A method for pipeline transportation of liquid dimethyl ether mixed with crude oil
By mixing liquid dimethyl ether with crude oil, the viscosity and freezing point are reduced, solving the problem of difficult crude oil transportation and realizing efficient and low-cost oil pipeline transportation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHONGKE LIQUID SUNSHINE (SUZHOU) HYDROGEN ENERGY TECH DEV CO LTD
- Filing Date
- 2025-04-28
- Publication Date
- 2026-06-30
AI Technical Summary
Crude oil is difficult to transport in oil pipelines due to its high viscosity and high freezing point, especially in low-temperature environments, where traditional methods increase energy consumption and costs.
By mixing liquid dimethyl ether with crude oil in a certain proportion to reduce viscosity and freezing point, and then transporting it under pressure at room temperature, and finally using an inexpensive heat source to separate the dimethyl ether from the crude oil after transportation, heating-free transportation can be achieved.
It reduces the viscosity and freezing point of crude oil, reduces the pressure required for transportation, saves energy consumption and costs, and improves transportation efficiency.
Abstract
Description
Technical Field
[0001] This invention relates to the field of oil pipeline transportation technology, and in particular to a method for improving crude oil transportation performance by adding liquid dimethyl ether. Background Technology
[0002] Dimethyl ether (DME) has the molecular formula CH3OCH3, a relative density (at 20℃) of 0.666, a melting point of -141.5℃, a boiling point of -24.9℃, and a vapor pressure of approximately 0.5 MPa at room temperature, similar to liquefied petroleum gas (LPG). It is soluble in water and many organic solvents such as alcohols, ether, acetone, and chloroform. Liquid dimethyl ether is a non-polar solvent and miscible with petroleum. DME is flammable, producing a slightly bright flame during combustion, with a heat of combustion (gaseous) of 1455 kJ / mol. At room temperature, DME is inert, does not readily oxidize spontaneously, and is non-corrosive and non-carcinogenic; however, it can decompose into methane, ethane, formaldehyde, etc., under radiation or heating conditions. Dimethyl ether is a homologue of ether, but unlike diethyl ether used as an anesthetic, it has extremely low toxicity. It can dissolve various chemical substances. Due to its easy compressibility, condensation, vaporization, and miscibility with many polar or non-polar solvents, it is widely used in aerosol product propellants, Freon substitute refrigerants, solvents, etc. It can also be used in chemical synthesis, and its applications are quite extensive.
[0003] During oil pipeline transportation, the high viscosity and high pour point of crude oil often lead to transportation difficulties, especially in low-temperature environments. Traditional methods typically require heating the pipeline or increasing the transportation pressure, which not only increases energy consumption but also raises transportation costs. Dimethyl ether has a viscosity coefficient of 0.15 mPa·s at 20°C, while the viscosity coefficient of medium-quality crude oil is 10–100 mPa·s. Mixing crude oil with dimethyl ether can significantly reduce both the viscosity coefficient and the pour point. Summary of the Invention
[0004] This invention aims to provide a method for improving crude oil transportation performance by adding liquid dimethyl ether, thereby addressing the problems existing in the prior art. Specifically, this invention is achieved through the following technical solution: 1. After passing dimethyl ether into the compressor, it is converted into liquid dimethyl ether. The liquid dimethyl ether is then mixed with crude oil in a certain ratio, ranging from 1:9 to 9:1. The specific ratio is adjusted according to the viscosity of the crude oil and the ambient temperature.
[0005] 2. The well-mixed liquefied dimethyl ether and crude oil are introduced into a dedicated pipeline for transportation under ambient temperature and pressure. By adding dimethyl ether, the viscosity and freezing point of the crude oil are reduced, eliminating the need for heating during transportation and lowering the transportation pressure.
[0006] 3. After the transportation is completed, at room temperature, the mixture is heated using inexpensive heat sources such as air, water, or industrial waste heat by reducing the pressure, so that the dimethyl ether is separated from the crude oil in gaseous form.
[0007] The above-mentioned technical solution not only solved the technical problems in crude oil transportation, but also transported dimethyl ether, an industrial necessity, achieving two goals at once, saving costs and improving transportation efficiency. Specific Implementation
[0008] This invention aims to provide a method for improving crude oil transportation performance by adding liquid dimethyl ether, thereby addressing the problems existing in the prior art. Specifically, this invention is achieved through the following technical solution: 1. After passing dimethyl ether into the compressor, it is converted into liquid dimethyl ether. The liquid dimethyl ether is then mixed with crude oil in a certain ratio of 4:6.
[0009] 2. The well-mixed liquefied dimethyl ether and crude oil are introduced into a dedicated pipeline for transportation under ambient temperature and pressure. By adding dimethyl ether, the viscosity and freezing point of the crude oil are reduced, eliminating the need for heating during transportation and lowering the transportation pressure.
[0010] 3. After the transportation is completed, at room temperature, the mixture is heated using inexpensive heat sources such as air, water, or industrial waste heat by reducing the pressure, so that the dimethyl ether is separated from the crude oil in gaseous form. Specific Implementation
[0011] This invention aims to provide a method for improving crude oil transportation performance by adding liquid dimethyl ether, thereby addressing the problems existing in the prior art. Specifically, this invention is achieved through the following technical solution: 1. Dimethyl ether is introduced into a compressor and converted into liquid dimethyl ether. The liquid dimethyl ether is then mixed with crude oil in a 1:1 ratio.
[0012] 2. The well-mixed liquefied dimethyl ether and crude oil are introduced into a dedicated pipeline for transportation at ambient temperature and pressure. The addition of dimethyl ether reduces the viscosity and pour point of the crude oil, eliminating the need for heating during transportation and lowering the transportation pressure.
[0013] 3. After the transportation is completed, at room temperature, the mixture is heated using inexpensive heat sources such as air, water, or industrial waste heat by reducing the pressure, so that the dimethyl ether is separated from the crude oil in gaseous form.
[0014] The optimal ratio can reduce the viscosity coefficient of crude oil from over 500 mPa·s to below 50 mPa·s. Specific Implementation
[0015] This invention aims to provide a method for improving crude oil transportation performance by adding liquid dimethyl ether, thereby addressing the problems existing in the prior art. Specifically, this invention is achieved through the following technical solution: 1. After passing dimethyl ether into the compressor, it is converted into liquid dimethyl ether. The liquid dimethyl ether is then mixed with crude oil in a certain ratio of 6:4.
[0016] 2. The well-mixed liquefied dimethyl ether and crude oil are introduced into a dedicated pipeline for transportation at ambient temperature and pressure. By adding dimethyl ether, the viscosity, water absorption, and freezing point of the crude oil are reduced, eliminating the need for heating during transportation and lowering the transportation pressure.
[0017] 3. After the transportation is completed, at room temperature, the mixture is heated using inexpensive heat sources such as air, water, or industrial waste heat by reducing the pressure, so that the dimethyl ether is separated from the crude oil in gaseous form.
Claims
1. A method for pipeline transportation of a mixture of liquid dimethyl ether and crude oil, characterized in that, Includes the following steps: • Dimethyl ether is compressed to produce liquid dimethyl ether, and the liquid dimethyl ether is mixed with crude oil in a ratio of 1:9 to 9:1; • The well-mixed dimethyl ether and crude oil are introduced into a specific pipeline and transported under pressure at room temperature; • At room temperature, the mixture is heated by reducing the container pressure to atmospheric pressure and using a heat exchanger, causing the dimethyl ether to separate from the crude oil in gaseous form.
2. The method according to claim 1, characterized in that, The mixing ratio uses a higher proportion of crude oil in summer and a lower proportion of crude oil in winter. Specifically, the volume ratio is 6-7:4-3 in summer and 3-4:7-6 in winter.
3. The method according to claim 1, characterized in that, The heating process utilizes inexpensive heat sources such as air, water, or industrial waste heat.