阅读说明：本技术 一种废弃动植物油脂脱氯加氢制液体石蜡的方法 (Method for preparing liquid paraffin by dechlorinating and hydrogenating waste animal and vegetable oil ) 是由 李保明 赵紫华 周凌 缪科杰 于 2019-08-29 设计创作，主要内容包括：本发明公开了一种废弃动植物油脂脱氯加氢制液体石蜡的方法,其步骤为：a)废弃动植物油脂与液体石蜡混合均匀得混合物；b)所得混合物与氢气混合进入加氢精制反应器,进行加氢精制反应；c)所得反应生成物料进入高温脱氯塔,进行脱氯反应；d)所得脱氯后物料进入高压分离器分离,分离压力4～8MPa,分离温度50～200℃,经分离得到气体、产品油和产品水；e)所述的产品油进入汽提塔脱硫；分馏,常压分馏塔上部得轻质液体石蜡,底部产出液体石蜡。本发明通过在废弃动植物油脂加氢精制后,不需要将产品分离后再去除氯化氢,而是直接通过高温脱氯剂将氯化氢吸收,基本能够消除氯化氢对后续工艺管道和设备的腐蚀。(The invention discloses a method for preparing liquid paraffin by dechlorinating and hydrogenating waste animal and vegetable oil, which comprises the following steps: a) uniformly mixing the waste animal and vegetable oil and liquid paraffin to obtain a mixture; b) mixing the obtained mixture with hydrogen, and allowing the mixture to enter a hydrofining reactor for hydrofining reaction; c) the obtained reaction product enters a high-temperature dechlorination tower to carry out dechlorination reaction; d) separating the dechlorinated materials in a high-pressure separator at the separation pressure of 4-8 MPa and the separation temperature of 50-200 ℃ to obtain gas, product oil and product water; e) the product oil enters a stripping tower for desulfurization; fractionating to obtain light liquid paraffin at the upper part of the atmospheric fractionating tower and liquid paraffin at the bottom. According to the invention, after the waste animal and vegetable oil is hydrorefined, the hydrogen chloride is directly absorbed by the high-temperature dechlorinating agent without separating the product and then removing the hydrogen chloride, so that the corrosion of the hydrogen chloride to subsequent process pipelines and equipment can be basically eliminated.)

1. A method for preparing liquid paraffin by dechlorinating and hydrogenating waste animal and vegetable oil comprises the following steps:

a) uniformly mixing the waste animal and vegetable oil and liquid paraffin to obtain a mixture; wherein the liquid paraffin accounts for 10-90 wt% of the waste animal and vegetable fat;

b) mixing the mixture obtained in the step a) with hydrogen, feeding the mixture into a hydrofining reactor, and carrying out hydrofining reaction in the presence of a hydrofining catalyst;

the hydrorefining reaction has the reaction conditions as follows: liquid airspeed of 0.5-2 h^-1The volume ratio of hydrogen to oil is 500: 1-2000: 1, the reaction pressure is 4-8 MPa, and the reaction temperature is 320-380 ℃;

c) the reaction product obtained in the step b) enters a high-temperature dechlorinating tower to carry out dechlorination reaction in the presence of a high-temperature dechlorinating agent;

the dechlorination reaction has the reaction conditions that: liquid airspeed of 2-8 h^-1The reaction pressure is 4-8 MPa, and the reaction temperature is 320-400 ℃;

d) separating the dechlorinated materials obtained in the step c) in a high-pressure separator, wherein the separation pressure is 4-8 MPa, the separation temperature is 50-200 ℃, and gas, product oil and product water are obtained through separation;

e) desulfurizing the product oil obtained in the step d) in a stripping tower; and (3) fractionating the desulfurized product oil in an atmospheric fractionating tower, collecting fractions at 0-150 ℃ from the upper part of the atmospheric fractionating tower to obtain light liquid paraffin, and producing the liquid paraffin at the bottom.

2. The method for preparing the liquid paraffin by dechlorinating and hydrogenating the waste animal and vegetable oil and fat according to claim 1, which is characterized by comprising the following steps of: in the step b), the hydrorefining catalyst takes two or three of nickel metal salt, molybdenum metal salt, cobalt metal salt and tungsten metal salt with the content of 1-30 wt.% as active components, and the modified molecular sieve/alumina is taken as a catalyst carrier.

3. The method for preparing the liquid paraffin by dechlorinating and hydrogenating the waste animal and vegetable oil and fat according to claim 2, which is characterized by comprising the following steps of: the modified molecular sieve/alumina is Al modified by molecular sieve₂O₃A carrier;

the molecular sieve is selected from one or more of SAPO-34 molecular sieve, ZSM-22 molecular sieve, ZSM-23 molecular sieve, NaX type molecular sieve, MCM-41 molecular sieve, SAPO-11 molecular sieve and ZSM-35 molecular sieve, and the content of the molecular sieve in the modified molecular sieve/alumina is 0.1-10 wt.%.

4. The method for preparing the liquid paraffin by dechlorinating and hydrogenating the waste animal and vegetable oil and fat according to claim 1, which is characterized by comprising the following steps of: in the step c), the high-temperature dechlorinating agent takes 20 wt.% to 80 wt.% of metal oxides and/or carbonates of metals in groups I and II as active components, and takes active alumina as a carrier.

5. The method for preparing the liquid paraffin by dechlorinating and hydrogenating the waste animal and vegetable oil and fat according to claim 1, which is characterized by comprising the following steps of: the waste animal and vegetable oil is selected from one or more of waste cooking oil, swill oil, palmitic acid oil, coconut oil, palm oil and the like.

6. The method for preparing the liquid paraffin by dechlorinating and hydrogenating the waste animal and vegetable oil and fat according to claim 1, which is characterized by comprising the following steps of: in the step d), the product water is discharged into a sewage tank; a part of the gas is recycled to be used in the step a), and a part of the gas is discharged to the flare tower.

7. The method for preparing the liquid paraffin by dechlorinating and hydrogenating the waste animal and vegetable oil and fat according to claim 1, which is characterized by comprising the following steps of: in the step e), one part of the liquid paraffin produced at the bottom of the atmospheric fractionating tower is removed to a product tank, and the other part of the liquid paraffin is refluxed to the step a) and mixed with the waste animal and vegetable oil.

Technical Field

The invention belongs to the field of energy chemical industry, and particularly relates to a method for preparing liquid paraffin by dechlorinating and hydrogenating waste animal and vegetable oil, wherein the prepared biodiesel can be applied to the industries of clean energy and biological oil.

Background

The quantity of waste grease produced in China every year is very large, and the waste grease and waste cooking oil recovered from large and medium cities are used for preparing the biodiesel, so that the production cost of the biodiesel can be reduced, the industrial waste oil and other waste oil can be comprehensively utilized, waste materials are changed into valuable materials, and the coordinated development of economy and environmental protection is realized.

Chlorine contained in the waste animal and vegetable oil is not beneficial to hydrofining to produce biodiesel, and mainly because water can be generated in the hydrogenation process of the waste animal and vegetable oil, the chlorine can be hydrogenated to be changed into hydrogen chloride, the temperature of materials is reduced at the outlet of a reactor, gaseous water is changed into liquid water, and the hydrogen chloride is dissolved in the water to be changed into hydrochloric acid, so that subsequent process pipelines and equipment are corroded.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: provides a method for preparing liquid paraffin by dechlorinating and hydrogenating waste animal and vegetable oil without corroding process pipelines.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: a method for preparing liquid paraffin by dechlorinating and hydrogenating waste animal and vegetable oil comprises the following steps:

a) uniformly mixing the waste animal and vegetable oil and liquid paraffin to obtain a mixture; wherein the liquid paraffin accounts for 10-90 wt% of the waste animal and vegetable fat; liquid paraffin is added as a solvent, so that the waste animal and vegetable oil can be diluted, the reaction energy consumption is reduced, and coking and carbonization in the reaction process of the waste animal and vegetable oil are prevented;

b) mixing the mixture obtained in the step a) with hydrogen, feeding the mixture into a hydrofining reactor, and carrying out hydrofining reaction in the presence of a hydrofining catalyst;

the hydrorefining reaction has the reaction conditions as follows: liquid airspeed of 0.5-2 h^-1The volume ratio of hydrogen to oil is 500: 1-2000: 1, the reaction pressure is 4-8 MPa, and the reaction temperature is 320-380 ℃;

c) the reaction product obtained in the step b) enters a high-temperature dechlorinating tower to carry out dechlorination reaction in the presence of a high-temperature dechlorinating agent;

the dechlorination reaction has the reaction conditions that: liquid airspeed of 2-8 h^-1The reaction pressure is 4-8 MPa, and the reaction temperature is 320-400 ℃;

d) separating the dechlorinated materials obtained in the step c) in a high-pressure separator, wherein the separation pressure is 4-8 MPa, the separation temperature is 50-200 ℃, and gas, product oil and product water are obtained through separation;

e) desulfurizing the product oil obtained in the step d) in a stripping tower; and (3) fractionating the desulfurized product oil in an atmospheric fractionating tower, collecting fractions at 0-150 ℃ from the upper part of the atmospheric fractionating tower to obtain light liquid paraffin, producing liquid paraffin at the bottom, removing a part of the liquid paraffin from a product tank, and refluxing a part of the liquid paraffin to the step a) to be mixed with the waste animal and vegetable oil.

The hydrofining catalyst takes two or three of nickel metal salt, molybdenum metal salt, cobalt metal salt and tungsten metal salt with the content of 1-30 wt.% as active components, and takes modified molecular sieve/alumina as a catalyst carrier.

The modified molecular sieve/alumina is Al modified by molecular sieve₂O₃A carrier;

the molecular sieve is selected from one or more of SAPO-34 molecular sieve, ZSM-22 molecular sieve, ZSM-23 molecular sieve, NaX type molecular sieve, MCM-41 molecular sieve, SAPO-11 molecular sieve and ZSM-35 molecular sieve, and the content of the molecular sieve in the modified molecular sieve/alumina is 0.1-10 wt.%. The modified molecular sieve/alumina carrier has the advantages of high hydrothermal stability and relatively good carbon deposition resistance.

The high-temperature dechlorinating agent takes 20-80 wt.% of metal oxides of I and II groups and/or metal carbonates of I and II groups as active components, and takes active alumina as a carrier. The high-temperature dechlorinating agent has the advantages of bearing high temperature and high pressure, having higher chlorine capacity, absorbing hydrogen chloride generated by hydrofining, reducing the material grade of a subsequent device and reducing the influence of hydrogen chloride corrosion on the device.

The waste animal and vegetable oil is selected from one or more of waste cooking oil, swill oil, palmitic acid oil, coconut oil, palm oil and the like.

In the step d), the product water is discharged into a sewage tank; a part of the gas is recycled to be used in the step a), and a part of the gas is discharged to the flare tower.

Has the advantages that: according to the invention, after the waste animal and vegetable oil is hydrorefined, the hydrogen chloride is not required to be removed after the product is separated, but is directly absorbed by the high-temperature dechlorinating agent, so that the Cl content is less than 0.5 mu g/g, the energy consumption of the reaction is reduced, and the corrosion of the hydrogen chloride to subsequent process pipelines and equipment can be basically eliminated.

Drawings

FIG. 1 is a flow chart of liquid paraffin produced by dechlorinating and hydrogenating waste animal and vegetable oil and fat;

in the figure, 1, a feed pump, 2, a fresh hydrogen compressor, 3, a hydrofining reactor, 4, a recycle hydrogen compressor, 5, a high-temperature dechlorinating tower, 6, a high-pressure separator, 7, a stripping tower, 8 and an atmospheric fractionating tower.

Detailed Description

The method of the present invention will be further described with reference to the accompanying drawings, but the invention is not limited thereto.

a) Uniformly mixing the waste animal and vegetable oil and the environment-friendly liquid paraffin to obtain a mixture; wherein the environment-friendly liquid paraffin accounts for 10-90 wt% of the waste animal and vegetable oil;

b) adding the mixture obtained in the step a) into a hydrofining reactor 3 through a feed pump 1, compressing hydrogen by a new hydrogen compressor 2, then entering the hydrofining reactor 3, and carrying out hydrofining reaction in the presence of a hydrofining catalyst; the hydrorefining reaction has the reaction conditions as follows: liquid airspeed of 0.5-2 h^-1The volume ratio of hydrogen to oil is 500: 1-2000: 1The reaction pressure is 4-8 MPa, and the reaction temperature is 320-380 ℃;

c) the reaction product obtained in the step b) enters a high-temperature dechlorinating tower 5, and dechlorination reaction is carried out in the presence of a high-temperature dechlorinating agent; the dechlorination reaction has the reaction conditions that: liquid airspeed of 2-8 h^-1The reaction pressure is 4-8 MPa, and the reaction temperature is 320-400 ℃;

d) the dechlorinated materials obtained in the step c) enter a high-pressure separator 6 for separation, and gas, product oil and product water are obtained through separation; the product oil enters a stripping tower 7 for desulfurization; discharging the product water into a sewage tank; a part of the gas enters a recycle hydrogen compressor 4 to be recycled to the step a) for use, and a part of the gas is discharged to a flare tower

e) And d) fractionating the product oil obtained in the step d) in an atmospheric fractionating tower 8, producing light liquid paraffin at the upper part of the fractionating tower, producing environment-friendly liquid paraffin at the bottom, removing a part of the environment-friendly liquid paraffin to a product tank, and refluxing a part of the environment-friendly liquid paraffin to the step a) and mixing the part of the environment-friendly liquid paraffin with the waste animal and vegetable oil.

Table 1: the properties of the waste animal and vegetable oil in the embodiment are as follows:

table 2: examples 1-3 Experimental conditions and liquid Paraffin Properties