Potential Bio-Fuel from Refinery Waste through Anaerobic Digestion

In this study we report biofuel potential in waste cake obtained from oil refinery. The sample was analyzed for its calorific value using auto bomb calorimeter (LECO AC-500), proximate analysis using Thermogravimetric analyzer (LECO 701) and elemental analysis using CHNS analyzer (LECO Tru-Spec). The elemental analysis of dry waste cake vs wet cake depicted the percentage composition of carbon (49.8%, 40.8%), hydrogen (7.9%, 6.0%), nitrogen (2.8%, 1.9%), Sulphur (1.9%, 0.5%) and oxygen content (37.6%, 40.4%). As for as the thermal degradation behavior of dry and wet cake in TGA is concerned, higher moisture contents (68.50%) found in wet cake and lower in dry cake (40.1%). Whereas the volatile matter in dry cake (30.9%) and low volatile in wet cake (14.3%). Similarly, %age of ash become high in dry cake (17.3%) and low in wet cake (5.11%). The results reflected that higher heating value of dry waste cake is higher (22.5 MJ/kg) than wet waste cake (20.5 MJ/kg) and commonly used sugarcane bagasse (17.88 MJ/kg).

Dynamic Mechanical Analysis of Thermally Aged Fique Fabric-Reinforced Epoxy Composites

Dynamic mechanical analysis (DMA) is one of the most common methods employed to study a material’s viscoelastic properties. The effect of thermal aging on plain epoxy and a fique fabric-reinforced epoxy composite was investigated by comparing the mass loss, morphologies, and DMA properties of aged and unaged samples. In fact, thermal aging presents a big challenge for the high-temperature applications of natural fiber composites. In this work, both plain epoxy and fique fabric-reinforced epoxy composite were found to have different molecular mobility. This leads to distinct transition regions, with different changes in intensity caused by external loadings from time-aging. Three exponentially modified Gauss distribution functions (EMGs) were applied to loss factor curves of fique fabric-reinforced epoxy composite and plain epoxy, which allowed identifying three possible mobility ranges. From these results it was proposed that the thermal degradation behavior of natural fibers, especially fique fiber and their composites, might be assessed, based on their structural characteristics and mechanical properties.

Thermal Degradation Behavior of Epoxy Resin Containing Modified Carbon Nanotubes

Via the surface-grafting of carbon nanotubes (CNTs) with a silicon-containing flame retardant (PMDA), a novel flame retardant CNTs-PMDA was synthesized. The flame retardancy was tested by cone calorimeter. Compared with pure epoxy resin, the total heat release (THR) and peak heat release rate (PHRR) of epoxy resin containing CNTs-PMDA were significantly reduced, by 44.6% and 24.6%, respectively. Furthermore, thermal degradation behavior of epoxy resin based composite was studied by the thermogravimetric analysis with differences in heating rates. The kinetic parameters of the thermal degradation for epoxy resin composites were evaluated by the Kissinger method and Flynn-Wall-Ozawa method. The results suggested that activation energy values of epoxy resin containing CNTs-PMDA in thermal degradation process were higher than those of pure epoxy resin in the final stage of the thermal degradation process, which was closely related to the final formation of char layer residues. Finally, the results from Dynamic mechanical thermal analysis (DMTA) and Scanning electron microscopy (SEM) measurements exhibited that the functionalization of CNTs with PMDA obviously improved the dispersion of CNTs in the epoxy resin matrix.

PROPERTIES OF LIGNIN MICROPARTICLES PREPARED BY MECHANICAL TREATMENT

The present study aimed to obtain Kraft lignin microparticles by mechanical treatment and compare them with initial Kraft lignin in terms of their chemical, thermal and structural properties, as well as possible antioxidant and antimicrobial effects. Ball milling reduced the particle size from 6.6 µm to 3.1 µm. The zeta potential and polydispersity index measurements revealed greater instability of the microparticles, with a higher tendency to agglomerate, and higher homogeneity, when compared with Kraft lignin. These findings were also evidenced by scanning electron microscopy. The thermal degradation behavior was not affected by the mechanical treatment utilized in the production of microparticles. X-ray diffraction showed crystalline and amorphous regions in the particles. Infrared spectroscopy revealed that the microparticles maintained the characteristic peaks of Kraft lignin, with lower peak intensity. The samples proved high antioxidant potential, as determined by the 2,2-diphenyl-1-picryl-hydrazyl assay, regardless of the concentration studied. Therefore, the results of the study demonstrated that the obtained Kraft lignin microparticles could be suitable for the development of antioxidant food packaging.