scholarly journals Catalytic Pyrolysis of Naphtha on SHS Catalysts

2009 ◽  
Vol 12 (1) ◽  
pp. 17 ◽  
Author(s):  
G. Xanthopoulou ◽  
G. Vekinis
Keyword(s):  
Conversion Efficiency ◽  
Strong Interaction ◽  
Catalytic Pyrolysis ◽  
Catalyst Surface ◽  
Active Phase ◽  
Light Olefins ◽  
High Yield ◽  
Partial Substitution ◽  
Process Conditions ◽  
Thermal Pyrolysis

High yield of light olefins by catalytic pyrolysis of naphtha on spinel-based catalysts is reported. The yields of ethylene and propylene reach over 50% and are at least 10% and 5% higher respectively than the yield using thermal Pyrolysis, under the same process conditions. The partial substitution of Mg by Co in MgAl<sub>2</sub>O<sub>4</sub> and the incorporation of Al<sub>2</sub>O<sub>3</sub>, SiO<sub>2</sub>, MgO, H<sub>3</sub>BO<sub>3</sub> in the spinel and SHS synthesis of KVO<sub>3</sub> all increase the catalytic conversion efficiency while at the same time they suppress substantially the formation of coke. It was found that SHS-KVO<sub>3</sub> catalytically accelerates the gasification of coke deposited on the catalyst surface and its optimum values were found to be more than 10 wt.%. The addition of B<sub>2</sub>O<sub>3</sub> into the KVO<sub>3</sub>-based catalyst causes a strong interaction between KVO<sub>3</sub> and SHS support, which decreases the loss by evaporation of the active phase

Regulating light olefins or aromatics production in ex-situ catalytic pyrolysis of biomass by engineering the structure of tin modified ZSM-5 catalyst

2021 ◽  
pp. 124975
Author(s):  
Jingyuan Shang ◽  
Guangbin Fu ◽  
Zhenping Cai ◽  
Xiang Feng ◽  
Yongxiao Tuo ◽  
...  
Keyword(s):  
Catalytic Pyrolysis ◽  
Ex Situ ◽  
Light Olefins ◽  
Pyrolysis Of Biomass

scholarly journals Experimental Study of Thermal and Catalytic Pyrolysis of Plastic Waste Components

2018 ◽  
Vol 10 (11) ◽  
pp. 3979 ◽  
Author(s):  
Azubuike Anene ◽  
Siw Fredriksen ◽  
Kai Sætre ◽  
Lars-Andre Tokheim
Keyword(s):  
High Density Polyethylene ◽  
Catalytic Pyrolysis ◽  
Batch Reactor ◽  
Decomposition Temperature ◽  
Nitrogen Atmosphere ◽  
Waste Plastics ◽  
Molecular Weight Range ◽  
Thermal Pyrolysis ◽  
Pp Blends ◽  
Hydrocarbon Distribution

Thermal and catalytic pyrolysis of virgin low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP) and mixtures of LDPE/PP were carried out in a 200 mL laboratory scale batch reactor at 460 °C in a nitrogen atmosphere. Thermogravimetric analysis (TGA) was carried out to study the thermal and catalytic degradation of the polymers at a heating rate of 10 °C/min. The amount of PP was varied in the LDPE/PP mixture to explore its effect on the reaction. In thermal degradation (TGA) of LDPE/PP blends, a lower decomposition temperature was observed for LDPE/PP mixtures compared to pure LDPE, indicating interaction between the two polymer types. In the presence of a catalyst (CAT-2), the degradation temperatures for the pure polymers were reduced. The TGA results were validated in a batch reactor using PP and LDPE, respectively. The result from thermal pyrolysis showed that the oil product contained significant amounts of hydrocarbons in the ranges of C7–C12 (gasoline range) and C13–C20 (diesel range). The catalyst enhanced cracking at lower temperatures and narrowed the hydrocarbon distribution in the oil towards the lower molecular weight range (C7–C12). The result suggests that the oil produced from catalytic pyrolysis of waste plastics has a potential as an alternative fuel.

Modulation of carbon nanotube yield and type through the collective effects of initially deposited catalyst amount and MgO underlayer annealing temperature

MRS Advances ◽  
2018 ◽  
Vol 4 (3-4) ◽  
pp. 139-146
Author(s):  
Takashi Tsuji ◽  
Guohai Chen ◽  
Kenji Hata ◽  
Don N. Futaba ◽  
Shunsuke Sakurai
Keyword(s):  
Carbon Nanotube ◽  
Annealing Temperature ◽  
Catalyst Surface ◽  
Catalyst System ◽  
Forest Growth ◽  
Collective Effects ◽  
High Yield ◽  
Force Microscopy ◽  
Atomic Force ◽  
Fe Catalysts

ABSTRACTRecently, the millimetre-scale, highly efficient growth of single-wall carbon nanotube (SWCNT) forests from iron (Fe) catalysts has been reported through the annealing of the magnesia (MgO) underlayer. Here, we report the modulation of the CNT yield (height) and average number of CNT walls for a Fe/MgO catalyst system through the collective effects of initial Fe amount and MgO annealing temperature. Our results revealed the existence of a well-defined region for high yield SWCNT forest growth in the domain of deposited Fe thickness and MgO annealing temperature. Through topographic examinations of the catalyst surface using atomic force microscopy, we confirmed that our results stem from the collective effects of increased amounts of surface-bound Fe through the amount of deposition and suppression of Fe subsurface diffusion, together govern the amount of surface-bound catalyst. The combination of these mechanisms determined the final nanoparticle size, density, and stability and could explain the three distinctly defined regions: low yield SWCNT growth, high yield SWCNT growth, and high yield multiwall CNT growth. Furthermore, we explained the observed borders between these three regions.

scholarly journals Study of Regularities and Optimization of the Process of Fir Wood Peroxide Delignification in the Medium of “Acetic Acid – Water” in the Presence of Sulfuric Acid Catalyst

2019 ◽  
pp. 590-603
Author(s):  
Olga V. Yatsenkova ◽  
Andrei M. Skripnikov ◽  
Boris N. Kuznetsov
Keyword(s):  
Acetic Acid ◽  
Lignin Content ◽  
Reaction Medium ◽  
Acid Catalyst ◽  
Acid Water ◽  
High Yield ◽  
Process Conditions ◽  
Residual Lignin ◽  
Acetic Acid Water ◽  
Peroxide Delignification

The work describes a one-stage method of cellulose obtaining from fir wood based on peroxide delignification of wood under mild conditions (100 °C, atmospheric pressure) in the presence of acetic acid, water and catalyst of 2% wt. H2SO4. The possibility of obtaining cellulose with a residual lignin content <1% wt. at a low concentration of hydrogen peroxide (3% wt.) in the reaction medium was established. The optimal concentrations of reagents (Н2О2 – 3% wt., CH3COOH – 38.9% wt.) and the duration of the process (4 h) were determined by experimental and calculation methods. This conditions provide a high yield of cellulose product (≥45% wt.) with a low content of residual lignin (<1% wt.). The composition and structure of fir cellulose was studied by chemical analysis and by FTIR and SEM methods. The cellulosic product which was obtained in optimal process conditions is high-quality cellulose

scholarly journals Production of Fuel Oil from Municipal Plastic Wastes Using Thermal and Catalytic Pyrolysis

2020 ◽  
pp. 1-8
Author(s):  
Dan Kica Omol ◽  
Ongwech Acaye ◽  
David Fred Okot ◽  
Ocident Bongomin
Keyword(s):  
Activated Carbon ◽  
Reaction Time ◽  
Clay Mineral ◽  
Catalytic Pyrolysis ◽  
Fuel Oil ◽  
Maximum Temperature ◽  
Heating Rates ◽  
Thermal Pyrolysis ◽  
Plastic Wastes ◽  
Acid Activated Clay

Plastics have become an essential part of modern life today. The global production of plastics has gone up to 299 million tonnes in 2013, which has increased enormously in the present years. The utilization of plastics and its final disposal pose tremendous negative significant impacts on the environment. The present study aimed to investigate the thermal and catalytic pyrolysis for the production of fuel oil from the polyethene plastic wastes. The samples collection for both plastic wastes and clay catalyst, sample preparation and pyrolysis experiment for oil production was done in Laroo Division, Gulu Municipality, Northern Uganda Region, Uganda. Catalysts used in the experiment were acid-activated clay mineral and aluminium chlorides on activated carbon. The clay mineral was activated by refluxing it with 6M Sulphuric acid for 3 hours. The experiment was conducted in three different phases: The first phase of the experiment was done without a catalyst (purely thermal pyrolysis). The second phase involves the use of acid-activated clay mineral. The third phase was done using aluminium chlorides on activated carbon. Both phases were done at different heating rates. In purely thermal pyrolysis, 88 mL of oil was obtained at a maximum temperature of 39ºC and heating rates of 12.55ºC /minute and reaction time of 4 hours. Acid activated clay mineral yielded 100 mL of oil with the heating rates of 12.55ºC/minute and reaction time of 3 hours 30 minutes. While aluminium chlorides on activated carbon produced 105 mL of oil at a maximum temperature of 400ºC and heating rates of 15.5ºC /minute and reaction time of 3 hours 10 minutes. From the experimental results, catalytic pyrolysis is more efficient than purely thermal pyrolysis and homogenous catalysis (aluminium chlorides) shows a better result than solid acid catalyst (activated clay minerals) hence saving the energy needed for pyrolysis and making the process more economically feasible.

scholarly journals A Novel Inulin-Mediated Ethanol Precipitation Method for Separating Endo-Inulinase From Inulinases for Inulooligosaccharides Production From Inulin

2021 ◽  
Vol 9 ◽  
Author(s):  
Xin Li ◽  
Qiannan Zhang ◽  
Wei Wang ◽  
Shang-Tian Yang
Keyword(s):  
Enzymatic Hydrolysis ◽  
Aspergillus Niger ◽  
Functional Food ◽  
Degree Of Polymerization ◽  
Precipitation Method ◽  
High Yield ◽  
Process Conditions ◽  
Food Ingredients ◽  
Ethanol Precipitation ◽  
Novel Method

Inulin is a kind of polysaccharide that can be obtained various biomass. Inulooligosaccharides (IOS), a kind of oligosaccharides that can be obtained from inulin by enzymatic hydrolysis using inulinases, have been regarded as the functional food ingredients. Commercially available inulinases produced by natural Aspergillus niger contained both endo- and exo-inulinase activities. For IOS production from inulin, it is desirable to use only endo-inulinase as exo-inulinase would produce mainly the monosacchairde fructose from inulin. In the present study, a simple inulin-mediated ethanol precipitation method was developed to separate endo- and exo-inulinases present in natural inulinases. IOS production from inulin using the enriched endo-inulinase was then optimized in process conditions including pH and temperature, achieving a high yield of ∼94%. The resultant IOS products had a degree of polymerization ranging from 2 to 7. The study demonstrated a novel method for obtaining partially purified or enriched endo-inulinase for IOS production from inulin in an efficient process.

Thermal Pyrolysis of Polyethylene in Fluidized Beds: Review of the Influence of Process Parameters on Product Distribution

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
K. Suresh Kumar Reddy ◽  
Pravin Kannan ◽  
Ahmed Al Shoaibi ◽  
C. Srinivasakannan
Keyword(s):  
Fluidized Bed ◽  
Process Parameters ◽  
Fluidized Beds ◽  
Pyrolysis Temperature ◽  
Liquid Product ◽  
Product Distribution ◽  
Major Influence ◽  
Process Conditions ◽  
Influence Of Process Parameters ◽  
Thermal Pyrolysis

The present work is an attempt to compile and analyze the most recent literature pertaining to thermal pyrolysis of plastic waste using fluidized bed reactors. The review is short owing to the small number of work reported in the open literature in particular to the fluidized beds. Although works on pyrolysis are reported in fixed beds, autoclaves, and fluidized beds, vast majority of them address to the utilization of fluidized bed due to their advantages and large scale adaptability. The pyrolysis temperature and the residence time are reported to have major influence on the product distribution, with the increase in pyrolysis temperature favoring gas production, with significant reduction in the wax and oil. The pyrolysis gas generally contains H2, CO, CO2, CH4, C2H4, C2H6 while liquid product comprises benzene, toluene, xylene, styrene, light oil, heavy oil, and gasoline with the variations depending on process conditions. The effects of other process parameters, namely fuel feed rate, fuel composition, and fluidizing medium have been reviewed and presented.

scholarly journals Methanol promoted naphtha catalytic pyrolysis to light olefins on Zn-modified high-silicon HZSM-5 zeolite catalysts

RSC Advances ◽  
2019 ◽  
Vol 9 (36) ◽  
pp. 20818-20828 ◽  
Author(s):  
Qi-tong Cheng ◽  
Ben-xian Shen ◽  
Hui Sun ◽  
Ji-gang Zhao ◽  
Ji-chang Liu
Keyword(s):  
Catalytic Pyrolysis ◽  
Coupling Reaction ◽  
Zeolite Catalysts ◽  
Light Olefins ◽  
Efficient Utilization ◽  
Catalytic Reactivity ◽  
High Silicon ◽  
The Relationship

Exploring the relationship between the properties and catalytic reactivity of the Zn-modified high-silicon ZSM-5 in the methanol/naphtha coupling reaction and achieving the efficient utilization of naphtha.

Effects of initial crystal structure of Fe2O3 and Mn promoter on effective active phase for syngas to light olefins

2020 ◽  
Vol 261 ◽  
pp. 118219 ◽  
Author(s):  
Yi Liu ◽  
Fangxu Lu ◽  
Yu Tang ◽  
Minyang Liu ◽  
Franklin Feng Tao ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Active Phase ◽  
Light Olefins ◽  
Initial Crystal

scholarly journals A Novel Method to Achieve Selective Emitter Using Surface Morphology for PERC Silicon Solar Cells

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5207
Author(s):  
Minkyu Ju ◽  
Jeongeun Park ◽  
Young Hyun Cho ◽  
Youngkuk Kim ◽  
Donggun Lim ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Sheet Resistance ◽  
Conversion Efficiency ◽  
Single Step ◽  
Process Conditions ◽  
Selective Emitter ◽  
Driving Time ◽  
Novel Method ◽  
The Difference ◽  
Surface Morphologies

Recently, selective emitter (SE) technology has attracted renewed attention in the Si solar cell industry to achieve an improved conversion efficiency of passivated-emitter rear-contact (PERC) cells. In this study, we presented a novel technique for the SE formation by controlling the surface morphology of Si wafers. SEs were formed simultaneously, that is, in a single step for the doping process on different surface morphologies, nano/micro-surfaces, which were formed during the texturing processes; in the same doping process, the nano- and micro-structured areas showed different sheet resistances. In addition, the difference in sheet resistance between the heavily doped and shallow emitters could be controlled from almost 0 to 60 Ω/sq by changing the doping process conditions, pre-deposition and driving time, and temperature. Regarding cell fabrication, wafers simultaneously doped in the same tube were used. The sheet resistance of the homogeneously doped-on standard micro-pyramid surface was approximately 82 Ω/sq, and those of the selectively formed nano/micro-surfaces doped on were on 62 and 82 Ω/sq, respectively. As a result, regarding doped-on selectively formed nano/micro-surfaces, SE cells showed a JSC increase (0.44 mA/cm2) and a fill factor (FF) increase (0.6%) with respect to the homogeneously doped cells on the micro-pyramid surface, resulting in about 0.27% enhanced conversion efficiency.

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