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A. Hydrotreatment: under a certain temperature and pressure, diesel contact with hydrogen, the sulfur is converted into hydrosulfuric acid, then removed by pickling method. This method can effectively reduce the sulfur content in diesel, However the plant investment is large and the energy consumption is high.

B. Solvent extraction method: choose an organic solvent that can form a substance with a large solubility with sulfur compounds, such as diphenyl ether, kerosene, etc., mix diesel with the solvent, so that the sulfur compounds are dissolved in the solvent, and then remove by separation and washing method. This method is easy to operate, but solvent recovery is difficult and may introduce new pollutants

C. Adsorption method: The use of activated carbon, molecular sieve and other substances with strong adsorption capacity, the sulfur in diesel is adsorbed on its surface, and then it is separated from the adsorbent by desorption or heating desorption method. This method is simple to operate, but the regeneration of the adsorbent requires energy consumption.

D. Oxidation method: The use of ozone, hydrogen peroxide and other strong oxidants, the sulfur oxide in diesel into soluble sulfate or thiosulfate, and then adjust the pH value with lye, so that the sulfur in the form of sodium sulfate or sodium thiosulfate precipitate out. This method can effectively reduce the sulfur content in diesel, but there may be equipment corrosion problems.

E. Biodegradation method: The use of microbial biodegradation, the sulfur in diesel fuel into harmless substances. This method is environmentally friendly, but it needs to choose the right kind of microorganisms, and the degradation rate is slow.

To completely solve the problem of exhaust gas, waste oil to diesel or base oil recovery plant is equipped with three levels of treatment, including A)Spray device; B)Activated carbon adsorption ;C)UV photolysis,then introduce the functions separately:

A)Spray device

1) Removal of acidic pollutants: alkali washing can effectively remove acidic components in exhaust gas and reduce environmental pollution.

2) Purify the air: through the neutralization reaction, harmful gases are converted into harmless substances to improve air quality.

3) Protection equipment: to prevent acid gas corrosion of subsequent treatment equipment, prolong the service life of equipment.

B)Activated carbon adsorption

The exhaust gas enters the activated carbon adsorption unit, and the activated carbon rapidly absorbs the organic matter in the exhaust gas by its porosity and high specific surface area, thereby reducing the concentration of the exhaust gas

C)UV photolysis

1)UV photolysis equipment uses special high-energy, high-ozone ultraviolet beams to irradiate malodorous gases and crack malodorous gases such as ammonia, trimethylamine, hydrogen sulfide, sulfur, methyl mercaptan, methyl sulfide, and dimethyl siloxane , carbon disulfide and the molecular chain structure of styrene, benzene, toluene, xylene and other compounds that cause the odor of organic or inorganic polymers when exposed to high-energy ultraviolet beams.

2)High-energy, high-ozone ultraviolet beams are used to decompose oxygen molecules in the air to produce free oxygen. Because the electrons carried by positive and negative free oxygen are unbalanced, it needs to be combined with oxygen molecules to produce ozone. Ultraviolet + oxygen → O- + O* (free oxygen) O + O2 → O3 (ozone). As we all know, ozone has a strong oxidizing effect on organic matter and has an immediate effect on removing odorous gases and other irritating gases.

3)After the odorous gas is input into the purification device through the exhaust device, the purification device uses high-energy ultraviolet beams and ozone to collaboratively decompose and oxidize the odorous gas, thereby converting the odorous gas substances into low molecular compounds, water, carbon, and carbon dioxide, and then through the line . The air duct is discharged to the outside.

After three-stage process as above,the emission gas will be colorless, odorless and harmless,and release to the air with pollution to the enviroment.

Heat exchanger is one of the two important devices in oil refinery industry. Each type of VBOLT heat exchanger is accurately calculated by the engineer team.  
1.Efficiency of heat exchanger determines oil recovery rate.
2.Reducing energy consumption.
3.Saving operating costs.

－HEAT EXCHANGERS CALCULATIONS:

The main basic Heat Exchanger equation is:  
 Q=UxAxΔTm=
   The log mean temperature difference ΔTm is:
ΔTm=(T1-t2)-(T2-t1)=°F
Where:
T1=Inlet tube side fluid temperature;
TemperutareiC
t2=Outlet shell side fluid temperature;
T2=Outlet tube side fluid temperature;

t1=Inlet shell side fluid temperature.

can be rearranged to become:

 A=Q/(UxΔTm)=
 Where:
 A=Heat transfer area(m2)(ft2);
 Q=Heat transfer rate (kJ/h) (Btu\h);
 U=Overall heat transfer coefficient(kJ/h.m2.°C)(Btu/h°F);
 ΔTm=Log mean temperature difference(°C)(°F).
 And:
 Ct=Liquid specific heat,tube side(kJ/kg° K)(Btu/lb°F);
 Cs=Liquid specific heat,shell side(kJ/kg°K)(Btu/lb°F).

If you are interested in the Used motor oil into diesel fuel distillation plant,please contact me and we have further discussion.

In Used Oil Recycling Plant, the reflux device plays an important role, the main roles include:

Improved separation efficiency: Reflux can increase the chance of contact between the liquid and the steam in the column, so that the light component and the recombination are separated several times in the column, thereby improving the Recycling efficiency and obtaining a purer product.

Improve product purity: Through reflux operation, can reduce the light components at the bottom of the column to produce liquid loss, increase product yield, improve product purity.

Energy savings: The reflux operation helps to reduce the energy consumption of the system because the separation efficiency is improved by constantly circulating the fluid in the column, while the heat energy is used efficiently and waste heat loss is reduced.

Stable production process: reflux operation can help stabilize the production process and avoid fluctuations in the operation process. By controlling the reflux ratio, the system runs more smoothly and ensures the consistency of product quality.

The advantages of reflux devices are reflected in the following aspects:

Improved product quality: Through reflux, separation efficiency can be improved, resulting in a purer product, which is particularly important for industries that require high purity products.

Improve production efficiency: Reflux can reduce operating costs, reduce scrap rates, and improve production efficiency, because reflux in the rectification process can effectively improve the purity of the product, thereby reducing subsequent processing steps.

Economic benefits: reflux can improve production efficiency, product quality, reduce energy consumption, thereby bringing economic benefits. Reasonable design of reflux system can bring significant economic benefits.

Strong adaptability: The reflux unit can be adjusted according to different production conditions and requirements to adapt to different distillation processes and product specifications.

In practical applications, the design and operation of reflux units need to be optimized according to the specific of Diesel fuel from used oil plant and objectives to ensure the best distillation results and economic benefits.