio 2:1:1, was coated to Stainless Steel gauze by dip coating method. The reaction was done by flowing methane into the reactor at atmospheric pressure and varying space time (0.0006; 0.0032; 0.006 g×kat×min/mL), temperature (700, 750, and 800°C), and feed ratio CH4:H2 (1:0, 4:1, 1:1). An online gas chromatograph is used to detect the gas products. Reactor performances were observed from methane conversion, hydrogen purity, carbon yield and quality of nanocarbon that have been produced. Experiment result showed that the highest reactor performance (except nanocarbon quality) occurred at space time 0.006 gr cat min/mL, temperature 700 °C, and with pure methane as feed which give methane conversion, hydrogen purity, and yield carbon results are 90.66%, 90.16%, and 37 g carbon/g catalyt, respectively. Based on SEM analysis indicated that the best nanocarbon morphology can be gained at CH4:H2 ratio of 1:1.Keyword : methane decompotition, gauze reactor, carbon nanotube Abstrak Dekomposisi katalitik metana adalah salah satu alternatif untuk memproduksi hidrogen dan nanokarbon bermutu tinggi secara simultan. Penggunaan reaktor gauze untuk dekomposisi metana terbukti dapat mengatasi permasalahan penyumbatan pada reaktor unggun diam. Penelitian ini dilakukan untuk mengetahui pengaruh kondisi operasi (space time, temperatur, dan rasio umpan) terhadap kinerja reaktor gauze. Katalis Ni-Cu-Al disiapkan dengan menggunakan metode sol-gel dengan perbandingan atomik 2:1:1 dilapiskan pada gauze Stainless Steel dengan metode dip-coating. Reaksi dilakukan dengan mengalirkan metana ke dalam reaktor pada tekanan atmosferik dan dengan memvariasikan space time (0,0006; 0,0032; 0,006 g×kat×min/mL), temperatur (700, 750, dan 800 °C), dan rasio umpan CH4:H2 (1:0, 4:1, 1:1). Produk gas dianalisis dengan menggunakan gas chromatography yang terpasang secara online. Kinerja reaktor pada penelitian ini ditinjau dari konversi metana, kemurnian hidrogen, perolehan dan kualitas nanokarbon yang dihasilkan. Berdasarkan hasil eksperimen diketahui bahwa kinerja reaktor paling tinggi (kecuali kualitas nanokarbon) terjadi pada space time 0,006 g×kat×min/mL, temperatur 700 °C, dan dengan menggunakan metana murni yang memberikan hasil konversi metana, kemurnian hidrogen, serta perolehan karbon secara berturut-turut 90,66%, 90,16%, dan 37 gram karbon/gram katalis. Hasil analisis menggunakan SEM menunjukkan bahwa morfologi nanokarbon paling baik didapat pada komposisi reaktan CH4: H2 = 1:1.Kata Kunci : dekomposisi metana, reaktor gauze, karbon nanotube

Lanthanum Modified Catalyst for Efficient Supply of Hydrogen through Dehydrogenation of Organic Chemical Hydrides

2011 ◽  
Vol 287-290 ◽  
pp. 2110-2115
Author(s):  
Gang Li Zhu ◽  
Tao Chen ◽  
Xue Dong Jiang ◽  
Hai Liang Zhang ◽  
Bo Lun Yang
Keyword(s):  
Energy Dispersive Spectrometer ◽  
Fixed Bed ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Metal Species ◽  
Organic Chemical ◽  
Impregnation Method ◽  
Active Components

Dehydrogenation process of organic chemical hydrides was improved by modifying the catalyst of nickel-activated carbon (Ni/AC) with lanthanum (La). The catalysts were prepared in impregnation method with different amounts of La and Ni. The textural properties and morphology of catalyst were analyzed by nitrogen adsorption and transmission electron microscope equipped with energy dispersive spectrometer respectively. The effects such as metal content and granule size on the dehydrogenation of cyclohexane were investigated in fixed bed reactor. The results show that the metallic active components can be well dispersed on the support, and the elements analysis indicates the metal species tend to assemble on the surface layer rather than being distributed equally in the whole catalyst. The La modified catalyst LaNi/AC exhibited superior catalytic performance to Ni/AC and the conversion was 45% for LaNi/AC catalyst at 673K, while only 34 % for Ni/AC under the same conditions.

scholarly journals Ni–Cu High-Loaded Sol–Gel Catalysts for Dehydrogenation of Liquid Organic Hydrides: Insights into Structural Features and Relationship with Catalytic Activity

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2017
Author(s):  
Yuliya Gulyaeva ◽  
Maria Alekseeva (Bykova) ◽  
Olga Bulavchenko ◽  
Anna Kremneva ◽  
Andrey Saraev ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Sol Gel ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Structural Features ◽  
Atomic Ratio ◽  
Fixed Bed Reactor ◽  
High Catalytic Activity ◽  
Wide Range ◽  
Structure Reactivity Relationship

The heightened interest in liquid organic hydrogen carriers encourages the development of catalysts suitable for multicycle use. To ensure high catalytic activity and selectivity, the structure–reactivity relationship must be extensively investigated. In this study, high-loaded Ni–Cu catalysts were considered for the dehydrogenation of methylcyclohexane. The highest conversion of 85% and toluene selectivity of 70% were achieved at 325 °C in a fixed-bed reactor using a catalyst with a Cu/Ni atomic ratio of 0.23. To shed light on the relationship between the structural features and catalytic performance, the catalysts were thoroughly studied using a wide range of advanced physicochemical tools. The activity and selectivity of the proposed catalysts are related to the uniformity of Cu distribution and its interaction with Ni via the formation of metallic solid solutions. The method of introduction of copper in the catalyst plays a crucial role in the effectiveness of the interaction between the two metals.

scholarly journals Hydrocracking of a Heavy Vacuum Gas Oil with Fischer–Tropsch Wax

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5497
Author(s):  
Olga Pleyer ◽  
Dan Vrtiška ◽  
Petr Straka ◽  
Aleš Vráblík ◽  
Jan Jenčík ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Positive Influence ◽  
Oil Refinery ◽  
Fixed Bed Reactor ◽  
Vacuum Gas Oil ◽  
Gas Oil ◽  
Fischer Tropsch ◽  
Heavy Petroleum ◽  
Liquid Products ◽  
Heavy Vacuum Gas Oil

Catalytic hydrocracking represents an optimal process for both heavy petroleum fractions and Fischer–Tropsch (FT) wax upgrading because it offers high flexibility regarding the feedstock, reaction conditions and products’ quality. The hydrocracking of a heavy vacuum gas oil with FT wax was carried out in a continuous-flow catalytic unit with a fixed-bed reactor and a co-current flow of the feedstock and hydrogen at the reaction temperatures of 390, 400 and 410 °C and a pressure of 8 MPa. The increasing reaction temperature and content of the FT wax in the feedstock caused an increasing yield in the gaseous products and a decreasing yield in the liquid products. The utilisation of the higher reaction temperatures and feedstocks containing the FT wax showed a positive influence on the conversion of the fraction boiling above 400 °C to lighter fractions. Although the naphtha and middle distillate fractions obtained via atmospheric and vacuum distillations of the liquid products of hydrocracking did not comply with the particular quality standards of automotive gasolines and diesel fuels, the obtained products still present valuable materials which could be utilised within an oil refinery and in the petrochemical industry.

scholarly journals High Selectivity and Stability of Nickel Catalysts for CO2 Methanation: Support Effects

Catalysts ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 24 ◽  
Author(s):  
Jeremías Martínez ◽  
Edgar Hernández ◽  
Salvador Alfaro ◽  
Ricardo López Medina ◽  
Guadalupe Valverde Aguilar ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Fixed Bed ◽  
Tetragonal Zirconia ◽  
Nickel Catalysts ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Methane Formation ◽  
Co2 Methanation ◽  
X Ray

In this work, we present an investigation concerning the evaluation of the catalytic properties of Ni nanoparticles supported on ZrO2, SiO2, and MgAl2O4 for CO2 hydrogenation to methane. The supports were prepared by coprecipitation and sol-gel, while Ni was incorporated by impregnation (10–20 wt %). X-ray diffraction, nitrogen physisorption, temperature-programmed reduction, H2 pulse chemisorption, Raman spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy were the main characterization techniques employed. A laboratory fixed-bed reactor operated at atmospheric pressure, a temperature range of 350–500 °C, and a stoichiometric H2/CO2 molar ratio was used for catalyst evaluation. The most outstanding results were obtained with nickel catalysts supported on ZrO2 with CO2 conversions of close to 60%, and selectivity to methane formation was 100% on a dry basis, with high stability after 250 h of reaction time. The majority presence of tetragonal zirconia, as well as the strong Ni–ZrO2 interaction, were responsible for the high catalytic performance of the Ni/ZrO2 catalysts.

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