Thermochemical conversion pathways of Kappaphycus alvarezii granules through study of kinetic models.
Kappaphycus alvarezii seaweed belongs to the class of red alga (Rhodophyta). The granules obtained after recovery of "sap" (liquid plant stimulant) from freshly harvested alga is a promising biomass feedstock for energy application. Herein we report the kinetic behaviour of the granules using thermogravimetric analysis (TGA) at different heating rates in N2atmosphere and thermogravimetric-mass spectrometry (TG-MS) analysis. Sawdust as lignocellulosic biomass is considered for comparative study. Four different kinetic models (i) multilinear regression technique, (ii) Friedman method, (iii) Flynn-Wall-Ozawa (FWO) method and (iv) Kissinger-Akahira-Sunose (KAS) method are used to evaluate the apparent activation energy (Ea), the pre-exponential factor (Aα) and the overall reaction order (n). Maximum SO2peak at 300°C and 950°C (from TG-MS), indicates that slow pyrolysis at 500°C, with a packed bed lime scrubber at the outlet during temperature rise, is the best suited thermochemical pathway for energy harnessing.
Process Design & Engineering Cell, CSIR-Central Salt & Marine Chemicals Research Institute, G.B. Marg, Bhavnagar 364002, Gujarat, India.
Prasanta
P
Das
CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Dibyendu
D
Mondal
Process Design & Engineering Cell, CSIR-Central Salt & Marine Chemicals Research Institute, G.B. Marg, Bhavnagar 364002, Gujarat, India. Electronic address: smaiti@csmcri.org.
Subarna
S
Maiti
D018533:Biomass; D007700:Kinetics; D008962:Models, Theoretical; D013696:Temperature; D013818:Thermogravimetry
Kappaphycus alvarezii granules as solid fuel; Kinetic parameters; TG-MS; TGA; Thermochemical pathway