Microwave-ultrasonic assisted extraction of lignin to synthesize new nano micellar organometallic surfactants for refining oily wastewater.

Abstract

In this work, a beneficial approach for efficient depolymerization of lignin and controllable product distribution is provided. Lignin, an abundant aromatic biopolymer, has the potential to produce various biofuels and chemical adsorption agents and is expected to benefit the future circular economy. Microwave-ultrasonic (MW/US) assisted efficient depolymerization of lignin affords some aromatic materials used in manufacturing the starting material to be investigated. Some nano organometallic surfactants (NOMS) based on Ni²⁺, Cu²⁺, Co²⁺, Fe³⁺, and Mn²⁺ besides 2-hydroxynaphth-sulphanilamide are synthesized to enhance oil recovery (EOR). In this work, the assessment of the NOMS's efficiency was improving the heavy oil recovery via the study of the dynamic interfacial tension (IFT), contact angle, and chemical flooding scenarios. The NOMS-Ni²⁺ exhibited the maximum reduction of viscosity and yield values. Dropping the viscosity to 819.9, 659.89, and 499.9 Pa s from blank crude oil viscosity of 9978.8, 8005.6, and 5008.6 Pa s respectively at temperatures of 40, 60, and 80 °C was investigated. The reduction of τ_B values was obtained also by OMS-Ni²⁺. The minimum IFT was recorded against the Ni²⁺ derivatives (0.1 × 10^-1 mN m^-1). The complete wettability alteration was achieved with the NOMS-Ni²⁺ surfactant (ɵ $\cong 6.01).$ The flooding test has been steered in 3 sets using the sand-packed model as a porous media at surfactant concentrations (1, 1.5, 2 and 2.5%) at 50 °C and 499 psi as injection pressure. The best value (ORs) formed for NOMS-Ni²⁺ were 62, 81, 85.2, and 89% respectively as compared with other NOMS-M²⁺ at the same concentrations. The mechanism of alternating wettability was described in the text. The rheology of the used heavy crude oil was investigated under temperatures of 40, 60, and 80 °C.