CN1242030C - Composite fuel - Google Patents

Abstract

The invention discloses a composite fuel, which is prepared by mixing (25-85)% by weight of dimethyl ether and (15-75)% by weight of liquefied petroleum gas, wherein the weight ratio of the dimethyl ether to the liquefied petroleum gas is linearly changed along with the change of ambient temperature, when the temperature is reduced from 40 ℃ to 6 ℃ in a gradient manner, the weight ratio of the dimethyl ether is reduced from 85% to 25% in a gradient manner, and the weight ratio of the liquefied petroleum gas is increased from 15% to 75% in a gradient manner. The composite fuel of the invention adopts dimethyl ether and liquefied petroleum gas as raw materials, has simple ingredients, adopts different proportions according to different environmental temperatures, has high heat value generated by complete combustion, less carbon deposition of a cooker and SO after combustion₂The discharge amount is reduced by 90% compared with liquefied petroleum gas, it can be used in common civil range and steel cylinder, and has no need of special range and steel cylinder, and when it is used, it has no need of preheating, and is convenient for use.

Description

composite fuel

Technical Field The present invention relates to a composite fuel, in particular to a civilian composite fuel mixed with dimethyl ether (DME) and liquefied petroleum gas (LPG).

BACKGROUND OF THE INVENTION At present, the gaseous fuels used by people mainly include natural gas, coal gas, and liquefied petroleum gas. Most of the cities with natural resources, as well as rural residents, use petroleum liquefied gas as fuel. However, liquefied petroleum gas contains some high-carbon hydrocarbons that are not easy to gasify, so that a large amount of residual liquid that cannot be gasified remains in the gas tank, resulting in a great waste of resources. Therefore, it is an urgent need to find a new fuel suitable for environmental protection as a substitute for petroleum liquefied gas. Chinese Patent Publication No. CN1417305, published on May 4, 2003, the name of the invention is "High Energy Composite Fuel and Its Special Combustion Appliance", the application discloses a C ₂ -C ₁₂ hydrocarbon, mono The composite fuel composed of alcohol, glycol, dimethyl ether and additives has the disadvantage that although the raffinate of liquefied petroleum gas is used, the combustion of a large amount of sulfur-containing components in the raffinate will pollute the environment, so it is not It is beneficial to environmental protection, and needs to be equipped with special steel cylinders and cooking ranges, so that its popularization and use is limited. Chinese Patent Publication No. CN1227864, the publication _date is September 8, 1999. The name of the invention is "Ether Hydrocarbon Liquid Composite Fuel". Composite fuel composed of ~70%, 0~20% of liquefied petroleum gas, its disadvantage is that the main raw material is C ₅ , which has a large sulfur content, which seriously pollutes the environment, C ₅ is not easy to gasify, and needs to be heated before use And burning, it is not easy to be completely oxidized during the combustion process, so that the stove will produce carbon deposits, which will pollute the stove. If it is not cleaned in time, the gas output will be reduced, the flame will be turned off, and danger will occur. In addition, cleaning the carbon deposits will also make people feel inconvenient to use. and trouble.

SUMMARY OF THE INVENTION The present invention aims at the deficiencies of the above-mentioned prior art, and provides a kind of ingredient that is simple, does not require preheating and pressurization, has less environmental pollution, less carbon deposition, and can adopt different proportions according to changes in ambient temperature. Clean environment-friendly composite fuel composed of dimethyl ether and liquefied petroleum gas

The technical scheme of the present invention is: it is to form by mixing (25～85)% dimethyl ether and (15～75)% liquefied petroleum gas by weight, and the weight proportion of dimethyl ether and liquefied petroleum gas is It changes linearly with the ambient temperature. When the temperature drops from 40°C to 6°C, the dimethyl ether drops from 85% by weight to 25% by weight, while the liquefied petroleum gas drops from 15% by weight. Gradient up to 75% by weight.

Dimethyl ether (DME) is a colorless gas, chemical formula CH ₃ OCH ₃ , molecular weight 46.07, relative liquid density (20°C) 0.666, boiling point/°C-24.9, melting point/°C-141.5, freezing point/°C-138.5, critical temperature /℃127, critical pressure/MPa 5.37. It has a pleasant smell, the flame is slightly bright when burning, and it is non-toxic. Has excellent miscibility, can be miscible with most polar and non-polar organic solvents, and partially miscible with water. After adding a small amount of additives, it can be miscible with water in any proportion.

The main components of LPG are propane, butane, propylene and butene, followed by a small amount of C ₂ (ethylene, ethane) and C ₅ (hydrocarbons above pentane) components. In addition, it also contains a small amount of impurities such as sulfide, H ₂ S, RSH, RSSR and elemental sulfur. It is gaseous at normal temperature and pressure, and it is easy to change into liquid when the pressure increases or the temperature decreases. The critical temperature is 92-162°C, and the critical pressure (absolute) is 3.53-4.45Mpa.

Since LPG is easy to become liquid under normal temperature and pressure (1.0Mpa), and the volume of liquid is about 1/250 of the volume of gas, so LPG is easier to transport and store than other city gases. When decompressed, it is in gaseous state, which is very convenient for users to use.

The calorific value of LPG is higher than that of other gases, and its low calorific value is 87.8-108.7MJ/m ³ (gas state) or 45.1-45.9MJ/kg (liquid state). Considering the completeness of combustion when using it, it is usually in gaseous state use.

DME is very easy to mix with petroleum liquefied gas, and it is easy to liquefy after mixing, which can make the canning more convenient to implement. Using different proportions at different ambient temperatures can not only maximize the gasification and combustion of the composite fuel in the tank, but also obtain the best combustion calorific value, and effectively control the sulfur content in the liquefied petroleum gas The amount of ingredients can reduce the generation of _SO2 as much as possible during combustion, which plays an environmental role. Due to the use of different proportions under different ambient temperatures, the combustion is more complete, so there is little carbon deposition, thereby reducing the pollution to the stove.

The composite fuel of the present invention adopts dimethyl ether and petroleum liquefied gas as raw materials, and the ingredients are simple, and different proportions are adopted according to the difference in ambient temperature, the calorific value produced by complete combustion is high, the carbon deposit in the stove is less, and _the SO emission after combustion is relatively low. Petroleum liquefied gas is reduced by nearly 90%, and it can be used on ordinary civilian stoves and steel cylinders without special stoves and steel cylinders. It does not need to be heated during use and is convenient to use.

Detailed ways

The composite fuel of the invention is formed by mixing (25-85)% dimethyl ether and (15-75)% liquefied petroleum gas.

The present invention has following proportioning according to ambient temperature: See Table 1

Table 1. Proportions of composite fuels at different ambient temperatures serial number Ambient temperature (℃) Proportion (%) DME LPG 1 40 85 15 2 36 78 twenty two 3 32 71 29 4 28 63 37 5 twenty four 56 44 6 twenty two 52 48 7 16 42.5 57.5 8 12 35.5 64.5 9 8 28.5 71.5 10 6 25 75

When the ambient temperature is about 28°C, 63% of the liquefied methyl ether is methyl ether, and about 37% is liquefied petroleum gas.

When the temperature is above 38°C and close to 40°C, the proportion of methyl ether in liquefied methyl ether is as ^high as 85%, and liquefied petroleum gas only accounts for 15%. At this time, the combustion calorific value is 32MJ/kg. Ordinary stoves are used for half an hour, and the SO ₂ content in the kitchen is less than 1.3mg/m ³ , and the SO ₂ emitted is far lower than the national standard. ,

The following is the comparison of common fuel properties and the combustion performance of the present invention when different proportions are used under different ambient temperatures, see Table 2 and Table 3 for details.

Table 2. Combustion value comparison of commonly used fuels name average calorific value combustion temperature DME 31.45 2250 LPG 45.76 2055 C ₅ 47.76 2120 CF 43.274 2170

Description: DME: dimethyl ether; LPG: liquefied petroleum gas; C ₅ : carbon five fuel; CF: compound fuel (compound Fud)

Table 3, the combustion value of the different proportioning of different ambient temperatures of the present invention serial number Ambient temperature (℃) Proportion (%) Average calorific value (MJ/Kg) Combustion temperature (℃) DME LPG 1 40 85 15 32.5 2200 2 36 78 twenty two 33.9 2178 3 32 71 29 35.25 2156 4 28 63 37 36.8 2134 5 twenty four 56 44 38.2 2112 6 twenty two 52 48 38.9 2100 7 16 42.5 57.5 41 2067 8 12 35.5 64.5 42.4 2045 9 8 28.5 71.5 43.8 2023 10 6 25 75 44.5 2015

Claims (1)

1. A kind of compound fuel, it is characterized in that: it is to be that 25%～85% dme and 15%～75% liquefied petroleum gas (LPG) mix by weight part, the weight proportion of dme and liquefied petroleum gas (LPG) is to be linear change with variation of ambient temperature, when temperature drops to 6 ℃ by 40 ℃ by gradient, dme drops to 25% weight part by 85% weight part by gradient, and liquefied petroleum gas (LPG) then rises to 75% weight part by 15% weight part by gradient.