FIELD OF THE INVENTION

The present invention relates to fuel blend composition comprising of ethanol, biodiesel and diesel fuel blend composition comprising of 50%-diesel, 30%-ethanol and 20%-Prickly Poppy Methyl Ester (PPME) for single cylinder, water-cooled, four stroke, and Direct Injection Diesel engines.

BACKGROUND OF THE INVENTION

The depletion of fossil fuel due to the increase in the population of automobiles and its ever-increasing price forced researchers to find suitable alternative fuels for internal combustion engines. Also, all transport vehicles, i.e. both SI and CI engines are equally responsible for emission of different kinds of pollutants. Some of these are primary kinds having direct hazardous effects e.g. carbon monoxide, hydrocarbons, nitrogen oxides etc, while others are secondary pollutants which undergo a series of reactions in the atmosphere and become hazardous to health and the environment. Therefore, there is a need for alternate fuels that are renewable and eco-friendly. Alternate fuels offer opportunities for significant emission reductions with the increase in efficiency. Different alternative fuels and technologies are in various stages of development and each has a unique performance and emission characteristics. Ethanol and vegetable oils have played an important role as alternate fuel for more than 70 years in many countries. The use of ethanol and vegetable oils can effectively substitute diesel fuel and help to reduce the depletion of petroleum crude reserves, reduce harmful emissions and also creates huge rural employment.

The vegetable oils as fuel has not picked up due to the perennial problems such as, high viscosity and low volatility resulting in heavy smoke emission, carbon build up and seizure of fuel system. The vegetable oil can be classified as edible and non-edible oils. However, India cannot afford to use edible oils as fuel, because the domestic demand is very high. Moreover the cost of the edible oil is higher than diesel.

Therefore, there is a need for finding a biodiesel substitute comprising of a non-edible oil variety which give results close to the neat diesel fuel in terms of Diesel engine (CI engine) performance and exhaust emission and is cost effective. In view of the need for an alternative diesel fuel that is technically and environmentally acceptable and economically competitive, the objective of the present invention is to provides an alternative biodiesel fuel blend in which there is maximum replacement of fossil fuel diesel without compromising the diesel engine performance and emission characteristics such as brake thermal efficiency, specific fuel consumption, the composition of exhaust gases and the combustion characteristics. The present invention uses Prickly Poppy Methyl Ester (PPME), obtained from prickly poppy oil, in the fuel blend as an alternative fuel in a diesel engine.

SUMMARY OF THE INVENTION

The present invention relates to a Biodiesel fuel blend composition for use in diesel engines comprising of diesel, ethanol and Prickly Poppy Methyl Ester (PPME) in a proportion of 50% diesel, 30%-ethanol and 20%-Prickly Poppy Methyl Ester (PPME).

The present invention more preferably relates to a biodiesel fuel blend composition for use in diesel engines comprising of diesel, ethanol and Prickly Poppy Methyl Ester (PPME) in a proportion of 50%-diesel, 30%-ethanol and 20%-Prickly Poppy Methyl Ester (PPME) wherein the diesel engine is a single cylinder, water-cooled, four stroke, and Direct Injection Diesel engine.

BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1: shows the block diagram of the experimental setup for testing the engine performance for various fuels.
Figure 2: shows the picture of the prickly Poppy plant used in the present invention.
Figure 3: is a graph showing the brake thermal efficiency for diesel and diesel-ethanol-PPME fuel blend at various loads
Figure 4: is a graph showing the variation of CO emissions for diesel and diesel-ethanol-PPME fuel blend with respect to different loads
Figure 5: is a graph showing the variation of un-burnt hydrocarbon (UBHC) emissions for diesel and diesel-ethanol-PPME fuel blend at various loads
Figure 6: is a graph showing the variation of smoke intensity for diesel and diesel-ethanol-PPME fuel blend at various loads

DETAILED DESCRIPTION:

Biodiesels are derived from vegetable oils or animal fats, more specifically the alkyl esters from these. The esters from vegetable oils are considered to be superior since they have a higher energetic yield and essentially no engine modifications are necessary for their use. Vegetable oils are integral part of today's fuel. Together with carefully formulated base fuel composition they contribute to efficiency and long life. Vegetable oils are renewable and potentially inexhaustible source with energy content close to the diesel. The edible oil such as rape seed oil in Europe, palm oil in Malaysia and soybean in USA are being used for the production of bio diesel. But in India to produce bio diesel use of edible oils is not feasible.
However, there are several non-edible oil seed species such as Karanja, Jatropha, Neem, Mahua, Simarouba, Prickly Poppy etc., which could be utilized as a source for production of oil. Among these, prickly poppy is an

oil seed bearing plant, which is non-edible and does not find more application.
Prickly poppies are annual herbs that grow upright to about 3 to 5 feet tall. They are covered with prickles and have large, showy flowers with six white, yellow, or pinkish red petals. All of the prickly poppies contain yellow to orange latex sap. The latex sap and prickly poppy seeds are known to have poisonous properties. At least three species of prickly poppy are common in the region, and a few others grow on the northern edge. These include Argemone mexicana (yellow prickly poppy), Argemone chisoensis (pink prickly poppy) , Argemone albiflora, and Argemone polyanthemos (to the north) . The seeds of prickly poppy plant are small dark-brown striated spheres about 1.5 to 2 mm. in diameter and somewhat resemble mustard seed in appearance. Several investigators have extracted the oil from Prickly poppy seeds grown in various places, and some have reported the characteristics of the oil they obtained.

Table 1: Characteristics of Prickly poppy oil

However, vegetable oils decrease power output and thermal efficiency while leaving carbon deposits inside the cylinder. These problems include: cold-weather
starting; plugging and gumming of filters lines, and injectors; engine knocking; coking of injectors on piston and head of engine; carbon deposits on piston and head of engine; excessive engine wear; and deterioration of engine lubricating oil. Vegetable oils decrease power output and thermal efficiency while leaving carbon deposits inside the cylinder. Most of these problems with vegetable oil are due to high viscosity, low cetane number, low flash point, and resulting incomplete combustion. The problems with substituting triglycerides for diesel fuels are mostly associated with their high viscosities, low volatilities and polyunsaturated character. The problems have been mitigated by developing vegetable oil derivatives that approximate the properties and performance and make them compatible with the hydrocarbon based diesel fuels through

> Pyrolysis
> Micro emulsification
> Dilution
> Trans-esterification

Trans-esterification has been widely used to reduce the viscosity of triglycerides. The trans-esterification works well when the starting oil is of high quality. However, quite often low quality oils are used as raw materials for biodiesel preparation. In cases where the free fatty acid content of the oil is above 1%, difficulties arise due to form of soap which promotes emulsification during the water washing stage and at FFA content above 5% the process become unworkable.

Trans-esterification is the chemical reaction between triglycerides and alcohol in the presence of a catalyst to produce monoesters. The long and branched chain triglyceride molecules are transformed to monoesters and glycerin. This process consists of a sequence of three consecutive reactions where triglycerides are converted to diglycerides; diglycerides are converted to monoglycerides followed by the conversion of monoglycerides to glycerol. In each step an ester is produced and thus three ester molecules are produced from one molecule of triglyceride. The properties of these esters are comparable to that of diesel.

A comparative table for properties of PPME biodiesel with that of neat diesel is given below in Table 1:

TABLE 1: Comparison of properties of biodiesel with neat diesel
Prickly Poppy seeds used in this investigation were collected from Argemone mexicana plants (as shown in Figure 2) growing in the surroundings of various villages in Vellore District of Tamil Nadu and dried in sunlight for a week. The dried seeds are peeled to obtain the kernel for extraction of Prickly Poppy oil by using a Mechanical expeller. Small traces of organic matter, water and other impurities present in the prickly poppy oil are removed by adding 5% by volume of hexane to the raw oil and stirring it for 15-20 minutes at 80-90°C and allowing it to settle for 30 minutes. Since hexane is having low boiling point (68.7°C), it gets evaporated on heating beyond the boiling point of hexane. The impurities and gum particles that settle down at the bottom are removed. The remaining oil is the purified oil. The purified oil is then used for trans-esterification process.
The free fatty acid content of unrefined prickly poppy oil was found to be 21.5%. The fatty acid content was determined by a standard titrimetric method. The yield of esterification process and quality of biodiesel decreases considerably if free fatty acid content is greater than 2%. Therefore development of any method to produce biodiesel from high acid value oil is significant. Hence, the efforts are made to esterify a typical high free fatty acid type of oil, i.e., prickly poppy seed oil in this invention.

Therefore, FFAs were first converted to esters in a two-step pre-treatment process using an acid catalyst (H2SO4 1% v/v) to reduce the acid value of prickly poppy oil. Experiments were conducted in a laboratory scale setup which consisted of 500cc glass flasks with a tight cap that retained any vaporized methanol to the reacting mixture. Hot plate with magnetic stirrer was used to maintain the temperature at 60°C just below the boiling point of methanol. The mixture was stirred well by means of magnetic stirrer.

The second step is the alkali esterification in which a solution of KOH in methanol (1% based on the prickly poppy seed weight) , based on the prickly poppy oil to methanol mole ratio of 1:6 , is heated at 60°C and then added with the pretreated prickly poppy seed oil. The contents are stirred till ester formation began. The mixture is heated to 65°C and held that temperature without stirring for an hour. The mixture is poured into a separating funnel and then it is allowed to cool for 24 hour without stirring. Two layers are formed. The bottom layer consisted of glycerol and the top layer is the ester. The bottom layer is removed and ester is collected and washed with hot distilled water three times. The lower layers consisting of glycerol can be discarded or used for other applications. The upper layer after the third washing is the bio diesel product.

Blending conventional diesel fuel with esters (usually methyl esters) of vegetable oils is presently the most common form of biodiesel. The most common ratio is 80% conventional diesel fuel and 20% vegetable oil ester , also termed as B20 indicating the 20% level of biodiesel. There have been numerous reports that significant emission reductions are achieved with these blends.

In the present invention Prickly Poppy Methyl

Ester (PPME) obtained from prickly poppy oil is blended with ethanol and diesel in a desired proportion for use in diesel engines. Experimental work has been carried out on the effective utilization of 50% diesel-30% ethanol-20% PPME fuel blend as an alternate fuel in a single cylinder, water cooled, direct injection CI engine.

The biodiesel fuel blend having a composition of 50% diesel, 30%-ethanol and 20%-Prickly Poppy Methyl Ester (PPME) is prepared by mixing parts by volume of the components namely fossil fuel diesel, ethanol and PPME in round bottom conical apparatus maintained at room temperature to give a ratio of 50%-fossil fuel diesel, 30% ethanol and 20%-PPME. The fuel mixture is stirred continuously for 2 hour.

The experimental setup for testing the engine performance for different fuel blends is done as per Figure 1.Specification of the diesel engine used in this experiment is given in table 2 given below:

TABLE 2: Specification of the test engine

Specification of the alternator used to load the test engine is given in table 3.
Table 3: Specification of the alternator
The following parameters are checked as a precaution before starting the engine and after the end of the experiment.
> Fuel level in the tank should be checked regularly
> Lubricating oil level Cooling water supply Load condition

The test engine is coupled with an eddy current dynamometer through a load cell. It is integrated with a data acquisition system to store the data for the off-line analysis. Cooling water is circulated separately to the engine and the dynamometer at the required flow rates. Necessary provisions are made to regulate and measure through electronic control unit of flow rates of air, fuel and coolant. The engine is operated on diesel baseline mode at a constant speed of 1500 rpm at no load to full load. At each load, the engine performance parameters are recorded. The engine was operated on diesel first and then on diesel-ethanol-biodiesel fuel blend. Carbon monoxide and unburned hydrocarbon emissions were measured by Wahun Cubic Gas analyzer. Smoke emissions were measured by means of a Bosch smoke meter.
The methods, parameters and the examples described in the disclosure are illustrative purpose only and are not to be construed to limit the scope of the invention.

EXAMPLE 1:

Biodiesel was produced based on laboratory scale by trans-esterification of Prickly Poppy oil according to the optimum reaction conditions obtained from laboratory study with maximum yield of 60 % of methyl esters. Trans-esterification of 300 ml of Prickly Poppy oil was carried out in 500mL round flask placed in an adjusted temperature hot plate magnetic stirrer. The reaction was performed in two-step transesterification process, first step of acid trans-esterification using concentrated sulphuric acid and the second step of alkaline acid trans-esterification using KOH in methanol as the catalyst. The molar ratio of alcohol to oil used in the reaction mixture is 6:1. The reaction mixture is maintained at 60°C by means of hot plate magnetic stirrer. The contents are stirred till ester formation begins. The mixture is heated to 65°C and held at that temperature without stirring for an hour. The resulting system is poured into a separating funnel and then it is allowed to cool for 24 hours. Two layers are formed. The bottom layer consists of glycerol and the top layer is the ester. The bottom layer is removed and the upper layer containing the ester is collected in a separate flask, and washed with hot distilled water three times. The upper layer after the third washing is the PPME bio diesel product.

The biodiesel thus obtained is used to prepare the biodiesel fuel blend comprising of 50% fossil fuel diesel, 30% ethanol and 20% PPME. In a flask 50 ml of neat diesel, 30 ml of ethanol and 20 ml of PPME biodiesel obtained above are mixed together at room temperature and pressure. The fuel mixture is stirred continuously for 2 hours and cooled to room temperature and pressure.

The experimental setup for testing the engine performance for the above biodiesel fuel blend is done as per Figure 1.Testing is done based on the procedure described above in the disclosure.

RESULTS AND DISCUSSIONS:

It was observed that, while operating the engine with blends of biodiesel, it was running smooth at all loads. The performance and emission characteristics such as brake thermal efficiency and the composition of exhaust gases are presented for different loads for diesel oil and diesel-ethanol-biodiesel blend in the disclosure.

The brake thermal efficiency is the true indication of the effectiveness with which the chemical energy input in the form of fuel is converted into useful work. Figure 3 shows the brake thermal efficiency for diesel and 50 D - 30 E - 20 PPME blend at various loads in different test engine. It is seen that the brake thermal efficiency of the engine increases with load for all test fuels. At all loads, the brake thermal efficiency of the engine was found to be the lower for diesel, when compared to 50D - 30E -20PPME.

Figure 4 shows variations of carbon monoxide emissions at various engine loads. CO emission was high at low load for all test fuels; it decreases at medium load and starts to increase after medium load. When compared to diesel, the CO emission is lower with 50D -30E - 20PPME blend in all the load conditions and that would be due to inbuilt fuel oxygen and improved combustion process.
Figure 5 shows the variation of unburnt hydrocarbon emission at various engine loads. It is seen from the figure that the UBHC emission decreases when the load increases. It was observed from the graph that the 50D - 30E - 20PPME produced relatively lower UBHC as compared to the neat diesel in all the load conditions.

This is because of better combustion of 50D

- 30E - 20PPME blend inside the combustion chamber due to the availability of oxygen atom.

Figure 6 shows the variation of smoke density at various engine loads. Smoke density increases with load for both the test fuels. It was observed that smoke decreases for the 50D - 30E - 20PPME compared to diesel. Due to insufficient combustion duration, insufficient air due to low volumetric efficiency at high load, as well as the richer mixture formed at increased load, soot formation increases. Lower smoke density for the blend compared with that of diesel may be caused due to higher oxygen content in the 50D - 30E

- 20PPME.

ADVANTAGES OF BIODIESEL FUEL BLENDS OF THE PRESENT INVENTION:

Biodiesel fuel blends of the present invention are economical when compared to the other biodiesel alternatives available as prickly poppy plants grow in wild in abundance in India and elsewhere in the world and the plant parts are non-edible and does not find more application.;

> Development of biodiesel industry for manufacturing the biodiesel of the present invention would help in strengthening the rural agricultural economy of agriculture based countries like India as it creates employment opportunities for people;

> Replacement of fossil fuel diesel with biodiesel helps in conserving fossil fuel reserves;
> Bio-diesel fuel blend degrades four times faster than diesel;
^ It has 80% heating value compared to that of diesel;
> The higher flash point makes the storage safer;
^ Bio-diesel fuel blend is ecofriendly;
> Diesel-Ethanol-biodiesel can be used directly
in compression ignition engines with no
substantial modifications of the engine.

We Claim:

1. A Biodiesel fuel blend composition for use in diesel engines comprising of diesel, ethanol and Prickly Poppy Methyl Ester (PPME) in a proportion of 50% diesel, 30%-ethanol and 20%-Prickly Poppy Methyl Ester (PPME);

2. A biodiesel fuel blend composition for use in diesel engines comprising of diesel, ethanol and Prickly Poppy Methyl Ester (PPME) in a proportion of 50%-diesel, 30%-ethanol and 20%-Prickly Poppy Methyl Ester (PPME) as claimed in claim 1, wherein the diesel engine is a single cylinder, water-cooled, four stroke, and Direct Injection Diesel engine.