Biodiesel Production Line factory Analysis on the Difficulties of Microemulsion Diesel Micro-emulsified fuels (currently referred to as micro-emulsified diesel) have been studied for nearly a century, and many countries in the world have been engaged in this research. China's research groups (including universities, research units), enterprises, individuals for a large number but because there are still many unresolved technical problems, the technology is still not a large number of applications. But emulsified diesel does have a unique advantage in reducing emissions and improving combustion performance, so the study is still enduring. Especially in the current energy-saving emission reduction as a long-term basic national policy of the case has led to some government and business concerns. China's production and operation of emulsified diesel private enterprises are few, but it can be said that these products have great flaws, to a certain range of circulation is because there is no such standard in China, lax management, and therefore prone to some use The problem. Micro-emulsified diesel Many people think that it can be made even transparent, can be a large number of promotion, sales. In fact, made transparent emulsion diesel is now no longer difficult, micro-emulsified diesel to be put into use there are many problems to be solved, so transparent is only completed the first step. I have long been engaged in fuel oil and additives research, in the field also carried out more attempts, quite experience, the following section to talk about my little humble opinion.
1, micro-emulsified diesel economy
The preparation of transparent microemulsified diesel oil is different from that of ordinary emulsified diesel oil. If the cost of the agent is high, it will be difficult to carry out the commercial operation, and no one will buy the emulsified diesel oil equivalent to the ordinary diesel price unless the government is forced Use or subsidy, many foreign use of emulsified diesel oil has a lot of government subsidies, or is to keep going. In order to reduce the amount of foreign countries currently use ordinary emulsified diesel is also more.
Preparation of micro-emulsified diesel oil should try to achieve a small dose, water content, the cost of additives is relatively low, so the economy naturally good, but there are many restrictions, it is necessary to ensure that the stability of micro-emulsified diesel and performance to meet Claim. Previously prepared microemulsified diesel water ratio of 1: 1, or even higher than this ratio. With the technology to improve this ratio is now more than 1: 2 is not difficult, this ratio can be further improved. Master the good skills for improving the economy of micro-emulsified diesel for a certain space, of course, must meet the performance requirements of the premise of the interests of the maximization. To prepare a good performance, and economical micro-emulsified diesel oil micro-emulsion technology must have a more profound understanding of the more thoroughly understand the technology, the easier it is to make both economic, good performance and micro-emulsified diesel. Microemulsion theory there is still a lot of room for development. The book says only some basic knowledge, the types of surfactants and additives involved, the variety is not much, the theory is not perfect, there are many places worth exploring.
2, micro-emulsified diesel performance
If micro-emulsified diesel is used for boiler fuel, the technical requirements are not high, but there are many technical requirements if used for travel. China has not specifically for the vehicle micro-emulsified diesel standards, the performance of micro-emulsified diesel oil is basically the performance requirements of ordinary diesel. The following indicators and micro-emulsified diesel oil problems one by one description.
Density: the density of water is higher than the density of diesel, so the density of micro-emulsified diesel oil is higher than ordinary diesel, GB252-2011 no limit on the density, but the vehicle diesel GB19147-2009 on the 5th, 0, -10 Diesel fuel at 20 ¡æ limit of 810-850 (kg / m3), if the micro-emulsified diesel is the vehicle, the diesel is used in the upper limit may be exceeded.
Color and oxidation stability: micro-emulsified diesel If the use of easy-oxidizing emulsifier, such as the current use of oleic acid emulsifier is very easy to make emulsified diesel oil darker, oxidized sediment increased. If the color is too deep will affect the sales. But this problem is not difficult to solve, I have in the micro-emulsified diesel oil by adding one thousandth of the diesel stabilizer, 3 months after the color is still very good.
Acidity, copper corrosion: these two indicators and the quality of diesel associated with the degree of large, for micro-emulsified diesel oil in general, there will be no problem.
Condensate point, cold filter point: these two indicators from the micro-emulsified diesel to see my point of view, and not the same water index of water, so there is no problem.
Flash point: micro-emulsified diesel If you add a low flash point of the alcohol to help the surfactant, the flash point is lower than the original diesel, but the decline will not be too large, this indicator is generally not large problem.
10% waste residue residue: If the surfactant is easy to oxidize and the boiling point is high, this indicator will have an impact.
Movement Viscosity: Diesel oil viscosity affects the size of the droplets when the diesel atomization, cone angle, range. And thus also affect its combustion performance and economy. So the viscosity of diesel to a limited value. Micro-emulsified diesel oil viscosity is generally higher than ordinary diesel, but if the formula is reasonable, the manufacturer's technical level is still high can still micro-emulsified diesel viscosity maintained in the ordinary diesel viscosity range, and the viscosity can be adjusted range Big. If you do a little micro-emulsified diesel viscosity is necessary to consider your use of additives and the formula is reasonable.
Cetane number: This indicator tests the resistance of diesel, the fire, the combustion performance of diesel has a great impact. Micro-emulsified diesel cetane number than ordinary diesel fell a lot, the greater the greater the drop of water. Generally need to join the cetane number improver to meet the combustion performance of diesel. However, the commonly used cetane number improvers alkyl nitrates are expensive and will add a lot of cost to microemulsified diesel oil, which is an important factor affecting the economy of microemulsified diesel.
3, micro-emulsified diesel stability and heating stability
Micro-emulsified diesel as long as the formula can be stable at room temperature for a long time. Textbooks that can instantly transparent micro-emulsified diesel due to a large dose of stability is generally not a problem. But for the use of smaller doses of micro-emulsified diesel, the degree of mastery of the technology is very important, skilled not only with a small dose can also be done very stable.
Heating stability is another problem of micro-emulsified diesel, do bad micro-emulsified diesel heating to about 60 ¡æ began to muddy, a large number of beakers around the beaker, and some bottom of the beaker there will be precipitation. Micro-emulsified diesel heating time-varying cloudy the higher the temperature the better, it is best to have been heated until the boiling is still the best opacity. This is the need for a certain skill, do a good micro-emulsified diesel heating to boiling still remain transparent, and there is no milk around the beaker, or in the late high temperature only a small amount of milk, the bottom of the beaker clear and transparent without precipitation. The presence of the precipitate will cause the fuel pump to cause an accident.
4, micro-emulsified diesel miscible
This indicator is important for microemulsified diesel. Micro-emulsified diesel oil and ordinary diesel immiscible will lead to oil turbidity, thereby affecting the stability of diesel, resulting in stratification affect the combustion. The user will not accept microemulsified diesel that can not be miscible with ordinary diesel. Miscibility problems related to the formula, good recipe will not have miscibility problems. For some time to do the experience of emulsified diesel people this problem is not difficult to solve.
5, micro-emulsified diesel dynamic water repellent
Micro-emulsified diesel need storage tanks, and storage tanks are often separated from the water when the water, and some also a lot (the tank also has a similar situation). Micro-emulsified diesel If there is no dynamic water repellent capacity, after the water will re-emulsification become cloudy, and even milky white. When it comes to micro-emulsified diesel water repellent, some of the domestic literature (including the paper) refers to the static water repellent, that is, micro-emulsified diesel into the water static for a few minutes the interface does not appear milky even if the water repellent. But this effect is not able to meet the actual requirements of the water, micro-emulsified diesel oil into the tank has a great impact, if there is no dynamic water repellent capacity is very easy to emulsify. Now there are many people in the country to carry out the study of the project, but the effect is not ideal.
Some people think that by improving the ability of micro-emulsified diesel oil can solve the problem of secondary emulsification of water, but the actual use is not the case, no matter how much preparation of micro-milk diesel oil solubilization capacity, when injected into the tank only Part of the mixture with water, which is caused by part of the emulsification, we can not be in the tank will be micro-emulsified diesel all stirred again. Because many people so spare no effort to solve the problem of dynamic water repellent. Here to specifically talk about this issue.
Micro-emulsified diesel dynamic water repellent problem is a very difficult problem of research, I have access to domestic and foreign literature has not found a special discussion on the issue of the article, perhaps their own ignorant, the problem has long been solved. If the problem has been resolved should be able to find some clues, at least theoretically did not solve this problem. If this problem has not yet been resolved is a world problem, it is not easy to completely solve it.
Micro-emulsified diesel dynamic water repellent is the micro-emulsified diesel oil under a certain pressure or by mixing the microemulsion and water mixture, if there is no secondary emulsification with a dynamic water repellent capacity. Of course, different micro-emulsified diesel dynamic water repellent capacity is a huge difference, can withstand the longer stirring time, the effect of dynamic water repellent better, if you can withstand long-term infinite mixing without emulsification, oil and water can be very good Separation is completely dynamic water repellent, and this is what we want to pursue the ideal state. There are many factors that affect the dynamic water repellency of microemulsified diesel fuel, and subtle changes in each factor will lead to significant changes in water repellent effect, which is the key to the technology is difficult to break through. I found a large number of experiments found that micro-emulsified diesel dynamic water repellent effect and the following factors.
1) is related to the formulation of the emulsifier. Micro-emulsified diesel oil prepared with an additive formulation that does not have at least dynamic water repellent is added to the water and agitated immediately to emulsify into creamy.
2) is related to the quality of the emulsifier. The same formula, different emulsifier quality prepared by the micro-emulsified diesel dynamic water repellent effect is very different. This effect is mainly on the main agent, the additive effect is small.
3) with micro-emulsified diesel water related. Due to the different pH and pH of the water, the dynamic water repellent effect of the microemulsified diesel oil prepared by different electrolytes is also different.
4) is related to the quality of the diesel used. Different diesel oil to do out of the micro-emulsified diesel dynamic water repellent effect is huge, in general, with aromatic hydrocarbons containing more diesel oil prepared micro-emulsified diesel oil or diesel oil mixed with low-grade diesel oil made of micro-emulsified diesel dynamic rejection The water effect is much worse than the standard diesel.
5) is related to the water that has been rejected. The same micro-emulsified diesel oil varies according to the different water effects. According to a good water micro-emulsified diesel, for a water its dynamic water repellent effect is much worse.
6) related to the preparation process. Preparation of micro-emulsified diesel If the process can be innovative or the use of auxiliary equipment, prepared micro-emulsified diesel dynamic water repellent effect will be greatly improved. This is mainly a good process to make the emulsifier evenly distributed in each microemulsion droplets, uneven distribution of emulsifiers will cause some milk droplets are defective, in the fierce mixing will first damage and then lead to damage to the entire emulsion, also reduced The water repellent effect.
These factors on the micro-emulsified diesel dynamic water repellent effect can be described as a move the whole body, to solve all the great difficulty, and some factors are not good to change, such as factors 2), 4), 5). Then the full dynamic water repellent micro-emulsified diesel can do it? The answer is yes. Because I have repeatedly made in the course of the study had a completely dynamic water-repellent micro-emulsified diesel, long-term mixing for more than a year is still not emulsified, oil phase, the water phase is completely transparent and separated. But because of these factors, in the change of water, oil change case is not completely dynamic water repellent, the difference is still great, that is, oil, water does not change the case, the proportion of emulsifier subtle changes will be serious Affect the effect of water repellent, and this change you are difficult to control. Of course, we can optimize the emulsifier by the formula to weaken the impact of the above factors, which is the key to master some of the reasons for dynamic water repellent, learn how to change the quality of oil and water and additives in the case of micro-emulsified diesel formula, Process to adjust to get better water repellent effect of micro-emulsified diesel.
is difficult to prepare a fully dynamic, water-repellent microemulsified diesel, but I do not think there is a need to pursue a complete dynamic water repellent as long as the microemulsified diesel is made to meet the actual requirements. I have done such a simulation experiment, the micro-emulsion diesel needle with high-speed injection into the water, if not emulsified, the interface is clear I think there should be no problem. This simulation method is somewhat similar to the oil tank filling situation. If you use the mixing method, can withstand more than 3 times (each time dozens of) stirring, to deal with the case of secondary emulsification of water will not be a problem. Of course, this simulation method needs to be tested in order to really explain the problem. In short, the preparation of micro-emulsified diesel oil even if not complete dynamic water repellent should also be as much as possible to improve the effect of dynamic water repellent, to prevent accidents.
Can be prepared in the oil, water and many other conditions under the conditions of the full dynamic water-repellent micro-emulsified diesel? It may be possible, but there must be a breakthrough in theory, to understand the truth, otherwise it is difficult. But we through the accumulation of experience to significantly improve the micro-emulsified diesel's dynamic water repellent performance, to approach the complete dynamic water repellent or can do. At present, the preparation of micro-emulsified diesel has been able to withstand more than 10 times (50 times each) of the mixing without secondary emulsification. After the first stirring can be basically restored to the state of the mirror interface when not stirring.
6, micro-emulsified diesel oil cleanliness and combustion performance
Micro-emulsified diesel oil generally use a large number of oxygen-containing emulsifier, and some very easy to oxidation, cleanliness is a problem, and not add a little detergent can solve the problem, with ordinary steam, diesel is not the same.
Emulsifier on the microemulsion state of the emulsified diesel oil combustion performance is affected, the state of the naked eye is invisible, can only be tested by the test. So the conditions should be investigated under the conditions of its performance, but because of the larger general will not do this work. If you want to promote your product, to ensure that the use of no problem, this work must be done. At least to do some driving test Caixing. Micro-emulsified diesel performance involved in the factors than ordinary diesel, the performance of the control is much more difficult, do not think that a formula to get an emulsion of diesel everything, and can be commercial production, and this is a problem. To make good performance, the use of micro-emulsified diesel oil requires both a deep understanding of micro-emulsification technology, but also need to have fuel oil expertise, so as to deal with a variety of possible situations. The community is currently selling a lot of the technology, it can be said that the gold content of these technologies is not high, and some later on the engine is harmful. Micro-emulsified diesel technology is not a formula can solve the problem, to master the technology is not a day of work, not to mention the technology has not fully understood from the theory very clearly, there is a lot of room for development. Micro-emulsified diesel to solve a lot of problems, each solution to a problem are likely to increase its cost, if you solve all of the above technical problems, but also to micro-emulsified diesel profit margins, then even micro-emulsified diesel made. The reason why this technology can not be a lot of promotion and application of technical problems and the economy is the two stumbling block, which is to great efforts to solve. But as long as we have the spirit of perseverance, a serious and serious scientific attitude, we will be able to solve these problems. Micro-emulsified fuel can significantly reduce the motor vehicle exhaust pollution, if the city can be used in general, the city's sky will turn blue again, which is the goal of all levels of government, but also the majority of people expect.
Above is my little humble opinion, not the place also hope you experts.Biodiesel Production Line factory Analysis on the Difficulties of Microemulsion Diesel.