With the development of industry, the increase in vehicles, waste oil more and more. Waste oil recovery project has become the focus of attention, in the past has been the use of acid-base refining or high-temperature clay purification method recovery, but because of the immature process equipment, poor quality product efficiency is low, most of the recycled waste oil is soil refining refining , Soil refining in addition to pollution of the environment, production is not safe, the benefits are not high, from our construction of waste oil recovery base oil project point of view. Soil refining is not only environmental security can not be compared, the economic benefits can not be compared, so I put a few sets of new device construction experience to write with you to share, but also for China's waste oil recycling to make due contributions.
First, the process selection
1, commonly used technology introduced waste oil recycling a general process as follows: raw material pretreatment – distillation – refined oil. According to the different nature of raw materials, product requirements are different, the different processes taken. Such as the recovery of raw materials, and the nature of a good, light components and less, only the oil can be refined, the recovery of the nature of the oil than the teachings, all kinds of oil, flash point is also low, you must Distillation off the light components, the following is the commonly used several advantages and disadvantages of the process:
(1) early distillation – pickling – clay refining process This is an ancient process, the process is simple, low cost of equipment, but the quality of recycled oil is poor, and there are acid pollution of environmental problems. The biggest problem with this process is that the distillation is incomplete distillation, steaming the fraction before 350 degrees, and then pickling with acid, the yield is low. Oil acid value is not qualified.
(2) sedimentation – pickling – clay distillation process This is the 70's development process, and now there are some commonly used, high temperature clay distillation color is better, the process is simple, but pickling sedimentation slow, especially modern lubricants contain A large number of additives, to pickling caused great difficulties. This process was later canceled pickling, changed to white soil high temperature contact without acid regeneration process, but the process yield is low, the equipment corrosion is heavy, the furnace tube is easy to plug and so on.
(3) distillation – ethanol extraction (or furfural refining) process of the high yield of good quality, but the process and equipment complex, high investment, long investment recovery period.
(4) distillation – hydrogenation process investment increased, not suitable for China's national conditions.
(5) molecular distillation (or high vacuum distillation) process This is the development of the process in recent years, high yield, good quality oil. But the installation of high vacuum equipment installation is difficult, high technical requirements. 2, the choice of production process Comparison of foreign waste oil recycling experience and the actual situation in China can be seen in different countries in the waste oil recycling industry management intervention and management focus is different, this difference led to the waste of each country Lubricant regeneration industry, the different technology. The US, German and Italian governments play a leading role in the management of waste oil recycling industry, which affects the development of the industry through legislation, environmental protection and industrial policy. The former Soviet Union and the Japanese government are involved in a higher degree of management and focus on pollution control Mainly. So they generally invest a larger, more concentrated oil. And China's oil source is scattered, not suitable for large investment, so I strive to meet the requirements of the oil quality requirements, to minimize the cost of construction equipment. So the process of the following options;
(1) hydrorefining and extraction of investment is too large, does not meet our national conditions, waste oil recycling more dispersed, not suitable for large investment, so I do not consider such a process.
(2) Flocculation method Although the investment is small, but the production of poor color products, low yield caused by a high cost, not economic. But some people first heating, remove some of the additives, and then pickling acid, the same product color is poor, and the oil has acid and alkali taste, acid value is not qualified, anti-emulsification is not good. Product quality is not up to standard. But regardless of which method of flocculation, comprehensive consideration is not desirable.
(3) China's 70 years of development of high-temperature clay refining process, high cost, and more and more modern lubricants additives, processing more difficult. So this kind of craft is not selected.
(4) Now the most popular online process of molecular distillation, it was it very quiet, indeed the process of production of oil than the above process is better than the investment to save hydrogen, but the investment is still high, the lowest investment in equipment To more than 200 million, and the production of high energy consumption, that is, high production costs, the product can not solve the discoloration problem, after the distillation of the product to be refined. Based on years of experience, with reference to the experience of the above device, plus my own experiment, I chose the chemical treatment of the oil – low vacuum cycle distillation – high vacuum flash steaming – oil refining after several sets of experiments, this process Low investment (the main equipment investment of more than 50 million), low energy consumption and low production costs (about 300-400 yuan), wide application of raw materials, recycling waste oil pollution is also available, and vacuum distillation before adding additives, In the distillation before the non-ideal components of oil reaction, oil quality is better.
Second, the choice of equipment
1, oil additives part of the oil to remove the non-ideal components, only by the back of the oil adsorption refining, not only the effect of poor, low yield, and poor quality of oil, poor color smell, before adding chemical chemicals Chemical reaction to remove the vast majority of non-ideal components, is a very good way to add chemical reagents between the chemical reaction, distillation after adsorption refining, oil non-ideal component treatment more thoroughly. Oil additives part of the equipment is relatively simple, with stirring tank or pump can be stirred.
2, low vacuum cycle distillation Low vacuum cycle distillation includes the following parts, filters, heaters, circulating tanks, circulating pumps, low vacuum distillation columns, vacuum pumps, coolers, receiving tanks, product extraction pumps. Filters can be used centrifuge or screen can be, but must be heated to 50 degrees before heating to reduce oil viscosity. Heater should be heated as far as possible to avoid direct fire to prevent oil cracking color deepening, recycling tank seemingly simple, it is not true, first of all to solve the problem of high temperature flocculation sediment, and secondly to solve the problem of uniform flow to prevent production Product flash point failure, the circulation tank is handled well, the oil yield is high, the benefit is good; The circulating tank treatment is not good, it is easy to cause the product unqualified. Circulation pump selection is also very knowledgeable, it is necessary to ensure that the flash dehydration does not take the time, but also to ensure that the pipeline should not produce air resistance, interrupt the cycle. But also to ensure that more than 300 degrees high temperature long-term operation. Low vacuum flash tower is better choice. According to the normal chemical design can be, to minimize fog entrainment, to ensure the quality of light component products. Vacuum pump to use water ring pump, because at this time to distill the water in the oil. Cooler, receiving tank, product pump is also commonly used chemical design selection can be, no longer say here.
3, high vacuum flashing high vacuum flash tower conditions as far as possible the selection of molecular distillation tower, no conditions optional film evaporation tower, but before the evaporation tower must add vaporization tower, I met a unit, the process is also more reasonable , The use of thin film evaporation tower, but that is out of the product, analysis of the reasons, the product into the evaporative tower before the part of the vaporization, resulting in steam load to carry serious. High vacuum flash tower to be designed in detail, to minimize the vacuum loss, reduce the carrying, increase the amount of gas. Pipeline equipment must not be sloppy, the equipment should be selected when the regular manufacturers, formal design, because the high vacuum operation, a little bit of disclosure is very difficult and inspection, and a little bit of leakage will affect the operation. So equipment installation pipeline installation requirements are very strict, must not be the slightest sloppy. Pipeline as short as possible to reduce the pipeline pressure drop, improve the flash section vacuum. Part of the equipment to transform their own, such as high temperature vacuum pump is the most difficult to choose, the market can not run the high temperature pump vacuum, high vacuum can run the pump is not high temperature, finally selected a high temperature and vacuum Can run the pump, but the waste oil operating conditions are poor, not like a good oil as clean, no way only their own transformation. Another example is the high temperature level gauge, high temperature heavy oil is difficult to choose the right level gauge, even if the election price is also very expensive, after the test, we do a high temperature level gauge, both cheap and easy to use.
So in the purchase of equipment, do not choose which cheap, such as buying a valve regardless of the cheap must buy. Because the temperature is high and high vacuum. Although you buy tens of dollars cheaper when the valve, when not only can not be used, and easy to safety problems. Some equipment is difficult to buy the right, only their own transformation. Also do not believe that any equipment sales staff, there are many problems with the manufacturers after the technical staff in the order, equipment sales staff are not proficient in the principle of equipment, whether your application is only you know.
Third, the construction process
1, to more and people to communicate, people are not God, it is inevitable that there are areas of ill-considered, small problems Fortunately, big problems can not be changed, when you regret too late.
2, there are ready-made, would rather spend more money, buy some experience, do not build regret, for example, I just built early, someone told me how much money to him, he told me how to do under the vacuum cycle, high vacuum cycle how to do The I gave him some money to let him solve the problem of high vacuum and high temperature cycle, did not expect the vacuum low temperature cycle encountered a lot of trouble, would like to this is a simple question, did not expect to spend several times wasted money.
3, do not easily believe that the so-called experts and scholars, a certain university experts, a certain research experts, of course, I am not here to deny the University or the Institute of experts, I mean that the theory and time there is a big gap between many inventions how much use of patents There is no problem. Experts and scholars some ideas or ideas are very valuable, but the experimental study and construction to create the benefits or there is a certain difference.
Fourth, security is the primary problem Construction project first to consider the safety, do not consider the safety not only earn money, sometimes make you all the capital, for example, construction projects must consider the fire facilities, electrostatic grounding. Another example is the gas considerations, we must add fire arrester. Do not worry about saving for a moment. Sometimes a problem is not equal to no security risks, security or should be cautious.