Mechanism of Magnetic Nanoparticle Enhanced Microwave Pyrolysis for Oily Sludge

Abstract

In view of the high dielectric constant of magnetic nanoparticles, this paper intends to use it as a new type of microwave absorbing medium to accelerate the microwave pyrolysis process of oily sludge. Microwave thermogravimetric reaction and pyrolysis product staged collection devices were established, respectively. The main stage of pyrolysis process of oily sludge was divided based on the thermogravimetric experiments. Mechanism was studied through the characteristics of pyrolysis products and reaction kinetics simulation. Experimental results showed that the addition of magnetic ZnFe2O4 particle did not change the microwave pyrolysis process of oily sludge and the pyrolysis efficiency could be improved. Pyrolysis process was divided into three stages, rapid heating and water evaporation stage (20~150 °C), light component evaporation stage (150~240 °C) and heavy component cracking stage (240~300 °C). Due to the addition of magnetic ZnFe2O4 particles, the content of C4~C12 increased by 3.5%, and the content of C18+ decreased by 4.1%, indicating that more recombinant components participated in the reaction pyrolysis to form light gas components. The kinetic analysis showed that the activation energy of oily sludge decreased by 36.49% and the pre-exponential factor decreased by 91.39% in stage III, indicating that magnetic nanoparticles had good catalytic activity.

Prospects for Combined Applications of Nanostructured Catalysts and Biocatalysts for Elimination of Hydrocarbon Pollutants

“…The method of photocatalytic oxidation has become the most widespread due to the availability of reagents, high efficiency, environmental friendliness and relatively low energy consumption compared to other physico-chemical methods. Among the NCS for photooxidation are TiO 2 , ZnO, ZrO [34][35][36]. In a number of processes related to the heterogeneous photocatalytic purification of water and soil from organic pollutants, NCs from the mentioned list are also used [15,17,[21][22][23]25,31,32].…”

“…Among the processes that differed from AOPs, pyrolysis is known as an approach to the destruction of organic pollutants using NCs [34]. The successful decomposition of oily sludge by ZnFe 2 O 4 (NPs = 30 nm) during three-stage pyrolysis with the activation of NCs by microwaves was shown.…”

Coconut Shell Liquid Smoke Production Quality from Size and Power Using Microwave-Assisted Pyrolysis

“…The addition of magnetic ZnFe2O4 will improve the efficiency of the pyrolysis process. It shows that the content of C 4-C12 increased by 3.5%, and the content of C18 + decreased by 4.1%, and this shows that magnetic nanoparticles have good catalytic [7]. The purpose of this study is to determine the optimal size of raw materials and microwave power in the manufacture of liquid smoke using the microwave-assisted pyrolysis method…”

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

“…This combination was conducive to accelerating the degradation of asphaltene. Qi et al 5 analyzed the main pyrolysis stages of oily sludge by thermogravimetric experiments. The mechanism of magnetic nanoparticles for enhancing the effect of the microwave pyrolysis of oily sludge was studied, and it was found that magnetic ZnFe 2 O 4 particles could improve the pyrolysis efficiency.…”