Method for preparing light-weight aromatic hydrocarbon through aromatizing waste edible oil

Abstract

The invention discloses a method for preparing light-weight aromatic hydrocarbon through aromatizing waste edible oil. The method comprises the following steps: (1) taking the waste edible oil or mixing the waste edible oil with a solvent; after pre-heating and gasifying, conveying a mixture into a fixed bed reactor filled with a catalyst and reacting; (2) condensing and separating a reaction product obtained by step (1) to obtain the aromatic hydrocarbon. According to the method disclosed by the invention, almost obtained aromatized products are the aromatic hydrocarbon and only contain traceoxygen-containing compounds; oxygen atoms in grease molecules are basically transformed into a form of water or carbon dioxide, so that the water is removed only through adopting a solvent extractionor extraction and distillation method, and an aromatic hydrocarbon product can be obtained; the method belongs to continuous operation and is suitable for industrial large-scale production.

Description

technical field [0001] The invention relates to a method for preparing light aromatics, in particular to a method for preparing light aromatics by aromatizing waste cooking oil. Background technique [0002] Edible oil is indispensable in people's daily diet, but it will inevitably produce a large number of waste edible oil after use. According to statistics, the output of waste cooking oil in China is as high as 5 million tons per year. At present, there is no effective utilization of waste cooking oil in the world. This has led to the stimulation of economic interests, many people have learned to "make the best use of everything" and reprocess it into cooking oil through local methods, so as to achieve the goal of shaming. level, seriously endangering human health. In addition, waste cooking oil will also enter rivers and lakes along with the urban drainage network, causing a large number of organic matter to grow, causing environmental pollution problems such as blue-gr...

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Problems solved by technology

This patent has the following defects: (1) It is a vacuum pyrolysis process, which is an intermittent operation. After each production of a kettle of products, the temperature must be lowered to separate the catalyst before adding raw materials and then heating up. It is not suitable for large-scale production

(2) During the reaction process, the contact time between the waste oil and the catalyst is too long, which will easily lead to further coking and carbonization of the generated aromatics, which reduces the yield of aromatics and shortens the service life of the catalyst

(3) Operate under vacuum, the scope of application is narrow, and the energy consumption is also high

(4) The gas products obtained by the reaction are not recycled, but directly discharged, which will reduce the yield of aromatics on the one hand, and easily cause environmental pollution on the other hand

(5) It directly mixes the liquid-phase oil with the solid-state catalyst and then warms the reaction (cold feed), which will lead to a large amount of oxygen-containing compounds in the aromatization product, and the oxygen atoms in the oil molecules are basically formed as oxygen-containing carbides. in the liquid phase product, resulting in lower yields of aromatics

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