• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.479-482
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• 2008

Since late of 2000, KIER has developed a novel pyrolysis process for production of fuel oils from polymer wastes. It could have been possible due to large-scale funding of the Resource Recycling R&D Center. The target was to develop an uncatalyzed, continuous and automatic process producing oils that can be used as a fuel for small-scale industrial boilers. The process development has proceeded in three stages bench-scale unit, pilot plant and demonstration plant. As a result, the demonstration plant having capacity of 3,000 tons/year has been constructed and is currently under test operation for optimization of operation conditions. The process consisted of four parts ; feeding system, cracking reactor, refining system and others. Raw materials were pretreated via shredding and classifying to remove minerals, water, etc. There were 3 kind of products, oils(80%), gas(15%), carbonic residue(5%). The main products i.e. oils were gasoline and diesel. The calorific value of gas has been found to be about 18,000kcal/$m^3$ which is similar to petroleum gas and shows that it could be used as a process fuel. Key technologies adopted in the process are 1) Recirculation of feed for rapid melting and enhancement of fluidity for automatic control of system, 2) Tubular reactor specially-designed for heavy heat flux and prevention of coking, 3)Recirculation of heavy fraction for prevention of wax formation, and 4) continuous removal & re-reaction of sludge for high yield of main product (oil) and minimization of residue. The advantages of the process are full automation, continuous operation, no requirement of catalyst, minimization of coking and sludge problems, maximizing the product(fuel oil) yield and purity, low initial investment and operation costs and environment- friendly process. In this presentation, background of pyrolysis technology development, the details of KIER pyrolysis process flow, key technologies and the performances of the process will be discussed in detail.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.1085-1089
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• 1998

The well-established nitric acid-sulfuric acid mixed acid process for the nitration of aromatic compounds has serious problems due to the large amount of waste acids and severe reaction conditions. Nitration of toluene can be conducted using nitrogen dioxide and ozone instead of mixed acid. We found that conc. nitric acid increased the reactivity as catalyst and the amount of nitrogen dioxide controlled the extent of nitration. Dinitration proceeded to more than 92 mole % conversion within 2 hr at $0^{\circ}C$ with 6 eq. of nitrogen dioxide and 2 eq./hr of ozone flow. Toluene completed mononitration within 30 min using 3 eq. of nitrogen dioxide, 3 eq. of nitric acid, and 1.5 eq./hr of ozone flow. As a clean process of aromatic nitration, this method is expected to replace the present process which causes the environmental problems.

• Journal of the Korean Ceramic Society
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• v.41 no.11
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• pp.864-871
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• 2004

Porous pseudo-boehmite gel was prepared through the aging process of amorphous aluminum hydroxides gel precipitated by the hydrolysis reaction of dilute NaOH solution and AlCl$_3$ solution. In this study, the synthesis method was studied on porous pseudo-boehmite gel having maximum pore volume, as being investigated the changes of crystal structure, infrared rays absorption spectrum, BET surface area and pore structure when the hydrolysis reaction is controlled in the range of pH 7.6~11.6 and the aging process is hold up for 2~24 h at 60~10$0^{\circ}C$. We could find that the gel precipitates deposited in in range of pH 7.6~9.6 were developed into porous pseudo-boehmite which surface area was 250~357 $m^2$/g, pore volume was 0.4~0.7 cc/g and average pore size was 58~l14$\AA$. However, the gel precipitates deposited in range of pH 10.6~11.6 were developed into bayerite which pore volume was very little.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2390-2395
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• 2009

In the condition of GHSV=$30000\;hr^{-1}$, $NO_x$ removal yield was higher as mole ratio of $SiO_2/Al_2O_3$ for Fe/ZSM-5 was lower regardless of preparation method such as CVD (chemical vapor deposition) and dry impregnation. In addition to this, Fe/ZSM-5 catalyst showed about 50% $NO_x$ removal yield between $350^{\circ}C$ - $400^{\circ}C$ while CO formed significantly. To remove newly formed CO over Fe/ZSM-5, Co-Pt/ZSM-5 was used in conjunction with Fe/ZSM-5 in the series and this demonstrated over 90% removal yield of both NOx and CO at $250^{\circ}C$ and GHSV=$30000\;hr^{-1}$.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.272-275
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• 2009

Carbon finance is the investment in Greenhouse Gas (GHG) emission reduction projects in developing countries and countries with economies in transition within the framework of the Kyoto Protocol's Clean Development Mechanism (CDM) or Joint Implementation (JI) and with creation of financial instruments, i.e., carbon credits, which are tradable in carbon market. The additional revenue generated from carbon credits will increase the bankability of projects by reducing the risks of commercial lending or grant finance. Meantime, it has also demonstrated numerous opportunities for collaborating across sectors, and has served as a catalyst in bringing climate issues to bear in projects relating to rural electrification, renewable energy, energy efficiency, urban infrastructure, waste management, pollution abatement, forestry, and water resource management. Establishing additionality is essential for successful CDM project development. One of the key steps is the investment analysis. As guided by UNFCCC, financial indicators such as IRR, NPV, DSCR etc are most commonly used in both Option II & Option III. However, economic indicator such as Economic Internal Rate of Return(EIRR) are often overlooked in Option III even it might be more suitable for the project. This could be due to the difficulties in economic analysis. Although Asian Development Bank(ADB) has given guidelines in evaluating EIRR, there are still large amount of works have to be carried out in estimating the economic, financial, social and environmental benefits in the host country. This paper will present a case study of a CDM development of a 18 MW hydro power plant with carbon finance option in central Vietnam. The estimation of respective factors in EIRR, such as Willingness to Pay(WTP), shadow price etc, will be addressed with the adjustment to Vietnam local provincial factors. The significance of carbon finance to Vietnam renewable energy development will also be addressed.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.514-520
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• 2014

In this study, the production potential of alternative coagulant ($Al_2(SO_4)_3$ solution) having the identical coagulation activity with respect to the commercial coagulant was investigated. The raw material of alternative coagulant was a spent catalyst including aluminium (waste activated alumina) generated in the manufacturing process of the polymer. The alternative coagulant was produced through a series of processes: 1) intense heat and grinding, 2) chemical polymerization and substitution with $H_2SO_4$ solution, 3) dissolution and dilution and 4) settling and separation. To determine the optimal operating conditions in the lab-scale autoclave and dissolver, the content of $Al_2O_3$ in alternative coagulant was analyzed according to changes of the purity of sulfuric acid, reaction temperature, injection ratio of sulfuric acid and water in the dissolver. The results showed that the alternative coagulant having the $Al_2O_3$ content of 7~8% was produced under the optimal conditions such as $H_2SO_4$ purity of 50%, reaction temperature of $120^{\circ}C$, injection ratio of $H_2SO_4$ of 5 times and injection ratio of water of 2.3 times in dissolver. In order to evaluate the coagulation activity of the alternative coagulant, the Jar-test was conducted to the effluent in aerobic reactor. As a result, in both cases of Al/P mole of 1.5 and 2.0, the coagulation activity of the alternative coagulant was higher than that of the existing commercial coagulant. When the production costs were compared between the alternative and commercial coagulant through economic analysis, the production cost reduction of about 50% was available in the case of the alternative coagulant. In addition, it was identified that the alternative coagulant could be applied at field wastewater treatment plant without environmental problem through ecological toxicity testing.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1B
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• pp.51-60
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• 2006

Water quality improvement in mattress/filter system using porous material like slag from industrial activity and zeolite that has been studied for environment improvement and pollution abatement is very useful in polluted stagnant stream channel. Slag is consisted of CaO, $SiO_2$, $Al_2O_3$ and $Fe_2O_3$. Slag with large specific surface area of porosity has been used such as sludge settling and adsorptive materials. Because slag is porous, it can be used for purification filter. As slag is used as filled materials of mattress/filter system and the system has good advantages for the waste water treatment, water recycling, and the improvement of water quality at the same time and so on. Because zeolite has much advantage of cation exchange, adsorption, catalyst and dehydration characteristics, It is used for environment improvement of livestock farms, treatment of artificial sewage and waste water, improvement of drinking water quality, radioactive waste disposal and radioactive material pollution control. In this study, according to verifying effects of water quality improvement of fill materials by porosity that 38.6%, 45.8% and 49.8% respectively in the stagnant stream channel, water quality monitoring of inflow and outflow was conducted on pH, DO, BOD, COD, SS, T-N and T-P. Mattress/filter system was able to accelerate water quality improvement by biofilter as waste water flows through gap of mattress/filter fill materials and by contact catalysis, absorption, catabolism by biofilm. Mattress/filter system used slag and zeolite forms biofilm easily and accelerates adsorption of organic matter. As a result, mattress/filter system increases water self-purification and accelerates water quality improvement available for stream water clean-up.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1575-1581
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• 2011

Rapeseed cake, which is the organic waste remaining after rapeseed oil production, is readily available and considered an ecologically-friendly resource with very low cost and high dietary fiber content. This research was carried out for two reasons. First, it was done to analyze the liberated reducing sugar content of rapeseed cake. Second, it was done to investigate the effects on the sugar yield of the various concentrations of acidic and alkaline catalysts used for the hydrolysis of rapeseed cake and the concentrations of rapeseed cake in each catalyst. Several amounts of ground rapeseed cake, 0.5 g, 1 g, and 2 g, were put into 100 mL of catalysts such as sulfuric acid (0.5~2%), hydrochloric acid (0.5~2%), and sodium hydroxide (0.5~2%). Then they were hydrolyzed for 5 min at 121$^{\circ}C$. After hydrolysis, HPLC equipped with an RI detector was used to analyze liberated reducing sugars such as sucrose, glucose, galactose, fructose, and arabinose separated from rapeseed cake. The degradation rate of rapeseed cake was the highest in hydrochloric acid. As the catalyst concentrations used for hydrolysis of rapeseed cake increased, the degradation rate of rapeseed cake also significantly increased. Total reducing sugar content was the highest in hydrochloric acid, and it increased with the increase of catalyst concentrations. However, as the amount of rapeseed cake increased, the total reducing sugar content decreased, exceptionally sucrose in the case of sodium hydroxide.

• 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%.

• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.3
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• pp.5-18
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• 2024

Chemical oxygen demand (COD), an organic material measurement index, has a limit to the management of the total amount of all organic materials including non-degradable organic materials due to low oxidation rate. So total organic carbon (TOC) that can measure organic materials more accurately is introduced and used as a measurement index. Several environmental companies including company A in Gyeonggi-do dilute raw wastewater first and then treats it with chemicals. And an activated carbon is used at the rear stage to treat total organic carbon even though various treatment processes can be applied to reduce TOC in wastewater. There are some problems such as use of a lot of diluting water and generation of an excessive amount of sludge, so it is urgent to come up with an alternative plan. Therefore, in this study, an application experiment was conducted on two different methods for improving the TOC reduction efficiency of waste water from Company A. The first method is the evaluation of the substitution potential of powered activated carbon(PAC), an adsorbent currently used, by manufacturing cellulose-based graphene like carbon (CGLC). This first study showed that CGLC had about 10% higher TOC adsorption efficiency than commercial PAC, showing the possibility of being applied as an alternative adsorbent for PAC in water treatment sites. The second method relates to the removal of TOC by sulfate radials produced by persulfate (PS) activation. Two activation methods were applied: using CGLC and PAC as carbon-based catalyst and using the high temperature of wastewater for PS activation. As a result of using PAC and CGLC as PS activation materials, the TOC removal rate was lower than the adsorption amount of TOC by CGLC and PAC due to excessive chlorine ions present in the real wastewater. However, as a result of using the high water temperature (55~60℃) of the field wastewater for PS activation, it showed a much greater TOC removal efficiency than PAC alone, CGLC alone, and using a carbon-based catalyst for PS activation. When PS was injected more than 0.5%, it showed a TOC removal efficiency of 95% or more within 24 hr. In addition, when PS was injected more than 0.3%, the TOC concentration could be lowered to less than 75 ppm, which is the wastewater discharge standard applied to company A. When these results were summarized, raw wastewater of high temperature can be treated with a simple process of only adding of PS and discharged by treating TOC below the wastewater discharge standard applied to company A.