Generally, turning plastic to diesel process needs two major steps. First is the plastic pyrolysis plant (also called plastic to oil plant) which is mainly used to turn waste plastic into fuel oil, and then through the oil distillation equipment, it can make the fuel oil processed into diesel. So we can know that the plastic pyrolysis plant has a close connection with the distillation machine. The whole plastic to diesel plant means turning plastic to fuel oil and then to diesel.
Brief introduction of waste plastic to diesel process
Firstly, the plastics need to be converted into fuel oil by plastic waste pyrolysis plant, which consists of reactor, manifold, condenser system, oil tank, cooling system, hydroseal and dedusting system. The pyrolysis equipment will heat the reactor with high temperature, and when it reaches the related temperature, the waste plastic will generate oil gas in the reactor; then the oil gas will become the liquid oil after passing through the subsequent connected cooling system. The oil can be used as fuel directly. When the oil is fully discharged, the left material is called carbon black, which can be used as additive.
Secondly, use the oil distillation machines to turn plastic oil into diesel. As for this kind of equipment, it is made up of the distillation system, heating system, dedusting system and intelligent electric control system. First of all, put the plastic pyrolysis oil into the tubular furnace to heat, and then through the distillation system, it can produce the oil steam; next, the oil steam will be fractionated into basic diesel through the condenser system; and then after sedimentation and filtration treatment, it will become qualified diesel adding bleaching agent.
Terminal products’ name and proportion in waste plastic into diesel process
The final products of waste plastic pyrolysis machines: fuel oil and carbon black. The proportion of the end products varies according to the kind of plastic material;
The final products of distillation: diesel or gasoline, waste gas and heavy oil slag, accounting for 70%, 10%, 5%, 15% respectively (also different from the different materials).
Environmental protection design of converting waste plastic into diesel process
First is the plastic to oil plant:
1. Waste gas recycling technology
About the dust gas, we adopt secondary treatment processes. Firstly, flue gas will be cooled down, then conveyed to strong atomization tower with diameter 1 meter height 3 meters through draft fun. The flue gas coming into strong atomization power would be dedusted with ceramic ring, then it passed by strong spray layer, and in the last, most of the gas stay in the mesh material lay, and few steam into chimney emissions. If adding alkaline substances into water, some sulfur, and chlorine gas will be neutralized, salt generated then solidify for recycling.
About the control of Dioxin, furnace producing few cracked gas into hot blast stove for combustion, temperature of hot blast stove up to 1000 degrees, at this temperature dioxin will decomposition and disappear, a small amount of dioxin will generated again in the process of furnace heating and for removal dioxin, activated carbon adsorber and bag type dedusting device would be equipped with strong spray tower for adsorption of dioxins. Therefore, the equipment is basically no dioxin emissions.
2. Waste liquid treatment scheme
The water consumption in the waste plastic to diesel process is very small, which is mainly used to flue gas purification and waste gas purification. The water will be acidic after absorbing the acid, however, the water will be recycled after alkali neutralization sedimentation. The small amount of salt from settlement generated can be harmless natural degradation.
3. Waste solid treatment scheme
The slag from the pyrolysis reactor, can be used as burdening for building material. The steel wire from the tires can be directly recycled for using.
Second is the plastic oil distillation machines:
1. Waste gas collection
Waste gas mainly generates the coal-fired fuel gas of the tubular furnace and some combustible gas which can not be condensed. Generally, we have four filters dedusting system which can thoroughly purify and clean the smoke to meet the national emission standard.
2. Waste water
The waste water of this program produced by the raw material cleaning and hydroseal. According to data provided by the construction unit, each ton of fuel oil will use 50 L water, and the whole program will use 7.5 thousand ton fuel oil, so based on this estimate, the waste water is about 4.3m3/d,1300 m3/a, there are some harmful and polluted elements including pH, SS, petroleum. So we also have made some efficient measures to deal with the waste water, firstly we can pull the processing waste water into weak harmonic liquid pool, after the oil treatment, making the neutral water have a three stage filtration. When the quality of water is good, we can use on part to cooling the reactor and push the combustible gas into burner, the left part will be pulled into sewage pipe network of industrial park. And finally runs into the river.
The whole plastic to diesel process has introduced the low noisy devices, which can also increase the accuracy of the machines to reduce the noise generated by vibration and friction of machine.