BIOSEPARATION TECHNOLOGY MK Mekanisasi Pertanian
Why Separation?
MOTIVASI PEMISAHAN • Pemurnian. Hal yang perlu diperhatikan: temperatur yang tinggi menyebabkan dekomposisi beberapa komponen • Pemindahan komponen yang tidak diinginkan. Hal yang perlu diperhatikan: kehilangan komponen yang berharga • Recovery: untuk proses berikutnya • Pemisahan padatan
Seaparation in Food Industries
Some Methods to Separate a Product by Bioseparation
UNIT OPERATION IN BIOSEPARATION
Separasi mekanik • • • •
Sedimentasi Separasi Sentrifugal Filtrasi Penyaringan
Gaya yang bekerja pada separasi mekanik: gravitasi, sentrifugal dan tekanan
Kecepatan pergerakan partikel dalam Fluida
Kecepatan partikel tergantung pada: ukuran, densitas dan bentuk partikel serta sifat-sifat fluida. Gaya yang berpengaruh: gaya eksternal yang bekerja dan drag force yang menahan gerakan.
FD
FB
FG
SEDIMENTASI • • • •
Sedimentasi gravitasi Flotasi Sedimentasi partikel dalam gas Pemisahan dengan kombinasi gaya
GRAVITATIONAL SEDIMENTATION
• Sedimentation uses gravitational forces to separate particulate material from fluid streams. • The particles are usually solid, but they can be small liquid droplets, and the fluid can be either a liquid or a gas. • Sedimentation is very often used in the food industry for separating dirt and debris from incoming raw material, crystals from their mother liquor and dust or product particles from air streams.
Thickener kontinyu
Clear fluid overflow Clear fluid Transition zone
Free settling zone
Thickened compression zone
Slow revolving rake
Thickened sludge underflow
PERALATAN SEDIMENTASI
Cyclone • Sering digunakan memisahkan aliran udara dari partikel-partikel dengan diameter sekitar 10 m atau lebih dan juga digunakan untuk memisahkan partikel dari cairan • Bentuk cyclone bagian atas: silinder vertikal udara sarat partikel membentuk spiral menciptakan gaya sentrifugal sehingga partikel ke bagian dinding • Gaya gravitasi mempercepat pemisahan
CENTRIFUGAL SEPARATION • Sedimentation process may be very slow because the specific gravities of the components may not be very different, or because of forces holding the components in association, for example as occur in emulsions. • For example, if whole milk is allowed to stand, the cream will rise to the top and there is eventually a clean separation between the cream and the skim milk. • However, this takes a long time, of the order of one day, and so it is suitable, perhaps, for the farm kitchen but not for the factory. • Hence, much greater forces can be obtained by introducing centrifugal action, in a centrifuge.
CENTRIFUGAL SEPARATION A centrifuge uses centrifugal force to separate liquids/solid from liquid.
Working principle
APPLICATIONS Separating fat from milk Cleaning dust from air De-watering or de-oiling of food
DISTILLATION
We owe a great debt to the Arabian alchemist (and physician) Ibn Sina also known as Avicenna, who lived 980 - 1037 AD, since he was the first one to perfect steam distillation - and his process was so good that it stayed unchanged for a couple of hundred years.
Principles • Distillation is a method of separating mixtures based on differences in their boiling points.
APPLICATIONS Production of essential oil Alcohol purification Sea water distilation Petroleum refineries
FILTRATION • Filtration is the separation of solids from liquids, by causing the mixture to flow through fine pores which are small enough to stop the solid particles but large enough to allow the liquid to pass. • The fine apertures necessary for filtration are provided by fabric filter cloths, by meshes and screens of plastics or metals, or by beds of solid particles. An advance filtration for fine materials uses many types of membrane
FILTRATION EQUIPMENTS
Centrifugal filters Plate & frame press
Rotary vacuum filters
MEMBRANE TECHNOLOGY An advance type of filtration Early membrane investigators experimented with every type of diaphragm available to them, such as bladders of pigs, cattle or fish and sausage casin made of animal gut. Later, collodion (nitrocellulose) membranes were preferred because they could be made reproducibly.
Types of Membrane
MEMBRANE PORE SIZE
APPLICATIONS • Water purifications • Separations of amino acids • Gas separations
