본 연구에서는 다양한 촉매를 제조하여 수소생산기술 중 바이오매스 열분해와 수전해방법에 적용시 각 촉매의 특성 및 수소생산특성을 확인하고자 하였다. 열분해실험에서는 바이오매스로써 폐지, HDPE(High Density Polyethylene), PP(Polypropylene), PET(Polyethylene terephthalate)의 독립적인 샘플과 혼합플라스틱[...
본 연구에서는 다양한 촉매를 제조하여 수소생산기술 중 바이오매스 열분해와 수전해방법에 적용시 각 촉매의 특성 및 수소생산특성을 확인하고자 하였다. 열분해실험에서는 바이오매스로써 폐지, HDPE(High Density Polyethylene), PP(Polypropylene), PET(Polyethylene terephthalate)의 독립적인 샘플과 혼합플라스틱[HDPE +PP + PET (1:1:1)] 그리고 혼합된 폐지/플라스틱(9:1, 3:1, 1:1, 1:3, 1:9)을 샘플로 하여 각각 열분해 반응기에서 10 ˚C/min의 속도로 800 ˚C 까지 승온하여 실험을 진행하였다. 열분해 결과, 고온에서는 바이오매스와 플라스틱을 혼합한 샘플에서 높은 효율을 보였으며, 플라스틱 비율이 높을수록 가스생산 시 부산물인 차르(char)의 생산량이 낮아짐을 확인할 수 있었다. Cu/Al₂O₃ 촉매를 이용한 바이오매스 열분해 실험 및 TGA결과, 400 ˚C 이하의 온도에서는 Cu의 성분이 높을수록(30>20>10 wt%) 촉매의 중량감소되는 온도지점이 더 낮아짐을 확인할 수 있었다. 또한, Cu의 성분이 10, 20 wt%의 촉매는 서로 비슷한 활성도를 보였으며, 30, 40 wt% 촉매에 비해 탈수소화반응이 증가함을 확인하였다. Ni/Al₂O₃, Ni/CeO₂, Ni/Al₂O₃-CeO₂ 촉매의 바이오매스 열분해 실험(고정층반응기, 800 ˚C -15분)을 통한 촉매의 특성, 활성도 및 수소생산량을 비교한 결과, 촉매사용시에 타르(tar)의 생산량이 현저히 줄어들었으며, 30 wt% Ni/CeO₂ 촉매에서 타르 및 CO가스 생산량이 가장 낮음을 확인하였다. 또한, Ni/Al₂O₃(30/70 wt%) 촉매에서 가장 높은 수소생산(43.5 vol%)을 나타내었다. 수전해 수소생산에서 사용될 Titanium에 Pt, Sn, Ba을 각각 올린 다공성촉매를 제작하여 각 촉매의 특성 및 수소생산을 확인하였다. 각 제작된 촉매의 SEM 및 TEM 분석결과, TiO₂(1 - 1.2 μm), Pt(900 - 1000 nm), Sn(0.4 - 0.6 μm), Ba(0.4 - 0.5 μm)로 측정되었으며, 각각의 다공성촉매를 수전해에 적용하여 CV(cyclic voltammetry)로 분석한 결과, 모든 다공성촉매에서 수소와 산소의 피크를 확인할 수 있었다. 또한, 60 wt% Ba/TiO₂ 다공성촉매(calcined 600 ˚C)를 이용하여 수전해시 전류밀도 13 mA cm^(-2)에서 가장 높은 환원피크를 나타내었으며, 산화피크의 경우 20 wt% Pt/TiO₂ 다공성촉매(calcined 400˚C), 전류밀도 11 mA cm^(-2)에서 가장 높게 나온 것을 확인하였다. 양극분극실험결과 Sn/TiO₂ 다공성촉매의 경우 50 mA cm^(-2)의 전류밀도값을 나타내었으며, Potentiostat을 이용하여 Tafel 실험결과, 약 130 mV에서 Sn과 Ba를 사용한 다공성촉매에서 비슷한 경향을 나타내었다. 수전해 수소생산에 사용된 Titanium 다공성 촉매는 전기화학적으로 안정적인 특성을 확인 하였다.
본 연구에서는 다양한 촉매를 제조하여 수소생산기술 중 바이오매스 열분해와 수전해방법에 적용시 각 촉매의 특성 및 수소생산특성을 확인하고자 하였다. 열분해실험에서는 바이오매스로써 폐지, HDPE(High Density Polyethylene), PP(Polypropylene), PET(Polyethylene terephthalate)의 독립적인 샘플과 혼합플라스틱[HDPE +PP + PET (1:1:1)] 그리고 혼합된 폐지/플라스틱(9:1, 3:1, 1:1, 1:3, 1:9)을 샘플로 하여 각각 열분해 반응기에서 10 ˚C/min의 속도로 800 ˚C 까지 승온하여 실험을 진행하였다. 열분해 결과, 고온에서는 바이오매스와 플라스틱을 혼합한 샘플에서 높은 효율을 보였으며, 플라스틱 비율이 높을수록 가스생산 시 부산물인 차르(char)의 생산량이 낮아짐을 확인할 수 있었다. Cu/Al₂O₃ 촉매를 이용한 바이오매스 열분해 실험 및 TGA결과, 400 ˚C 이하의 온도에서는 Cu의 성분이 높을수록(30>20>10 wt%) 촉매의 중량감소되는 온도지점이 더 낮아짐을 확인할 수 있었다. 또한, Cu의 성분이 10, 20 wt%의 촉매는 서로 비슷한 활성도를 보였으며, 30, 40 wt% 촉매에 비해 탈수소화반응이 증가함을 확인하였다. Ni/Al₂O₃, Ni/CeO₂, Ni/Al₂O₃-CeO₂ 촉매의 바이오매스 열분해 실험(고정층반응기, 800 ˚C -15분)을 통한 촉매의 특성, 활성도 및 수소생산량을 비교한 결과, 촉매사용시에 타르(tar)의 생산량이 현저히 줄어들었으며, 30 wt% Ni/CeO₂ 촉매에서 타르 및 CO가스 생산량이 가장 낮음을 확인하였다. 또한, Ni/Al₂O₃(30/70 wt%) 촉매에서 가장 높은 수소생산(43.5 vol%)을 나타내었다. 수전해 수소생산에서 사용될 Titanium에 Pt, Sn, Ba을 각각 올린 다공성촉매를 제작하여 각 촉매의 특성 및 수소생산을 확인하였다. 각 제작된 촉매의 SEM 및 TEM 분석결과, TiO₂(1 - 1.2 μm), Pt(900 - 1000 nm), Sn(0.4 - 0.6 μm), Ba(0.4 - 0.5 μm)로 측정되었으며, 각각의 다공성촉매를 수전해에 적용하여 CV(cyclic voltammetry)로 분석한 결과, 모든 다공성촉매에서 수소와 산소의 피크를 확인할 수 있었다. 또한, 60 wt% Ba/TiO₂ 다공성촉매(calcined 600 ˚C)를 이용하여 수전해시 전류밀도 13 mA cm^(-2)에서 가장 높은 환원피크를 나타내었으며, 산화피크의 경우 20 wt% Pt/TiO₂ 다공성촉매(calcined 400˚C), 전류밀도 11 mA cm^(-2)에서 가장 높게 나온 것을 확인하였다. 양극분극실험결과 Sn/TiO₂ 다공성촉매의 경우 50 mA cm^(-2)의 전류밀도값을 나타내었으며, Potentiostat을 이용하여 Tafel 실험결과, 약 130 mV에서 Sn과 Ba를 사용한 다공성촉매에서 비슷한 경향을 나타내었다. 수전해 수소생산에 사용된 Titanium 다공성 촉매는 전기화학적으로 안정적인 특성을 확인 하였다.
In the present work, biomass pyrolysis and water electrolysis, two major hydrogen production technologies have been taken into account and special attention has been given to evaluate the role of catalysts in the above-said methods. Thermogravimetric study and kinetic analysis of biomass co-pyrolysi...
In the present work, biomass pyrolysis and water electrolysis, two major hydrogen production technologies have been taken into account and special attention has been given to evaluate the role of catalysts in the above-said methods. Thermogravimetric study and kinetic analysis of biomass co-pyrolysis with plastics has been carried out in this study. The pyrolysis of pure biomass, high density polyethylene (HDPE), polypropylene (PP) and polyethylene terephthalate (PET), plastic mixtures [HDPE +PP + PET (1:1:1)], and biomass/plastic mixture (9:1, 3:1, 1:1, 1:3 and 1:9) were investigated by using a thermogravimetric analyzer under a heating rate at 10℃/min from room temperature to 800℃. Paper was selected as the biomass sample. These thermogravimetric results indicate the presence of significant interaction and synergistic effect between biomass and plastic mixtures during their co-pyrolysis at the high temperature region. With increase in the amount of plastic mixture in blend material, the char production has diminished at final pyrolysis temperature range. Additionally, a kinetic analysis was performed to fit with TGA data, the entire pyrolysis pr˚Cesses being considered as one or two consecutive first order reactions. Thermogravimetric study on catalytic pyrolysis of biomass in presence of Cu/Al₂O₃ catalysts has been investigated. The Cu/Al₂O₃ catalysts of three different compositions have been investigated with regard to their catalytic effects on pyrolysis of paper biomass species (up to 800℃) by thermal gravimetric analysis (TGA) experiments. The results show that catalysts made devolatilization at lower (below 200℃) and middle temperature (200-400℃) regions in the pyrolysis of the biomass species, and the temperature reduction effects follow the order: 30>20>10 wt% copper loading. Although the catalysts with 10 and 20 wt% copper have shown almost similar activity, whereas dehydration reaction was enhanced almost 40% in the presence of 30 wt% copper loaded catalyst. At the same time, the amount of residue at the end of the reaction also decreased with increase in the copper loading from 10 to 30 wt%. Ni/Al₂O₃, Ni/CeO₂, and Ni/Al₂O₃-CeO₂ catalysts with various compositions have been prepared, characterized and investigated for their catalytic activity in biomass pyrolysis. In a fixed-bed reactor, untreated and catalyst mixed biomasses had been pyrolyzed up to 800℃, with the residence time of 15 min. The non-condensable gases were collected through gas bags every after 100℃ and also at 5, 10, and 15 min residence time at 800℃, which were analyzed using TCD-GC equipment. The comparative distributions of solid, liquid and gaseous components were made. Results are indicating diminished amount of tar production in presence of catalysts. 30 wt% Ni/CeO₂ catalyst had yielded least amount of tar product. The least amount of CO had produced over the same catalyst. According to gas analysis result, 30 wt% Ni doped alumina sample had produced maximum amount of H2 production with 43.5 vol% at 800℃ (15 mins. residence time). Platinum, tin, and barium doped titnia hollow spheres were prepared, characterized and examined their electr˚Catalytic activity in hydrogen and oxygen production from water electrolysis. Titania hollow spheres have been synthesized by using poly(styrene-methacrylic acid) latex particles as a template, and metals were doped over the spheres with appropriate amount of precursor materials. The surface characteristics have been evaluated by XRD, SEM and TEM analysis. Diameter of pure TiO₂, Pt, Sn and Ba doped TiO₂ hollow spheres were found from SEM and TEM images in the range of 1-1.2 μm, 900-1000 nm, 0.4-0.6 μm, and 0.4-0.5 μm, respectively. Cyclic voltammetric studies had revealed the presence of hydrogen and oxygen evolution peaks for all the hollow sphere samples. Among all the catalysts, the catalyst with 60 wt% Ba loading calcined at 600℃ had produced highest cathodic peak current density of 13 mA cm^(-2). On the other hand, 20 wt% Pt/TiO₂ hollow sphere sample (calcined at 400℃) had shown the best performance in anodic peak current density value of 11 mA cm^(-2); this peak is attributed to oxygen evolution reaction. The performances of the Sn/TiO₂ hollow sphere electr˚Catalysts were evaluated up to current densities of 50 mA cm^(-2) during anodic polarization measurement. Tafel slopes are similar for Sn and Ba doped titania sample with the values around 130 mV. Titania electr˚Catalysts have also shown long time electr˚Chemical stability in acidic media.
In the present work, biomass pyrolysis and water electrolysis, two major hydrogen production technologies have been taken into account and special attention has been given to evaluate the role of catalysts in the above-said methods. Thermogravimetric study and kinetic analysis of biomass co-pyrolysis with plastics has been carried out in this study. The pyrolysis of pure biomass, high density polyethylene (HDPE), polypropylene (PP) and polyethylene terephthalate (PET), plastic mixtures [HDPE +PP + PET (1:1:1)], and biomass/plastic mixture (9:1, 3:1, 1:1, 1:3 and 1:9) were investigated by using a thermogravimetric analyzer under a heating rate at 10℃/min from room temperature to 800℃. Paper was selected as the biomass sample. These thermogravimetric results indicate the presence of significant interaction and synergistic effect between biomass and plastic mixtures during their co-pyrolysis at the high temperature region. With increase in the amount of plastic mixture in blend material, the char production has diminished at final pyrolysis temperature range. Additionally, a kinetic analysis was performed to fit with TGA data, the entire pyrolysis pr˚Cesses being considered as one or two consecutive first order reactions. Thermogravimetric study on catalytic pyrolysis of biomass in presence of Cu/Al₂O₃ catalysts has been investigated. The Cu/Al₂O₃ catalysts of three different compositions have been investigated with regard to their catalytic effects on pyrolysis of paper biomass species (up to 800℃) by thermal gravimetric analysis (TGA) experiments. The results show that catalysts made devolatilization at lower (below 200℃) and middle temperature (200-400℃) regions in the pyrolysis of the biomass species, and the temperature reduction effects follow the order: 30>20>10 wt% copper loading. Although the catalysts with 10 and 20 wt% copper have shown almost similar activity, whereas dehydration reaction was enhanced almost 40% in the presence of 30 wt% copper loaded catalyst. At the same time, the amount of residue at the end of the reaction also decreased with increase in the copper loading from 10 to 30 wt%. Ni/Al₂O₃, Ni/CeO₂, and Ni/Al₂O₃-CeO₂ catalysts with various compositions have been prepared, characterized and investigated for their catalytic activity in biomass pyrolysis. In a fixed-bed reactor, untreated and catalyst mixed biomasses had been pyrolyzed up to 800℃, with the residence time of 15 min. The non-condensable gases were collected through gas bags every after 100℃ and also at 5, 10, and 15 min residence time at 800℃, which were analyzed using TCD-GC equipment. The comparative distributions of solid, liquid and gaseous components were made. Results are indicating diminished amount of tar production in presence of catalysts. 30 wt% Ni/CeO₂ catalyst had yielded least amount of tar product. The least amount of CO had produced over the same catalyst. According to gas analysis result, 30 wt% Ni doped alumina sample had produced maximum amount of H2 production with 43.5 vol% at 800℃ (15 mins. residence time). Platinum, tin, and barium doped titnia hollow spheres were prepared, characterized and examined their electr˚Catalytic activity in hydrogen and oxygen production from water electrolysis. Titania hollow spheres have been synthesized by using poly(styrene-methacrylic acid) latex particles as a template, and metals were doped over the spheres with appropriate amount of precursor materials. The surface characteristics have been evaluated by XRD, SEM and TEM analysis. Diameter of pure TiO₂, Pt, Sn and Ba doped TiO₂ hollow spheres were found from SEM and TEM images in the range of 1-1.2 μm, 900-1000 nm, 0.4-0.6 μm, and 0.4-0.5 μm, respectively. Cyclic voltammetric studies had revealed the presence of hydrogen and oxygen evolution peaks for all the hollow sphere samples. Among all the catalysts, the catalyst with 60 wt% Ba loading calcined at 600℃ had produced highest cathodic peak current density of 13 mA cm^(-2). On the other hand, 20 wt% Pt/TiO₂ hollow sphere sample (calcined at 400℃) had shown the best performance in anodic peak current density value of 11 mA cm^(-2); this peak is attributed to oxygen evolution reaction. The performances of the Sn/TiO₂ hollow sphere electr˚Catalysts were evaluated up to current densities of 50 mA cm^(-2) during anodic polarization measurement. Tafel slopes are similar for Sn and Ba doped titania sample with the values around 130 mV. Titania electr˚Catalysts have also shown long time electr˚Chemical stability in acidic media.
주제어
#Biomass pyrolysis Water electrolysis Hydrogen Catalysts
학위논문 정보
저자
챠토패드히야 제이타
학위수여기관
서울산업대학교 에너지환경대학원
학위구분
국내박사
학과
신에너지공학과
발행연도
2010
총페이지
208
키워드
Biomass pyrolysis Water electrolysis Hydrogen Catalysts
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