Temperature and residence time influence on the cattle manure separated solid phase carbonization

This work aim to investigate the effect of temperature and residence time on the carbonization of the cattle manure separated solid phase. The same lab scale auger pyrolizer presented at the 26th European Biomass Conference and Exhibition in the work “Carbonization of residual biomass from river maintenance using waste heat from gasification power plants” was used to carbonize the separated solid obtained from the “SEPCOM Cow Bedding” cattle manure separator. This material is a high quality organic soil conditioner, easy to shovel, store and transport, it is odorless and it can be use as bedding or as soil conditioner. First of all, the material was analyzed measuring its ash percentage, its moisture and its elemental composition, and performing thermal gravimetric and differential thermal analyses on it. 11 pyrolysis tests were carried out with three different temperatures, 300 °C, 400 C° and 500 °C, and 5 residence times, 11, 22, 30, 60 and 90 minutes. As thermal source the exhaust gas from a portable petrol powered generator was used sending it into the jacket around the auger. The residence time was controlled through an Arduino Board that managed the auger movement. The residues of the 11 carbonization tests were analyzed again to measure their ash quantitative and elemental composition. The results showed that with the pyrolysis temperatures at 500 °C it was possible to achieve a percentage of carbon over the 70% and reduce the dry matter of the material by two – third, moreover longer residence times bring to higher weight losses, compared to the shorter ones, mostly for low pyrolysis temperatures.