• Title/Summary/Keyword: 슬러지탄화

Search Result 59, Processing Time 0.029 seconds

SiC aggregates synthesized from carbonized rice husks, paper sludge, coffee grounds, and silica powder (탄화왕겨, 제지슬러지, 커피찌거기 및 실리카 혼합물로부터 탄화규소 결정체 합성)

  • Park, Kyoung-Wook;Yun, Young-Hoon
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.29 no.2
    • /
    • pp.45-49
    • /
    • 2019
  • Relatively fine silicon carbide (SiC) crystalline aggregates have been synthesized with the carbonized rice husks, paper sludge, coffee grounds as the carbon sources and the silica powder. The main reaction source to obtain silicon carbide (SiC) aggregates from the mixture of carbon sources and silica was inferred as the gaseous silicon monoxide (SiO) phase, being created from this mixture through the carbothermal reduction reaction. The silicon carbide (SiC) crystalline aggregates, fabricated from the carbonized rice husks and paper sludge, coffee grounds and silica ($SiO_2$) powder, were investigated by XRD patterns, FE-SEM and FE-TEM images. In these specimens, obtained from the carbonized rice husks, paper sludge and silica, XRD patterns showed rather high strong peak of (111) plane near $35^{\circ}$. The FE-TEM images and patterns of specimens, synthesized from carbonized rice husks, paper sludge, coffee grounds and silica under Ar atmosphere, showed relatively fine particles under $1{\mu}m$ and crystalline peak (110) of silicon carbide (SiC) diffraction pattern.

Development of a Carbonization Activator (하수슬러지 활성탄화로 개발)

  • Jung, Dong Hyun;Lim, Mun Sup;Song, Joo Sub;Chun, Young Nam
    • Applied Chemistry for Engineering
    • /
    • v.20 no.1
    • /
    • pp.109-115
    • /
    • 2009
  • The purposes of this study are to treat sewage sludge that has increasingly become an issue and to recycle it as the adsorbent. The adsorbent was produced by carbonization and simultaneous steam activation, and its characteristics were studied. Parametric screening studies were carried out for the preparation of good adsorbent. Optimum operating conditions were confirmed as input carbonization-activated temperature of $840^{\circ}C$, feed steam flow rate of 70 g/min, carbonization-activated time of 30 min and feed dried sludge of 10.8 kg/day, respectively. At this time, the iodine adsorptivity was maximized as 328.1 mg/g. Pore development, structure, element compound and content were confirmed by using nanoPOROSITY, SEM (Scanning electron microscope), and EDS (Energy dispersive spectroscopy). Through this result, it was known that the adsorbent derived from sewage sludge could be used for the treatment of leachate in a landfill, VOCs (Volatile organic compounds), and so on.

A study on the Optimization of Sewage Sludge-based Adsorbent Carbonization Condition for Improving Adsorption Capacity of Hydrogen Sulfide (H2S) (황화수소(H2S) 흡착성능 증진을 위한 하수슬러지 기반 흡착제 탄화조건 최적화 연구)

  • Choi, Sung Yeol;Jang, Young Hee;Kim, Sung Su
    • Applied Chemistry for Engineering
    • /
    • v.29 no.6
    • /
    • pp.765-771
    • /
    • 2018
  • In this study, the optimization of carbonization conditions in manufacturing processes was performed to improve the absorption performance of sewage sludge based sorbent used for treating $H_2S$ out of all odorous substances generated by various environmental facilities. Adsorbents applied were manufactured from the sewage treatment plant under different carbonization conditions, such as temperature and heating rate, and the correlation between the adsorption performance and physical properties of the adsorbents was verified. As a result, the adsorption performance of sludge at $900^{\circ}C$ with a heating rate of $10^{\circ}C/min$ was the best, and the SEM and BET analysis revealed that specific surface area and characteristics of pore (size, volume) were major parameters for the adsorption. In addition, the effect of K ions used for improving the adsorption performance of the optimum carbonization condition sorbent was insignificant for the sewage sludge based sorbent.

A Study on the Development of Activated Carbons from Sewage Sludge (하수슬러지를 이용한 활성탄 개발에 관한 연구)

  • Lee, Taek-Ryong;Chung, Chan-Kyo;Joe, Young-Cheon
    • Clean Technology
    • /
    • v.15 no.1
    • /
    • pp.31-37
    • /
    • 2009
  • This study deals with the production process of activated carbons from the sewage sludge char by chemical activation reaction. KOH and NaOH were used as activating agents, which react well with carbon. From the experiments, it was found that activated carbons made with KOH treatment had better physicochemical properties in terms of iodine number and BET value than those made with NaOH treatment. It was also found that the optimal deposition ratio of an activating agent to the sewage sludge char was 75 wt% of KOH and 50 wt% of NaOH. Activated carbons were washed out by distilled water after neutralization with 5 M hydrochloric acid solution. The activated carbons that were produced from a sewage sludge char at this optimal conditions have BET surface areas of approximately $600m^2/g$.

Study on the Co-firing of Sewage Sludge to a 80 kWth-scale Pulverized Coal Combustion System (80 kWth급 미분탄 연소 시스템에서 하수슬러지 혼소시 연소 특성 연구)

  • Chae, Taeyoung;Lee, Jaewook;Lee, Youngjae;Yang, Won
    • Clean Technology
    • /
    • v.25 no.1
    • /
    • pp.74-80
    • /
    • 2019
  • Thermochemical treatment of sewage sludge is an energy-intensive process due to its high moisture content. To save the energy consumed during the process, the hydrothermal carbonization process for sewage sludge can be used to convert sewage sludge into clean solid fuel without pre-drying. This study is aimed to investigate co-firing characteristics of the hydrothermally carbonated sewage sludge (HCS) to a pulverized coal combustion system. The purpose of the measurement is to measure the pollutants produced during co-firing and combustion efficiency. The combustion system used in this study is a furnace with a down-firing swirl burner of a $80kW_{th}$ thermal input. Two sub-bituminous coals were used as a main fuel, and co-firing ratio of the sewage sludge was varied from 0% to 10% in a thermal basis. Experimental results show that $NO_x$ is 400 ~ 600 ppm, $SO_x$ is 600 ~ 700 ppm, and CO is less than 100 ppm. Experimental results show that stable combustion was achieved for high co-firing ratio of the HCS. Emission of $NO_x$ and $SO_x$ was decreased for higher co-firing ratio in spite of the higher nitrogen contents in the HCS. In addition, it was found that the pollutant emission is affected significantly by composition of the main fuel, regardless of the co-firing ratios.

Anaerobic Degradation of Petroleum Hydrocarbons in Soil by Application of a Digestion Sludge (소화슬러지를 이용한 토양 내 석유계 탄화수소의 혐기성 분해)

  • Lee, Tae-Ho;Byun, Im-Gyu;Park, Jeung-Jin;Park, Hyun-Chul;Park, Tae-Joo
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.29 no.8
    • /
    • pp.938-943
    • /
    • 2007
  • Anaerobic degradation of petroleum hydrocarbons in a soil artificially contaminated with 10,000 mg/kg soil of diesel fuel was tested by adding an anaerobic sludge taken from a sludge digestion tank. Treatments of soil(50 g) with 15 mL/kg soil and 30 mL/kg soil of the digestion sludge(2,000 mg/L of vss(volatile suspended solids)) showed 37.2% and 58.0% of total petroleum hydrocarbons(TPH) removal during 90 days incubation, respectively. In evaluation of several anaerobic conditions including nitrate reducing, sulfate reducing, methanogenic, and mixed electron accepters condition, treatments with the digested sludge showed significant degradation of diesel fuel under all anaerobic conditions compare to a control treatment of soil without the sludge and a treatment of autoclaved soil treatment with autoclaved digestion sludge. The rate of diesel fuel degradation was the highest in the treatment with the sludge and mixed electron accepters (75% removal of TPH) for 120 days incubation followed in order by sulfate reducing, nitrate reducing, methanogenic condition as 67%, 53%, 43%, respectively. However, the removal rate of non-biodegradable isoprenoid was the highest in the sulfate reducing condition. These results suggest that anaerobic degradation of diesel fuel in soil with digested sludge is effective for practical remediation of soil contaminated with petroleum hydrocarbons.

Preparation and Characterization of Tungsten Carbide Using Products of Hard Metal Sludge Recycling Process (초경합금 슬러지 재활용 공정 산물을 활용한 텅스텐 탄화물 제조 및 특성 평가)

  • Kwon, Hanjung;Shin, Jung-Min
    • Resources Recycling
    • /
    • v.31 no.4
    • /
    • pp.19-25
    • /
    • 2022
  • In this study, tungsten carbide (WC) powder was prepared using a novel recycling process for hard metal sludge that does not use ammonium paratungstate. Instead of ammonia, acid was used to remove the sodium and crystallized tungstate, resulting in the formation of tungstic acid (H2WO4). The WC powder was successfully synthesized by the carbothermal reduction of tungstic acid through H2O decomposition, reduction of WO3 to W, and formation of WC. The carbon content and holding time at the carbothermal reduction temperature were optimized to remove free carbon from the WC powder. As a result, most of the free carbon in the WC powder prepared from sludge was removed, and the content of free carbon in the synthesized WC powder was lower than that in commercial WC powder. Moreover, the crystallite size of WC prepared from H2WO4 was much smaller than that of commercial micron-sized WC powder produced from APT. The small crystallite size of WC induces grain growth during the sintering of the WC-Co composite; thus, a WC-Co composite with large WC grains was fabricated using the WC powder prepared from H2WO4. The large WC grains affected the mechanical properties of the WC-Co composite. Further, due to the large grain size, the WC-Co composite fabricated from H2WO4 exhibited a higher toughness than that of the WC-Co composite prepared from commercial WC powder.

Recycling Organic Sludge into Modification Block by Hydrothermal Carbonization (HTC) (열수가압탄화공법을 적용한 유기성 슬러지의 응용 블록 제조에 관한 연구)

  • Hyewon Park;Minah Oh;Seungjin Oh;Woori Cho;Jinman Chang;Jai-young Lee
    • Clean Technology
    • /
    • v.29 no.2
    • /
    • pp.102-108
    • /
    • 2023
  • This study applied a hydrothermal carbonization (HTC) method to carbonize sewage sludge in order to satisfy the criteria of the Waste Management Act for recycled products and to explore the possibility of recycling sludge into modification blocks. Cement was mixed with carbonized sludge generated at the optimal temperature and reaction time during HTC. After that, the compressive strengths of the modification blocks were measured by conducting both a performance and leaching test. The results of the leaching test showed that heavy metals were not detected, and the specific gravity and absorption rates were less than 1.7 and 10%, respectively, indicating that all species satisfied the criteria. The results of the compressive strength test showed that a mixing ratio of 5% and 7% with cement cured for 28 days satisfied the criteria of A, B, and C type blocks but a mixing ratio of 3% with cement did not satisfy the criteria of A type blocks after 28 days. However, after additional curing for 42 days, the mixing ratio of 3% also satisfied the A type block criteria. Therefore, the optimal mixing ratio of carbonized sludge and cement was considered to be between 3% and 5% and confirmed that the modified blocks could be utilized as aggregates.

Co-firing Characteristics and Slagging Behavior of Sewage Sludge with Coal and Wood Pellet in a Bubbling Fluidized Bed (기포 유동층 반응기를 이용한 하수 슬러지와 석탄 및 우드 펠렛의 혼소 특성 및 슬래깅 성향 연구)

  • Ahn, Hyungjun;Kim, Donghee;Lee, Youngjae
    • Clean Technology
    • /
    • v.24 no.4
    • /
    • pp.323-331
    • /
    • 2018
  • The results of an experimental investigation on the co-firing characteristics and slagging behavior of dried and hydrothermal carbonization sewage sludge, sub-bituminous coal, and wood pellet in a fluidized bed were presented. Combustion tests were conducted in a lab-scale bubbling fluidized bed system at the uniform fuel-air equivalence ratio, air flow rate, and initial bed temperature to measure bed temperature distribution and combustion gas composition. 4 different fuel blending cases were prepared by mixing sewage sludge fuels with coal and wood pellet with the ratio of 50 : 50 by the heating value. $NO_x$ was mostly NO than $NO_2$ and measured in the range of 400 to 600 ppm in all cases. $SO_2$ was considered to be affected mostly by the sulfur content of the sewage sludge fuels. The cases of hydrothermal carbonization sewage sludge mixture showed slightly less $SO_2$ emission but higher fuel-N conversion than the dried sewage sludge mixing cases. The result of fly ash composition analysis implied that the sewage sludge fuels would increase the possibility of slagging/fouling considering the contents of alkali species, such as Na, K, P. Between the two different sewage sludge fuels, dried sewage sludge fuel was expected to have the more severe impact on slagging/fouling behavior than hydrothermal carbonization sewage sludge fuel.

A study on the fuel of sewage sludge by torrefaction process (반탄화를 이용한 하수슬러지 연료화에 관한 연구)

  • Lee, Yoonkyung;Kim, Jae-Hyeong;Gang, Seol-Song;Kim, Gyeong-A;Pak, Daewon
    • Journal of Energy Engineering
    • /
    • v.22 no.4
    • /
    • pp.355-361
    • /
    • 2013
  • In this work, torrefaction of the sewage sludge was investigated the characteristics of torrefied products and the value of as energy resource to improve energy density and to maintain consistent quality of SRF. Torrefaction was performed two important torrefaction operational parameter, temperature($150-230^{\circ}C$) and reaction time(10-60min). As raising the torrefaction temperature at long reaction times, the moisture content of torrefied products was decreased, while the heating value was increased. Moreover, increasing of the torrefaction temperature led to a increase of the content of the carbon up to 60% compare to the initial the sample, and a decrease of the content hydrogen and oxygen. Especially, Average heating value was 4,818 kcal/kg regardless of the reaction time when torrefaction was performed over $210^{\circ}C$. In addition, the fuel ration and coal band were improved after torrefaction because the O/C and the H/C ratio were decreased.