Experimental study of methane decarbonization to produce hydrogen using a laminar premixed flame

• Author / Creator

  Falahati, Farjad

• Hydrogen is a promising source of energy with various applications. The most common method of producing hydrogen is steam reforming of methane; however, thermal cracking of methane can be used alternatively for hydrogen production with less CO2 emissions. In this study, thermal cracking of methane in the products of premixed air-fuel flames was studied. A quartz cylinder filled with insulation blocks was used as the reaction chamber with the placed flame placed at the inlet to create the reaction zone and methane was injected into the flame. The exhaust products were then sampled and passed through a gas chromatography analyzer to determine the methane conversion efficiency into hydrogen as the main goal of this study. Two types of premixed flames (i.e., methane and propane-based fuels) that were slightly fuel rich to minimize free-oxygen were used to study methane cracking. The temperature distribution along the center-line inside the reaction chamber was measured for both flames. The highest temperature recorded in the reaction chamber was 1170 °C and 1135 °C for propane and methane flame, respectively, and it dropped dramatically further from the flame in the reaction chamber for both flames. Methane conversion into hydrogen with the premixed air-propane flame was measured for various flow rates of pyrolysis methane from 0 to 5 ln/min for a fixed flow rate flame. The highest measured conversion efficiency for this flame was 69% when the pyrolysis methane flow rate of 0.5 ln/min. The same sets of experiments were done with a premixed air-methane flame, and the highest measured methane conversion to hydrogen of 78% was obtained with the pyrolysis methane flow rate of 0.5 ln/min. The gas chromatography analysis showed the efficiency of methane conversion into solid carbon was very low as the carbon atoms mainly preferred to form CO when in contact with the hot products of combustion.

• Subjects / Keywords

  • Hydrogen production
  • Methane thermal cracking
  • Air-fuel premixed flame

• Graduation date

  Spring 2018

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3JH3DH8P

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.