Oil Sludge Pyrolysis Process
The effectiveness of oil sludge pyrolysis technology in treating oil sludge stems from its rigorous and scientific process. This process primarily includes key steps such as pretreatment, pyrolysis reaction, oil-gas separation, tail gas treatment, and residue treatment.
Pretreatment
Pretreatment is the first step in the entire pyrolysis process. This stage requires a series of meticulous treatments of the oil sludge.
First, large impurities are removed through screening and filtration. Next, the moisture content of the oil sludge is adjusted to a suitable range for pyrolysis using methods such as mechanical dehydration or natural drying.
Pyrolysis Stage
The pretreated oil sludge then enters the pyrolysis reaction stage, the core of the entire process. Inside the pyrolysis equipment, the oil sludge is placed in a special oxygen-free or micro-oxygen environment. The pyrolysis reactor is typically constructed from special high-temperature and corrosion-resistant materials and incorporates internal features such as a rotary propeller, heat transfer surfaces, and anti-coking and anti-sticking designs.
As the temperature gradually increases, generally controlled within the critical range of 200-550℃, the organic matter in the oil sludge begins to undergo remarkable changes. Heavy hydrocarbon molecules are gradually broken down and cracked into light oil and gas. Moisture also evaporates rapidly at high temperatures, while the remaining solid residue slowly forms carbon black or coke. Solid carbon black is discharged through a water-cooled spiral slag discharge system.
Precise temperature control is crucial in this process, as different temperatures will cause changes in the types and proportions of pyrolysis products.
Collection of Oil Sludge Pyrolysis Products
The oil and gas produced by the pyrolysis reaction then enters the oil-gas separation system. In the condenser, most of the light oil and water vapor in the oil and gas are cooled and liquefied. After condensation, the liquid oil and uncondensed gas are initially separated. To further improve the purity of the liquid oil, subsequent processing steps such as oil-water separation are required.
The separated liquid oil can be used directly as fuel or chemical feedstock, or it can be further refined to produce higher-quality oil products. The uncondensed gas, after purification, also has high utilization value. It can be used as fuel gas for combustion heating or power generation, achieving energy recycling.
Exhaust Gas Treatment
Harmful exhaust gases are produced during the pyrolysis of oil sludge. If these exhaust gases are released directly into the atmosphere without treatment, they will cause serious air pollution. Exhaust gas treatment systems typically employ a combination of processes to ensure emissions meet standards.
First, a desulfurization and dust removal tower removes dust and sulfur. This tower uses a specific desulfurizing agent to chemically react with sulfides in the exhaust gas, converting them into harmless substances. Simultaneously, dust is removed through filtration and adsorption.
Next, a denitrification process removes nitrogen oxides from the exhaust gas. Furthermore, activated carbon adsorption and other processes are used to further remove organic pollutants and other trace harmful substances. After this series of rigorous treatment steps, the content of harmful substances in the exhaust gas is significantly reduced, meeting the prescribed emission standards before it can be safely released into the atmosphere.
