Utilization of pressurized CO2, pressurized ethanol and CO2-expanded ethanol mixtures for de-oiling spent bleaching earths

Cleaner lipid processing: Supercritical carbon dioxide (Sc-CO2) and short path distillation

Today, regulations and consumer awareness demand production technologies with minimum impact on the environment and maximum utilization of available resources. In the field of lipids, two well-known technologies for avoiding the use of organic solvents and chemicals stand out: supercritical (Sc) fluids and short path distillation (SPD). To date, both technologies involve high operating costs that have limited their application to selected high value-added products which are high temperature sensitive. However, improvements in process control and materials make further implementation of these techniques possible. In this chapter, an integrative review has been carried out with the aim of compiling the literature on the application of these technologies to lipid extraction, micronization and fractionation of liquid mixtures. Special attention has been paid to the separation of compounds by both technologies: deacidification, partial purification of acylglycerol compounds, isolation of unsaponifiable compounds and separation of toxic and polluting compounds.

Adsorption of toxic dye Eosin Y from aqueous solution by clay/carbon composite derived from spent bleaching earth

The environmentally friendly clay/carbon composite (SBE/C) was prepared by one-step pyrolysis under N₂ atmosphere at 700°C of spent bleaching earth (SBE) from the industrial waste of the refined oil industry. SBE/C was tested to remove anionic dye Eosin Y from aqueous water. The results revealed that SBE/C had larger specific surface area than SBE, and the equilibrium adsorption capacity of SBE/C (11.15 mg/g) was about 3 times than that of SBE (4.04 mg/g). The adsorption process was found to be exothermic and spontaneous. The adsorption capacity of SBE/C was independent on pH (5-12), and exhibits satisfactorily recyclable performance. Combined with characterization analysis, the adsorption mechanism likely includes electrostatic interaction, hydrogen bonding, hydrophobic interaction, halogen bonding, and π-π interaction. Overall, this exploration of SBE/C might open a window to the design of an efficient and low-cost adsorbent for Eosin Y dye elimination from wastewater. PRACTITIONER POINTS: The resource utilization of industrial waste SBE was achieved. SBE/C was synthesized and tested to adsorb Eosin Y for the first time. SBE/C had characteristics with porous structure and large surface area. pH had little effect on adsorption capacity of SBE/C for Eosin Y. SBE/C exhibited potential for dye elimination from wastewater.