scholarly journals Investigation of thermal and catalytic degradation of polystyrene waste into styrene monomer over natural volcanic tuff and Florisil catalysts

2013 ◽  
Vol 11 (5) ◽  
pp. 725-735 ◽  
Author(s):  
Miuţa Filip ◽  
Aurelia Pop ◽  
Ioana Perhaiţa ◽  
Mărioara Moldovan ◽  
Roxana Truşcă
Keyword(s):  
Textural Properties ◽  
Product Distribution ◽  
Catalytic Degradation ◽  
Gas Chromatography Mass Spectrometry ◽  
Conversion Degree ◽  
Infrared Spectrometry ◽  
Volcanic Tuff ◽  
Styrene Monomer ◽  
Liquid Products ◽  
Polystyrene Waste

AbstractThermal and catalytic degradation of polystyrene waste over two different samples of natural volcanic tuff catalyst comparative with Florisil catalyst has been carried out in order to establish the conversion degree into styrene monomer. The polystyrene waste (PS) was subjected to a thermal degradation process in the range of 380–500°C in presence of studied catalysts in a ratio of 1/10 in mass, catalyst/PS. The catalysts were characterized by N2 adsorption-desorption isotherms (BET), Scanning Electron Microscopy (SEM) and Fourier-transform infrared spectrometry (FTIR). Influences of temperature and type of catalysts on the yields and on the distribution of end-products obtained by thermal and catalytic degradation of polystyrene waste have been studied. The maximum yields of liquid products were obtained at 460°C degradation temperature and were calculated between 83.45% and 90.11%. The liquid products were characterized by gas chromatography mass spectrometry (GC-MS) and FTIR analytical techniques. The GC-MS results showed that the liquid products contained styrene monomer up to 55.62%. The FTIR spectra of liquid products indicated the specific vibration bands of the functional groups of compounds of liquid products. The amounts of styrene monomer obtained were influenced by structural and textural properties of studied catalyst and the contribution on product distribution is discussed.

scholarly journals The Effect of Natural Clays Catalysts on Thermal Degradation of a Plastic Waste Mixture

2013 ◽  
Vol 8-9 ◽  
pp. 103-114 ◽  
Author(s):  
Miuţa Filip ◽  
Aurelia Pop ◽  
Ioana Perhaiţa ◽  
Roxana Trusca ◽  
Tiberiu Rusu
Keyword(s):  
Electronic Energy ◽  
Catalytic Degradation ◽  
Plastic Waste ◽  
Gas Chromatography Mass Spectrometry ◽  
Infrared Spectrometry ◽  
Chemical Compositions ◽  
Polymer Waste ◽  
Plastic Wastes ◽  
Natural Clays ◽  
Waste Mixture

The thermal and catalytic degradation of a plastic wastes mixtures using two types of natural clays catalysts has been carried out in order to obtaining liquid oils with potential use in the chemical industry. Thus, the polymer waste mixture (PWM) of polystyrene (PS), poly (ethylene terephthalate) (PET) and poly (vinyl chloride) (PVC) were thermally degraded at 420 °C in absence and presence of studied catalysts in mass ratio 1:10, catalyst/PWM. The catalysts were characterized by N2 adsorption-desorption isotherms (BET), Scanning Electron Microscopy (SEM) and Fourier-transform infrared spectrometry (FTIR) for determined the structural and textural properties. The degradation of plastic wastes produces gases, liquids and solid residue products. The effect of the catalyst types on the yields and distribution of end-products obtained by thermal and catalytic degradation of mixed plastic waste has been studied. The yields of liquid oils fractions were calculated between 54.98 wt.% and 62.18 wt.%. The liquids and solid products were analyzed by different analytical techniques: gas chromatography mass spectrometry (GC-MS), ultraviolet visible spectroscopy (UV-Vis) and/or FTIR, in order to establish the chemical compositions. The GC-MS results showed that the liquid products contain in principal monoaromatic compounds like styrene, toluene, ethylbenzene or α-methylstyrene. The FTIR and UV-Vis spectra of products indicated the specific vibration bands or transitions between electronic energy levels of the functional groups of the constituent compounds.

scholarly journals Effect of Zn/ZSM-5 and FePO4Catalysts on Cellulose Pyrolysis

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Haian Xia ◽  
Xiaopei Yan ◽  
Siquan Xu ◽  
Li Yang ◽  
Yuejie Ge ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Value Added ◽  
Product Distribution ◽  
Acid Sites ◽  
Gas Chromatography Mass Spectrometry ◽  
Lewis Acid Sites ◽  
Liquid Products ◽  
Temperature Programmed ◽  
Xrd Techniques ◽  
Brønsted And Lewis Acid

A series of Zn/ZSM-5 catalysts with different Zn contents and FePO4were used to pyrolyze cellulose to produce value added chemicals. The nature of these catalysts was characterized by ammonia-temperature programmed desorption (NH3-TPD), IR spectroscopy of pyridine adsorption, and X-ray diffraction (XRD) techniques. Noncatalytic and catalytic pyrolytic behaviors of cellulose were studied by thermogravimetric (TG) technique. The pyrolytic liquid products, that is, the biooils, were analyzed by gas chromatography-mass spectrometry (GC-MS). The major components of the biooils are anhydrosugars such as levoglucosan (LGA), 1,6-anhydro-β-D-glucofuranose (AGF), levoglucosenone (LGO, 1,6-anhydro-3,4-dideoxy-β-D-pyranosen-2-one), and 1,4:3,6-dianhydro-α-D-glucopyranose (DGP), as well as furan derivatives, alcohols, and so forth. Zn/ZSM-5 samples with Brønsted and Lewis acid sites and the FePO4catalyst with Lewis acid sites were found to have a significant effect on the pyrolytic behaviors of cellulose and product distribution. These results show that Brønsted and Lewis acid sites modified remarkably components of the biooil, which could promote the production of furan compounds and LGO. On the basis of the findings, a model was proposed to describe the pyrolysis pathways of cellulose catalyzed by the solid acid catalysts.

scholarly journals Effect of Temperature on Gas and Liquid Products Distribution in Thermal Cracking of Nigerian Bitumen

2021 ◽  
Vol 22 (2) ◽  
pp. 7-16
Author(s):  
ABIMBOLA GEORGE OLAREMU ◽  
Ezekiel Oluyemi ODEBUNMI ◽  
Jim A ANDERSON
Keyword(s):  
Thermal Cracking ◽  
Product Distribution ◽  
Reaction Scheme ◽  
Effect Of Temperature ◽  
Gas Chromatography Mass Spectrometry ◽  
Reaction Products ◽  
Sulphur Compounds ◽  
Oil Reserves ◽  
Liquid Products ◽  
Cracking Reaction

The increasing population growth resulting in the tremendous increase in consumption of fuels, energy, and petrochemical products and coupled with the depletion in conventional crude oil reserves and production make it imperative for Nigeria to explore her bitumen reserves so as to meet her energy and petrochemicals needs. Samples of Agbabu bitumen were subjected to thermal cracking in a tubular steel reactor operated at 10 bar pressure to investigate the effect of temperature on the cracking reaction. The gas produced was analyzed in a Gas Chromatograph while the liquid products were subjected to Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Heptane was the dominant gas produced in bitumen cracking at all temperatures and the reaction products show a distribution of lighter hydrocarbons most of which are in the gasoline range. The product distribution of bitumen conversion depends strongly on the cracking temperature and the oil produced contains the valuable liquid fractions. The products of thermal cracking of bitumen can be classified into the following groups; alkanes, alkenes, amines, aromatics, alkanoic acids, alkanols, esters, ethers, ketones, sulphur compounds, and nitrogen compounds. The activation energies of the products formed were determined. The LNG produced all have unusually low values activation energy (hence easily converted) pointing to the high quality of Agbabu crude      The conversion process was affected by the reaction time and suggests that the transformation of bitumen into smaller fractions follows a definite reaction scheme in which the heavy oil transformed to lower fractions and was subsequently converted to smaller liquid fractions and gases.

scholarly journals UV Stimulated Manganese Dioxide for the Persulfate Catalytic Degradation of Bisphenol A

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 502
Author(s):  
Guihua Dong ◽  
Bing Chen ◽  
Bo Liu ◽  
Stanislav R. Stoyanov ◽  
Yiqi Cao ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Reaction Mechanisms ◽  
Reduction Rate ◽  
Catalytic Degradation ◽  
Gas Chromatography Mass Spectrometry ◽  
Degradation Pathways ◽  
Industrial Chemicals ◽  
Oh Groups ◽  
Long Term Adverse Effects

One of the most commonly produced industrial chemicals worldwide, bisphenol A (BPA), is used as a precursor in plastics, resins, paints, and many other materials. It has been proved that BPA can cause long-term adverse effects on ecosystems and human health due to its toxicity as an endocrine disruptor. In this study, we developed an integrated MnO2/UV/persulfate (PS) process for use in BPA photocatalytic degradation from water and examined the reaction mechanisms, degradation pathways, and toxicity reduction. Comparative tests using MnO2, PS, UV, UV/MnO2, MnO2/PS, and UV/PS processes were conducted under the same conditions to investigate the mechanism of BPA catalytic degradation by the proposed MnO2/UV/PS process. The best performance was observed in the MnO2/UV/PS process in which BPA was completely removed in 30 min with a reduction rate of over 90% for total organic carbon after 2 h. This process also showed a stable removal efficiency with a large variation of pH levels (3.6 to 10.0). Kinetic analysis suggested that 1O2 and SO4•− played more critical roles than •OH for BPA degradation. Infrared spectra showed that UV irradiation could stimulate the generation of –OH groups on the MnO2 photocatalyst surface, facilitating the PS catalytic degradation of BPA in this process. The degradation pathways were further proposed in five steps, and thirteen intermediates were identified by gas chromatography-mass spectrometry. The acute toxicity was analyzed during the treatment, showing a slight increase (by 3.3%) in the first 30 min and then a decrease by four-fold over 2 h. These findings help elucidate the mechanism and pathways of BPA degradation and provide an effective PS catalytic strategy.

scholarly journals Heterogeneous Photo-Fenton Catalytic Degradation of Practical Pharmaceutical Wastewater by Modified Attapulgite Supported Multi-Metal Oxides

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 156
Author(s):  
Manjing Lu ◽  
Jiaqi Wang ◽  
Yuzhong Wang ◽  
Zhengguang He
Keyword(s):  
Photocatalytic Oxidation ◽  
Removal Rate ◽  
Catalytic Degradation ◽  
Gas Chromatography Mass Spectrometry ◽  
Pharmaceutical Wastewater ◽  
High Concentration ◽  
Modified Attapulgite ◽  
Cod Removal Rate ◽  
Pre Treatment ◽  
Almost All

Chemical synthetic pharmaceutical wastewater has characteristics of high concentration, high toxicity and poor biodegradability, so it is difficult to directly biodegrade. We used acid modified attapulgite (ATP) supported Fe-Mn-Cu polymetallic oxide as catalyst for multi-phase Fenton-like ultraviolet photocatalytic oxidation (photo-Fenton) treatment with actual chemical synthetic pharmaceutical wastewater as the treatment object. The results showed that at the initial pH of 2.0, light distance of 20 cm, and catalyst dosage and hydrogen peroxide concentration of 10.0 g/L and 0.5 mol/L respectively, the COD removal rate of wastewater reached 65% and BOD5/COD increased to 0.387 when the reaction lasted for 180 min. The results of gas chromatography-mass spectrometry (GC-MS) indicated that Fenton-like reaction with Fe-Mn-Cu@ATP had good catalytic potential and significant synergistic effect, and could remove almost all heterocycle compounds well. 3D-EEM (3D electron microscope) fluorescence spectra showed that the fluorescence intensity decreased significantly during catalytic degradation, and the UV humus-like and fulvic acid were effectively removed. The degradation efficiency of the nanocomposite only decreased by 5.8% after repeated use for 6 cycles. It seems appropriate to use this process as a pre-treatment for actual pharmaceutical wastewater to facilitate further biological treatment.

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.

scholarly journals Pyro-Oil and Wax Recovery from Reclaimed Plastic Waste in a Continuous Auger Pyrolysis Reactor

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2040 ◽  
Author(s):  
Sultan Majed Al-Salem ◽  
Yang Yang ◽  
Jiawei Wang ◽  
Gary Anthony Leeke
Keyword(s):  
Product Distribution ◽  
Plastic Waste ◽  
Densification Process ◽  
Plastic Pollution ◽  
Waste Plastic ◽  
Diesel Fuels ◽  
Plastic Recycling ◽  
Plastic Wastes ◽  
Liquid Products ◽  
Pyrolysis Reactor

The increasing global waste plastic pollution is urging people to take immediate actions on effective plastic recycling and processing. In this work, we report the results of processing reclaimed plastic wastes from unsanitary landfill site in Kuwait by using a bench scale continuous auger pyrolysis system. The plastic feedstock was characterised. After a simple thermal densification process, the material was fed to the pyrolysis system at 500 °C. The pyro-oil and wax products were collected and characterised. The process mass balance was developed on dry basis, and the yields of pyro-oil, light wax, heavy wax and gases were 5.5, 23.8, 69.4 and 1.3 wt%, respectively. The findings have indicated that the reclamation of plastic waste from landfill was feasible in terms of the product distribution and characteristics. Further liquid analysis confirmed that the liquid products contained fractions that are comparable to petrol and diesel fuels. The wax products are viable and have potential application as coating, covering and lubrication.

scholarly journals Carbon-Supported Fe Catalysts forCO2Electroreduction to High-Added Value Products: A DEMS Study: Effect of the Functionalization of the Support

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
S. Pérez-Rodríguez ◽  
G. García ◽  
L. Calvillo ◽  
V. Celorrio ◽  
E. Pastor ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Ethylene Glycol ◽  
Surface Chemistry ◽  
Physicochemical Properties ◽  
Electrochemical Properties ◽  
Textural Properties ◽  
Carbon Support ◽  
Product Distribution ◽  
Added Value ◽  
Fe Catalysts

Vulcan XC-72R-supported Fe catalysts have been synthesised for the electroreduction of CO2to high-added value products. Catalysts were obtained by the polyol method, using ethylene glycol as solvent and reducing agent. Prior to the metal deposition, Vulcan was subjected to different oxidation treatments in order to modify its surface chemistry and study its influence on the physicochemical and electrochemical properties of the catalysts, as well as on the product distribution. The oxidation treatments of the supports modify their textural properties, but do not affect significantly the physicochemical properties of catalysts. However, DEMS studies showed that the carbon support degradation, the distribution of products, and the catalytic activity toward the CO2electroreduction reaction depend significantly on the surface chemistry of the carbon support.

Simultaneous GC-FT-IR/GC-MS Analysis for Isomer-Specific Identification and Quantitation of Complex Mixture Components

1992 ◽  
Vol 46 (2) ◽  
pp. 277-282 ◽  
Author(s):  
N. R. Smyrl ◽  
D. M. Hembree ◽  
W. E. Davis ◽  
D. M. Williams ◽  
J. C. Vance
Keyword(s):  
Mass Spectrometry ◽  
Sampling Method ◽  
Capillary Column ◽  
Complex Mixture ◽  
Gas Chromatography Mass Spectrometry ◽  
Infrared Spectrometry ◽  
New Instrument ◽  
Ft Ir ◽  
The Fourier Transform ◽  
Conventional Manner

The construction and capabilities of a new instrument combining infrared and mass spectrometry to simultaneously examine the effluent from a single capillary column gas chromatographic injection are described. Gas chromatography-mass spectrometry (GC-MS) is performed in the conventional manner. However, the Fourier transform infrared (FT-IR) portion of the instrument employs a new sampling method involving low-temperature trapping of the effluent from the gas chromatograph. The mass spectrometer was over two orders of magnitude more sensitive (161 fg detection limit for naphthalene) than the infrared (40 pg). The qualitative capabilities of infrared spectrometry, particularly when isomerspecific identifications are necessary, are shown to be highly complementary to the usual GC-MS method for analyzing complex mixtures

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