Influence of Pyrolysis Temperature on Physico-Chemical Properties of Corn Stover (Zea mays L.) Biochar and Feasibility for Carbon Capture and Energy Balance

PLoS One. 2016 Jun 21;11(6):e0156894. doi: 10.1371/journal.pone.0156894. eCollection 2016.

Abstract

This study examined the influence of pyrolysis temperature on biochar characteristics and evaluated its suitability for carbon capture and energy production. Biochar was produced from corn stover using slow pyrolysis at 300, 400 and 500°C and 2 hrs holding time. The experimental biochars were characterized by elemental analysis, BET, FTIR, TGA/DTA, NMR (C-13). Higher heating value (HHV) of feedstock and biochars was measured using bomb calorimeter. Results show that carbon content of corn stover biochar increased from 45.5% to 64.5%, with increasing pyrolysis temperatures. A decrease in H:C and O:C ratios as well as volatile matter, coupled with increase in the concentration of aromatic carbon in the biochar as determined by FTIR and NMR (C-13) demonstrates a higher biochar carbon stability at 500°C. It was estimated that corn stover pyrolysed at 500°C could provide of 10.12 MJ/kg thermal energy. Pyrolysis is therefore a potential technology with its carbon-negative, energy positive and soil amendment benefits thus creating win- win scenario.

MeSH terms

  • Agriculture
  • Carbon / analysis*
  • Carbon-13 Magnetic Resonance Spectroscopy
  • Charcoal / chemistry*
  • Chemical Phenomena*
  • China
  • Feasibility Studies
  • Hydrogen-Ion Concentration
  • Porosity
  • Spectroscopy, Fourier Transform Infrared
  • Surface Properties
  • Temperature*
  • Thermogravimetry
  • Waste Products / analysis*
  • X-Ray Diffraction
  • Zea mays / chemistry*

Substances

  • Waste Products
  • biochar
  • Charcoal
  • Carbon

Grants and funding

This experiment was financially assisted under Chinese Ministry of Science and Technology Project No. 2012BAC01B02-3 and National Natural Science Foundation of China, grant no. 411714. ZS.