• Journal of the Korea Organic Resources Recycling Association
• /
• v.27 no.4
• /
• pp.71-81
• /
• 2019

This research was conducted to improve availability of agricultural by-products, national natural resources that could be used as fertilizer source, by estimating the amount of production and collecting main contents of fertilizer substances from previous studies and data, in order to be used as basic data to investigate national resources that could be used as alternatives for imported oil-cakes in the future. Conversion factor was used to estimate annual production of agricultural by-products for main 34 crop types in 2018. For total agricultural by-products, rice straws accounted at 50.3% for the highest proportion, followed by 8.7% of rice husks, showing that by-products from rice harvest accounted at 59.0% for all by-products. Further, there were listed the contents of fertilizer substances (nitrogen, phosphoric acid, potash) in 40 types of by-products from agricultural areas. The average contents of nitrogen, phosphoric acid, and potash in agricultural by-products were 1.43%, 0.59%, and 1.90%, respectively. As a result of estimating the annual nitrogen supply amount from 26 agricultural by-products in 2018, it was found that it could supply 44,911 tons of nitrogen. The investigated by-products contained fertilizer substances such as nitrogen, phosphoric acid, and potash, but the contents were lower compared to castor oil-cake used as main component of organic fertilizer. Therefore, resource management plan needs to be established for efficient use of by-products because time, location, and nutrient content of agricultural by-product production were extremely different. Research on fertilizer and manure using agricultural by-products need to be conducted to develop and distribute alternatives for imported oil-cakes.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.9 no.1
• /
• pp.89-94
• /
• 2003

As ship's fuel oil recently becomes viscous and the amount of sludge increases, many researches and studies are underway to process the sludge onboard the ship and to recycle it as a fuel for ship's boiler. Of many researches, especially ultrasonic emulsifier to break the particle of sludge into fine pieces is recognized as a most possible recycling device. In this regards, the author investigates the property change of sludge's temperature and pressure at the early stage of the study of ultrasonic emulsifier. This study can be used as a useful dora to determine the proper temperature and pressure to inject the processed sludge in the boiler injector and the results can also be comparable dora with the experimental data by ultrasonic emulsifier. In addition, the results will be a fundamental data to study the filtering efficiency of the sludge particle broken by temperature and pressure. It is expected that this study ultimately play a role to prevent marine oil pollution as the sludge is recycled onboard the ship and used as a fuel for boiler.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.27 no.4
• /
• pp.61-70
• /
• 2019

This study aimed to investigate the physicochemical characteristics of fish meal, bone meal, and sesame oil cake, which are readily available by-products from agriculture and fisheries, during the process of liquid fertilizer fermentation, and to examine the effects of liquid fertilizer application on seed germination and growth of tomatoes. During processing the fermentation for liquid fertilizers by using fish meal, bone meal, and sesame oil cake liquid fertilizers, the pH of the fertilizer increased in the order of bone meal > fish meal > sesame oil cake, and the concentration increased rapidly up to 30 days in all types of liquid fertilizer. The nitrogen content of the liquid fertilizers increased as fermentation progressed in the order of fish meal > bone meal > sesame oil cake. The phosphorus content increased as fermentation progressed and the highest was 1.0 % in the liquid fertilizer of sesame oil cake. The germination rate and its index of radish seeds were compared for different dilutions of each of the liquid fertilizers. Excluding the 10-fold dilution of the fish meal and oil cake liquid fertilizer, all the treatment groups showed a germination rate ≥ 95 % and the germination index tended to increase with dilution rate of liquid fertilizers. For responses of tomato growth, there were no significant differences among the liquid fertilizer treatment groups; however, the organic content, microbial density, and microbial biomass C in the soil were higher than chemical fertilizer treatment. These results demonstrated that there were differences in the characteristics of liquid fertilizers depending on the materials used, and that liquid fertilizer can be used for nutrition management for the organic crop cultivation.

• Resources Recycling
• /
• v.27 no.2
• /
• pp.55-62
• /
• 2018

This study aims to investigate the characteristics on bottom ash flotation using vegetable oils as a collector. The experiment of changing the kerosene dosage as a collector for the flotation of coal ashes, the recovery of unburned carbon and unburned carbon content were 80% and 63%, respectively, when the dosage of kerosene was 9 kg/ton. The experiment of using soybean oil as a collector to improve flotation efficiency, the recovery of unburned carbon and unburned carbon content increased to 95% and 68%, respectively, when the dosage of soybean oil was 9 kg/ton. The recovery of unburned carbon and unburned carbon content were 99% and 78%, respectively, when safflower oil containing more poly unsaturated fats with double bonds than soybean oil was 9 kg/ton. The calorific value of the unburned carbon was 5,803 cal/g, confirming that it was possible to be used as a fuel for thermal power plants. Lastly, using vegetable oil as a collector it showed higher recovery of unburned carbon and higher unburned carbon than kerosene, which was mineral oil. Moreover, oil containing a large amount of poly unsaturated fat with two or more double bonds was found to have higher unburned carbon than other vegetable oils; thus showing excellent adsorbability for unburned carbon.

• Journal of the Korean Society of Industry Convergence
• /
• v.22 no.2
• /
• pp.105-110
• /
• 2019

Most titanium alloy waste with cutting oil was discarded without recycling process so that it can be caused by metal and oil fires. However, there is no fire management system and studies on the titanium or titanium alloy waste in spite of high fire risk. The purpose of this experimental study is to identify the fire risk of the titanium alloy waste with cutting oil. We collected the 120g waste which was made in the biomedical titanium alloy cutting process. The waste was burned and conducted thermal image analysis with infrared camera. The experimental results which illustrated the process, characteristics, and trends of fire are presented. Firstly, the cutting oil was burned and partially the titanium alloy waste was burned. The maximum temperature of the fire was more than $650^{\circ}C$ in some specific spots. These results means when a lot of titanium alloy waste with cutting oil was ignited, this fire could connect the titanium fire. In other words, the fire has a flammable liquid fire and combustible metal fire at the same time. The experimental study could be used fire prevention, response, and investigation of the titanium alloy waste.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.14 no.1
• /
• pp.160-168
• /
• 2006

This study was performed to evaluate the effect of the addition of vegetable oils on Fenton treatment of PAHs-contaminated soil. Fenton reaction can be proceeded in the soils contaminated with PHAs only in the presence of $H_2O_2$ because of Fe content in the soil. In this case, optimum $H_2O_2$ concentration was 3%. When 17.5 mM $FeSO_4$(III) was added with 3% $H_2O_2$, the removal rate was increased up to 25%, whereas 19% of PAHs was removed with $H_2O_2$ alone. The addition of 1% of olive oil to the contaminated soil before the Fenton reaction or simultaneously increased the removal rate about 15%, compared to the case of Fenton reaction only. There were no significant differences in the removal rates of PAHs, regardless of different kinds and concentration of oils. (olive oil, soybean oil, and used-vegetable oil). The used-vegetable oils were not different from the new, expensive oils in the removal rate, so their use will be desirable in saving the money. In addition of 1% of olive oil after the reaction of 3% $H_2O_2$ and 2.5 mM $FeSO_4$(III), the removal rates of 3~4 and 5~6 ring compounds were increased 13% and 17%, respectively, compared to the case of Fenton reaction only.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.18 no.1
• /
• pp.104-109
• /
• 2010

Hydro-thermal liquefaction technology for rapeseed straws was investigated the biomass conversion rate with different catalysts and reaction temperatures. NaOH and KOH were used for catalysts, and the reaction temperature were ranged from 180 to $320^{\circ}C$ at every $20^{\circ}C$ of intervals for 10 minutes. The reaction was carried out in a 5,000 mL liquefaction system with dispenser and external electrical furnace. Raw materials (160g), 2,000 mL of distilled water and 10% (wt/wt) of catalyst to plant residue were fed into the reactor. It was observed that the maximum crude oil yield was about 36% at temperature range, $260{\sim}280^{\circ}C$ with KOH and at $300^{\circ}C$ with NaOH, respectively. It was observed that the more calorific values of crude oil, the higher reaction temperature with KOH, but it had the reverse pattern in NaOH.

• Resources Recycling
• /
• v.19 no.3
• /
• pp.16-23
• /
• 2010

Coal briquette use has dramatically increased because of high oil prices. Hence, it is necessary to develop an environment-friendly recycling technique of the coal briquette ash. The coal briquette ash contains a large amount of an unburned carbon content and a mullite with high thermal property, so it is considered to be used as raw materials of sintered eco-brick. This study aimed to investigate on how the unburned carbon affects properties of the sintered eco-brick. The eco-brick was mixed with the ratio of 50 wt% coal briquette ash having the unburned carbon 10.5 wt% and 50 wt% cullet, then being sintered at $950^{\circ}C$, which of the compressive strength was in line with the first class of the sintered clay brick standard(KS L 4201). In particular, the compressive strength of the sintered eco-brick was equal to the first class of the KS L 4201 despite the increase of mixing ratio for coal briquette ash with 1.0 wt% unburned carbon to 70 wt%.

• Elastomers and Composites
• /
• v.52 no.4
• /
• pp.249-256
• /
• 2017

The history of polyurethane is relatively shorter compared to that of the other polymers, though its importance has grown rapidly. Due to its unique properties, polyurethanes are widely applied in various fields. In particular, the automotive industry is one of the important application fields. To date, polyols and isocyanates used in the polyurethane industry are generally of petrochemical origin. Recently, owing to the oil crisis, legislation, and growing awareness towards environmental preservation, the demand for more sustainable and eco-friendly raw materials has increased. In this paper, the latest research and development trends in polyurethane applications were reviewed, with a focus on the automobile industry in areas such as seat comfort, noise reduction, light weight, biomass-based polyurethane, and recycling.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.7 no.1
• /
• pp.67-77
• /
• 1999

The biodegradation of algae coagulated with poly aluminum chloride(PAC) was investigated by using the thermophilic oxic process. The compositions of coagulated algae were 83.5% of water content, 24.6% of ash, 32% of organic carbon with in total solid, respectively. In present study, food waste oil was used for the increment of calorie of mixtures in order to accelate the microbial activity. As a result, the maximum temperature of mixtures was higher than $50^{\circ}C$ when the mixing ratio of food oil was over 10%. However the temperature indicated the lower than $50^{\circ}C$ when conditions of no mixing with waste food oil, and 5% of mixing ratio. Therefore, the optimum condition was 10% of the mixing ration at $217l{\cdot}m^{-3}{\cdot}min^{-1}$ of air supply rate. The conversion efficiency of carbon was highest as 92% at the optimum condition. And then water was evaluated from imxture without accumulation at 10% of mixing ratio. The thermophilic oxic process well conducted that is good process for the treatment of waste algae without effluents however it has to consider the retreatment of accumulated aluminum in the reactor.