TY - BOOK

T1 - Investigation on thermal plasma pyrolysis of methane for hydrogen gas and solid carbon production

AU - Daghagheleh, Oday

N1 - no embargo

PY - 1800

Y1 - 1800

N2 - As an intermediate step toward phasing out fossil fuels, natural gas can be cracked into hydrogen with solid carbon as a valuable byproduct, preventing atmospheric carbon release. This study explores the innovative concept of cracking natural gas into hydrogen and solid carbon via plasma pyrolysis. Initial feasibility testing shows high-efficiency potential, though process optimization is essential. A statistical parameter study highlights the significant influence of parameters such as plasma gas, power input, and arc length on process outcomes. Experiments are conducted using a thermal plasma reactor with a variable gas mixture of Ar and CH4 to form a DC-transferred plasma arc. The product gas is analyzed, and the plasma arc is recorded with a camera on the top lid. Images reveal carbon formation and growth, leading to disruptive interruptions and reduced process efficiency. Despite this, a high H2 yield of 67% to 100% is achieved. Higher CH4 content and extended arc lengths disturb the plasma arc, lowering the H2 yield, while increased power input and a wider reaction zone improve it. Characterization of the produced carbon shows distinct microstructural differences between samples from the gas filter and reaction chamber. SEM analyses reveal finer textures in the former and larger dendritic particles in the latter. Raman spectroscopy confirms crystalline graphite-like structures with low defect concentrations. XRD supports these findings, indicating graphitic crystalline structures. EDS and ICP-MS analyses confirm high-purity carbon. BET surface area analysis shows significant variations, with filter-collected samples ranging from 40 to 170 m²/g compared to 7 to 30 m²/g for chamber-collected samples, correlating with smaller particle size and higher defect numbers. Establishing a new plasma testing facility is the next crucial step, providing a platform for data production and validation, paving the way for commercial-scale implementation.

AB - As an intermediate step toward phasing out fossil fuels, natural gas can be cracked into hydrogen with solid carbon as a valuable byproduct, preventing atmospheric carbon release. This study explores the innovative concept of cracking natural gas into hydrogen and solid carbon via plasma pyrolysis. Initial feasibility testing shows high-efficiency potential, though process optimization is essential. A statistical parameter study highlights the significant influence of parameters such as plasma gas, power input, and arc length on process outcomes. Experiments are conducted using a thermal plasma reactor with a variable gas mixture of Ar and CH4 to form a DC-transferred plasma arc. The product gas is analyzed, and the plasma arc is recorded with a camera on the top lid. Images reveal carbon formation and growth, leading to disruptive interruptions and reduced process efficiency. Despite this, a high H2 yield of 67% to 100% is achieved. Higher CH4 content and extended arc lengths disturb the plasma arc, lowering the H2 yield, while increased power input and a wider reaction zone improve it. Characterization of the produced carbon shows distinct microstructural differences between samples from the gas filter and reaction chamber. SEM analyses reveal finer textures in the former and larger dendritic particles in the latter. Raman spectroscopy confirms crystalline graphite-like structures with low defect concentrations. XRD supports these findings, indicating graphitic crystalline structures. EDS and ICP-MS analyses confirm high-purity carbon. BET surface area analysis shows significant variations, with filter-collected samples ranging from 40 to 170 m²/g compared to 7 to 30 m²/g for chamber-collected samples, correlating with smaller particle size and higher defect numbers. Establishing a new plasma testing facility is the next crucial step, providing a platform for data production and validation, paving the way for commercial-scale implementation.

KW - Methanpyrolyse

KW - Thermisches Plasma

KW - Wasserstoffproduktion

KW - Kohlenstoff

KW - Türkiser Wasserstoff

KW - Methane pyrolysis

KW - Thermal plasma

KW - Hydrogen production

KW - Carbon

KW - Turquoise hydrogen

M3 - Doctoral Thesis

ER -