A PROCESS FOR PREPARING GREEN PETROL FROM CASHEW NUT SHELL OIL

FIELD OF INVENTION
[0001] The embodiments herein generally relate to the field of bio fuel  particularly use of cashew nut shell oil as a bio-fuel. More specifically it relates to the extraction process of green petrol by using cashew net shell to produce bio-fuel.

BACKGROUND AND PRIOR ART
[0002] "Fossil fuels" are materials that can be used today to produce energy (heat or power) that were created from plants and animals that lived millions of years ago. The danger of depletion of the fossil fuels and the release of environmental pollutants by the combustion of such fuels is increasing day by day. At present  crude oil  coal and gas are the main resources for world energy supply. Bio-fuels can be used as an alternative energy source because these fuels are helpful in increasing the security of energy supplies and also in reducing greenhouse gas emissions.
[0003] Biofuels are fuels derived from biomass. Biomass is organic matter taken from or produced by plants and animals. It comprises mainly wood  agricultural crops and products  aquatic plants  forestry products  wastes and residues  and animal wastes. Biofuels are all types of solid  gaseous and liquid fuels that can be derived from biomass. Examples of solid biofuels include wood  charcoal and bagasse. Examples of gaseous biofuels include methane gas and producer gas. Examples of liquid biofuels include methanol  ethanol  plant oils and the methyl esters produced from these oils commonly referred to as biodiesel.
[0004] Since petroleum  diesel and gasoline consist of blends of hundreds of different chemicals of varying hydrocarbon chains  many of these are hazardous and toxic. They include volatile compounds such as benzene  toluene and xylene that are identified as responsible for the health hazards and pollution associated with the combustion of petroleum-based fuels. Carbon monoxide (produced when combustion is inefficient or incomplete)  nitrogen oxides (produced when combustion occurs at very high temperatures)  sulfur oxides (produced when elemental sulfur is present in the fuel)  and particulates that are generally produced during combustion are other specific emissions of concern.
[0005] An important environmental and health benefit of using biofuels as an additive to or replacement of petroleum-based transportation fuels is a reduction in these harmful emissions  in particular sulfur oxides and particulates. Since both ethanol and biodiesel contain oxygen in their chemical structure they can be used as fuel oxygenates to improve combustion characteristics. The presence of chemically-bound oxygen results in more complete combustion  which reduces carbon monoxide emissions. This is a significant environmental and health benefit that can result from replacing petroleum fuels with biofuels. A wide variety of different agricultural crops can be turned into fuel for motor vehicles. In different parts of the world  products as diverse as sugar cane  wheat and rapeseed are used to make substitutes for petrol or diesel. These fuels are usually mixed with conventional fuels to make a blend.
[0006] The cashew tree is a small to medium tree  generally single-trunked and spreading in habit  up to 40"" in height but generally 10-20"" in cultivation. A cashew nut has a hard shell outside with two layers. The outer layer is oily and inner layer hard within the soft nut is contained. The nut has a shell of about 1/8 inch thickness inside which is a soft honey comb structure containing a dark reddish brown viscous liquid. It is called Cashew Nut Shell Oil or CNSL which is the pericap fluid of the Cashew Nut. It is often considered as the better and cheaper material for unsaturated phenols. Cashew shells are widely processed into oil by using different techniques and equipments. Various cashew nut oil manufacturers use sophisticated machines in carrying out the processes of shell conveying  expelling  and oil treatment.
[0007] Cashew nut is regarded as lost crop in the content of agricultural products of countries like Nigeria despite its industrial and export potentials. CNSL is amber-colored  poisonous  viscous oil obtained from the by-product shells of the cashew nut by extraction. It is a versatile by-product of the cashew industry which is often considered as the better and
cheaper source of unsaturated phenols. It has innumerable applications  such as friction linings  paints  laminating resins  rubber compounding resins  cashew cements  polyurethane based polymers  surfactants  epoxy resins  foundry chemicals  and intermediates for chemical industry. CSNL is an effective material for industrial usage. It also has an advantage over synthetics. It has an innumerable application and widely used for its versatility.
[0008] CSNL has a chemical property that has special structural features  which transform the chemicals and high value polymers. The oil thus  provides a value addition of chemical features that provides 100% chemically pure products. Therefore  cashew nut shell oil is widely used in chemicals  high value products  and polymers.
[0009] Various processes are employed for the extraction of shell oil from the raw nut which have already been roasted for the recovery of kernels. Most important processes of shell oil extraction are Oil Bath process  Kiln method  and Solvent Extraction process. The Kiln method is adopted in most part of India for the extraction of the shell oil because of its inherent simplicity.
[00010] Patent Application No. PT 101761 discloses a process for the manufacture of polymers based on cashew nut shell oil. In this process of manufacture possible reactions are interactions of polyisocyanates with reactive groups in cashew oil  these being: the carboxylic groups of anacardic acid  the phenol groups of benzenoic acid and the double bonds in the chains. A variety of products such as insulating foams  thermoplastic elastomers or heat setting adhesives can result from the various processes.
[00011] Another Patent Application No.US 2002/0066225 A1 describes about a process for the preparation of novel Mannich bases from hydrogenated and distilled Cashew Nut Shell Liquid (CNSL) for use as additive in hydrocarbon fuels for removing and protecting build up of deposits on carburetor surfaces and intake valve systems in a gasoline powered engine system comprising: reacting hydrogenated and distilled Cashew Nut Shell Liquid (CNSL)  an amine having at least one reactive hydrogen atom  and an aldehyde in the molar ratio of 1:0.1 to 10:0.1 to 10 at a temperature ranging from 70° C.-175° C. for 6 to 12 hours in presence of an organic solvent  distilling said solvent and unreacted amine  and cooling and filtering the reaction product to obtain Mannish base.
[00012] However  these processes have their own disadvantages and do not describe a simple method by which the CSNL can be used as a bio-fuel. Therefore  there is a need for developing a process which not only make use of cashew nut shell oils but also process it to use as a biofuel in an easy manner. Further  the composition can also be used in place of gasoline to overcome the drawbacks of “Fossil fuels”. And also there is a need of a biofuel which can replace the use of gasoline and a novel process by green petrol can be extracted from cashew nut shell oil.

OBJECTS OF THE INVENTION
[00013] A main object of the present invention is to provide a process to extract green petrol from cashew nut shell oil.
[00014] Another object of the invention is to provide bio-oil which can serve as a fuel in an I.C. Engine.
[00015] Still another object of the present invention is to make use of the by-products of cashew nuts.
[00016] Yet another object of the present invention is to increase the yield and improve the quality of the green petrol.
[00017] The other objects and advantages of the present invention will be apparent from the following description when read in conjunction with the accompanying pictures which are incorporated for illustration of preferred embodiments of the present invention and are not intended to limit the scope thereof.

SUMMARY OF THE INVENTION
[00018] In view of the foregoing  the embodiment herein provides a novel process of extraction of green petrol from the cashew nut shell oil. The invention also relates to the performance test on an I.C. Engine using the blended green petrol with ethanol as fuel. The present invention describes a process of extracting oil which is being further processed by hydrogenation and cracking before being used as a biofuel.
[00019] According to an embodiment  the oil is distilled and is filtered to remove the solid and floating impurities. Thereafter  the oil is passed over active charcoal to remove the presence of harmful ions. This oil is made to undergo a process called hydrogenation which makes the oil less vesicant and more stable. Accordingly  the hydrogenation is a process of adding hydrogen at the double and triple bonds; consequently  the multiple bond unsaturated fatty acids gets converted into single bond saturated fatty acids.
[00020] Further  the hydrogenated oil is subjected to decomposition in a cracking unit consisting of fractionating column surrounded by a double surface condenser. The decomposition is performed at a temperate in the range of 100° to 150°.Cracking increases the yield of green petrol and also improves the quality of gasoline in terms of antiknock properties. Since large hydrocarbon molecules breakup to produce hydrocarbons of short hydrocarbons  there is a change in the boiling range or the volatility of the resulting product. The highly volatile cracked oil is mixed in a proportion 1:10 by volume with ethanol  and the blended oil is served as a fuel in an I.C. Engine  according to an embodiment.
[00021] The engine performance test is conducted by using the novel blended oil and it is observed that the blended fuel accords characteristic curves similar to that of gasoline and thus it can be used as a fuel in an I.C engine.
[00022] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying tables. It should be understood  however  that the following descriptions  while indicating preferred embodiments and numerous specific details thereof  are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof  and the embodiments herein include all such modifications.

DETAILED DESCRIPTION OF THE DRAWINGS
[00023] The detailed description is set forth with reference to the accompanying figures. In the figures  the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.
[00024] Fig. 1 illustrates the steps involved in the extraction of green petrol starting from the CNSO  according to an embodiment herein;
[00025] Fig. 2 illustrates the graphical representation of the total fuel consumption (TFC) of the engine against the brake power (BP) for both the blend and the gasoline  according to an embodiment herein;
[00026] Fig. 3 illustrates the graphical representation of the specific fuel consumption (SFC) of the engine against the brake power (BP) for both the blend and the gasoline  according to an embodiment herein;
[00027] Fig. 4 illustrates the graphical representation of the brake thermal efficiency (BE) of the engine is plotted against the brake power (BP) for both the blend and the gasoline  according to an embodiment herein.

DETAILED DESCRIPTION OF EMBODIMENTS
[00028] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying figures and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly  the examples should not be construed as limiting the scope of the embodiments herein.
[00029] As mentioned above  there is a need to develop a process to extract green petrol from cashew nut shell and also mitigate the drawbacks observed in the prior arts. The embodiments herein achieve this object by providing a novel process of extracting green petrol from the cashew nut shell oil  blending the same with ethanol. Referring now to the Table 1 and Figures 1-4 where similar reference characters denote corresponding features consistently throughout the figures  there are shown preferred embodiments.
[00030] This disclosure is directed to a novel process by which green petrol can be extracted from cashew nut shell oil and it can be used as a very good biofuel. It has been observed that  the cashew nut shell oil is unstable in its natural form and froth formation occurs at about 80o C making it difficult to be handled as a fuel in an I.C. Engine. The inventors have come up with novel process by which the cashew net shell oil can be used as a fuel. Fig.1 Illustrates the steps involved in the extraction of green petrol starting from the CNSO/CNSL  according to an embodiment.
[00031] According to an embodiment of the present invention  the oil is subjected to distillation and filtrations steps to remove the solid and floating impurities. Thereafter  the oil is subjected to hydrogenation process and then undergoes cracking step. Consequently  the multiple bond unsaturated fatty acids get converted into single bond saturated fatty acids which makes the oil less vesicant  more stable and free from all the impurities. The highly volatile cracked oil is mixed in a proportion 1:10 by volume with ethanol  and the blended oil can be served as a fuel.
[00032] While oil is subjected to the engine performance test  it has been observed that the blended fuel accorded characteristic curves similar to that of gasoline.
[00033] As mentioned hereinbefore  the cashew nut shell oil is unstable in its natural form and froth formation occurs at about 80o C making it difficult to be handled as a fuel in an I.C. Engine. So the oil needs to be processed before it can be used as a fuel. This is done in the following steps:
[00034] Extraction of CNSL from cashew nut shell: In an embodiment  Cashew nut shell liquid (CNSL) is extracted from cashew nut shell by indirect leaching process using soxhlet extraction equipment. Normal hexane (n-hexane) is used as solvent. The operating conditions for the extraction are 680°C and 1 atmosphere in every 100g of cashew nut shell used for the extraction wherein 35gCNSL is obtained. Any other known method can also be used for the extraction of CSNL from cashew nut shell.
[00035] Processing of CNSL: The CNSL is further separated into cardol  cardanol and anacardic acid (polyphenol) using an amine extractant (alanine) with the aid of shake-out separation equipment. Subsequently  the polyphenol is further separated into dihydric phenols (resorcinol) and monohydric phenol (phenol). Any known process like Oil Bath process  Kiln method  and Solvent Extraction process can be used for separating. The Kiln method is mostly adopted for the extraction of the shell oil because of its inherent simplicity.
[00036] Hydrogenation: The CSNL is subjected undergo a process called hydrogenation which makes the oil less vesicant and more stable. Hydrogenation is a process of adding hydrogen at the double and triple bonds; consequently  the multiple bond unsaturated fatty acids got converted into single bond saturated fatty acids. While experimenting  there were two unsuccessful attempts wherein the CSNL was subjected to molecular hydrogenation in the power bomb apparatus at a very high pressure for a period of 7 to 8 hours in the presence of Rany Nickel as a catalyst. When this oil is subjected to Atomic Spectroscopy  it indicated the presence of calcium  sodium and sulphur ions. The presence of calcium  sodium and sulphur ions would poison the catalyst rendering the process of hydrogenation a futile one; thus  it has been observed that these ions needed to be removed before the oil is hydrogenated. These ions were removed by passing the oil through the activated charcoal  according to an embodiment. Thereafter  the oil is subjected to hydrogenation process. While the hydrogenated oil is subjected to the Iodine Value Test  the test indicated the reduction of iodine value from 255 to 112. The thick hydrogenated oil is less volatile and contained a long chain of hydrocarbons.
[00037] Cracking: This hydrogenated oil is further subjected to decomposition at a temperature of 1500 C in a cracking unit consisting of fractionating column surrounded by a double surface condenser. It has been observed that cracking increases the yield of green petrol and also improves the quality of gasoline in terms of antiknock properties. Therefore  the oil is subjected to cracking to improve its gasoline quality. It is also known that when large hydrocarbon molecules breakup to produce hydrocarbons of short hydrocarbons  there is a change in the boiling range or the volatility of the resulting product. The highly volatile fractionate received from the condenser was collected in a flask kept in a freezing mixture.
[00038] Therefore  the processing of the CSNL includes the steps of extraction of CSNL from the cashew nut shell by any known method  distillation and filtration of the oil  the oil being passed through active charcoal to reduce the calcium  sodium and sulphur ions and the same being subjected to hydrogenation and cracking.
[00039] In an embodiment  for use of the processed CSNL as a bio-fuel  the same is blended with ethyl alcohol. Ethyl alcohol is obtained by fermentation of carbohydrates in the absence of oxygen. Ethanol or Ethyl alcohol is a volatile  flammable  clear  colourless liquid under normal atmospheric temperature and pressure.
[00040] In an embodiment  the biofuel is produced by blending in 1:10 proportion by volume of green petrol and ethanol at 1000 RPM. The biofuel is then used to carry a series of engine tests on an I.C. Engine [Four Stroke Petrol Engine] to check the efficiency of the fuel.
[00041] Performance and emission tests were being conducted at various loads. For every load applied  the time taken for 10cc of the fuel consumption was noted. For the comparison purpose  the engine test was being conducted for the commercially available gasoline too.
Fuel Calorific Value (kJ/kg) Specific Gravity
Green petrol blend 31 000 0.79
Gasoline 42 000 0.72

Table 1

[00042] Accordingly  the calorific value and specific gravity of the blended fuel was found accurately to be 31 000 kJ/ kg and 0.79 respectively. The engine specifications were noted  and the performance parameter were calculated using standard relations. The Table 1 provides the comparison of the calorific value (kJ/kg) and specific gravity of the blend and the gasoline.
[00043] According to the present invention  the total fuel consumption (TFC)  the specific fuel consumption (SFC)  and the brake thermal efficiency (BE) of the engine are plotted against the brake power (BP) for both the blend and the gasoline as shown in Fig. 2  Fig. 3  and Fig. 4  respectively. Fig.2 and Fig.3 indicate that the blended fuel consumption is more than gasoline for the same BP produced because the blended fuel had lower calorific value.
[00044] According to the present invention  it has been observed  as illustrated in Fig 4  that the BTE of the engine was greater for the blended fuel and this might be due to the higher thermal conductivity of the green petrol.
[00045] Therefore  from the experiments conducted  it can be safely concluded that the green petrol has gasoline like properties  and the characteristic curves obtained by the engine performance using the blended fuel are comparable with that of the gasoline. The blended fuel in fact  is superior to the gasoline for the lower brake power applications. The high calorific value  the high thermal conductivity and the high volatility make the green petrol a promising bio – oil with a potential as a fuel.
[00046] Therefore  according to present invention  the cashew nut shell oil has got a great potential as a biofuel because of its high calorific value and high thermal conductivity  making it a very efficient biofuel.
[00047] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can  by applying current knowledge  readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept  and therefore  such adaptations and modifications should are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore  while the embodiments herein have been described in terms of preferred embodiments  those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.

We Claims:
1. A novel process for the preparation of green petrol from cashew nut shell oil comprising the step of:
subjecting the cashew nut shell oil to distillation and filtrations step to remove the solid and floating impurities;
passing the cashew nut shell oil through activated charcoal;
subjecting the cashew nut shell oil to hydrogenation step;
subjecting the hydrogenated oil to cracking process;
mixing the cracked oil with ethanol in a predetermined proporation  thereby forming blended oil for using as bio-fuel.
2. The novel process of claim 1  wherein said cashew nut shell oil is extracted from cashew nut shell by using any known process.
3. The novel process of claim 1  wherein said mixing the cracked oil with ethanol is performed in the proportion of 1:10.
4. The novel process of claim 1  wherein said hydrogenation step includes adding hydrogen at the double and triple bonds  thereby the multiple bond unsaturated fatty acids get converted into single bond saturated fatty acids.
5. The novel process of claim 4  wherein said hydrogenation is performed at power bomb apparatus at a very high pressure for a period of 7 to 8 hours in the presence of Rany Nickel as a catalyst.
6. The novel process of claim 1  wherein said cracking process includes decomposing in a cracking unit  wherein the cracking unit consisting of fractionating column surrounded by a double surface condenser.
7. The novel process of claim 6  wherein said cracking process is performed at a temperature in the range of 100° to 150° C.