WO2003064567A1 - Alcohol-containing composite fuel which can initiate easily at low temperature and the power available equals to that of gasoline - Google Patents

Abstract

The present invention relates to a methanol-contained composite fuel for vehicle, which can not demix below 25°C and the power available equals to that gasoline. The fuel is comprised of: alcohol,7-25wt%; C4-C14 alkane or mixture thereof, 5-40wt%; aromatics, 5-30wt%; straightrun oil, 10-50wt%; modifying agent, 0.5-10wt%; cosolvent, 0.1-5.5wt%.

Description

 Alcohol-containing composite fuel that is easy to start at low temperatures and has a power equivalent to gasoline

 The present invention relates to a vehicle fuel, in particular to a compound fuel containing methanol or ethanol which has non-stratified at minus 25 ° C and is easy to start at a low temperature and has a usable power equivalent to gasoline. Background technique

Alcohol fuel is mainly a liquid fuel. It refers to methanol and ethanol. Because the liquid fuel can still use the traditional petroleum fuel transportation and storage system, and the related infrastructure construction investment is small, it is a promising future. Alternative fuel. Methanol can be extracted from raw materials such as natural gas, coal, biomass, etc. In addition, any raw material that can obtain CO and H ₂ can synthesize methanol. Ethanol is mainly produced by fermenting crops containing sugar and starch. Therefore, there are abundant resources for the production of alcohol fuels, and the production process is relatively mature, which indicates that alcohol fuels are very attractive. Because the structure of alcohol molecules contains a certain amount of oxygen, the stoichiometric ratio is lower than that of gasoline and diesel, and because of the large oxygen and C / H values, more water and less C0 ₂ are produced during complete combustion. Due to the high water content in the exhaust gas, there will be a noticeable phenomenon of white vapor tails behind alcoholic combustion engines in winter. When the alcohol internal combustion engine is started, during warm-up, and when the temperature in the cylinder is not high, condensate is easily formed on the cylinder wall, which promotes the generation of acidic substances and increased wear. After the alcohol fuel is burned, the molecular change coefficient of the mixture is increased. Methanol is a light, colorless, slightly odorous, and low-polluting fuel. It is infinitely miscible with water. Because methanol has only one C atom, no CC bond, and contains 50% oxygen, it is an oxygen-containing fuel with less exhaust pollution after combustion, and has a lower heating value. Compared with gasoline and diesel, methanol has a higher ignition temperature, has a higher octane number and explosion resistance, and has a lower cetane number, which has attracted people's attention.

 Although the low boiling point of alcohol fuels contributes to the formation of fuel-air mixtures, it has the disadvantage of being detrimental to the starting of automobile engines due to the lack of highly volatile components therein.

 Because of its polarity, alcohols have strong hydrogen-oxygen bonds between molecules, the latent heat of vaporization is large, and the temperature drop of the mixed gas is also large. In the case of = 1, the temperature drop of gasoline in the adiabatic state is about 20 ° C, while the temperature drop of pure methanol is 122 ° C. The cooling effect caused by high latent heat of vaporization prevents complete vaporization at the operating temperature, making methanol atomization and vaporization difficult, and it is difficult to form a homogeneous, well-atomized mixture. At the end of compression, the temperature in the cylinder is lowered, which makes the ignition delay longer, and also affects the starting performance of the engine; therefore, the practical use of alcohol fuels is still difficult.

Due to the above shortcomings of simply using methyl alcohol and ethanol as fuel, people are looking for alcohol and gasoline to make alcohol substitute fuel. For example: Chinese Patent Application No. 91106611.X, the invention name is "synthetic gasoline". It accounts for 25-80%, gasoline 10-40%, solvent oil 5-30%, etc. The above formula shows: First, the energy is insufficient, which makes the fuel consumption per kilometer large, and the car climbing and acceleration performance are worse than gasoline. The formula cannot reach the low temperature for the next start. This type of alcohol is used to burn a certain percentage of alcohol fuels during the combustion process of a gasoline engine or a diesel engine, and to ensure that the performance of the engine is not significantly reduced. An engine working in this way is called an alcohol mixed fuel engine. How much alcohol fuel is burned in an internal combustion engine is usually used in the total fuel Volume percentage (Vol%) or weight percentage (Wt%). For example, M10 means that methanol accounts for 10%, and E5 means that ethanol accounts for 5%. It can also be expressed as a percentage of energy.

 In order to ensure that the internal combustion engine uses alcohol fuel to obtain good results, it is necessary to appropriately adjust the properties of the fuel according to the different burning methods, improve the structure of the internal combustion engine and design a good burning and control device. For example, in the aspect of fuel adjustment, the components of gasoline can be adjusted or additives can be added to improve the starting performance of ignition-type internal combustion engines and to avoid vapor resistance. Add ignition modifiers to alcohol fuels to improve the performance of alcohol fuels in compression-ignition internal combustion engines. Ignition performance. In terms of the structure of the internal combustion engine, the ignition type internal combustion engine must be added with a mixture enrichment device and a mixture preheating device at startup; an auxiliary ignition device is added to the compression ignition internal combustion engine; the compression ratio of the internal combustion engine is changed, and the ignition advance angle and Injection advance angle and so on. In terms of burners and control devices, we studied mechanical and emulsification devices for alcohol and petroleum fuels, multiple fuel injection equipment, multiple fuel mixture formation methods, fumigation devices, and alcohol fuel and air volume control devices. Cosolvents can also be added, but the economic benefits of the cosolvents after calcination should be considered.

 Burning an alcohol fuel on an ignition internal combustion engine can increase the compression ratio, thereby improving the power and economy of the internal combustion engine. Alcohol fuels have a high octane number, and have a certain volatility. They are easy to mix with gasoline and are more suitable as fuels for ignition internal combustion engines. However, they are susceptible to damage to rubber and synthetic materials, which must be taken into account when designing oil supply systems. Alcohol fuels have poor cold start performance, so 15% gasoline or short-term gasoline injection is required to start.

 From the existing state of the art described in the above documents: 1. When cars use pure methanol as fuel, on the one hand, the calorific value is low, and the heat of vaporization is large; on the other hand, the use of the above-mentioned methanol-doped fuel formula shows: First, the proportion of gasoline Low, high solvent oil ratio, the octane reconciliation effect of methanol is not enough to meet the standards of today's gasoline. Therefore, when the load increases, such as climbing, acceleration and resistance to acceleration, external vibration will inevitably occur. The second is that the heat of vaporization of methanol is 2.8 times greater than that of gasoline and it is difficult to vaporize, and starting difficulties at low temperatures are bound to occur.

 2. Automobiles using alcohol-based alternative fuels, such as methanol and gasoline, must be redesigned. Changing the starting structure will cause difficulties in the practical promotion of this alcohol-based alternative fuel.

 3. Other alcohol alternative fuels have not solved the problem that the fuel liquid is not stratified at low temperatures and can be started at low temperatures, which makes the use of alcohol alternative fuels extremely limited, especially there is no solution available. With low power, it cannot reach the problem of practical fatal weakness. Summary of the Invention

 The purpose of the present invention is to: (1) solve the problem that the alcohol alternative fuel is stratified at minus 25 ° C and cannot be started arbitrarily at low temperatures;

 (2) In order to solve the problem that the available power of alcohol alternative fuels is lower than that of gasoline, and at the same time, the price of composite fuels for vehicles containing alcohol must be reduced;

(3) It is more important to provide a gasoline engine suitable for use in any existing type without changing A composite fuel for vehicles with a gasoline engine structure, which has a usable power equivalent to gasoline, and has certain water resistance.

The present invention provides a vehicle composite fuel, which includes-alcohol 3-25 wt% _; light hydrocarbons (C _4- ( ₁₄垸 hydrocarbon mixture) 5- 40 wt% _; aromatic hydrocarbons 5-30 wt%; straight run 5wt%; Oil (naphtha or head oil) 10_50wt%; modifier 0. 5- 10wt%; co-solvent 0. 1-5. 5wt% _;

(All percentages above are calculated by weight)

 The alcohols include: methanol, ethanol;

Modifiers include: petroleum ether, diethyl ether, methyl tert-butyl ether, methyl tert-amyl ether, ethyl t-butyl ether; wherein light hydrocarbons including alkanes or C ₄ -C _I4 at room temperature in the fractionation of C ₄ - C _M alkane mixture; (: ^ alkanes include: n-butane, embankment pentyl, isopentyl embankment, heptane, octane and the like;

 The aromatic hydrocarbons include light aromatics other than benzene, including: toluene, xylene (including para-, ortho-, meta-xylene) or a mixture thereof;

 The co-solvent includes: isopropanol, n-butanol, isobutanol, isoamyl alcohol, fu alcohol, or other high-carbon alcohols, and the co-solvent may use one or two or more mixtures of any ratio or Span 80 and Tween 80 is a mixture of 8: 1.

 The steps for preparing the vehicle composite fuel are as follows-the first step is to weigh according to the above formula: methanol 3- 25wt%; light hydrocarbon 10-40wt%;

 Aromatics 5-30wt%; Straight run oil 10-50wt%; modifiers 0.1-5wt%;

 Co-solvent 0.1 to 10%;

 Step 2: Clean the ingredients tank, first scrub it with a cleaning agent (purchased from the market), and then wash it with methanol for the last time until the color does not change. Because methanol is an organic solvent, you must put the ingredients tank before the ingredients tank is batched. Cleaning, especially the greasy in the tank must be cleaned;

 The third step: first place the light hydrocarbons in the batching tank, and then add the straight run oil, light hydrocarbons, modifiers, methanol, aromatics, and co-solvents weighed in step 1 in order;

 Step 4: Stir the mixture prepared in Step 3 until the sampling is clear and transparent.

 Advantages of the invention:

 (1) In the present invention, the straight oil (head oil) produced in the first process of the refinery is directly blended into auxiliary refined oil, and the hydrogenation, catalysis, and cracking reforming steps in the 90 # oil processing step are omitted. It greatly saves time and money, and because straight-run oil is used directly, the straight-run oil does not contain olefins. Therefore, the composite fuel for vehicles of the present invention does not contain olefins. It burns to achieve clean engines, so it has significant social benefits and Economic benefits

(2) Light hydrocarbons and other energy release agents are obviously infiltrated into the composite fuel for vehicles of the present invention. This is a prerequisite for ensuring energy equivalent to gasoline. Since the calorific value of methanol is 19,916 MJ / Kg lower than that of gasoline, the caloric value of gasoline is 43.9-44.4MJ / Kg, plus methanol has 2.25 times greater heat of vaporization than gasoline, which makes evaporation more difficult. Simply mixing methanol or ethanol with alkanes is difficult because of the lower energy accumulation of some alkanes in the front-end oil. Enough, of course, the pressure curve is low-lying and tilted backwards, resulting in a significant decrease in available power. After the addition of light hydrocarbons, on the one hand, the ratio of alkanes to methanol in the first half of the evaporation curve is improved, the gas temperature is increased, and the pressure curve is smoothed This has widened the rapid burning period and improved the available power. Therefore, the addition of light hydrocarbons is a key additive to prevent the available power of methanol gasoline or alcohol-containing fuels from decreasing;

 (3) Adding ether-based modifiers solves the disadvantages that general alcohol-containing composite fuels do not delaminate at minus 25 ° C, and can be easily started at low temperatures;

 (4) the engine using the alcohol-containing composite fuel of the present invention does not need to change gasoline, that is, the methanol substitute fuel of the present invention is suitable for any existing type of gasoline engine;

 (5) the alcohol-resistant composite fuel has a water resistance of 1%;

 (6) The price of the alcohol-containing composite fuel of the present invention is significantly lower than the price of gasoline, which is 1/10 lower than the price of gasoline, or even less;

 (7) Various indicators of the vehicle composite fuel of the present invention have reached the national 90 # or 93 # gasoline standards, and the product does not contain olefins, does not cause carbon deposition to the engine, and the exhaust emissions reach Europe 2-3 Level emission standards. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a comparison chart of three fuel evaporation curves

Figure 2 Comparison chart of three fuel pressure curves

 Example 1

5wt%; Formulated according to the following formula: straight run oil (58 # oil produced by the refinery) 30wt%; ( ₄ -C ₁₄ alkane mixture (light oil) produced by the refinery 30wt%; toluene 25wt%; methanol 12. 5wt%;

Methyl tert-butyl ether 2wt%; isobutanol 0.5wt% _;

 Configured as 90 # gasoline.

 The vehicle composite fuel is prepared as follows:

The first batch is weighed according to the following formula: methanol 12.5wt%; light oil 30wt% _;

 Toluene 25wt%; straight run oil 30wt%; isobutanol 0.5 wt%;

 Methyl tert-butyl ether 2wt%;

 Step two: first scrub the ingredients tank with a cleaning agent purchased from the market, and then wash with methanol for the last time until the color does not change;

 The third step: first place the light hydrocarbons in the batching tank, and then sequentially add the straight run oil, modifier, methanol, and aromatics weighed in step 1;

 Step 4: Stir the mixture prepared in Step 3 until the sampling is clear and transparent.

The gasoline configured in this embodiment 1 has the following properties − The various indicators of the vehicle composite fuel of the present invention have reached the national 90 # or 93 # gasoline standards, and there is no stratification at minus 25%, and the alcohol-containing composite fuel has a water resistance of 1%; its price is higher than the price of gasoline Lower 1/10; The exhaust emission of the vehicle using the composite fuel of the present invention meets European 2-3 level emission standards. Example 2

2wt% _; Example 3 methanol 8.3wt% cyclobutane 6wt% xylene 30wt% straight-through oil (naphtha) 50wt% petroleum ether 5. 5wt% isopropanol

 It is the same as the preparation method of Example 1, except that the following formula is changed-straight oil 50wt% light oil 10wt%

 P-xylene 5wt% methanol 24.4wt%

 Ethyl t-butyl ether 10wt%; isoamyl alcohol 0.1 lwt%;

5wt% _;实施 例 4 The mixture of Span 80 and Tween 80 at a ratio of 8: 1

 The same preparation method as in Example 1, except that the following formula was changed-straight run oil 44. 4wt% 庚 垸 5wt%

 P-xylene 20wt% methanol 25wt%

 Methyl tert-amyl ether 5wt%; fusel 0.1 wt%;

5wt _;实施 例 5 Span 80 and Tween 80 mixed at a ratio of 8: 1 0.5wt _; Example 5

 It is the same as the preparation method of Example 1, except that the following formula is changed:

 Straight run oil 50wt% light oil 20wt%

 P-xylene 3wt% methanol 20wt%

 Mixture of Span 80 and Tween 80 in an 8: 1 ratio 2.5% by weight

Lwt% _; tert-butanol, isopentanol and isobutanol mixed mixture

Diethyl ether 4. 4wt% _; Example 6

 It is the same as the preparation method of Example 1, except that the following formula is changed:

 Straight run oil 10wt% light oil 40 t%

15% by weight of paraxylene, 25% by weight of ethanol 5wt%; Mixture of Span 80 and Tween 80 in a 8: 1 ratio;

Lwt% _; tert-butanol, isopentanol and isobutanol mixed mixture

Diethyl ether 4. 4wt% _;

The above raw straight-run oils, C ₄ -C ₁₄ hydrocarbons mixtures (light oils) were purchased from refineries, and the rest were purchased from the market.

Claims

Rights request What is claimed is: 1. An alcohol-containing composite fuel that is easy to start at low temperature and has a power equivalent to gasoline, which is characterized in that: the alcohol-containing composite fuel includes: Alcohols 3- 25wt%; C ₄ -C ₁₄ fluorene or mixtures thereof 5- 40wt%; aromatic hydrocarbons naphtha oil 10-50% by weight; modifiers 0.5- 10wt. /. Co-solvent 0.1-5.5 wt%; all percentages above are calculated by weight 2. The alcohol-containing composite fuel equivalent to gasoline and having a usable power that is easy to start at low temperature according to claim 1, characterized in that: the -CM alkane includes (-alkane or Mixtures thereof; C ₄ -C ₁₄ fluorenes include: n-butane, pentane, isopentane, heptane, etc., octane.  3. The alcohol-containing composite fuel equivalent to gasoline that can be easily started at low temperature and has an available power equivalent to gasoline according to claim 3, wherein the aromatic hydrocarbons include light aromatics other than benzene.  4. The alcohol-containing composite fuel equivalent to gasoline and having a usable power that is easy to start at low temperature according to claim 1, characterized in that: said light aromatics other than benzene include: toluene, xylene or their mixture.  5. The methanol-containing composite fuel having an available power comparable to gasoline that can be started at minus 25 ° C according to claim 5, characterized in that the modifier comprises: petroleum ether, ether, methyl tertiary Butyl ether, methyl tert-pentyl ether or ethyl tert-butyl ether.  6. The alcohol-containing composite fuel equivalent to gasoline that can be easily started at low temperature and has an available power equivalent to gasoline according to claim 1, characterized in that the co-solvent includes: isopropanol, n-butanol, isobutanol, Isoamyl alcohol, fu alcohol, or other high-carbon alcohols, and the co-solvent may be used in one or two or more mixtures at any ratio.  7. The alcohol-containing composite fuel equivalent to gasoline that can be easily started at low temperature and has an available power equivalent to gasoline according to claim 1, characterized in that the co-solvent comprises: Span 80 and Tween 80 at 8: 1. Proportionally mixed mixture.  8. The alcohol-containing composite fuel equivalent to gasoline with an available power that is easy to start at low temperature according to claim 1, wherein the alcohol comprises: methanol or ethanol.