Pine Wood and Sewage Sludge Torrefaction Process for Production Renewable Solid Biofuels and Biochar as Carbon Carrier for Fertilizers

Abstract

This work presents the results of research on the thermo-chemical conversion of woody biomass–pine wood coming from lodzkie voivodship forests and sewage sludge from the Group Sewage Treatment Plant of the Łódź Urban Agglomeration. Laboratory scale analyses of the carbonization process were carried out, initially using the TGA technique (to assess activation energy (EA)), followed by a flow reactor operating at temperature levels of 280–525 °C. Both the parameters of carbonized solid biofuel and biochar as a carrier for fertilizer (proximate and ultimate analysis) and the quality of the torgas (VOC) were analyzed. Analysis of the pine wood and sewage sludge torrefaction process shows clearly that the optimum process temperature would be around 325–350 °C from a mass loss ratio and economical perspective. This paper shows clearly that woody biomass, such as pine wood and sewage sludge, is a very interesting material both for biofuel production and in further processing for biochar production, used not only as an energy carrier but also as a new type of carbon source in fertilizer mixtures.