scholarly journals Recycling techniques of polyolefins from plastic wastes

2013 ◽  
Vol 10 (1) ◽  
pp. 114-122 ◽  
Keyword(s):  
Liquid Fraction ◽  
Fixed Bed ◽  
Raw Material ◽  
Fixed Bed Reactor ◽  
Major Type ◽  
Mechanical Recycling ◽  
Experimental Conditions ◽  
Waste Products ◽  
Plastic Wastes ◽  
Recycling Techniques

Disposing of plastic wastes to landfill is becoming undesirable due to legislation pressures, rising costs and the poor biodegradability of commonly used polymers. In addition, incineration meets with strong societal opposition. Therefore, recycling either mechanical or chemical, seems to be the only route of plastic wastes management towards sustainability. Polyolefins, mainly polyethylene (LDPE or HDPE) and polypropylene (PP) are a major type of thermoplastic used throughout the world in a wide variety of applications. In Western Europe alone approximately 22 million tones of these polymers are consumed each year, representing an amount of 56% of the total thermoplastics. In the present investigation the recycling of LDPE, HDPE and PP was examined using two different methods: the dissolution/reprecipitation and pyrolysis. The first belongs to the mechanical recycling techniques while the second to the chemical/feedstock recycling. During the first technique the polymer can be separated and recycled using a solvent/non-solvent system. For this purpose different solvents/non-solvents were examined at different weight percent amounts and temperatures using either model polymers as raw material or commercial waste products (packaging film, bags, pipes and food retail products). At all different experimental conditions and for all samples examined the polymer recovery was always greater than 90%. The quality of the recycled polymer was examined using FTIR and DSC. Furthermore, pyrolysis of LDPE, HDPE and PP was investigated with or without the use of an acid FCC catalyst. Experiments were carried out in a laboratory fixed bed reactor. The gaseous product was analyzed using GC, while the liquid with GC-MS. A small gaseous and a large liquid fraction were obtained from all polymers. Analysis of the derived gases and oils showed that pyrolysis products were hydrocarbons consisting of a series of alkanes and alkenes, with a great potential to be recycled back into the petrochemical industry as a feedstock for the production of new plastics or refined fuels.

scholarly journals Production and Optimization of Energy Rich Biofuel through Co-Pyrolysis by Utilizing Mixed Agricultural Residues and Mixed Waste Plastics

2022 ◽  
Vol 2022 ◽  
pp. 1-9
Author(s):  
Chirag Vibhakar ◽  
R. S. Sabeenian ◽  
S. Kaliappan ◽  
Pandurang Y. Patil ◽  
Pravin P. Patil ◽  
...  
Keyword(s):  
Synergistic Effects ◽  
Fixed Bed ◽  
Value Added ◽  
Agricultural Residues ◽  
Oil Products ◽  
Fixed Bed Reactor ◽  
Waste Plastics ◽  
Waste Products ◽  
Industrial Sectors ◽  
Plastic Wastes

Two totally waste products, agricultural residues and mixed plastic wastes collected from domestic and industrial sectors, are used in this study for the recovery of energy rich biofuel and value-added chemicals. The copyrolysis experiments using fixed bed reactor are conducted in order to analyse the synergetic effects. The experimental works are carried out with different proportion of mixed plastics blended with agricultural residues. The reaction temperature and biomass-to-waste plastics ratio on product distributions are studied and addressed. The thermogravimetric analysis conducted at different temperatures clearly distinguished the pyrolysis behaviours of biomass and plastics. The positive synergistic effects defined as higher yield of volatiles compared to predicted yield for bio-oil were identified at particular mixing ratio. Both biomass wastes and plastic wastes show optimal performance of 60.42 wt% oil yield at 60% addition of waste plastics. The oil products obtained under favourable conditions have a higher heating value compared to the oil obtained from biomass pyrolysis. The GC-MS study confirmed that the interaction between biomass and plastics during copyrolysis resulted in decreased oxygenated contents in the oil products.

scholarly journals The Effect of Pyrolysis Temperature on Copyrolysis of Lignite and Pistachio Seed in a Fixed-bed Reactor

2021 ◽  
Vol 15 ◽  
pp. 49-52
Author(s):  
Özlem Onay
Keyword(s):  
Elemental Analysis ◽  
Pyrolysis Temperature ◽  
Fixed Bed ◽  
Product Distribution ◽  
The Other ◽  
Fixed Bed Reactor ◽  
Oil Yield ◽  
Pyrolysis Oil ◽  
Nitrogen Gas ◽  
Experimental Conditions

Co-pyrolysis of lignite and pistachio seed (CPLPS) under nitrogen gas was performed in a Heinze retort. The effect of pyrolysis temperature on product distribution of CPLPS investigated under heating rate of 10°Cmin-1 and blending ratio of 50(wt)%. Biomass is higher yield to be pyrolyzed than lignite and addition of biomass promotes the pyrolysis of lignite. In the range of the experimental conditions investigated the yield of the product is proportional to pyrolysis temperature. On the other hand, considerable synergetic effects were observed during the co-pyrolysis in a fixed bed reactor leading to increase in oil yield. Maximum pyrolysis oil yield of 27.2% was obtained at pyrolysis temperature of 550°C. The obtained oils are characterized by GC, and elemental analysis.

Population dynamics in an aerobic submerged fixed bed reactor (ASFBR) process

2002 ◽  
Vol 46 (1-2) ◽  
pp. 257-260 ◽  
Author(s):  
I. Lorda-de-los-Ríos ◽  
E. Bécares-Mantecón ◽  
I. Tejero-Monzón
Keyword(s):  
Population Dynamics ◽  
Oxygen Concentration ◽  
Fixed Bed ◽  
High Load ◽  
Fixed Bed Reactor ◽  
Synthetic Wastewater ◽  
Organic Load ◽  
Experimental Conditions ◽  
Low Load ◽  
Aeration Conditions

In this study, an aerobic submerged fixed bed reactor's (ASFBR) population dynamics has been studied in order to know its behavior in different conditions of organic load and oxygen concentration. The reactor was fed with synthetic wastewater. Tested variables and applied values were: 1) Variations in organic load (OL): 16–65 g COD/m2/d. 2) Variations in influent's COD concentration: 40–400 g COD/m3. 3) Variations in specific air flow (SAF): 15–127 m3air/kgCOD. Biofilm samples were taken at the top of the reactor. This study showed important variations in the composition and abundance of the microfauna depending on the experimental conditions. Variations in influent concentration had no significant effect on the abundance of the studied groups. However, differences depending on organic load and aeration conditions were observed. Organic load influenced every group studied but with different results. Sessile cilliates, metazoa and flagellates were abundant in low load, while crawling ones were in high load. Aeration intensity influenced most of the groups except Peranema and Vorticella spp. Despite obtaining good yields, not many protozoa, typical of biofilms under conventional processes, were found. Thus, a great variety of microorganisms, such as many classes of sessile and crawling cilliates, were not found. Important nitrifying activity was obtained at 20 cm depth in a bed. From this point, the heterotrophic and nitrifying populations exist but are inactive.

scholarly journals Microwave-assisted direct synthesis of butene from high-selectivity methane

2017 ◽  
Vol 4 (12) ◽  
pp. 171367
Author(s):  
Yi-heng Lu ◽  
Kang Li ◽  
Yu-wei Lu
Keyword(s):  
Methane Conversion ◽  
Liquid Fuel ◽  
Impact Ionization ◽  
Direct Synthesis ◽  
Fixed Bed ◽  
Volume Ratio ◽  
Raw Material ◽  
Fixed Bed Reactor ◽  
Ionization Mass ◽  
Catalytic Dehydrogenation

Methane was directly converted to butene liquid fuel by microwave-induced non-oxidative catalytic dehydrogenation under 0.1–0.2 MPa. The results show that, under microwave heating in a two-stage fixed-bed reactor, in which nickel powder and NiO x –MoO y /SiO 2 are used as the catalyst, the methane–hydrogen mixture is used as the raw material, with no acetylene detected. The methane conversion is more than 73.2%, and the selectivity of methane to butene is 99.0%. Increasing the hydrogen/methane feed volume ratio increases methane conversion and selectivity. Gas chromatography/electron impact ionization/mass spectrometry chromatographic analysis showed that the liquid fuel produced by methane dehydrogenation oligomerization contained 89.44% of butene, and the rest was acetic acid, ethanol, butenol and butyric acid, and the content was 1.0–3.0 wt%.

scholarly journals Gas-phase elemental mercury removal by nano-ceramic material

2020 ◽  
Vol 10 ◽  
pp. 184798041989975
Author(s):  
Tao Zhu ◽  
Weidong Jing ◽  
Xing Zhang ◽  
Wenjing Bian ◽  
Yiwei Han ◽  
...  
Keyword(s):  
Gas Phase ◽  
Gas Flow ◽  
Removal Rate ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Mercury Removal ◽  
Bet Surface Area ◽  
Mercury Adsorption ◽  
Experimental Conditions ◽  
Physical And Chemical

The nano-ceramic which is mesoporous silica material was applied to test the removal efficiency of gas-phase Hg0 using a fixed-bed reactor. The physical and chemical properties of nano-ceramic were investigated by various techniques such as BET surface area (BET), X-ray diffraction, fourier transform infrared spectrometer (FTIR), and scanning electron microscope (SEM); then, the sample was tested for mercury adsorption under different conditions. The mercury adsorption tests shown that different Hg0 concentration, adsorption temperature, gas flow rate, and different gas components have significant effects on the mercury removal performance of nano-ceramic, and the adsorption removal rate of nano-ceramic can be 75.58% under the optimal experimental conditions. After fitting the experimental data to the adsorption model, it was found that the theoretical maximum mercury adsorption amount q max of nano-ceramic is 1.61 mg g−1 and there were physical and chemical adsorption at the same time. The adsorption kinetics fitting results shown that the adsorption process of nano-ceramic exhibits multi-segment characteristics of “transmembrane–diffusion–adsorption.”

scholarly journals Determination of intraparticle diffusivity and fluid-to-solid mass transfer coefficient from single concentration history curve in circulated-type fixed-bed reactor

2017 ◽  
Vol 36 (1-2) ◽  
pp. 571-585 ◽  
Author(s):  
Noriyoshi Sonetaka ◽  
Yoshimi Seida ◽  
Takuto Nakano ◽  
Eiji Furuya
Keyword(s):  
Analytical Method ◽  
Decay Curve ◽  
Batch Reactor ◽  
Fixed Bed ◽  
Adsorption Kinetic ◽  
Test Method ◽  
Fixed Bed Reactor ◽  
Experimental Conditions ◽  
Reactor Test ◽  
Mixed Batch

In this study, a simple analytical procedure for determining the adsorption kinetic parameters Ds and kF from a single concentration history (decay curve) in circulate-type fixed-bed reactor test method was investigated. A simple and reliable method to obtain the parameters Ds and kF from the decay curve of circulate-type fixed-bed reactor was developed based on an advanced analytical method for the completely mixed batch reactor test method. The experimental conditions in the circulate-type fixed-bed reactor method that meet the application criteria of the advanced analytical method for the completely mixed batch reactor test method were investigated based on the theoretical decay curves of the test methods. Experimental conditions, such as large liquid–solid ratio Zϕ, short contact time z/u, and small bed height Z, which make the decay behaviors in the circulate-type fixed-bed reactor close to those of the completely mixed batch reactor, were evaluated quantitatively on theoretical basis. Furthermore, the reliability of the adsorption kinetic parameters obtained in this study was verified by comparing the kF values with those from a reported empirical correlation equation for kF.

Chemical Kinetics Modeling on Bio-Oil Production from Pyrolysis of Sugarcane Bagasse

2021 ◽  
Vol 1034 ◽  
pp. 199-205
Author(s):  
Dewi Selvia Fardhyanti ◽  
Megawati ◽  
Haniif Prasetiawan ◽  
Noniek Nabuasa ◽  
Mohammad Arik Ardianta
Keyword(s):  
Sugarcane Bagasse ◽  
Alternative Energy ◽  
Fixed Bed ◽  
Raw Material ◽  
Fixed Bed Reactor ◽  
Thermochemical Conversion ◽  
Pyrolysis Process ◽  
Product Analysis ◽  
Biomass Waste ◽  
Bio Oil

Biomass is a source of alternative energy that is environmentally friendly and very promising as one of the sources of renewable energy at present. The best candidate for the biomass waste for pyrolysis raw material is sugarcane bagasse. The sugarcane bagasse is a fibrous residue that is produced after crushing sugarcane for its extraction. Sugarcane bagasse is very potential to produce bio-oil through a pyrolysis process. The advantage of utilizing sugarcane bagasse is to reduce the amount of waste volume. Pyrolysis is a simple thermochemical conversion that transforms biomass with the near absence of absence of oxygen to produce fuel. Experiments were carried out on the fixed bed reactor. The analysis was carried out over a temperature range of 300-500 °C under atmospheric conditions. Products that are usually obtained from the pyrolysis process are bio-oil, char, and gas. Product analysis was performed using Gas Chromatography (GC) and Mass Spectrometry (MS) analysis. This research is aimed to study the kinetics of the sugarcane bagasse pyrolysis process to produce bio-oil. Three different models were proposed for the kinetic study and it was found that model III gave the best prediction on the calculation of pyrolysis process. From the calculation results, kinetic parameters which include activation energy (Ea) and the k factor (A) at a temperature of 300 °C is 2.4730 kJ/mol and 0.000335 s-1, at a temperature of 400 °C is 3, 2718 kJ/mol and 0.000563 s-1, and at a temperature of 500 °C is 4.8942 kJ/mol and 0.0009 s-1.

Production and characterization of bio-oil from algae using pyrolysis

2021 ◽  
Vol 1 (1) ◽  
pp. 032-038
Author(s):  
J Sani ◽  
T Abubakar
Keyword(s):  
Liquid Fraction ◽  
Fixed Bed ◽  
Volatile Matter ◽  
Proximate Analysis ◽  
Gaseous Product ◽  
Fixed Bed Reactor ◽  
Official Method ◽  
Powdered Sample ◽  
Bio Oil

Pyrolysis of the algae (chlorophyceac) was carried out using fixed bed reactor at 4500C. The mass balance of the pyrolysed algae were liquid fraction (oil) (10%), gaseous product (11%), solid product (char) (79%) and extent of conversion (21%. The proximate analysis of powdered sample was carried out in accordance with the official method of analytical chemistry (AOAC). The moisture content, ash content, volatile matter and fixed carbon determined were 3 + 0.33, 70.3 + 0.5, 6.3 + 0.3 and 20.2 + 0.07 respectively. The result obtained indicate that algae (chlorophyceae) could be used as feedstock for generation of pyrolysed oil which could probably be upgraded to fuel for both domestic and industrial purposes.

An Experimental Study of Steam Gasification of Biomass over Precalcined Copper Slag Catalysts

2013 ◽  
Vol 634-638 ◽  
pp. 479-489 ◽  
Author(s):  
Shuang Hui Deng ◽  
Jian Hang Hu ◽  
Hua Wang ◽  
Juan Qin Li ◽  
Wei Hu
Keyword(s):  
Fixed Bed ◽  
Copper Slag ◽  
Biomass Gasification ◽  
Steam Gasification ◽  
Fixed Bed Reactor ◽  
Hydrogen Yield ◽  
Mass Ratio ◽  
Experimental Conditions ◽  
Gasification Efficiency ◽  
Gasification Temperature

Biomass gasification was separated from catalytic pyrolysis in a two-stage fixed bed reactor with precalcined copper slag catalysts placed in a secondary reactor. The effects of gasification temperature (720-950°C), steam to biomass (S/B) mass ratio (0-2g/g), precalcined copper slag to biomass (C/B) mass ratio (0-2g/g) and copper slag precalcined at different temperatures (800-1000°C) on characteristics of biomass gasification were investigated. The experimental results show that the increase of gasification temperature, S/B mass ratio, C/B mass ratio and precalcination temperature are all favorable for raising gasification efficiency and enhancing the H2 production. With copper slag precalcined at 1000°C for 5 hours as catalyst under the experimental conditions examined, the H2 content, the hydrogen yield, the gas yield and the gasification efficiency reach the maximum of 59.16%, 0.72 Nm3/kg, 1.22 Nm3/kg and 77.56%,respectively.

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