(23 intermediate revisions by 10 users not shown)
Line 1: Line 1:
Vegetable oil can be used as a fuel. This is useful for transportation (use in vehicles), electricity generation (stationary use), ...
[[Plant oil]], which includes [[Pure plant oil|pure plant oil (PPO)]] and [[Waste plant oil|waste plant oil (WPO)]], can be used as a [[biofuel|(bio)fuel]]. PPO is new [[Vegetable fats and oils|plant oil]] whereas WPO is pure plant oil that has already been used for frying food. Plant oil is a very useful fuel as it uses [[plants]] as the source material. Plants are able to gather a huge amount of solar energy at a relatively low cost (due to the numbers in which they occur and the amount of space they can occupy). Note that PPO can be further divided in the ''First-generation'' and ''Second-generation'' fuel type. WPO is always a second-generation fuel.


Diesel engines can be modified to run on straight vegetable oil or waste vegetable oil (used cooking oil). Problems can occur with some engine types when operated for extended periods at idle or low load as vegetable oil does not burn well in these conditions. Suitable engine modifications along with attention to fuel quality, ambient temperatures and operating regime generally avoids these issues.
==Aplications==
Plant oil can be used as a heating or cooking fuel, and for use in piston steam engines, internal combustion engines (diesel), Stirling engines, steam and fuel-powered turbines. By using them in an engine, mechanical work can be provided (ie for transportation purposes, milling of grain, ...), or electricity generation (by adding a [[alternator]] or [[dynamo]]; the device is then called a "generator-set" or gen-set, they are often used for stationary application). Finally, the vegetable oils can be used in generator-sets to generate not only electricity but also heat. Typically, these too are general gensets, and the heat generated is just waste heat from the engine, regardless, due to the smart use of the gensets, the efficiency goes up and these gensets are then called [[Combined heat and power|CHP systems]].


Petrol engines can only be made to run on [[ethanol]]. However, [biodiesel]] may also be used in petrol engines, if mixed with ethanol<ref>[http://biofuel.org.uk/types-of-biofuel.html Petrol engines able to run on ethanol]</ref> {{Fact|That link does not say that biodiesel can be used in gasoline engines... does it?}} Some engines, oil types, and ambient conditions though can cause problems.
==Use in internal combustion engines==
At present, few IC engines are standardly equipped to operate on plant oil, requiring modification of the engine.


Finally, vegetable oils can also be used in [[stirling engine]]s. This is slightly (10%) more efficient. Finally, the vegetable oils can be used in systems generate both heat and power (see [[Combined heat and power]]).
Direct-injection equipped Diesel engines can be modified to run on pure plant oil or waste plant oil (used cooking oil). Problems can however occur with some engine types when operated for extended periods at idle or low load as vegetable oil does not burn well in these conditions. Problems can also occur when running the engine in cold weather. Even regular diesel vehicles have trouble starting when it is very cold, and vegetable oil is thicker than diesel. Vehicles employ various methods to heat up the oil, and vehicles used in cold climates can add extra heaters. One type of heater is called a "hot fox" which can be installed for example in the trunk; it heats up the oil before it gets to the front of the vehicle, where there is another heater that finishes the job before the fuel reaches the fuel injectors.


==Vegetable oil extraction and conversion ==
Suitable engine modifications along with attention to fuel quality, ambient temperatures and operating regime generally avoids these issues.
 
Gasoline engines can only be made to run on [[ethanol]]. However, [[biodiesel]] may also be used in gasoline engines, if mixed with alcohols (ethanol or methanol)<ref>[http://biofuel.org.uk/types-of-biofuel.html Gasoline engines able to run on ethanol]</ref> {{Fact|That link does not say that biodiesel can be used in gasoline engines... does it?}} Some engines, oil types, and ambient conditions though can cause problems.
 
==Conversion of diesel engines ==
{{Main|PPO single tank system}}
{{Main|PPO two tank system}}
 
As stated above, [[Pure_plant_oil_as_fuel|pure plant oil]] can only be used in combination with a diesel engine, and even then, modifications may still need to be done for running on this oil. This is a result of the current use of direct injection systems (as opposed to indirect injection systems which can run on plant oils without modification)<ref>Both 4-stroke and 2-stroke engines with indirect injection allow this, 2-stroke (uniflow) crosshead engines can even run on very low-quality oils</ref>. If the engine used is a gasoline engine, it can only be converted to run on either (very lean/good quality) biodiesel, or alternatively pure [[ethanol]].
 
Vegetable oil is too thick to burn well in the engine unless it is hot. To deal with this problem, some vehicles use a two-tank system: one tank for petrodiesel -or another starting fuel, ie ethanol- and one tank for vegetable oil. The engine is started on petrodiesel (or another starting fuel) and run until it heats up, then the driver switches to the vegetable oil tank. When done driving, the vehicle must be switched back to the petrodiesel tank in order to get the vegetable oil out of the fuel lines. If this is not done, the lines will still be full of vegetable oil when the car is started, and it will be difficult to start. A single tank system can also be used, this system has the advantage that no petrodiesel (or another starting fuel -ie ethanol) needs to be carried in the vehicle, saving weight and thus fuel consumption. Another advantage is the lower complexity (one less tank and a lot of extra lines being eliminated). A downside though is that the engine isn't heated up as well (only the fuel is heated suitably, due to the electric heater in or near the PPO fuel line). Another downside is that the electric heater can not be powered directly from the alternator (a car battery must always be present in the system). 
 
Oil that is not hot enough when it enters the engine will not burn properly and will cause buildup that will damage the engine.
 
[[Waste plant oil]] can also be used in a diesel engine. It must be [[filtered]] and water must be removed before it can be used as fuel, or it will damage the engine.
 
==Plant oil extraction and conversion ==
{{Main|Decentralised pure plant oil fuel production}}
{{Main|Decentralised pure plant oil fuel production}}
{{Main|Vegetable fats and oils}}
{{Main|Plant fats and oils}}
The process of oil extraction is carried out the same way as for extraction of edible oil from plants. There are many crops grown in rural areas of the developing world which are suitable for oil production. Most of these have high energy contents; sunflower oil, for example, has an energy content of about 85% of that of diesel fuel.
The process of oil extraction is carried out the same way as for extraction of edible oil from plants. There are many crops grown in rural areas of the developing world which are suitable for oil production. Most of these have high energy contents; sunflower oil, for example, has an energy content of about 85% of that of diesel fuel.


Line 17: Line 35:


The oil, as well as being used for lighting and heating, can be used as a fuel in internal combustion engines.
The oil, as well as being used for lighting and heating, can be used as a fuel in internal combustion engines.
Biodiesel production is not complex and can be done on a small scale. The vegetable oil is converted to a useable fuel by adding ethanol or methanol alcohol along with a catalyst to improve the reaction. Small amounts of potassium hydroxide or sodium hydroxide (commonly called lye or caustic soda, which is used in soapmaking) are used as the catalyst material. Glycerine separates out as the reaction takes place and sinks to the bottom of the container. This removes the component that gums up the engine so that a standard diesel engine can be used. The glycerine can be used as a degreasing soap or refined to make other products.


{{content from|Original:Biogas and liquid biofuels|Practical Action}}
{{content from|Original:Biogas and liquid biofuels|Practical Action}}


==Advantages==
==Advantages and disadvantages==
Biofuels are not made from petroleum; not purchasing petroleum products allows you to avoid supporting business practices such as oil drilling that are harmful to the environment and human rights.
Biofuel is arelatively easy and cheap fuel. This, as the extraction of the fuel from the plants is easy and the fuel can also be stored for a long time<ref>How long ?</ref> without requiring complex or expensive storage methods.
 
Waste cooking oil is discarded by restaurants and other businesses and can be obtained for free or very cheap. This allows you to recycle something that would otherwise go to waste.  Since the vegetable oil is not produced in respond to an economic demand for fuel, using it is [[Wikipedia:carbon neutral|carbon neutral]].
 
==Conversion of the engine ==
As stated above, pure vegetable oil can also be used in a diesel engine, and even then, modifications may still need to be done for running on pure vegetable oil. If the engine used is a petrol engine, it can only be converted to run on either (very lean/good quality) biodiesel, or alternatively pure [[ethanol]].
 
Vegetable oil is too thick to burn well in the engine unless it is hot.  To deal with this problem, some vehicles use a two-tank system: one tank for biodiesel or petrodiesel, and one for vegetable oil.  The engine is started on diesel and run until it heats up, then the driver switches to the vegetable oil tank.  When done driving, the vehicle must be switched back to the diesel tank in order to get the vegetable oil out of the fuel lines; otherwise, the lines will still be full of vegetable oil when the car is next started, and it will be difficult to start.  


Oil that is not hot enough when it enters the engine will not burn properly and will cause buildup that will damage the engine.
Since waste plant oil (both WPO and PPO from crops intented for human consumption) is not produced in respond to an economic demand for fuel, using it is [[Wikipedia:carbon neutral|carbon neutral]]. Plant oils that are produced especially for use as a fuel (PPO from crops also useful for human consumption) are less ecological, yet are still closed-end recycled since the CO<sub>2</sub> that is emitted is sucked up by the next year's oil crops. In addition, crops that produce this PPO [[Biofuel#Biomass_energy_and_the_environment|may still be more beneficial for the environment than were it not grown]], depending on the location where the crop is grown and the vegetation that existed on this location.  


[[Waste vegetable oil]] must be [[filtered]] and water must be removed before it can be used as fuel, or it will damage the engine.
The pollution from PPO is not as well studied as that of biodiesel, but it is thought to be similar to biodiesel -and much less than [[petrodiesel]] pollution-. The [http://www.folkecenter.dk/plant-oil/publications/PPO-emissions.htm Danish Center for Plant Oil Technology] has some interesting figures comparing rapeseed (Canola) oil and diesel fuel: 42% lower carbon monoxide, 63% lower unburned hydrocarbons, 19% lower nitrogen oxides, and 42% lower particulates. Cleaned WVO should have the same pollution charisteristics as PPO coming from the same crops.  


===Two-tank system===
Depending on the source of the oil, PPO and WPO it has more or less the same energy content as petrodiesel and more energy than biodiesel. This can be noticeable on under-powered vehicles. <ref>Portions (cc) [http://www.aum.ca/seeds/ S.E.E.D.S.] under [http://creativecommons.org/ Creative Commons]</ref>
Processes for converting to vegetable oil vary.  One process is outlined below. 
 
In the two-tank system, the following modifications are made:
*A second gas tank is added; this can be a purchased gas tank or another receptacle that can hold fuel, such as a bucket. 
*The new tank is installed somewhere on the vehicle, e.g. in the trunk.
*A valve is installed that allows the driver to switch from one tank to the other.  It uses electricity from the vehicle's battery, and a switch is installed in the vehicle that the driver can switch. 
*An extra fuel filter is installed in the vehicle to filter particles and water out of the vegetable oil. Hoses can be spliced from the coolant system and run to this filter; this brings hot coolant to the filter and heats it up, in order to get the oil hotter.
*Fuel lines are run from the tank that will hold diesel to the valve that allows switching between tanks.
*Fuel lines are run from the tank that will hold vegetable oil to the new filter, and from there to the valve that allows switching between tanks.
*A heater is installed near the fuel injectors to ensure that oil is as hot as possible before it enters the engine.
*Fuel lines are run from the valve to the vehicle's fuel pump, then to the heater, then to the fuel injectors.
*Return lines are added that return unused diesel to the diesel tank.
*A buzzer is installed that sounds when the vehicle is turned off and the tank is still set to vegetable oil. This warns the driver that they forgot to purge vegetable oil from the fuel lines and the vehicle may not start next time. When this happens, the driver turns the vehicle back on (possible since the engine is still hot) and switches to the diesel tank and runs it long enough to replace the oil in the fuel lines with diesel.


==See also==
==See also==
* [[Pure plant oil as fuel]]
* [[Pure plant oil as fuel]]
==References==
{{reflist}}
*Tickell, J., Teickell, K., From the Fryer to the Fuel Tank: The Complete Guide to Using Vegetable Oil as an Alternative Fuel, Greenteach Publishing, 1999.
* [http://www.builditsolar.com/Projects/BioFuel/biofuels.htm Collection of fossil to biofuel conversion projects by BuilditSolar]


== External links ==
== External links ==
*[http://www.green-trust.org/freebooks/ DIY Diesel to veggie oil conversion e-books]
*[http://voconversionbasics.websitetoolbox.com/ Several plans and info on vegoil conversions, site made by Dana Linscott]
*[[Biogas and liquid biofuels (original)]]
*[[Biogas and liquid biofuels (original)]]
*[[Making Biodiesel]]
*[[Making Biodiesel]]
Line 61: Line 64:
*[http://biodiesel.infopop.cc/eve/ubb.x/a/tpc/f/159605551/m/347104314 10 steps to converting to wvo...the basic process]
*[http://biodiesel.infopop.cc/eve/ubb.x/a/tpc/f/159605551/m/347104314 10 steps to converting to wvo...the basic process]
*[http://www.biotuning.co.uk/Background.htm]
*[http://www.biotuning.co.uk/Background.htm]
<references/>


[[Category:Transport]]
[[Category:Transport]]
[[Category:Biofuel]]
[[Category:Biofuel]]
[[Category:Vegetable oils]]
[[Category:Vegetable oils]]

Revision as of 07:01, 11 July 2013

Plant oil, which includes pure plant oil (PPO) and waste plant oil (WPO), can be used as a (bio)fuel. PPO is new plant oil whereas WPO is pure plant oil that has already been used for frying food. Plant oil is a very useful fuel as it uses plants as the source material. Plants are able to gather a huge amount of solar energy at a relatively low cost (due to the numbers in which they occur and the amount of space they can occupy). Note that PPO can be further divided in the First-generation and Second-generation fuel type. WPO is always a second-generation fuel.

Aplications

Plant oil can be used as a heating or cooking fuel, and for use in piston steam engines, internal combustion engines (diesel), Stirling engines, steam and fuel-powered turbines. By using them in an engine, mechanical work can be provided (ie for transportation purposes, milling of grain, ...), or electricity generation (by adding a alternator or dynamo; the device is then called a "generator-set" or gen-set, they are often used for stationary application). Finally, the vegetable oils can be used in generator-sets to generate not only electricity but also heat. Typically, these too are general gensets, and the heat generated is just waste heat from the engine, regardless, due to the smart use of the gensets, the efficiency goes up and these gensets are then called CHP systems.

Use in internal combustion engines

At present, few IC engines are standardly equipped to operate on plant oil, requiring modification of the engine.

Direct-injection equipped Diesel engines can be modified to run on pure plant oil or waste plant oil (used cooking oil). Problems can however occur with some engine types when operated for extended periods at idle or low load as vegetable oil does not burn well in these conditions. Problems can also occur when running the engine in cold weather. Even regular diesel vehicles have trouble starting when it is very cold, and vegetable oil is thicker than diesel. Vehicles employ various methods to heat up the oil, and vehicles used in cold climates can add extra heaters. One type of heater is called a "hot fox" which can be installed for example in the trunk; it heats up the oil before it gets to the front of the vehicle, where there is another heater that finishes the job before the fuel reaches the fuel injectors.

Suitable engine modifications along with attention to fuel quality, ambient temperatures and operating regime generally avoids these issues.

Gasoline engines can only be made to run on ethanol. However, biodiesel may also be used in gasoline engines, if mixed with alcohols (ethanol or methanol)[1] [verification needed] Some engines, oil types, and ambient conditions though can cause problems.

Conversion of diesel engines

As stated above, pure plant oil can only be used in combination with a diesel engine, and even then, modifications may still need to be done for running on this oil. This is a result of the current use of direct injection systems (as opposed to indirect injection systems which can run on plant oils without modification)[2]. If the engine used is a gasoline engine, it can only be converted to run on either (very lean/good quality) biodiesel, or alternatively pure ethanol.

Vegetable oil is too thick to burn well in the engine unless it is hot. To deal with this problem, some vehicles use a two-tank system: one tank for petrodiesel -or another starting fuel, ie ethanol- and one tank for vegetable oil. The engine is started on petrodiesel (or another starting fuel) and run until it heats up, then the driver switches to the vegetable oil tank. When done driving, the vehicle must be switched back to the petrodiesel tank in order to get the vegetable oil out of the fuel lines. If this is not done, the lines will still be full of vegetable oil when the car is started, and it will be difficult to start. A single tank system can also be used, this system has the advantage that no petrodiesel (or another starting fuel -ie ethanol) needs to be carried in the vehicle, saving weight and thus fuel consumption. Another advantage is the lower complexity (one less tank and a lot of extra lines being eliminated). A downside though is that the engine isn't heated up as well (only the fuel is heated suitably, due to the electric heater in or near the PPO fuel line). Another downside is that the electric heater can not be powered directly from the alternator (a car battery must always be present in the system).

Oil that is not hot enough when it enters the engine will not burn properly and will cause buildup that will damage the engine.

Waste plant oil can also be used in a diesel engine. It must be filtered and water must be removed before it can be used as fuel, or it will damage the engine.

Plant oil extraction and conversion

The process of oil extraction is carried out the same way as for extraction of edible oil from plants. There are many crops grown in rural areas of the developing world which are suitable for oil production. Most of these have high energy contents; sunflower oil, for example, has an energy content of about 85% of that of diesel fuel.

There are two well-established technologies for oil extraction:

  • The simple screw press, which is a device for physically extracting the oil from the plant - this technology is well suited to small-scale production of oil as fuel or as foodstuff in rural areas. The press can be motorised or hand-operated.
  • Solvent extraction is a chemical process which requires large, sophisticated equipment. This method is more efficient - that is, it extracts a greater percentage of the oil from the plant - but is less suited to rural applications.

The oil, as well as being used for lighting and heating, can be used as a fuel in internal combustion engines.

Template:Content from

Advantages and disadvantages

Biofuel is arelatively easy and cheap fuel. This, as the extraction of the fuel from the plants is easy and the fuel can also be stored for a long time[3] without requiring complex or expensive storage methods.

Since waste plant oil (both WPO and PPO from crops intented for human consumption) is not produced in respond to an economic demand for fuel, using it is carbon neutral. Plant oils that are produced especially for use as a fuel (PPO from crops also useful for human consumption) are less ecological, yet are still closed-end recycled since the CO2 that is emitted is sucked up by the next year's oil crops. In addition, crops that produce this PPO may still be more beneficial for the environment than were it not grown, depending on the location where the crop is grown and the vegetation that existed on this location.

The pollution from PPO is not as well studied as that of biodiesel, but it is thought to be similar to biodiesel -and much less than petrodiesel pollution-. The Danish Center for Plant Oil Technology has some interesting figures comparing rapeseed (Canola) oil and diesel fuel: 42% lower carbon monoxide, 63% lower unburned hydrocarbons, 19% lower nitrogen oxides, and 42% lower particulates. Cleaned WVO should have the same pollution charisteristics as PPO coming from the same crops.

Depending on the source of the oil, PPO and WPO it has more or less the same energy content as petrodiesel and more energy than biodiesel. This can be noticeable on under-powered vehicles. [4]

See also

References

Template:Reflist

External links

  1. Gasoline engines able to run on ethanol
  2. Both 4-stroke and 2-stroke engines with indirect injection allow this, 2-stroke (uniflow) crosshead engines can even run on very low-quality oils
  3. How long ?
  4. Portions (cc) S.E.E.D.S. under Creative Commons
Cookies help us deliver our services. By using our services, you agree to our use of cookies.