Mechanism of Magnetic Nanoparticle Enhanced Microwave Pyrolysis for Oily Sludge

Magnetic biochar as a revolutionizing approach for diverse dye pollutants elimination: A comprehensive review

The term "biomass" encompasses all substances found in the natural world that were once alive or derived from living organisms or their byproducts. These substances consist of organic molecules containing hydrogen, typically oxygen, frequently nitrogen, and small amounts of heavy, alkaline earth and alkali metals. Magnetic biochar refers to a type of material derived from biomass that has been magnetized typically by adding magnetic components such as magnetic iron oxides to display magnetic properties. These materials are extensively applicable in widespread areas like environmental remediation and catalysis. The magnetic properties of these compounds made them ideal for practical applications through their easy separation from a reaction mixture or environmental sample by applying a magnetic field. With the evolving global strategy focused on protecting the planet and moving towards a circular, cost-effective economy, natural compounds, and biomass have become particularly important in the field of biochemistry. The current research explores a comparative analysis of the versatility and potential of biomass for eliminating dyes as a sustainable, economical, easy, compatible, and biodegradable method. The elimination study focused on the removal of various dyes as pollutants. Various operational parameters which influenced the dye removal process were also discussed. Furthermore, the research explained, in detail, adsorption kinetic models, types of isotherms, and desorption properties of magnetic biochar adsorbents. This comprehensive review offers an advanced framework for the effective use of magnetic biochar, removing dyes from textile wastewater.

Influence of Sodium Metal Nanoparticles on the Efficiency of Heavy Oil Aquathermolysis

In this study, for the first time we investigated the in situ upgrading performance of Na metal nanoparticles, which were obtained by dispersing small pieces of sodium in liquid paraffin up to certain dispersity. In situ aquathermolytic reactions were modeled in a high pressure–high temperature reactor coupled with a Gas Chromatography (GC) system at a temperature of 250 °C for 24 h using a heavy oil sample, produced from the Ashal’cha reservoir, Republic of Tatarstan (Russia). The mean particle size of Na nanoparticles was 6.5 nm determined by the Dynamic Light Scattering (DLS) method. The nanoparticles were introduced to the reaction medium with a concentration of 2 wt.% The upgrading performance of Na nanoparticles was evaluated by several analytical methods such as Gas Chromatography (GC), elemental analysis (CHNS), SARA, Gas Chromatography–Mass Spectroscopy (GC-MS), FT-IR spectroscopy and viscosity measurements. It was revealed that Na nanoparticles interact with water to yield hydrogen gas, the concentration of which increases from 0.015 to 0.805 wt.% Moreover, the viscosity of upgraded heavy oil was reduced by more than 50% and the content of low-molecular-weight hydrocarbons in saturated and aromatics fractions was increased. The Na nanoparticles contributed to the utilization of hydrogen sulfide and carbon dioxide by 99 and 94 wt.%, respectively.

Probing the separation mechanism of solid-liquid components in oily sludge and sludge containing polymers for a harmless treatment process of sludge

In this study, the compositions of oily sludge and sludge containing polymers were analyzed. Sludge was separated preliminarily by conditioning centrifugal technology, whereby the temperature of the centrifugal process and the amount of oil/water separating agent were optimized. Thermal decomposition technology was combined in order to achieve the efficient treatment of sludge. The results showed that the compositions of oily sludge and sludge containing polymers were complex. Therefore, they could not meet the requirements of environmental protection only by conditioning centrifugal technology. After optimization, the best conditioning centrifugal temperature was 70 °C and the content of the oil/water separating agent was 2%. The high efficiency treatment of oily sludge and sludge containing polymers could be realized by combining conditioning centrifugal technology with the thermal decomposition technology. It is found that the sludge could meet the requirements of environmental protection after this combined treatment. This technology has strong adaptability to different types of oilfield sludge. This work is of great significance for the efficient treatment of oily sludge and sludge containing polymers and for environmental protection.

Changes in Heavy Oil Saturates and Aromatics in the Presence of Microwave Radiation and Iron-Based Nanoparticles

Our knowledge of electromagnetic heating’s effect on heavy oil upgrading is largely based on very limited data. The aim of the present research was thus to study in detail the effect of microwave exposure in the absence and presence of nanosized magnetite on the composition of heavy oil. The obtained data reveal that the use of nanosized magnetite improves not only microwave radiation application as a result of its absorption and release of thermal energy but also that these nanoparticles have a catalytic ability to break carbon–heteroatom bonds in the composition of resins and asphaltene molecules. In fact, the overall reduction in asphaltenes or resins does not always adequately describe very important changes in asphaltene composition. Even a small fraction of broken carbon–heteroatom bonds can lead to an increase in the mobility of asphaltenes. Moreover, this study has shed light on the important evidence for asphaltenes’ transformation, which was found to be the formation of light aromatic compounds, such as alkylbenzenes, naphthalenes and phenanthrenes. These compounds were fixed in the composition of the aromatic fraction. We believe that these compounds could be the fragments obtained from asphaltenes’ degradation. The evidence from this study points toward the idea that asphaltenes’ destruction is crucial for increasing oil mobility in the reservoir rock during its thermal stimulation.

Numerical Simulation of Oil Shale Pyrolysis under Microwave Irradiation Based on a Three-Dimensional Porous Medium Multiphysics Field Model

The pyrolysis characteristics of oil shale during heat treatment dominate the oil production of kerogen. In this study, the pyrolysis characteristics of oil shale in a laboratory microwave apparatus were investigated based on a novel fully coupled three-dimensional electromagnetic-thermal-chemical-hydraulic model according to the experimental microwave apparatus. By simulating the electric field, temperature distribution, and kerogen decomposition within oil shale subjected to microwave irradiation, several parameters, including waveguide, position, and power, were successfully optimized. The results indicated that the non-uniform temperature distribution was consistent with the distribution of the electric field. Double microwave ports were more effective than single ports in terms of heating rate and temperature uniformity. There was an optimal location where the highest heating efficiency was obtained, which was on the left of the cavity center. When irradiation was conducted over a range of microwave powers, a higher power was suitable for achieving a rapid temperature increase, whereas a lower power was suitable to gain a high efficiency of the pyrolysis rate. Therefore, a variable power heating mode was introduced to decrease the heating time and improve the heat uniformity simultaneously during oil shale pyrolysis. Specifically, the secondary reactions of oil products should be maximally avoided by controlling the microwave power.