• Resources Recycling
• /
• v.15 no.1 s.69
• /
• pp.37-45
• /
• 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
• /
• 2005.10a
• /
• pp.34-46
• /
• 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.

• Applied Chemistry for Engineering
• /
• v.17 no.5
• /
• pp.451-457
• /
• 2006

We synthesized phase pure CrN having surface areas up to $47m^2/g$ starting from $CrCl_{3}$ with $NH_{3}$. Thermal Gravimetric Analysis coupled with X-ray diffraction was carried out to identify solid state transition temperatures and the phase after each transition. In addition, the BET surface areas, pore size distributions, and crystalline diameters for the synthesized materials were analyzed. Space velocity influenced a little to the surface areas of the prepared materials, while heating rate did not. We believe it is due to the fast removal of reaction by-products from the system. Temperature programmed reduction results revealed that the CrN was hardly passivated by 1% $O_{2}$. Molecular nitrogen was detected from CrN at 700 and $950^{\circ}C$, which may be from lattice nitrogen. In temperature programmed oxidation with heating rate of 10 K/min in flowing air, oxidation started at or higher than $300^{\circ}C$ and resulting $Cr_{2}O_{3}$ phase was observed with XRD at around $800^{\circ}C$. However the oxidation was not completed even at $900^{\circ}C$. CrN catalysts were highly active for n-butane dehydrogenation reaction. Their activity is even higher than that of a commercial $Pt-Sn/Al_{2}O_{3}$ dehydrogenation catalyst in terms of volumetric reaction rate. However, CrN was not active in pyridine hydrodenitrogenation.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.10
• /
• pp.1809-1816
• /
• 2000

The catalytic combustion of methanol as a model volatile organic compound(VOC) was been investigated over metal-phthalocyanine(PC) in a fixed bed flow reactor system. The catalytic activity of Co-PC pretreated with air and methanol mixture at $450^{\circ}C$ and 60 cc/min for 1 hr was very excellent. The order of catalytic activity on methanol combustion was summarized as follows: metal free-PC < Zn-PC < Fe-PC < Cu($\alpha$)-PC < Co-PC. By TG/DTA analysis, the tendency of thermal decomposition was increased as follows: metal free-PC < Zn-PC < Cu($\alpha$)-PC < Co-PC < Fe-PC. Under this pretreatment condition, the basic structures of Co-PC, Cu($\alpha$)-PC and Fe-PC were destroyed, and the new metal oxide such as $Co_3O_4$ from Co-PC was confirmed by EA and XRD analysis. But Zn-PC and metal free-PC were retained its basic structure under this pretreatment condition. On the combustion of methanol over Co-PC, HCHO and $HCOOCH_3$ were observed as an intermediate products in the high concentration of reactant or the short contact time(W/F).

• Clean Technology
• /
• v.28 no.2
• /
• pp.174-181
• /
• 2022

Biomass is a sustainable alternative resource for production of liquid fuels and organic compounds that are currently produced from fossil fuels including petroleum, natural gas, and coal. Because the use of fossil fuels can increase the production of greenhouse gases, the use of carbon-neutral biomass can contribute to the reduction of global warming. Although biological and chemical processes have been proposed to produce petroleum-replacing chemicals and fuels from biomass feedstocks, it is difficult to replace completely fossil fuels because of the high oxygen content of biomass. Production of petroleum-like fuels and chemicals from biomass requires the removal of oxygen atoms or conversion of the oxygen functionalities present in biomass derivatives, which can be achieved by catalytic hydrodeoxygenation. Hydrodeoxygenation has been used to convert raw biomass-derived materials, such as biomass pyrolysis oils and lignocellulose-derived chemicals and lipids, into deoxygenated fuels and chemicals. Multifunctional catalysts composed of noble metals and transition metals supported on high surface area metal oxides and carbons, usually selected as supports of heterogeneous catalysts, have been used as efficient hydrodeoxygenation catalysts. In this review, the catalysts proposed in the literature are surveyed and hydrodeoxygenation reaction systems using these catalysts are discussed. Based on the hydrodeoxygenation methods reported in the literature, an insight for feasible hydrodeoxygenation process development is also presented.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.41 no.10
• /
• pp.639-647
• /
• 2017

This basic study is focused on the physically removal method of carbon dioxide from the decomposition of ammonium carbarmate to prevent the recombination of ammonium salts. A basic visual experimental set-up was designed and constructed to observe the recombination phenomena from the proper composition of ammonia gas, carbon dioxide gas, and compressed air dilution gas. To quantify the recombination phenomena, a simple device was designed to measure the weight change under severe cases for three different tube sizes. The temperature and pressure in the visual tube and the volumetric flow rates of the nitrogen dilution gas were studied and the conditions to avoid recombination were analyzed according to mean free path theory. Diffusivity values based on the Chapman-Enskog theory were calculated from the experimental data. These value may serve as an index for the prevention of recombination.

• Applied Chemistry for Engineering
• /
• v.27 no.4
• /
• pp.397-401
• /
• 2016

A new solid oxidizer, pyridinium dinitramide (Py-DN) is a low toxic energetic material which can be utilized as a HPGP (high performance green propellant). In this work, Py-DN was synthesized using various starting materials including potassium sulfamate, pyridine hydrochloride, strong nitric acid and sulfuric acid. Physical and chemical properties of the Py-DN were characterized using UV-Vis, FT-IR and a thermal analyzer and their properties were compared to those of previously prepared salts including ammonium dinitramide[ADN, $NH_4N(NO_2)_2$] and guanidine dinitramide[GDN, $NH_2C(NH_2)NH_2N(NO_2)_2$] in our lab. Endothermic and exothermic decomposition temperatures of Py-DN were $77.4^{\circ}C$ and $144.7^{\circ}C$, respectively. The combustion caloric value was 1739 J/g, which is thermally more sensitive than that of conventional dinitramides. It may enable to lower the decomposition temperature, which can reduce preheating temperature required for satellite thruster applications.

• Journal of the Korean Applied Science and Technology
• /
• v.31 no.4
• /
• pp.541-548
• /
• 2014

This study was performed to obtain high conversion efficiency of $C_7H_8$ using non-thermal plasma and metal-supported catalyst. Adsorption-desorption characteristics of toluene was performed using 4A type (Zeolite) filled in a concentration reactor. Through this test, it was found that the concentration reactor has 0.020 g/g of adsorption capacity (at ambient temperature and pressure) and 3,600 ppm of desorption property at $150^{\circ}C$ (with in 20 min). In case of developed catalyst, toluene decomposition rate of Pd-AO (Pd coated catalyst) was better than Pd/Cu-AO and Pd/Ag-AO (Pd/Ag composite metal catalyst). Developed non-thermal plasma system was obtained flame amplification effect using injection process of desorbed tolune, and 98% of removal efficiency.

• Journal of the Korean Wood Science and Technology
• /
• v.14 no.3
• /
• pp.43-46
• /
• 1986

A stainless steel autoclave reactor, which is the property of Pacific Northwest Laboratories(PNL) and located in PNL, was acted for pyrolysis and gasification of sawdust, ricestraw, and ricehusk. The initial reaction temperature of this reactor was 300$^{\circ}C$, and up to 500$^{\circ}C$ to complete pyrolysis and gasification reaction. The maximum exerted pressure on this reactor was 800 psig. In order to examine the effect of catalyst on reaction temperature, $K_2CO_3$, and nickel/alkali carbonate catalyst mixture were also used. The experimental results obtained with this reactor indicated that good yields of methane-rich gas(exceeding 40% methane) can be produced. The product gas mixtures were also identified to be CO. $CO_2$, $C_2H_4$, and $CH_3CHO$ etc. by Gas Chromatography and Mass Spectrometer.

• Korean Chemical Engineering Research
• /
• v.45 no.3
• /
• pp.209-214
• /
• 2007

Sr hexaaluminate($Sr_{1-x}La_xMnAl_{11}O_{19-\alpha}$) were prepared by sol-gel method of metal alkoxide with 1-butanol or ethylene glycol as a solvent. The physical properties of prepared hexaaluminates were examined by TG/DTA, XRD and $N_2$ adsorption. When ethylene glycol was used as a solvent, the decomposition reaction and dehydroxylation reaction was observed above $400^{\circ}C$ and the temperature of the formation of a crystal structure of hexaaluminate was also increased resulting in small specific surface area and low catalytic activity of methane compared to Sr-hexaaluminate with 1-butanol.