• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.205-213
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• 2021

The present study aimed to determine the effect of co-pyrolysis of sawdust biomass and scrap tyre waste employing different blending ratios of sawdust to waste tyre such as 100:0, 75:25, 50:50, 25:75, and 0:100. The thermochemical characterization of feedstocks was carried out by employing the proximate, ultimate analysis, and thermogravimetric (TGA) analyses, calorific values, and scanning electron microscope coupled with energy dispersive x-ray analysis (SEM-EDX) to select the blending ratio having better bioenergy potential amongst the studied ratios. The blending ratio of 25:75 (sawdust to waste tyre) was selected for the co-pyrolysis study in a fixed-bed pyrolysis reactor system based on its solid biofuels properties such as heating value (30.18 MJ/kg), and carbon (71.81 wt%) and volatile matter (63.82 wt%) contents. The pyrolysis temperatures were varied as 500, 600 and 700 ℃ while the other parameters such as heating rate and nitrogen flowrate were maintained at 30 ℃/min and 0.5 L/min respectively. The bio-oil yields as 31.9, 47.1 and 61.2 wt%, bio-char yields as 34.5, 34.2 and 31.4 wt% and gaseous product yields as 33.6, 18.60 and 7.3 wt% at the pyrolysis temperatures of 500, 600 and 700 ℃ respectively were obtained. The blends of sawdust and waste tyres showed the improved energy characteristics which could provide the solution for the beneficial management of sawdust and scrape tyre wastes via co-pyrolysis processing.

• Journal of Korea Society of Waste Management
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• v.34 no.5
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• pp.518-527
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• 2017

The development of renewable energy is currently strongly required to address environmental problems such as global warming. In particular, biomass is highlighted due to its advantages. When using biomass as an energy source, the conversion process is essential. Fast pyrolysis, which is a thermochemical conversion method, is a known method of producing bio-oil. Therefore, various studies were conducted with fast pyrolysis. Most studies were conducted under a lab-scale process. Hence, scaling up is required for commercialization. However, it is difficult to find studies that address the process analysis, even though this is essential for developing a scaled-up plant. Hence, the present study carries out the process analysis of biomass pyrolysis. The fast pyrolysis system includes a biomass feeder, fast pyrolyzer, cyclone, condenser, and electrostatic precipitator (ESP). A two-stage, semi-global reaction mechanism was applied to simulate the fast pyrolysis reaction and a circulating fluidized bed reactor was selected as the fast pyrolyzer. All the equipment in the process was modeled based on heat and mass balance equations. In this study, process analysis was conducted with various reaction temperatures and residence times. The two-stage, semi-global reaction mechanism for circulating fluidized-bed reactor can be applied to simulate a scaled-up plant.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.4
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• pp.385-391
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• 2014

A control system for ultrasonic spray pyrolysis deposition was developed that can coat a large size glass panel with a transparent conductive oxide. It consists of several ultrasonic atomizer devices to cover a large area and a host computer for individually controlling the devices. The sub-controller in an ultrasonic atomizer device can adjust the flow rate of the atomized conductive oxide gas by setting the flow rate of the solution and regulating the level of the solution in the tank. To construct a feedback control loop for level regulation, a level sensor that utilized an infrared distance sensor and an electric circuit for adjusting the ultrasonic oscillator were developed. The host program was also developed, which can monitor and control the sub-controllers. A proportional-integral controller was developed for a simplified model, and its operation was verified through an experiment.

• Clean Technology
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• v.29 no.3
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• pp.185-192
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• 2023

This study was conducted to obtain basic process simulation data before conducting pyrolysis experiments for the development of a thermochemical conversion system by recirculation of heat carrier and gases thereby. In this study, polypropylene (PP) was used as a pyrolysis sample material as an alternative to waste plastics, and fluid sand was used as a heat transfer medium in the system. Manganese (Mn) was chosen as the catalyst for the pyrolysis experiment, and the catalyst pyrolysis was performed by impregnating it in the sand. The basic properties of PP were analyzed using a thermogravimetric analyzer (TGA), and liquid oil was generated through catalytic pyrolysis under a nitrogen atmosphere at 600℃. The carbon number distribution of the generated liquid oil was confirmed by GC/MS analysis. In this study, the effects of the presence and the amount of Mn loading on the yield of liquid oil and the distribution of hydrocarbons in the oil were investigated. When Mn/sand was used, the residue decreased and the oil yield increased compared to pyrolysis using sand alone. In addition, as the Mn loading increased, the ratio of C₆~C₉ range gasoline in the liquid oil gradually increased, and the distribution of diesel and heavy oil with more carbon atoms than C₁₀ in the oil decreased. In conclusion, it was found that using Mn as a catalyst and changing the amount of Mn could increase the yield of liquid oil and increase the gasoline ratio in the product.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.4
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• pp.469-474
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• 2015

In ultrasonic spray pyrolysis deposition, a precursor solution is evaporated by an ultrasonic atomizer, then gas-carried into a furnace where the solute is separated from the water vapor. After condensation, polymerization, and nucleation, the solute oxide forms a thin film. To improve the deposition efficiency, the ultrasonic atomizer was studied to optimize the evaporated gas flow. The vat cover was redesigned, using three versions with different inlet factors being tested through a computational fluid dynamic analysis as well as a water evaporation experiment. The atomization rate with a hemispherical cover with a $30^{\circ}$ inlet was found to be 2.4 times higher than that with the original. This improvement was verified with fluorine-doped tin oxide spray pyrolysis deposition. The film obtained with the modified vat cover was 2.4 times thicker than that obtained with the original vat cover.

• Journal of Energy Engineering
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• v.17 no.1
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• pp.8-14
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• 2008

The effects of calcium type catalysts addition on the thermal decomposition of low density polyethylene (LDPE) and ethylene vinyl acetate (EVA) resin have been studied in a thermal analyze. (TGA, DSC) and a small batch reactor. The calcium type catalysts tested were calcinated dolomite, lime, and calcinated oyster shell. As the results of TGA experiments, pyrolysis starting temperature for LDPE varied in the range of $330{\sim}360^{\circ}C$ according to heating rate, but EVA resin had the 1st pyrolysis temperature range of $300{\sim}400^{\circ}C$ and the 2nd pyrolysis temperature range of $425{\sim}525^{\circ}C$. The calcinated dolomite enhanced the pyrolysis rate in LDPE pyrolysis reaction, while the calcium type catalysts reduced the pyrolysis rate in EVA pyrolysis reaction. In the DSC experiments, addition of calcium type catalysts reduced the melting point, but did not affect to the heat of fusin. Calcinated dolomite reduced 20% of the heat of pyrolysis reaction. In the batch system experiments, the mixing of calcinated dolomite and lime enhanced the yield of fuel oil, but did not affect to the distribution of carbon numbers.

• Clean Technology
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• v.27 no.3
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• pp.232-239
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• 2021

In order to develop a novel system named "thermal medium and gas circulation type pyrolysis system," this study was conducted to obtain basic data for process simulation before performing the pyrolysis experiment. Polypropylene (PP) was chosen as model material in the basic pyrolysis experiment instead of waste plastic and fluidized sand (hereinafter referred to as "sand"), and it was used as a heat transfer material in the "thermal medium and gas circulation type pyrolysis system." Ni was impregnated as an active catalyst on the sand to promote catalytic pyrolysis. The basic physical properties of PP were analyzed using a thermogravimetric analyzer, and pyrolysis was performed at 600 ℃ in an N₂ atmosphere to produce liquid oil. The distribution of the carbon number of the liquid oil generated through the catalytic pyrolysis reaction was analyzed using GC/MS. We investigated the effects of varying the pyrolysis space velocity and catalyst amount on the yield of liquid oil and the carbon number distribution of the liquid oil. Using Ni/sand, the yield of liquid oil was increased except with the pyrolysis condition of 10 wt% Ni/sand at a space velocity of 30,000 h^-1, and the composition of C₆ ~ C₁₂ hydrocarbons increased. With increases in the space velocity, higher yields of liquid oil were obtained, but the composition of C₆ ~ C₁₂ hydrocarbons was reduced. With 1 wt% Ni/sand, the oil yield obtained was greater than that obtained with 10 wt% Ni/sand. In summary, when 1 wt% Ni/sand was used at a space velocity of 10,000 h^-1, the oil yield was 60.99 wt% and the composition of C₆ ~ C₁₂ hydrocarbons was highest at 42.06 area%.

• Fire Science and Engineering
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• v.31 no.3
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• pp.41-48
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• 2017

In order to investigate the influence of changes in the thermal properties of solid combustibles on thermal decomposition, a series of solid pyrolysis experiments were performed using a cone calorimeter specified in KS F ISO 5660-1. In the present study, Poly Methyl Methacrylate (PMMA) which does not produce Char during pyrolysis process was used as solid fuel. Results obtained from cone calorimeter experiments were compared to ones obtained from numerical analysis of Fire Dynamics Simulator (FDS) 1D pyrolysis model adopted with thermal properties of solid fuel as input parameters. Comparisons between experimentally calculated and model-predicted mass loss rate were then made to elucidate the effect of changes in the thermal properties on pyrolysis of PMMA.

• Resources Recycling
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• v.15 no.1 s.69
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• pp.37-45
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• 2006

For treating a huge amount of plastic waste with the environment problem, pyrolysis of plastic waste into alternative fuel oil is one or important issue in recycling methods. This study was introduced over the trend or generation of plastic waste, in Korea pyrolysis technology in domestic and foreign countries, basic technology in pyrolysis process and new technology of pyrolysis developed in KIER (Korea Institute of Energy research). The characteristics of process developed in KIER are the continuous loading treatment or mixed plastic waste with an automatic control system, the minimization of wax production by circulation pyrolysis system in non-catalytic reactor, the reuse of gas produced and the oil recovery from sludge generated in pyrolysis plant, which have greatly the advantage economically and environmetally. The experiment result data in 300 ton/yr pilot plant showed about $81\;wt\%$ liquid yield for 3 days continuous reaction time, and also the boiling point distribution of light oil (LO) and heavy oil (HO) produced in distillation tower was a little higher than that of commercial gasoline and diesel, respectively.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.10a
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• pp.34-46
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• 2005

For treating a huge amount of plastic waste with the environment problem, pyrolysis of plastic waste into alternative fuel oil is one of important issue in recycling methods. This study was introduced over the trend of generation of plastic waste, pyrolysis technology in domestic and foreign countries, basic technology in pyrolysis process and new technology of pyrolysis developed in KIER (Korea Institute of Energy Research). The characteristics of process developed in KIER are the continuous loading treatment of mixed plastic waste with an automatic control system, the minimization of wax production by circulation pyrolysis system in non-catalytic reactor, the reuse of gas produced and the oil recovery from sludge generated in pyrolysis plant, which have greatly the advantage economically and environmetally. The experiment result data in 300 ton/yr pilot plant showed about 81 wt% liquid yield for 3 days continuous reaction time, and also the boiling point distribution of light oil (LO) and heavy oil (HO) produced in distillation tower was a little higher than that of commercial gasoline and diesel, respectively.