Development of stability criteria for biomass open-top downdraft gasifiers

Angelika Michaela Zachl*, Markus Buchmayr, Johann Gruber, Andres Anca-Couce, Robert Scharler, Christoph Hochenauer

*Korrespondierende/r Autor/-in für diese Arbeit

Publikation: Beitrag in einer FachzeitschriftArtikelBegutachtung


In the past, few researchers have presented objective criteria that can be applied for the stability assessment of a gasification process for woody biomass. When exploring new operating points, however, an objective rating of the operation must be performed. Therefore, in this paper, a useful stability criterion by comparing different statistical parameters (i.e., standard deviation, relative standard deviation, interquartile range and stability index) for several gasifier variables (i.e., temperatures, pressure loss, air flow, permanent gases, total hydrocarbon content THC and flame front position) is described. Therefore, 124 operating points from different evaluations in a commercial open-top gasifier operated with wood chips were used. These data points include fuel water contents from 2 m% to 21 m%, exhaust gas recirculation, loads within the range of ±20% of the nominal load, water injection and air preheating. By taking this novel approach, three main findings were revealed: (1) The summarized standard deviation of the gasifier temperatures is suitable to rate the process stability; however, the temperature fluctuations showed no influence on the permanent gases. (2) A correlation was found between the standard deviation of the air flow and the absolute value of the THC; this enables an estimation of the gas quality with a cheap air flow sensor. (3) A novel method was developed to identify stable operating timespans during post-processing based on the moving standard deviation. This procedure enables researchers to objectively rate operating points in future gasification development.

Seiten (von - bis)442-453
FachzeitschriftJournal of the Energy Institute
Frühes Online-Datum31 Okt. 2022
PublikationsstatusVeröffentlicht - Dez. 2022

ASJC Scopus subject areas

  • Physik der kondensierten Materie
  • Energieanlagenbau und Kraftwerkstechnik
  • Elektrotechnik und Elektronik
  • Steuerungs- und Systemtechnik
  • Feuerungstechnik
  • Erneuerbare Energien, Nachhaltigkeit und Umwelt

Fields of Expertise

  • Sustainable Systems

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