| Abstract
| - Nowadays, black liquor recovery is important for the economics of the pulp and paper productionindustry. As a result of the high capital cost of the recovery unit, the corrosive nature of thesmelt, and the risk of smeltwater explosions, alternatives to the conventional recovery cycle areunder research in order to achieve more efficient and environmentally cleaner processes. Thesealternatives fall into two categories: high-temperature and low-temperature, according to whetheror not the melting point of the black liquor inorganics is reached. The advantage of low-temperature processes is to avoid the formation of smelt. In this work, the feasibility of the thermalprocessing at low temperature of straw black liquor in two different bench scale reactors hasbeen tested. In the fluidized bed, the loss of fluidization due to bed agglomeration was found tobe the main problem in the reactor used. The second reactor used, a spouted bed, presents differentcharacteristics from the fluidized bed, and has been tested in order to overcome the agglomerationobserved. Experiments in different operating conditions were carried out in order to get a basicknowledge about the behavior of this residue during pyrolysis, gasification, and combustionprocesses. To work below the melting point of the black liquor inorganics, reaction temperaturewas kept under 600 °C. Liquid black liquor and dry black liquor were used as feedstocks. Nitrogen,air, and nitrogen−oxygen mixtures were considered as reaction atmospheres.
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