This division covers all the needed process technologies for the following industrial applications:
- Hydrolitic splitting
- Fats/fatty acids hydrogenation
- Fatty acids distillation
- Fatty acids fractional distillation
- Fatty acids crystallization (detergent process)
Splitting can process all sorts of oils and fats, such as palm oil, palm kernel oil, coconut oil, tallow etc. acid oils with crude fatty acids and sweet water as products.
Splitting is carried out in a single high pressure tower with internal heat recovery section realized with fouling proof grids.
Fat/oil is fed at the bottom of the tower and water, that is totally recovered condensate, on top; the fatty matters flowing upwards reacts with the water forming fatty acids and glycerine, that is removed by the water flowing downwards, consequently allowing the completion of the reaction.
Heating is by direct high pressure steam injection in the tower.
Fatty acids at the outlet of the splitter are flashed under vacuum to ensure drying to avoid splitting reversion.
Sweet water are flashed at atmospheric pressure and the flashed steam is utilized to preconcentrate the sweet water under vacuum.
FATS/FATTY ACIDS HYDROGENATION
The same plant can process either fat ,fatty acids or methylesters provided the plant is in stainless steel and the design pressure is sufficiently high.
Catalyst is Nickel based.
Typical operating hydrogenation pressure is 20 bar for fatty acids, while methylesters and neutral fat could be hydrogenated also at pressures as low as 10 bar, but with higher catalyst consumption.
Fat or fatty acids are normally hydrogenated to an IV of 0.2-0.3, while a max IV of 0.1 is required for ME to be used for MES (methyl esters sulphonic acid) production.
Two process, both slurry based are available, continuous and batch.
In both cases the reaction is carried out in a batch reactor with a jet mixer to guarantee the intimate contact between product to be hydrogenated, catalyst and hydrogen.
The mixing energy is given by an external circulation and the heat of reaction is removed in an external exchanger generating low pressure steam.
Two buffer tanks, both on feed and discharge convert the process to a continuous operation allowing a maximum heat recovery.
The batch process, utilized for smaller capacities, foresees a similar reactor but the product after hydrogenation, is discharged to a drop tank for feed preheating and final cooling with water.
In both cases the hydrogenated product is then fed to a cricket filter for catalyst separation.
The cricket filter, that does not require precoat, allows the catalyst recycle typical of oil hydrogenation.
FATTY ACIDS DISTILLATION
Fatty acids distillation is carried out under high vacuum in towers with structured packing to minimize pressure drops and consequently operating temperatures.
The unit is normally composed by a precut tower, a distillation tower and a secondary distiller.
In small units the precut operation can be incorporated in the main distiller to reduce the investment cost.
The fatty acids distiller is designed in a way to separate the feed into various cuts that are:
- The residue that is sent to a separate secondary distiller for maximum recovery of fatty acids
- The main stream of distilled fatty acids extracted as a sidedraw
- The light boiling fatty acids (in case of combined precut or special design)
Falling film reboilers are normally adopted to avoid overheating of the fatty acids.
Maximum energy recovery is achieved by feed/effluent heat exchangers and low pressure steam generation in the fatty acids condenser.
FATTY ACIDS FRACTIONAL DISTILLATION
The fatty acids fractional distillation unit is composed normally one or more towers, typically two, and total distiller.
As in the case of the total distillation, the towers are with structured packing, that guarantees a high number of theoretical stages and a limited pressure drop.
In case of high purities required (up to 99.5 % for medium chain fatty acids) the main product is extracted as a sidedraw with the lighter components removed as top product.
The condenser is internal to the tower, tubes type, with minimal hold up to facilitate products change over.
Falling film reboilers are utilized to minimize fatty acids overheating.
Materials of construction are selected according to the products to be fractionated.
Heat recovery is, like in the case of the total distillation, with feed/effluent heat exchangers for sensible heat and low pressure steam generation for latent heat.
FATTY ACIDS CRYSTALLIZATION
The process is based on the use of detergent solution with electrolyte to separate the saturated from unsaturated fatty acids.
Typical raw materials for wet crystallization are palm or tallow distilled fatty acids; no specific composition is required as in the case of dry fractionation where a specific C16:C18 ratio is required to get a proper separation.
Standard achievable characteristics are a Cloud Point of 5-6°C for oleic acid and an Iodine Value of 20 approximately with an yield in oleic close to 50 %.
The process can be fully continuous with four centrifuges or semi continuous with both oleic and stearic acids washing carried out batchwise, in which case only two centrifuges are required.
Technically, biodiesel is a biofuel produced through a transesterification reaction, a process in which a vegetable oil or animal fat is reacted with excess of methyl alcohol in presence of an alkaline catalyst. The final product is composed of blend of methylester which can be used as a fuel for either automotive or heating purposes, either pure or blended with conventional diesel.
Biodiesel has been demonstrated to have significant environmental benefits in terms of decreased global warming impacts, reduced emissions, greater energy independence and a positive impact on agriculture.
The use of biodiesel results in a significant reduction in CO2 emission (65%-90% less than conventional diesel), particulate emission and other harmful emissions. Biodiesel is extremely low in sulphur, and has a high lubricity and fats biodegradability. These are all advantages which have been confirmed by various EC Commission programmes and tests of independent research institutes.
In specific cases, used vegetable oils can be recycled as feedstock for biodiesel production. This can reduce the loss of used oils in the environment and provides a competitive and CO2 advantageous way of transforming a waste into transport energy.
As such, an increased use of biodiesel in Europe represents an important step for the European Union to meet its emission reduction target as agreed under the Kyoto agreement. Additionally reducing pollutant emissions alleviates various human health problems.
BRIEF PROCESS HIGHLIGHTS
Typically, the process for EN14214 Biodiesel production is obtained through the following technological steps:
- Oil drying section
- Reaction section
- Settling & evaporation section
- Biodiesel washing and drying section
- Glycerine treatment section
ANDREOTTI IMPIANTI'S BIODIESEL EXPERIENCE
Taking advantage of a six-decade experience in the field of oils and fats processing, Andreotti Impianti supplied its first biodiesel production complex in Germany in 1998.
Many other such plants have been sold over the years, allowing our Company to be among the major actors in this professionally highly demanding and competitive sector. For specific references, please contact us.