c© ARISER Vol. 4 No. 4 (2008) 227-231Engineering: Re En

Arab Research Institute in Sciences & Engineeringhttp://www.arabrise.org

Online Publishing Group ISSN 1994-3253

New Concept of Bio-Diesel in Six Stroke EnginesA Review

M.K.PASWAN1, PAUL SAYAN2, J. RAJATH2 and Y. KARUN1

1Department of Mechanical Engineering, NIT, Jamshedpur, INDIA2Department of Production and Industrial Engineering, NIT, Jamshedpur, INDIA

{mkpaswan 1@rediffmail.com; sayanpaul14@gmail.com; rajath.jaysankar@gmail.com; engg87@gmail.com}

Received 26 November 2008; Accepted 20 December 2008

Conventional fuels are depleting day by day as they are limited reserves. These finite reserves are highlyconcentrated in certain regions of the world. The increasing industrialization and motorization in the worldhas led to a steep rise on the demand of petroleum-based fuels. Therefore, countries not having theseresources are facing energy/foreign exchange crisis, mainly due to the import of crude petroleum. Hence,it is necessary to look for alternative fuels which can be produced from resources available locally withinthe country such as Jatropha alcohol, biodiesel, vegetable oils, etc. This paper reviews the production,characterization and current status of jatropha oil and biodiesel as well as the experimental research workcarried out in various countries.Internal combustion engines are basically four stroke engines and generatea considerable amount of power. But the problem with these engines is that they generate only 40-50%of the energy and the rest is lost in various forms. Since these engines use non renewable fuels such aspetrol or diesel, and since the depletion of these resources is a growing concern in the modern day, it hasbecome mandatory to find alternative sources or fuel, or at least, change the design of the engine in such away so as to get maximum possible efficiency. This paper talks about a two pronged approach in tacklingthis problem. Firstly, we plan to introduce biofuels instead of the conventional non renewable fuels, andsecondly, we plan to convert four stroke engines into a six stroke ones so as to increase efficiency.

Contents

1 A Comparative Study Between Fossil FuelsAnd Bio-Fuels . . . . . . . . . . . . . . . . 227

2 Six Stroke Engine . . . . . . . . . . . . . . 2283 Engine Types . . . . . . . . . . . . . . . . 229

3.1 Griffin six stroke engine . . . . . . . 229

3.2 Bajulaz six stroke engine . . . . . . . 2293.3 Velozeta six-stroke engine . . . . . . 2303.4 Crower six stroke engine . . . . . . . 2303.5 Beare Head . . . . . . . . . . . . . . 2303.6 Charge pump engine . . . . . . . . . 230

4 Six Stroke Engine Using Jatropha Oil . . . 2315 Conclusion . . . . . . . . . . . . . . . . . 231

1 A Comparative Study Between Fossil Fuels And Bio-Fuels

The fossil fuel, no doubt, is one of the most useful and efficient resources in modern day living. It produces veryhigh calorific values during combustion and is used by people everywhere. During the fractional distillation of thisfuel, a number of products are produced which are used widely around the world in various walks of life. But, itis quite obvious that disadvantages of these fossil fuels outnumber their advantages. It is common knowledge thatair pollution and the resulting greenhouse gas emissions have taken a toll on the health of the planet. Vehicularemissions, in particular, have led to major environmental disasters since non-renewable fuels contain atmosphericpollutants like nitrogen oxides, hydrocarbons, carbon monoxide, sulfur oxides, lead, and so on. Many nationsin the world rely on imports to meet their soaring fuel requirements. This dependence can be reduced with asecure supply of fuel and, if possible, clean fuel. Hence, it is necessary to look for alternative fuels which can beproduced from resources available locally within the country. Biodiesel is a renewable, inexhaustible and a cleanfuel. Biodiesel is methyl or ethyl ester of fatty acid made from virgin or used vegetable oils (both edible and non-edible) and animal fat. The main resources for biodiesel production can be non-edible oils obtained from plantspecies such as Jatropha Curcas (Ratanjyot), Pongamia pinnata (Karanj), Calophyllum inophyllum (Nagchampa),Hevca brasiliensis (Rubber) etc. It can be stored just like mineral diesel and hence does not require separate

228 M.K. Paswan et al.

infrastructure. The use of biodiesel in conventional diesel engines results in substantial reduction in emission ofunburned hydrocarbons, carbon monoxide and particulate. In the present work non-edible Jatropha Curcas oil ischosen as a fuel for investigation. It is popularly known as physic nut in some parts of the world.

Jatropha Curcas is a wild shrub, which grows in hostile conditions like infertile soil; is not grazed upon byanimals; and yields sulfur free, non-polluting biofuel. Jatropha’s use for production of biofuel is an exercise im-plementing sustainable solutions. It is a non-toxic, 100% natural, biodegradable supplement for diesel. Excited bythe possibility of its wide-scale use in transport, electrical equipment, and other machines that run on petroleumor diesel, Jatropha is being studied in many countries. Jatropha Curcas is viewed as the new solution for vehicularpollution. It produces seeds containing up to 40% oil, which can be processed to produce a high-quality biodieselfuel, usable in a standard diesel engine, while, the residue can also be processed into biomass to power electric-ity plants. Biodiesel produced from Jatropha Curcas oil meets all the requirements stipulated by the EU-StandardEN-14214.

oils (both edible and non-edible) and animal fat. The main resources for biodiesel production can be non-edible oils obtained from plant species such as Jatropha Curcas (Ratanjyot), Pongamia pinnata (Karanj), Calophyllum inophyllum (Nagchampa), Hevca brasiliensis (Rubber) etc. It can be stored just like mineral diesel and hence does not require separate infrastructure. The use of biodiesel in conventional diesel engines results in substantial reduction in emission of unburned hydrocarbons, carbon monoxide and particulate. In the present work non-edible Jatropha Curcas oil is chosen as a fuel for investigation. It is popularly known as physic nut in some parts of the world. Jatropha Curcas is a wild shrub, which grows in hostile conditions like infertile soil; is not grazed upon by animals; and yields sulfur free, non-polluting biofuel. Jatropha’s use for production of biofuel is an exercise implementing sustainable solutions. It is a non-toxic, 100% natural, biodegradable supplement for diesel. Excited by the possibility of its wide-scale use in transport, electrical equipment, and other machines that run on petroleum or diesel, Jatropha is being studied in many countries. Jatropha Curcas is viewed as the new solution for vehicular pollution. It produces seeds containing up to 40% oil, which can be processed to produce a high-quality biodiesel fuel, usable in a standard diesel engine, while, the residue can also be processed into biomass to power electricity plants. Biodiesel produced from Jatropha Curcas oil meets all the requirements stipulated by the EU-Standard EN-14214.

Advantages • It can be grown almost anywhere - even in sandy, saline, or otherwise infertile soil • It costs almost nothing to grow • It is drought resistant • It is easy to propagate (a cutting simply pushed into the ground will take root) • It stabilizes sand dunes, acts as a windbreak, and combats desertification • It grows quickly and establishes itself easily

Advantages– It can be grown almost anywhere - even in sandy, saline, or otherwise infertile soil– It costs almost nothing to grow– It is drought resistant– It is easy to propagate (a cutting simply pushed into the ground will take root)– It stabilizes sand dunes, acts as a windbreak, and combats desertification– It grows quickly and establishes itself easily– It does not exhaust the nutrients in the land– It is frost hardy (does not like hard freezes)– It naturally repels both animals and insects– It lives for over 50 years producing seeds all the time– It does not require fertilizers– It has a high yield (oil content of the seed is 30-35%)– No displacement of food crops is necessary– It is great for developing countries in terms of energy and jobs– The waste plant mass after oil extraction can be used as a fertilizer

New Concept of Bio-Diesel in Six Stroke Engines A Review 229

2 Six Stroke Engine

The term six stroke engine describes two different approaches in the internal combustion engine, developed sincethe 1990s, to improve its efficiency and reduce emissions: In the first approach, the engine captures the usuallywasted heat from the four stroke Otto cycle or Diesel cycle and uses it to power an additional power and exhauststroke of the piston in the same cylinder. Designs of such an engine either use steam or air as the working fluidfor the additional power stroke. This not only helps increase the power extracted but also cools the engine andeliminates the need for using a cooling system making the engine lighter and hence increasing the efficiency overthe normal Otto or diesel cycle. The piston in such a six stroke engine undergoes reciprocating motion six times forevery injection of fuel. These six stroke engines have 2 power strokes: one due to the fuel and one due to the steamor air. The currently notable six stroke engine designs in this class are the Crower’s six stroke engine, inventedby Bruce Crower of the U.S. ; the Bajulaz engine by the Bajulaz S A company, of Switzerland; and the VelozetaSix-stroke engine built by the College of Engineering, at Trivandrum in India.

3 Engine Types

3.1 Griffin six stroke engine

In 1883, the Bath-based engineer Samuel Griffin was an established maker of steam and gas engines. He wished toproduce an internal combustion engine, but without paying the licensing costs of the Otto patents. His solution wasto develop a ’Patent slide valve’ and a single-acting six-stroke engine using it. By 1886, Scottish steam locomotivemaker Dick, Kerr & Co. saw a future in large oil engines and licensed the Griffin patents. These were double acting,tandem engines and sold under the name ”Kilmarnock”. A major market for the Griffin engine was in electricitygeneration, where they developed a reputation for running light for long periods, then suddenly being able to takeup a large demand for power. Their large heavy construction didn’t suit them to mobile use, but they were capableof burning heavier and cheaper grades of oil. The key principle of the ”Griffin Simplex” was a heated exhaust-jacketed external vaporizer, into which the fuel was sprayed. The temperature was held around 550 ◦F (288 ◦C),sufficient to physically vaporize the oil but not to break it down chemically. This fractional distillation supportedthe use of heavy oil fuels, the unusable tars and asphalts separating out in the vaporizer. Hot bulb ignition wasused, which Griffin termed the ’Catathermic Igniter’, a small isolated cavity connected to the combustion chamber.The spray injector had an adjustable inner nozzle for the air supply, surrounded by an annular casing for the oil,both oil and air entering at 20 lbs sq in pressure, and being regulated by a governor. Griffin went out of business in1923.

Only two known examples of a Griffin six-stroke engine survive. One is in the Anson engine museum. Theother was built in 1885 and for some years was in the Birmingham Museum of Science and Technology, but in2007 it returned to Bath and the Museum of Bath at Work.

3.2 Bajulaz six stroke engine

The Bajulaz six stroke engine is similar to a regular combustion engine in design. There is however modifications tothe cylinder head, with two supplementary fixed capacity chambers: a combustion chamber and an air preheatingchamber above each cylinder. The combustion chamber receives a charge of heated air from the cylinder; theinjection of fuel begins an isochoric burn which increases the thermal efficiency compared to a burn in the cylinder.The high pressure achieved is then released into the cylinder to work the power or expansion stroke. Meanwhile asecond chamber which blankets the combustion chamber has its air content heated to a high degree by heat passingthrough the cylinder wall. This heated and pressurized air is then used to power an additional stroke of the piston.

The advantages of the engine include reduction in fuel consumption by at least 40%, two expansion strokes insix strokes, multi-fuel usage capability, and a dramatic reduction in pollution.

The Bajulaz Six Stroke Engine was invented in 1989 by the Bajulaz S A company, based in Geneva, Switzer-land; it has U.S. Patent 4,809,511 and U.S. Patent 4,513,568 .

The Bajulaz six stroke engine features:– Reduction in fuel consumption by at least 40%– Two expansion (work) strokes in six strokes– Multi fuel, including liquefied petroleum gas– Dramatic reduction in air pollution– Costs comparable to those of a four-stroke engine

230 M.K. Paswan et al.

3.3 Velozeta six-stroke engine

In a Velozeta engine, during the exhaust stroke, fresh air is injected into the cylinder, which expands by heat andtherefore forces the piston down for an additional stroke. The valve overlaps have been removed and the twoadditional strokes using air injection provide for better gas scavenging. The engine seems to show 40% reductionin fuel consumption and dramatic reduction in air pollution. Its specific power is not less than that of a four-strokepetrol engine. The engine can run on a variety of fuels, ranging from petrol and diesel to LPG. An altered engineshows a 65% reduction in carbon monoxide pollution when compared with the four stroke engine from which itwas developed.

The Velozeta engine features are:– Reduction in fuel consumption– Dramatic reduction in pollution– Better scavenging and more extraction of work per cycle– Lower working temperature makes it easy to maintain optimum engine temperature level for better perfor-

mance– The six-stroke engine does not require significant modification to existing engines.– Better cooling due to additional air strokes, which mostly removes the need for a cooling system– Lighter engine

This six-stroke engine was developed by the students of College of Engineering, Trivandrum in India. TheEngineering students have been awarded the ’Indian Society for Technical Education - National awarded’ for BestB. Tech project of 2006. (ISTE/BBSBEC-B.Tech./Award/2006).The technology is being developed by Velozeta, aTechno park (Trivandrum) supported by the National Institute of Technology based in Calicut. Velozeta has beenawarded a Phase-I research grant from the Department of Scientific & Industrial Research (Govt. of India) underthe Technopreneur Promotion Programme (TePP).

3.4 Crower six stroke engine

In a six-stroke engine developed in the U.S. by Bruce Crower, fresh water is injected into the cylinder after theexhaust stroke, and is quickly turned to superheated steam, which causes the water to expand to 1600 times itsvolume and forces the piston down for an additional stroke {Avinash Kumar Agarwal [9]}. This design also claimsto reduce fuel consumption by 40%.

The Crower six stroke engines was invented in 2004 by 75 year old American inventor Bruce Crower who hasapplied for a patent on a design involving fresh water injection into the cylinders. As of May 2008, no patent hasbeen awarded. Mr. Dyer invented the first six-stroke internal combustion water injection engine in 1915, which isvery similar to Crower’s design. Crower’s six stroke engine features:

– No cooling system required– Improves a typical engine’s fuel consumption– Requires a supply of distilled water to act as the medium for the second power stroke.

3.5 Beare Head

The term ”Six Stroke” was coined by the inventor of the Beare Head, Malcolm Beare. The technology combines afour stroke engine bottom end with an opposed piston in the cylinder head working at half the cyclical rate of thebottom piston. Functionally, the second piston replaces the valve mechanism of a conventional engine.

3.6 Charge pump engine

In this engine, similar in design to the Beare head, a ”piston charger” replaces the valve system. The piston chargercharges the main cylinder and simultaneously regulates the inlet and the outlet aperture leading to no loss of airand fuel in the exhaust. In the main cylinder, combustion takes place every turn as in a two-stroke engine andlubrication as in a four-stroke engine. Fuel injection can take place in the piston charger, in the gas transfer channelor in the combustion chamber. It is also possible to charge two working cylinders with one piston charger. Thecombination of compact design for the combustion chamber together with no loss of air and fuel is claimed to givethe engine more torque, more power and better fuel consumption. The benefit of less moving parts and design is

New Concept of Bio-Diesel in Six Stroke Engines A Review 231

claimed to lead to lower manufacturing costs. The engine is claimed to be suited to alternative fuels since there isno corrosion or deposits left on valves. The six strokes are: aspiration, pre-compression, gas transfer, compression,ignition and ejection.

claimed to be suited to alternative fuels since there is no corrosion or deposits left on valves. The six strokes are: aspiration, pre-compression, gas transfer, compression, ignition and ejection. Problems and potential solutions for using vegetable oils as engine fuels

Problem Probable cause Potential solution

Short-term

1. Cold weather starting

High viscosity, low cetane, and low flash point of vegetable oils

Preheat fuel prior to injection. Chemically alter fuel to an ester

2.Plugging and gumming of filters, lines and injectors

Natural gums (phosphatides) in vegetable oil. Ash.

Partially refine the oil to remove gums. Filter to 4 microns

3. Engine knocking Very low cetane of some oils. Improper injection timing.

Adjust injection timing. Preheat fuel prior to injection. Chemically alter fuel to an ester

Long-term

4. Coking of injectors and carbon deposits on piston and head of engine

High viscosity of vegetable oil, incomplete combustion of fuel. Poor combustion at part load.

Heat fuel prior to injection. Switch engine to diesel when operating at part load. Chemically alter the vegetable oil to an ester.

5. Excessive engine wear

High viscosity, incomplete combustion of fuel. Poor combustion at part load. Possibly free fatty acids in vegetable oil. Dilution of engine lubricating oil due to blow-by of vegetable oil.

Heat fuel prior to injection. Switch engine to diesel when operating at part load. Chemically alter the vegetable oil to an ester. Increase lubricating oil changes. Lubricating oil additives to inhibit oxidation.

6. Failure of engine lubricating oil due to polymerization

Collection of poly-unsaturated vegetable oil blow-by in crank-case to the point where polymerization occurs

Same as in 5.

SIX STROKE ENGINE USING JATROPHA OIL Jatropha curcas has been used in four stroke engines effectively in many places. But our work is going to be the first time that the bio-diesel from Jatropha curcas is going to be tried out in six stroke engines in order to get a holistic improvement in efficiency. This six stroke engine is based on the principle of crower’s six stroke engine of using steam for the 2nd power stroke. The six stroke engine as such improves engine’s efficiency and the bio-diesel helps address the growing concern about loss of non renewable fuel. The advantages • Two power strokes in six strokes, multi-fuel usage capability • Reduction in fuel consumption by at least 40%. • Dramatic reduction in pollution as we are using, Jatropha oil: A promising, clean

4 Six Stroke Engine Using Jatropha Oil

Jatropha curcas has been used in four stroke engines effectively in many places. But our work is going to be thefirst time that the bio-diesel from Jatropha curcas is going to be tried out in six stroke engines in order to get aholistic improvement in efficiency. This six stroke engine is based on the principle of crower’s six stroke engine ofusing steam for the 2nd power stroke. The six stroke engine as such improves engine’s efficiency and the bio-dieselhelps address the growing concern about loss of non renewable fuel.The advantages

– Two power strokes in six strokes, multi-fuel usage capability– Reduction in fuel consumption by at least 40%.– Dramatic reduction in pollution as we are using, Jatropha oil: A promising, clean alternative energy– Better scavenging and more extraction of work per cycle– Lower working temperature makes it easy to maintain optimum engine temperature level for better perfor-

mance– The six-stroke engine does not require significant modification to existing engines.– No cooling system required– Improves a typical engine’s fuel consumption.– Besides providing power, the additional stroke cools the engine and removes the need for a cooling system

making the engine lighter and giving 40% increased efficiency over the normal Otto cycle or Diesel cycle.

5 Conclusion

If all the internal combustion engines are run using the above two pronged approach, the pollution levels arereduced considerably and the non-renewable resources are given enough time for their replenishment. Hence,biodiesel may be considered as diesel fuel substitutes.

232 M.K. Paswan et al.

The use of biofuels as internal combustion engines fuels can play a vital role in helping the developed anddeveloping countries to reduce the environmental impact of fossil fuels. Biodiesel has become more attractiverecently because of its environmental benefits and the fact that it is made from renewable resources.

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