- By Aries Roda D. Romallosa
ABSTRACT
Four gasifier stoves, all developed at the Appropriate Technology (APPROTECH Center) of CPU, were evaluated in this study. These include: Gasifier A or the cylindrical-type single-burner, top-lit updraft (T-LUD); Gasifier B of the cylindrical-type double-burner, T-LUD (for household use); Gasifier C or the conical-type double-burner T-LUD (for industrial use). Evaluation was conducted at the APPROTECH Center on April 23 to May 29, 2007. The stoves consisted of similar parts, namely: air moving device, burner, char chamber, char grate, char level, chimney, control switch, gas pipe, gas regulators, reactors, and pot support. Results of the study revealed that Gasifier A significantly (P<0.01) had the highest percentage production of char and thermal efficiency while Gasifier D significantly (P<0.01) produced the highest fuel consumption rate. In general, however, all the three double-burner stoves (Gasifier B, C, and D) significantly (P<0.01) had the highest fire zone rate and consumption of electric energy compared to Gasifier A since these have the same number of burners and air moving devices used. The gas emitted by the gasifier stoves were estimated to contain from 20-24% carbon monoxide, 3-23% hydrogen gas, 8-15% carbon dioxide, 38-42% nitrogen, 0-2 methane and 7-9% water or moisture. Among the gasifiers evaluated, only Gasifier A has the economic advantage over the LPG stove when used. The three other stoves were not practical to use in the household level.