Combustion of hydrolysis lignin in a drop tube furnace and subsequent gaseous and particulate emissions

Abstract

The aim of the study was to analyze the combustion of hydrolysis lignin in industrial plants which use pulverized combustible and which are characterized by very high heating rates (up to 10⁵ K/min). Pulverized samples of hydrolysis lignin and of spruce bark or spruce trunk for comparison were injected in a drop tube furnace under an oxidative flow (synthetic air) and under an isothermal temperature (between 800 and 1200 °C) in the reaction zone. The gaseous and particulate emissions were analyzed. Ash was collected at the bottom of the drop tube furnace and analyzed. The fly ash were collected in an electrical low-pressure impactor and analyzed. Whatever the sample, the number of particles PM_2.5 was sensitive to the temperature and a minimum was observed which is reached at 900 °C for hydrolysis lignin and spruce bark and at 1100 °C for spruce trunk.

Keywords: Combustion; Drop tube furnace; Gaseous emission; Hydrolysis lignin; Particulate matter; Woody biomass.