The process method of producing fuel oil is by cracking waste plastics. Features: preheating feeding, catalytic, cracking and fractionation, its catalyst is a Y-type zeolite molecular sieve, and the filler is a porcelain ball. The process method production, catalytic cracking sufficient, high oil output rate up to 60-85%, good oil quality, gasoline 90, diesel 0 a negative 20. The whole production process is a fully enclosed clean continuous production, waste plastic raw materials do not need to be sorted, cleaned and dried, the use of an alkali washing method to achieve automatic neutralization, and no secondary pollution; reduce production costs.

Problems of cracking fuel oil from waste plastics
The waste plastic in daily life is called “white waste”, which seriously endangers the living environment of human beings and is the most difficult problem for governments to control white waste. In the past few years, there are methods to crack fuel oil from waste plastics, but there are several shortcomings in these methods.

1, the use of cheap white clay (active silica) as a catalyst, the liquid phase reaction cracking is not sufficient, producing a large amount of heavy oil, only part of the light oil, especially for the cracking of polyethylene to produce more heavy oil.
2, Using coal-fired heating, the temperature is difficult to control, the equipment life is short, the process is simple and cannot form industrialized continuous operation, and there is secondary pollution.
3, Similar foreign equipment has strict requirements for processing waste plastics, such as waste plastics needing to be sorted, cleaned and dried, to be hydrogenated at high temperatures or cracked under pressure.

Through the improvement of the catalyst and processing process, we provide a process method for producing fuel oil by atmospheric pressure catalytic cracking of waste plastics without cleaning and drying treatment of waste plastic raw materials, sufficient cracking and high ratio of light oil output.

The specific process and process conditions are as follows
1, the process method for the production of fuel oil by atmospheric pressure catalytic cracking of waste plastics, characterized by:

 

A, the waste plastic raw materials that do not need to be cleaned and dried, crushed by the crusher and sent by the conveyor to the feeding port of the screw extruder; preheating the barrel through the heating mechanism of the screw extruder, the preheating set temperature of 200 ℃, preheating time of 30 minutes; raw materials are squeezed in at a rate of 150 kg per hour, in forward process of extrusion and dehydration, and is heated and plasticized, into the electric cracking kettle.

 

B, before feeding the electrothermal cracking kettle in the top outlet channel connected to the catalytic tower, in the tower to add 10Kg catalysts and protection filler; the said catalyst is a Y-type zeolite molecular sieve, the passage diameter in the range of 0.9-1 nanometer; said protection filler is porcelain balls; and the feed before the electrothermal cracking kettle preheating, to the electrothermal cracking kettle set temperature for the upper part of the kettle 350 ℃, the lower part of the kettle 400 ℃, outside the kettle bottom 500 ℃; preheating time of 30 minutes preheating temperature at about 100 ℃.

 

C. After the raw material is heated and plasticized, it enters the electric cracking kettle, which has a reduction mixer on the electric cracking kettle, and the speed of the reduction mixer is 20-23 rpm; that is, the material is heated and stirred while feeding.

 

D. After the raw material is fed, the set temperature of the electro-thermal cracking kettle is 380℃ at the upper part of the kettle, 420℃ at the lower part of the kettle and 550℃ at the bottom outside the kettle; the temperature inside the electro-thermal cracking kettle is maintained at 380℃-400℃ for 3-4 hours to catalyze the cracking reaction, then, the temperature is lowered to 300℃ and the high temperature slagging starts, with a slagging time of 5 minutes; then the above feeding, heating, reaction and slagging processes are cycled.

 

E, the cracked low molecular hydrocarbons are mostly changed into liquid by cooling to room temperature, and most of the liquid yield accounting for 60-85% of the total liquid goes to the tank through the gas-liquid separator, oil-water separator and filter; a small portion of the non-condensable gas separated by the gas-liquid separator goes to the gas recovery device.

 

F. The oil from the tank is sent to the fractionation kettle through the pipeline, the oil level shall not exceed 2/3 of the kettle capacity, electric heating to raise the temperature between room temperature and 180℃, at a rate of 1℃/min; the main fractionation out of this range is C4-C11 hydrocarbons, which are the components of gasoline; the components of gasoline are fractionated in the fractionation process through the temperature fractionation three components: 20℃-70℃, 70℃-120 ℃, 120 ℃-180 ℃, respectively, accounting for 10%, 50%, 90% of the total volume ratio (V/V). After entering the mixed component tank, then add the concentration of 3-5% sodium hydroxide alkali solution by weight ratio of 5-10% to clean through the mixer, and then enter the finished oil tank through the depth filter; continue to electrically heat up to 180°C-350°C, and heat up at the rate of 2°C/min; the main component of this range of fractionation is C12-C20 hydrocarbon, which is the component of kerosene and diesel oil; the fractionated kerosene and excess component oil as fuel oil; the component of diesel oil is also fractionated in the fractional distillation process through temperature fractionation three components: not higher than 300℃ for one group, 300℃-330℃ for the second group, 330℃-350℃ for the third group, accounting for 50%, 90% and 95% of the total volume ratio (V/V) respectively.

 

After entering the tank of mixed components, then add the concentration of 3-5% sodium hydroxide alkali solution by weight ratio of 5-10% to clean through the mixer, and then enter the finished oil tank through the depth filter.
2, according to to claim 1 of the process method of cracking waste plastics to produce fuel oil, characterized in that: said Y zeolite molecular sieve, for silica-aluminum molecular sieve pass diameter in the range of 0.9-1 nanometer catalyst.
3. The process method of producing fuel oil by cracking waste plastics according to claim 1, is characterized in that: the diameter range of said packed porcelain balls is 8-12 mm.

 

The beneficial technical effects of the process method of the present invention are as follows:

 

1, The process method of the present invention produces catalytic cracking fully, a high oil output rate of up to 60-85%, good oil quality, gasoline 90, diesel 0 – negative 20.
2, the whole production process is fully enclosed clean continuous production, waste plastic raw materials without classification, cleaning, and drying, the production process eliminates acid washing and water washing, the use of alkali washing method to achieve automatic neutralization, no secondary pollution; reduce production costs.
3, To achieve high-temperature automatic slag discharge, atmospheric pressure operation, and high safety.
4, The process method is widely adaptable and not restricted by terrain and area, which is easy to promote and apply to various urban and rural waste treatment plants.