Transformation Of Potassium In Different Speciations During Pyrolysis Of Biomass In A Fixed-bed Reactor

Pyrolysis as the common primary step of thermochemical conversion of biomass, that the transformation of potassium has an obvious effect on the catalysis reaction and slagging agglomeration, deposition. Thus a well understanding of transformation of potassium during pyrolysis is highly significant for resourceful utilization of reactor design and equipment select. Based on pyrolysis in the fixed bed reactor, rice straw, corn straw, cotton straw, rice straw-H2O, rice straw-NH4Ac, rice straw-HCl and the microcrystalline cellulose loaded5%KC1were selected to investigate the transformation of potassium for four speciations potassium.The result shows that release ratio of potassium changed little with pyrolysis temperature below700℃, and dramatically increased with pyrolysis temperature above700℃. During pyrolysis, four speciations potassium existed the transformation and transportation, in which the decreased of water soluble and residue potassium created the main release of potassium. It was confirmed that water soluble and organically potassium exchanged each other during pyrolysis. The residue potassium changed to water soluble and partly still for the residue potassium with the cracked of carbon framework during pyrolysis. The mainframe of straws unchanged during pyrolysis, potassium of intraparticle much more than external part, the transformation of potassium based on the main frame. The ternary constituent, inorganic elements and speciations have effect on the transformation of potassium. For cotton straw, the K2SO4and KCaPO4formed during pyrolysis decreased the rate of release. Simulation result of Fact Sage can reflect the transformation of potassium, different anions of potassium salt lead to different of transformation.