SALT-ASSISTED MICROWAVE DEMULSIFICATION

Fluorinated polyether-coated Fe3O4-functionalized oxidized carbon nanotubes as a recyclable demulsifier for crude oil emulsion treatment

Based on the excellent adsorption properties of carbon materials, a new magnetic nanodemulsifier was prepared in this study. First, carbon nanotubes were oxidized using a solvothermal method. Then, Fe3O4 was combined with oxidized carbon nanotubes using a one-pot method, and then grafted onto fluorine-containing polyether to prepare a magnetic composite demulsifier (Fe3O4@C-F) with good demulsification properties. The surface morphology of the composite demulsifier was analyzed using scanning electron microscopy (SEM). The structure of the composite demulsifier was characterized using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectrometry (XPS). The stability of the composite demulsifier was characterized using thermogravimetric analysis (TGA). Results showed that the oxidized carbon nanotubes and fluorinated polyether were successfully attached to Fe3O4. The experimental objective was to obtain a self-made crude oil emulsion. The demulsification test and recovery performance test were then performed, and the main factors affecting the demulsification performance of the demulsifier were investigated. Results showed that when the dosage was 800 mg L-1, the temperature was 65 °C, the demulsification time was 90 min, and the pH value was 6. The demulsification effect of the Fe3O4@C-F magnetic composite demulsifier was the best, whereby the demulsification rate could reach 91.68%, and the oil-water interface was clear. Fe3O4@C-F had a magnetic response and could be recycled from the two-phase system six times under the action of an external magnetic field. Fe3O4@C-F is an efficient and environmentally friendly demulsifier that has important application value for enriching demulsification technology systems.

Conversion of plastic waste into fuel oil using zeolite catalysts in a bench-scale pyrolysis reactor

Catalytic pyrolysis of mixed plastic waste to fuel oil experiment was tested with ZSM-5 zeolite (commercial and synthesized) catalysts along with other catalysts.

The antioxidant and tyrosinase inhibition properties of essential oil from the peel of Chinese Torreya grandis Fort

The antioxidant and tyrosinase inhibition properties of essential oil from the peel of Chinese Torreya grandis Fort. (CTGF oil) were investigated. The antioxidant properties of CTGF oil were evaluated via 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging tests, and it showed an IC₅₀ value of 0.88 ± 0.06 μg mL^-1 compared to V _C with a value of 1.0 ± 0.1 μg mL^-1 and BHT with a value of 2.9 ± 0.1 μg mL^-1. CTGF oil had relatively significant DPPH scavenging activity (p < 0.05), which could be compared to other natural oils as follows: cassia oil (92.4%) > peppermint oil (89.1%) > clove leaf oil (87.7%) > nutmeg oil (80.1%) > CTGF oil (42.6%) > lemon oil (25.5%). Furthermore, changes in the peroxide values of different treatment groups during storage for 60 days were estimated. CTGF oil displayed better antioxidant activity than lemon oil, with activity similar to that of BHT for the reduction of the peroxide value. Moreover, CTGF oil effectively inhibited the oxidation of 3,4-dihydroxy-l-phenylalanine (l-DOPA) through tyrosinase (P < 0.05). The essential oil obtained after hydrodistillation from the peel of Chinese Torreya grandis Fort. could be potentially utilized as a good new alternative source of natural antioxidants for the food and cosmetics industries.

Microwave-Assisted Brine Extraction for Enhancement of the Quantity and Quality of Lipid Production from Microalgae Nannochloropsis sp

Toward attaining a sustainability and eco-friendly process, a green and low-cost solvent-brine (NaCl solution) is proposed, as microwave-assisted extraction (MAE) technique solvent to extract lipids from microalgae Nannochloropsis sp. The effect of NaCl concentration on the quantity and quality of the extracted lipid was assessed, while MAE parameters were optimized using response surface methodology (RSM). The content of fatty acid methyl esters (FAMEs) in the lipid was analyzed by using a gas chromatography-flame ionization detector (GC/FID). The highest lipid yield (16.1%) was obtained using 10% (w/v) brine at optimum extraction parameters of 5% (w/v) solid loading, 100 °C, and 30 min. The lipid extraction yield via optimized MAE-brine technique was thrice better than that Soxhlet extraction did and only 2% less than Bligh and Dyer (B&D) lipid extraction, which utilized harmful solvents. The proposed MAE-brine technique offered better quality lipids containing the highest amount of polyunsaturated fatty acids (PUFA) (44.5%) and omega-3 fatty acids (FAs) (43%). Hence, the MAE-brine solvent technique appears to be a promising extraction method for cheaper, greener, and faster extraction of a high-quality lipid for specialty food applications.

Recent development in the treatment of oily sludge from petroleum industry: a review

Oily sludge is one of the most significant solid wastes generated in the petroleum industry. It is a complex emulsion of various petroleum hydrocarbons (PHCs), water, heavy metals, and solid particles. Due to its hazardous nature and increased generation quantities around the world, the effective treatment of oily sludge has attracted widespread attention. In this review, the origin, characteristics, and environmental impacts of oily sludge were introduced. Many methods have been investigated for dealing with PHCs in oily sludge either through oil recovery or sludge disposal, but little attention has been paid to handle its various heavy metals. These methods were discussed by dividing them into oil recovery and sludge disposal approaches. It was recognized that no single specific process can be considered as a panacea since each method is associated with different advantages and limitations. Future efforts should focus on the improvement of current technologies and the combination of oil recovery with sludge disposal in order to comply with both resource reuse recommendations and environmental regulations. The comprehensive examination of oily sludge treatment methods will help researchers and practitioners to have a good understanding of both recent developments and future research directions.