| 
  • If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • You already know Dokkio is an AI-powered assistant to organize & manage your digital files & messages. Very soon, Dokkio will support Outlook as well as One Drive. Check it out today!

View
 

IS4D: Energy

This version was saved 11 years, 4 months ago View current version     Page history
Saved by editor
on November 25, 2012 at 12:41:04 pm
 

 


 

Biodiesel

 

NAEF: Biodiesel: A guide for policy maker and enthusiasts

 

Introduction

 

Biodiesel is a cleaner burning alternative fuel produced from renewable vegetable oil resources such as soy beans, palm and waste vegetable oil (cooking oil) or any other source of organic oil (animal fat). Biodiesel is
suitable for modern, high performance diesel engines. Biodiesel contains no petroleum product but can be blended with petroleum diesel to create a biodiesel blend. This type of fuel is gaining popularity not only due to its environmental advantages but also because of how easy it is to use as it can be used in current compression-ignition (diesel) engines with little or no modifications. Biodiesel is not only easy to use; it is biodegradable, nontoxic and free of sulfur and aromatics. Replacing conventional diesel with biodiesel in engines results in considerable reduction of unburned hydrocarbons, carbon monoxide, and particulate matter. Moreover, with flash point over 260˚F (127 ˚C), biodiesel is safer to handle and to store than
petroleum based diesel fuel, which has a flashpoint of around 125˚F (52˚C). Biodiesel is defined as the mono-alkyl esters of fatty acids derived from vegetable oils or animal fats. In more general terms, biodiesel is the product you get when a vegetable oil or animal fat is chemically reacted with an alcohol to produce a new compound that is known as a fatty acid alkyl ester. A catalyst such as sodium or potassium hydroxide is required. Glycerol (glycerin) is produced as a byproduct. The process is known as transesterification.
Soybean oil and methanol are the most popular feedstock in the United States. Soybeans are a major U.S. crop and government subsidies/reduced taxes are available to make the fuel economically attractive to consumers who need or want to use a non-petroleum based fuel. In Europe, most biodiesel is made from
rapeseed (Brassica napus) oil and methanol and it is known as rapeseed methyl esters (RME).

 

Advantages of Biodiesel

 

Biodiesel has some clear advantages over SVO: it works in any diesel, without any conversion or modifications to the engine or the fuel system -- just put it in and go. It also has better cold-weather properties than SVO (but not as good as petro-diesel). Unlike SVO, it's backed by many long-term tests in many countries, including millions of miles on the road. It has as well many advantages over petro-diesel.

 

  • Biodiesel substantially reduces unburned hydrocarbons, carbon monoxide and particulate matter in exhaust fumes
  • Sulphur dioxide emissions are eliminated (biodiesel contains no sulphur)
  • Biodiesel is plant-based and adds no CO2 to the atmosphere. As a sustainable energy source it merely recycles carbon, with the help of the sun and photosynthesis.
  • The ozone-forming potential of biodiesel emissions is nearly 50% less than conventional diesel fuel
  • Nitrogen oxide (NOx) emissions could slightly increase but can be reduced to well below conventional diesel fuel levels by adjusting engine timing and other means
  • Biodiesel can be used in any diesel engine
  • Fuel economy is about the same as conventional diesel fuel
  • Biodiesel has a high cetane rating, which improves engine performance: 20% biodiesel added to conventional diesel fuel improves the cetane rating 3 points, making it a Premium fuel
  • Biodiesel can be mixed with ordinary petroleum diesel fuel in any proportion, with no need for a mixing additive.
  • Even a small amount of biodiesel means cleaner emissions and better engine lubrication
  • Biodiesel can be produced from any fat or vegetable oil, including waste cooking oil.

 

See the US National Biodiesel Board's complete evaluation of biodiesel emissions and potential health effects at  http://www.biodiesel.org/pdf_files/fuelfactsheets/emissions.pdf

 

The process of making biodiesel

 

Biodiesel can be made following various but similar processes. A simple process is to use vegetable oil, methanol and sodium hydroxide.  Again in general terms vegetable and animal fats and oils are triglycerides, containing glycerine. The biodiesel process turns the oils and fats into esters, separating out the glycerine. The glycerine sinks to the bottom and the biodiesel floats on top and can be syphoned off.  The process is called transesterification, which substitutes alcohol for the glycerine in a chemical reaction, using a catalyst. The result is usually a 90% biodiesel and 10% glycerine.

 

In Short -

  • The oil is heated to about 50 degrees Centigrade.
  • In a separate container you slowly (to prevent unstable reaction/heating) mix the methanol and the sodium hydroxide (NaOH).
  • Next this solution is added (again slowly) to the heated oil and mixed and is then allowed to settle.
  • By gravitation the glycerol will settle at the bottom of the tank and above you will have the biodiesel.

 

Jatropha curcus L. (Physic nut)

 

The main “ingredient” to produce biodiesel is organic oil either vegetable or animal (fat). Vegetable fats and oils are substances derived from plants that are composed of triglycerides. Nominally, oils are liquid at room temperature, and fats are solid. Although many different parts of plants may yield oil, in actual commercial practice oil is extracted primarily from the seeds of oilseed plants. There are many types of commercial and wild plants that can produce oil (oil plant) depending on the specific region. Jatropha curcus, castor, pongamia pinnata (Indian beech tree), rapeseed, sunflower, palm tree, etc… Jatropha curcus have been the choice in many countries while Indonesia and Malaysia prefers mainly palm trees. The genus Jatropha belongs to genus  Joannesieae of Crotonoideae in the Euphorbiaceae family and contains approximately 170 known species. According to Correll and Correll (1982) and Heller (1994), curcas is the common name for physic nut in Malabar, India.  

The physic nut is a drought-resistant species which is widely spread by the Portuguese in colonial times and is currently cultivated throughout the tropics as a living fence.  Many parts of the plants are used in traditional medicine.  The seeds, however, are toxic to humans and many animals.  Considerable amounts of physic nut seeds were produced on Cape Verde during the first half of this century, and this constituted an important contribution to the country’s economy.  Seeds were exported to Lisbon and Marseille for oil extraction and soap production.  Today’s global production is, however, negligible.

 

It grows on well-drained soils with good aeration and is well adapted to marginal soils with low nutrient content. In heavy soils, root formation is reduced.  Physic nut is a highly adaptable species, but its strength as a crop comes from its ability to grow on poor, dry sites.

 

Jatropha Properties

Jatropha Curcas is Predominately a Bio Diesel crop, as well as having pharmaceutical and industrial values.  

  • 3Kg(6.6lb) Jatropha seed will yield 1 litre of Bio Diesel
  • Jatropha Curcas prefers temperatures averaging 20 - 28degrees C
  • Recommended planting rates are 2,500 plants /Hectare
  • Jatropha Curcas will produce a small crop after 2 years and reach full production at 5 years
  • Jatropha Curcas will grow for 50 years and bear seed for up to 40 years
    • There is approximately 1000 seeds per kilogram
    • Contains 34-36% oil content
    • Dried seeds should have 7-8% moisture content

 

Jatropha Advantages

Planning Commission of India has nominated it as ideal plant for biodiesel and the Government of India has selected the plant for National Program compared to others, due to following reasons:

  • Low cost seeds
  • High oil content
  • Small gestation period
  • Growth on good and degraded soil
  • Growth in low and high rainfall areas
  • Seeds can be harvested in non-rainy season
  • Plant size is making collection of seeds more convenient
  • Income generation from previously Unusable areas
  • Provide huge opportunities from new sustainable and renewable land resources
  • And crops Creating employment Nursery development, soil preparation, irrigation systems, Plantation maintenance, seed collection

 

Comments (0)

You don't have permission to comment on this page.