Pyrolysis of black liquor from alkaline straw pulping

Black liquor is a biomass generated as a byproduct from the production of pulp and paper from wood or straw. A great deal of studies about the behaviour of kraft black liquors from wood pulping, in relation to pyrolysis and gasification can be found in the literature. In contrast, there is not much data about the behaviour of kraft black liquors from straw. However, the pyrolysis studies of these kind of liquors are interesting on subsequent gasification studies for energy proposes. With this objective, pyrolysis tests using dry black liquor as feedstock were carried out in a bench scale plant. It consists of a fixed bed reactor, discontinuous for the solid, heated by an electrically furnace. The main parameters are continuously monitored. The particle size of dry black liquor was less than 250 mum for all the experiments. This paper analyses the influence of The heating rate on the products distribution and gas composition (H-2, CO, CO2,CH4, C2H2. C2H4) Three different heating rates, 5, 10 and 12 degreesC/min respectively, were set up to observe this effect. Temperature profiles. The temperature was measured by five thermocouples placed at different lengths and radius into the sample cup. The flue gas composition was analysed at regular intervals by GC. The tar composition was determined by GC-MS.