The Legend of Pitung

The Legend of Pitung

Si Pitung

Si Pitung is a youth who soleh from Rawa Belong. He studied diligently mengaji on the Hajj Naipin. Done learning mengaji he also trained silat. After many years the science of religion capabilities and increasing self-care.

At that time the Netherlands is being colonize Indonesia. Si Pitung feel compassionate witnessing the suffering experienced by small people. Meanwhile, kumpeni (designation for the Netherlands), a group of employer and the Lord of life wander the land of luxury. Houses and their gardens are kept by the watchman who ferocious.

With the assistance of friends of the Rais and Jii, Si Pitung start planning a robbery of the employer's house and Mr rich soil. Results rampokannya share on the poor. In front of the house of the family who hunger laid sepikul rice. Families with dibelit debt loan diberikannya santunan. And children orphaned dikiriminya parcel clothes and other gifts.

Seeing the information that the police catch any kumpeni Si Pitung. Of course Pitung Si and friends against friends. Malangnya However, confidential information about the body's immune Si Pitung already open. He dilempari eggs and rotten-egg ditembak. He also died so seketika.Meskipun to Jakarta, Si Pitung still seen as defenders of the people small.

source :

http://story-en.blogspot.com/2009/04/legend-of-pitung.html

Cultivation of Algae in Photobioreactor

Cultivation of Algae in Photobioreactor

Algae cultivation can be achieved in two ways: open ponds and photobioreactors (PBR). A photobioreactor is a closed equipment which provides a controlled environment and enables high productivity of algae. As it is a closed system, all growth requirements of algae are introduced into the system and controlled according to the requirements. PBRs facilitate better control of culture environment such as carbon dioxide supply, water supply, optimal temperature, efficient exposure to light, culture density, pH levels, gas supply rate, mixing regime, etc.,
Photobioreactor - How it works

Working of a photobioreactor:

Flow description:

1. From the feeding vessel, the flow progresses to the diaphragm pump which moderates the flow of the algae into the actual tube. Built into the pump is the CO2 inlet valve.

2. The photobioreactor itself is used to promote biological growth by controlling environmental parameters including light. The tubes are made of acrylic and are designed to have light and dark intervals to enhance the growth rate.

3. The photobioreactor has a built-in cleaning system that internally cleans the tubes without stopping the production.

4. After the algae have completed the flow through the photobioreactor, it passes back to the feeding vessel.  As it progresses through the hoses, the oxygen sensors determine how much oxygen has built up in the plant and this oxygen is released in the feeding vessel itself. It is also at this stage that the optical Cell Density sensor determines the harvesting rate.

5. When the algae are ready for harvesting, they pass through the connected filtering system. This filter collects the algae that are ready for processing, while the remaining algae passes back to the feeding vessel.

6. The flow continues.

Advantages of Photobioreactors

• Cultivation of algae is in controlled circumstances, hence potential for much higher productivity
• Large surface-to-volume ratio. PBRs offer maximum efficiency in using light and therefore greatly improve productivity. Typically the culture density of algae produced is 10 to 20 times greater than bag culture in which algaeculture is done in bags - and can be even greater.
• Better control of gas transfer.
• Reduction in evaporation of growth medium.
• More uniform temperature.
• Better protection from outside contamination.
• Space saving - Can be mounted vertically, horizontally or at an angle, indoors or outdoors.
• Reduced Fouling - Recently available tube self cleaning mechanisms can dramatically reduce fouling.

Covering ponds does offer some of the benefits that are offered by photobioreactors, but enclosed systems will still provide better control of temperature, light intensity, better control of gas transfer, and larger surface area-to-volume ratio. An enclosed PBR design will enhance commercial algal biomass production by keeping algae genetics pure and reducing the possibility of parasite infestation.

Source :
http://www.oilgae.com/algae/cult/pbr/pbr.html

Oil Extraction

Oil extraction from algae is a hotly debated topic currently because this process is one of the more costly processes which can determine the sustainability of algae-based biodiesel.

In terms of the concept, the idea is quite simple: Harvest the algae from its growth medium (using an appropriate separation process), and extract the oil out of it. Extraction can be broadly categorized into two methods:

1. Mechanical methods

The mechanical methods are further classified into:

• Expression/Expeller press
• Ultrasonic-assisted extraction

1. Chemical methods

The chemical methods are further classified into:

• Hexane Solvent Method
• Soxhlet extraction
• Supercritical fluid Extraction 

Each of these methods has drawbacks: 

1. The mechanical press generally requires drying the algae, which is energy intensive
2. The use of chemical solvents present safety and health issues
3. Supercritical extraction requires high pressure equipment that is both expensive and energy intensive. 

Many manufacturers of algae oil use a combination of mechanical pressing and chemical solvents in extracting oil.

source :

http://www.oilgae.com/algae/oil/extract/extract.html

Transesterification

The process of converting vegetable & plant oils into biodiesel fuel is called transesterification, and is fortunately much less complex than it sounds.
Transesterification refers to a reaction between an ester of one alcohol and a second alcohol to form an ester of the second alcohol and an alcohol from the original ester, as that of methyl acetate and ethyl alcohol to form ethyl acetate and methyl alcohol ( see also interesterification. Chemically, transesterification means taking a triglyceride molecule or a complex fatty acid, neutralizing the free fatty acids, removing the glycerin and creating an alcohol ester. This is accomplished by mixing methanol with sodium hydroxide to make sodium methoxide. This liquid is then mixed into vegetable oil. The entire mixture then settles. Glycerin is left on the bottom and methyl esters, or biodiesel, is left on top. The glycerin can be used to make soap (or any one of 1600 other products) and the methyl esters is washed and filtered.
Transesterification is not a new process. Scientists E. Duy and J. Patrick conducted it as early as 1853. One of the first uses of transesterified vegetable oil was powering heavy-duty vehicles in South Africa before World War II.

Transesterification of Algal Oil into Biodiesel

Transesterification of algal oil is normally done with Ethanol and sodium ethanolate serving as the catalyst. Sodium ethanolate can be produced by reacting ethanol with sodium.
Thus, with sodium ethanolate as the catalyst, ethanol is reacted with the algal oil ( the triglyceride) to produce bio-diesel & glycerol. The end products of this reaction are hence biodiesel, sodium ethanolate and glycerol.
This end-mixture is separated as follows: Ether and salt water are added to the mixture and mixed well. After sometime, the entire mixture would have separated into two layers, with the bottom layer containing a mixture of ether and biodiesel. This layer is separated.

source : http://www.oilgae.com/algae/oil/biod/tra/tra.html

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