• Journal of Industrial Technology
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• v.21 no.A
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• pp.251-256
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• 2001

This research is focused on an improvement of additional value of high grade limestone. To obtain the basic data of precipitated calcium carbonate(PCC), studies of physical properties of limestone, calcination and hydration characteristics, the characteristics to manufacture quick lime, hydrated lime, ground calcium carbonate and precipitated calcium carbonate were performed. In the carbonation process, formation of rombohedral must be kept under $10^{\circ}C$ for reaction. Although the temperature of reaction of lime milk was limited under $30^{\circ}C$ for a colloidal PCC manufacture, over $50^{\circ}C$ for spindle type PCC. The recommended reaction conditions for colloidal PCC are $20^{\circ}C$ of reaction temperature, 4% of $Ca(OH)_2$ concentration, 1000rpm of stirring rate and 200ml/min of $CO_2$ gas flow rate.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.643-646
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• 2005

The gas hydrate exploration using seismic reflection data, the detection of BSR(Bottom Simulating Reflector) on the seismic section is the most important work flow because the BSR have been interpreted as being formed at the base of a gas hydrate zone. Usually, BSR has some dominant qualitative characteristics on seismic section i.e. Wavelet phase reversal compare to sea bottom signal, Parallel layer with sea bottom, Strong amplitude, Masking phenomenon above the BSR, Cross bedding with other geological layer. Even though a BSR can be selected on seismic section with these guidance, it is not enough to conform as being true BSR. Some other available methods for verifying the BSR with reliable analysis quantitatively i.e. Interval velocity analysis, AVO(Amplitude Variation with Offset)analysis etc. Usually, AVO analysis can be divided by three main parts. The first part is AVO analysis, the second is AVO modeling and the last is AVO inversion. AVO analysis is unique method for detecting the free gas zone on seismic section directly. Therefore it can be a kind of useful analysis method for discriminating true BSR, which might arise from an Possion ratio contrast between high velocity layer, partially hydrated sediment and low velocity layer, water saturated gas sediment. During the AVO interpretation, as the AVO response can be changed depend upon the water saturation ratio, it is confused to discriminate the AVO response of gas layer from dry layer. In that case, the AVO modeling is necessary to generate synthetic seismogram comparing with real data. It can be available to make conclusions from correspondence or lack of correspondence between the two seismograms. AVO inversion process is the method for driving a geological model by iterative operation that the result ing synthetic seismogram matches to real data seismogram wi thin some tolerance level. AVO inversion is a topic of current research and for now there is no general consensus on how the process should be done or even whether is valid for standard seismic data. Unfortunately, there are no well log data acquired from gas hydrate exploration area in Korea. Instead of that data, well log data and seismic data acquired from gas sand area located nearby the gas hydrate exploration area is used to AVO analysis, As the results of AVO modeling, type III AVO anomaly confirmed on the gas sand layer. The Castagna's equation constant value for estimating the S-wave velocity are evaluated as A=0.86190, B=-3845.14431 respectively and water saturation ratio is $50\%$. To calculate the reflection coefficient of synthetic seismogram, the Zoeppritz equation is used. For AVO inversion process, the dataset provided by Hampson-Rushell CO. is used.

• Applied Chemistry for Engineering
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• v.30 no.6
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• pp.712-718
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• 2019

A combustible producer gas composed of H₂, CO and CH₄ could be obtained by the thermal-chemical conversion of biomass. However, a large amount of particulate matters including tar generated causes the mal-function of turbines and engines or the fouling of pipelines. In this study, a wet scrubber using the soybean oil and bag filter were installed, and the removal efficiency was investigated. Hydrate limestone and wood char base activated carbon were pre-coated on the filter medium to prevent clogging of open pores. The removal efficiencies by the bag filter were 86 and 80% for the hydrated limestone and activated carbon coating, respectively. Overall, the collection when using a series of oil scrubbers and bag filters were 88%, while 83% for the filter coating material.

• Journal of Korean Society of Water and Wastewater
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• v.9 no.2
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• pp.84-96
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• 1995

The dewatering characteristics of the sewage sludge was investigated through the experimental observations and model simulations. The activated sludge and the anaerobically digested sludge were examined for the dewaterability evaluation within the pressure range of $0{\sim}10^6N/m^2$. Modified Buchner funnel test and compression test by the consolidometer were conducted to evaluate average specific resistance, porosity, and moisture percentage of filter cake. Shirato's technique of compression-permeability test was followed for the pressure range lower than about $10^2N/m^2$. The flocculation effects on sludge dewatering was also examined for ferric chloride and polymeric flocculant. The application of hydrated lime which can be used for flue-gas desulfurization showed improved moisture percentage, and was thought to have positive feasibility in combined system of sludge dewatering and incineration. Determined characteristic constants were applied to Tiller's cake filtration model to simulate liquid pressure distribution and porosity distribution in cake. Model simulations showed a sharp drop of the porosity close to the cake-medium interface for the highly compressible material such as the activated sludge and the anaerobically digested sludge.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.804-815
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• 2019

Due to the depletion and environmental problems of fossil fuel, biomass has arisen as an alternative energy source. Biomass is a renewable and carbon-neutral source. However, it is moister and has lower energy density. Therefore, biomass needs thermal chemical conversion processes like gasification, and it does not only produce a flammable gas, called 'syngas', which consists of CO, H2, and CH4, but also some unwanted byproducts such as tars and some particulates. These contaminants are condensed and foul in pipelines, combustion chamber and turbine, causing a deterioration in efficiency. Thus this work attempted to find a method to remove tars and particles from syngas with a filter which adopts a pre-coating technology for preventing blockage of the filter medium. Hydrated limestone powder and activated carbon(wood char) powder were used as the pre-coat materials. The removal efficiency of the tars was 86 % and 80 % with activated carbon(wood char) coating and hydrated limestone coating, respectively.

• Resources Recycling
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• v.19 no.3
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• pp.33-44
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• 2010

In this study, the possibility of utilizing carbide lime waste, obtained from the generation of acetylene process, as a alkali activator of blast furnace slag cement was investigated. The physical and chemical analysis of the carbide lime waste was studied and three types lime waste in order to investigate behaviour as alkali activator were used. Lime wastes were added 0, 10, 20 and 30 wt.% in blast furnace slag and blast furnace slag containing lime waste were added 0, 10, 30 and 50 wt.% in OPC. As a result of analysis of hydration properties, in the case of calcium hydroxide rehydrated after heat treatment at $800^{\circ}C$, it was higher hydration rate than other specimens. For the results of compressive strength test, when lime waste passed 325 mesh sieve and rehydrated calcium hydroxide were used, it was higher compressive strength than OPC from hydration 7days. At OPC50 wt.%-BFS45 wt.%-AA5 wt.% system using lime waste of 325 mesh under, the highest compressive strength appeared.