Research on Treatment of Oily Sludge from the Tank Bottom by Ball Milling Combined with Ozone-Catalyzed Oxidation

Xie

et al. 2022

IJERPH

In this study, Mn/Zn@palygorskite (PG) catalysts with developed pores and good salt tolerance were prepared and applied to the treatment of coal chemical wastewater. A doping ratio of metal elements, calcination temperature, and calcination time was used to optimize the preparation conditions and determine the optimal preparation conditions of the Mn/Zn@PG catalysts. The catalysts, obtained under various preparation conditions, were characterized and analyzed by XRD, SEM, EDS, BET, XRF, XPS, and other techniques. Results showed that the Zn and Mn elements in the Mn/Zn@PG catalyst existed as ZnO and MnO2, respectively. The optimal working conditions of the Mn/Zn@PG catalyst for catalytic oxidation treatment of coal chemical wastewater, obtained through the optimization of working conditions, are the following: reaction time 60 min, wastewater pH = 9.28, ozone ventilation rate 0.2 L/min, catalyst filling ratio 20%. The height-to-diameter ratio of the tower was 6:1. The abrasion resistance and catalytic performance of the Mn/Zn@PG catalyst after repeated use were investigated, and the mechanism of the loss of active components of the Mn/Zn@PG catalyst was explored. The coal chemical wastewater, before and after treatment, was analyzed by UV–vis spectroscopy and 3D fluorescence spectroscopy. The hierarchical–principal component comprehensive evaluation system (AHP–PCA) was established to evaluate the catalytic ozonation process of coal chemical wastewater, so that the overall evaluation of the process performance can be achieved.

Section: Resultsmentioning

confidence: 99%

Preparation of Mn/Zn@PG Catalyst for Catalytic Oxidation Treatment of Coal Chemical Wastewater

Xie

et al. 2022

IJERPH

“…Fig. 2 compares oily sludge treatment and its application level and the average oil recovery rate percentage extracted from different papers [50,[57][58][59][60][61][62][63]. Because technology selection incorporates several factors, assessing the overall performance of available technologies is challenging.…”

Section: ■ Overview Of Oil Sludge Disposal Methodsmentioning

confidence: 99%

An Overview of the Current State and Prospects for Oil Recovery from Oily Sludge

et al. 2022

Oily sludge is a solid emulsified waste created by the petroleum industry. Solid particles, crude oil, and water comprise most of their composition. Because it contains high concentrations of cycloalkanes, benzene series, polycyclic aromatic hydrocarbons, and other harmful and hazardous substances, it poses a severe risk to human health and the environment. It must be treated to reduce its toxicity. However, crude oil is a significant component of oily sludge and has a high recycling value. As a result, numerous procedures for extracting crude oil from oily sludge have been developed, including solvent extraction, pyrolysis, centrifugation, ultrasonic treatment, electronic treatment, flotation, supercritical treatment, and combination processes. The primary purpose of this review is to describe the evolution of various recycling technologies and to compare their benefits, drawbacks, and ways of action. This concept is expected to be the cornerstone for future recycling technology development.

“…Petroleum-containing sludges are usually recovered at high quantities at refineries, liquid fuel tanks, ship bunkers, and sewage treatment plants. Recent literature suggests management techniques such as incineration, photo-catalysis, bio-degradation, and pyrolysis [32,33]. However, due to their very inconsistent composition (poly-aromatic hydrocarbons, heavy metals, inorganic salts, and humidity) the most commonly applied management technique is incineration [34].…”

Section: Introductionmentioning

confidence: 99%

Valorization of Hazardous Organic Solid Wastes towards Fuels and Chemicals via Fast (Catalytic) Pyrolysis

Rekos

Charisteidis

Tzamos

et al. 2022

Sustainable Chemistry

The management of municipal and industrial organic solid wastes has become one of the most critical environmental problems in modern societies. Nowadays, commonly used management techniques are incineration, composting, and landfilling, with the former one being the most common for hazardous organic wastes. An alternative eco-friendly method that offers a sustainable and economically viable solution for hazardous wastes management is fast pyrolysis, being one of the most important thermochemical processes in the petrochemical and biomass valorization industry. The objective of this work was to study the application of fast pyrolysis for the valorization of three types of wastes, i.e., petroleum-based sludges and sediments, residual paints left on used/scrap metal packaging, and creosote-treated wood waste, towards high-added-value fuels, chemicals, and (bio)char. Fast pyrolysis experiments were performed on a lab-scale fixed-bed reactor for the determination of product yields, i.e., pyrolysis (bio)oil, gases, and solids (char). In addition, the composition of (bio)oil was also determined by Py/GC-MS tests. The thermal pyrolysis oil from the petroleum sludge was only 15.8 wt.% due to the remarkably high content of ash (74 wt.%) of this type of waste, in contrast to the treated wood and the residual paints (also containing 30 wt.% inorganics), which provided 46.9 wt.% and 35 wt.% pyrolysis oil, respectively. The gaseous products ranged from ~7.9 wt.% (sludge) to 14.7 (wood) and 19.2 wt.% (paints), while the respective solids (ash, char, reaction coke) values were 75.1, 35, and 36.9 wt.%. The thermal (non-catalytic) pyrolysis of residual paint contained relatively high concentrations of short acrylic aliphatic ester (i.e., n-butyl methacrylate), being valuable monomers in the polymer industry. The use of an acidic zeolitic catalyst (ZSM-5) for the in situ upgrading of the pyrolysis vapors induced changes on the product yields (decreased oil due to cracking reactions and increased gases and char/coke), but mostly on the pyrolysis oil composition. The main effect of the ZSM-5 zeolite catalyst was that, for all three organic wastes, the catalytic pyrolysis oils were enriched in the value-added mono-aromatics (BTX), especially in the case of the treated wood waste and residual paints. The non-condensable gases were mostly consisting of CO, CO2, and different amounts of C1–C4 hydrocarbons, depending on initial feed and use or not of the catalyst that increased the production of ethylene and propylene.