• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.671-681
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• 2017

Oil palm trunk (OPT) is a potential source of biomass for the production of biopellet. In the present research, biopellet were prepared from the meristem part of 25 years old OPT with various percentages of its bark (0, 10, and 30%). The highest biopellet durability was found for biopellet produced at $130^{\circ}C$ of pelletizing temperature with 30% bark content. Scanning electron microscopy (SEM) of biopellet showed the weak of particle bonding due to the low pelletizing pressure. The moisture content, unit density, ash content, and caloric value of OPT-based pellets were 3.55-5.35%, $525.56-855.23kg/m^3$, 2.76-3.44%, and 17.89-19.14 MJ/kg, respectively. The combustion profiles obtained by thermogravimetric analysis (TGA) seemed to be unaffected by the bark content on. Differential thermal analysis of TGA curve indicated different pyrolysis characteristic of hemicellulose, cellulose, and lignin.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.627-630
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• 2011

We focus on a catalytic process based on direct injection method that can produce high-quality oils of gasoline and kerosene with various carbon-number feed oils. The reaction characteristics of a commercial catalyst were analyzed using a spouted bed reactor. Decane and pentadecane were used to compare the characteristics of the fixed bed and the spouted bed reactor. The yield of gasoline plus kerosene was highest at the reaction temperature of $550^{\circ}C$. For the spouted bed reactor, the at-a-pulse injection was more effective for catalytic cracking of feed oils than multiple consecutive injections. The reaction activity became higher as the carbon number of feed oil is larger.

• Applied Chemistry for Engineering
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• v.27 no.4
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• pp.407-414
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• 2016

Ex-situ catalytic pyrolysis of a Korean native oak tree over microporous zeolites (HZSM-5, HBeta, and HY) was performed by using a fixed bed reactor. The effect of sample to catalyst ratio and reaction temperature was also investigated to optimize production conditions of high quality bio-oil. Among three catalysts, HZSM-5 showed the highest aromatic formation due to its proper pore size and strong acidity. Although HY and HBeta also showed the catalytic activity, they produced larger amounts of coke due to their larger pore size. The smaller ratio of the sample to the catalyst and higher reaction temperature were also required to maximize the yields of aromatic hydrocarbons via the catalytic pyrolysis of oak tree over HZSM-5.

• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.199-204
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• 2008

Hemicellulose, consisteing of pentose as xylose and mannose, is usable as high octane fuels and heavy oil additives if depolymerized to monomer unit. In this study, thermochemical degradation by pyrolysis-liquefaction of hemicellulose, the effects of reaction temperature, conversion yield, degradation properties and degradation products were investigated. Experiments were performed in a tube reactor by varying reaction temperatures from $200^{\circ}C$ to $400^{\circ}C$ at 40 min of reaction time. The liquid products from pyrolysis-liquefaction of hemicellulose contained various kinds of ketones. Ketones, as 2,3-dimethyl-2-cyclopenten-1-one, 2,3,4-trimethyl-2-cyclopentan-1-one, and 2-methyl-cyclopentanone, could be used as high-octane-value fuels and fuel additives. However, phenols are not valuable as fuels. Combustion heating value of liquid products obtained from thermochemical conversion processes of hemicellulose was in the range of 6,680~7,170 cal/g. After 40 min of reaction at $400^{\circ}C$ in pyrolysis-liquefaction of hemicellulose, the energy yield and mass yield were as high as 72.2% and 41.2 g oil/100 g raw material, respectively.

• Clean Technology
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• v.29 no.4
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• pp.262-271
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• 2023

Globally, the amount of waste plastics has been occurring to environmental problems. As a result, it is necessary to research methods that utilize waste plastic pyrolysis oil (WPPO) produced by pyrolysis. One such method being studied is utilizing WPPO as a naphtha feedstock. In this study, five types of WPPO were analyzed to determine whether they can be used as raw materials for naphtha. Because of their wide boiling point range, the WPPOs were fractionated into light and heavy fractions through vacuum distillation, and the separation and purification techniques were analyzed using GC-VUV to determine the content of paraffin, olefin, and other compounds. All WPPOs showed high olefin content regardless of the source and fraction. Aromatic and paraffin content varied depending on the source, and oxygen and other compounds also varied significantly by source and fraction. In addition, the light fraction showed a carbon distribution similar to that of naphtha, whereas the heavy fraction showed a carbon distribution of C₁₁ ~ C₁₄. In conclusion, additional processes and raw material selection are required to utilize waste plastic pyrolysis oil as a raw material for naphtha.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.975-984
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• 2018

Fast pyrolysis bio-oil has unfavorable properties that restrict its use in many applications. Among the main issues are high acidity, instability, and water and oxygen content, which give rise to corrosiveness, polymerization during storage, and a low heating value. Esterification and azeotropic water removal can improve all of these properties. A 500 g of Quercus mongollica which grounded 0.8~1.4 mm was processed into bio-oil via fast pyrolysis for 2 seconds at $550^{\circ}C$. The esterification consists of treating pyrolysis oil with a high boiling alcohol like n-butanol at $70^{\circ}C$ under reduced pressure (100 hPa). All products are analyzed for water mass fraction, viscosity, higher heating value, pH, FT-IR and GC/MS. The water mass fraction can be reduced by 91.4 % (from 31.5 % to below 2.7 %), the viscosity by 65.8 % (from 36.5 to 12.5 cP) and the higher heating value can be increased by 96.8 % (from 3,918 to 7,712 kcal/kg), the pH by 1.3 (from 2.7 to 4.0). FT-IR and GC/MS analysis indicated that labile acids, aldehydes, ketones and lower alcohols were transformed to stable target products. Using this approach, the water content of the pyrolysis oil is reduced significantly. These improvements should allow the utilization of upgraded pyrolysis liquids in standard boilers and as fuel in CHP (Combined heat and power) plants.

• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.36-43
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• 2024

Fishing net waste (FNW) constitutes over half of all marine plastic waste and is a major contributor to the degradation of marine ecosystems. While current treatment options for FNW include incineration, landfilling, and mechanical recycling, these methods often result in low-value products and pollutant emissions. Importantly, FNWs, comprised of plastic polymers, can be converted into valuable resources like syngas and pyrolysis oil through pyrolysis. Thus, this study presents a process for generating high-purity hydrogen (H₂) by catalytically pyrolyzing FNW in a CO₂ environment. The proposed process comprises of three stages: First, the pretreated FNW undergoes Ni/SiO₂ catalytic pyrolysis under CO₂ conditions to produce syngas and pyrolysis oil. Second, the produced pyrolysis oil is incinerated and repurposed as an energy source for the pyrolysis reaction. Lastly, the syngas is transformed into high-purity H₂ via the Water-Gas-Shift (WGS) reaction and Pressure Swing Adsorption (PSA). This study compares the results of the proposed process with those of traditional pyrolysis conducted under N₂ conditions. Simulation results show that pyrolyzing 500 kg/h of FNW produced 2.933 kmol/h of high-purity H₂ under N₂ conditions and 3.605 kmol/h of high-purity H₂ under CO₂ conditions. Furthermore, pyrolysis under CO₂ conditions improved CO production, increasing H₂ output. Additionally, the CO₂ emissions were reduced by 89.8% compared to N₂ conditions due to the capture and utilization of CO₂ released during the process. Therefore, the proposed process under CO₂ conditions can efficiently recycle FNW and generate eco-friendly hydrogen product.

• 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 Recycled Construction Resources Institute
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• v.11 no.4
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• pp.391-399
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• 2023

Recently, low-temperature pyrolysis technology has been studied as a recycling method for waste plastic. Low-temperature pyrolysis technology for waste plastic produces pyrolysis oil that can be used as an energy resource, but solid residue remains. Waste plastic pyrolysis residues are mostly landfilled due to their limited use. In this study, it is investigated that mixed waste plastic pyrolysis residues could be recycled into activated carbon. It was confirmed that the fixed carbon content of the residue was 33.69 % from proximate Analysis. Chemical activation was used to manufacture activated carbon. KOH was used as an activator. To investigate the effect of the mixing ratio of KOH and residue, samples were mixed at ratios of 0.5, 1.0, and 2.0. The mixed sample was chemically activated at an activation temperature of 800 ℃ for 1 hour. As a result of analyzing the characteristics of activated carbon through BET, it was confirmed that the specific surface area increased as the mixing ratio of KOH increased.