Table 6.

Operational issues observed during first campaign's tests and solutions applied.

Issue observed	Practical solution
Rotary feeding valve was not big enough for the pellets to pass by without having jamming problems	Design and manufacture of a bigger valve; internal diameter of the body of the valve increased from 18 mm to 36 mm. This enhanced the fuel feeding although the problem has not been fully solved when looking at prolonged tests (over 70 min)
Funnel connecting the fuel hopper with the rotary valve was causing bridging of the fuel pellets	Cylindrical bottom section of the fuel feeder was shortened by 15 mm
Ash blocking bottom part of the ceramic reactor after 30 min of operation	Installation of additional axial ash disturber
Tars condensation in exhaust line	Installation of two bubblers in an iced bath and one with rock wool in the gas sampling line. Also wider connector (previous: 5 mm, new: 12 mm) between ash container and exhaust line
Exhaust not flowing through gas sampling lines, passing instead by the rotary feeding valve; this generated a char cake in the body of the valve, blocking the system	Installation of a Coanda air mover at the end of the exhaust line to induce the flow in this direction