Thermo-physical, Chemical and Structural Modifications in Torrefied Biomass Residues

The study examined the modifications in the thermo-physical and chemical structure of Tectona grandis (TK) and Sorghum bicolour stalk residues that occurred during the process of torrefaction. The analytical techniques used are Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) alongside some basic data characterisation techniques. Data from specific FTIR spectra were used quantitatively in the evaluation of total crystalline and lateral order indices (TCI and LOI) for cellulose and syringyl to guaiacyl (S/G) ratio in lignin. The indices and the ratio were applied in monitoring modifications in cellulose crystallinity and lignin structure. The S/G ratio for untreated TK dropped significantly from 0.6 to 0.12 after torrefaction. An appreciable rise in the TCI and LOI was observed for both samples following the thermochemical conversion process. A distinct thermal decomposition pathway, which widen in discrepancy with increasing torrefaction temperature, was established between untreated and torrefied biomass residues via the TGA. The basic data analysis demonstrated a significant rise in the calorific value of torrefied biomass; approximately from an average of 19.1–26.8 MJ/kg

Data on drying kinetics of a semi-automated gas-fired fish dryer

The dataset presented in this article represent the drying characteristics of a semi-automated gas-fired fish dryer. A cabinet dryer was constructed mainly from mild steel sheet metal and stainless steel, and was used for drying prepared fish samples of Clarias gariepinus species. Major operating parameters which included mass of fish, mass of Liquefied Petroleum Gas used, inside temperature of the dryer, and drying time were monitored. Also, output parameters such as the moisture content and energy utilization amongst others were observed and recorded at varying time intervals and specified drying temperatures. The drying temperature was sustained via an incorporated PID temperature controller that allowed drying to proceed until a relatively constant mass of the dried fish samples was attained. The information contained in this data article include a schematic drawing of drying kinetics analysis of the semi-automated gas-fired fish dryer and a pictorial view of the gas-fired cabinet dryer. Also included are pictorial representations of the washed and neatly folded degutted fish samples and dried fish samples. Data provided in this article are those relating to process parameters of the semi-automated fish dryer, data of output parameters of the fish dryer and comparisons of moisture content and energy utilization at different drying temperatures with time

Torrefaction of some Nigerian lignocellulosic resources and decomposition kinetics

Torrefaction experiments were carried out on some Nigerian woody (Albizia pedicellaris (AP), Tectona grandis (TK), Terminalia ivorensis (TI)) and non-woody (Sorghum bicolour glume (SBG) and stalk (SBS)) biomass resources. The influence of process conditions and consequent change in the elemental configuration of the biomass samples were observed. Biomass type played a dominant role in the solid yield recording 71% for woody and 58% for non-woody samples at 270ºC, while temperature showed the greatest influence with solid yield dropping from an average of 80% (at 240°C) to 50% (at 300°C). Both volatile matter and fixed carbon contents experienced significant changes after torrefaction and a decline in O/C ratio from 0.6 to 0.3 was noted. Among the woody biomass, TI experienced the highest increase in higher heating value (HHV) of approximately 38% as compared to AP (32%) and TK (32%), and was subsequently selected for decomposition kinetic study. The decomposition kinetics showed that activation energy (E(α)) for the hemicellulose degradation stage ranged between 137 and 197 kJ mol-1 for conversion (α) between 0.1 and 0.24 implying that biomass kinetics within this decomposition region is a multi-step reaction. The GC/MS analytical technique revealed that the presence of levoglucosan was highest (7.1%) in woody biomass, while phenolic compounds made up more than one-third of the group of compounds identified