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

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 PM2.5 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.

Thermal degradations of wood biofuels, coals and hydrolysis lignin from the Russian Federation: Experiments and modeling.

The thermal degradation of wood biofuels (spruce, pine), of coals from different fields of the Russian Federation and of hydrolysis lignin is investigated using a thermogravimetric analyzer under different heating conditions and under non-oxidative or oxidative atmospheres. The samples are indeed submitted to a linear temperature ramp of 10K/min or to a temperature ramp of 200K/min up to a residence temperature between 250 and 450°C where they are maintained during 4h (isothermal conditions). The values of the kinetic parameters are determined for these different samples in both thermal conditions, either using the differential isoconversional method or by means of an Extended Independent Parallel Reaction (EIPR) model. The values of the kinetic parameters obtained with this EIPR model for spruce trunk are also compared with that of its main constituents (hemicellulose, cellulose and lignin).