Turning trash to treasure

The Australian dairy processing industry has successfully trialled an exciting new processing technology known as Continuous Separation (CSEP) which is able to turn waste streams into income streams.

CSEP is a process that separates biological molecules or components, like proteins in cheese and whey, using simulated moving bed chromatography continuously rather than sequentially which has been the case since the process was developed in the early 1900s.

CSEP was developed and patented by US-based company Advanced Separation Technologies, Inc. (AST), but is now part of Calgon Carbon Corporation. It was initially developed for, and used in, mining, chemical manufacture and water treatment. Food Science Australia is the first organisation anywhere in the world to licence and adapt the technology for the food industry, in particular dairy protein and peptide fractionation.

Traditionally, the fluid that is to be separated flows into the first of a series of columns with a resin bed. After a period of time to allow for adsorption of the required component, the column is then washed to displace the original fluid leaving the component adsorbed in a resin bed. The component is then eluted from the resin bed, a process known as desorption.

“Basically there’s four different steps that you need to do one after the other” says Food Science Australia’s Kirthi De Silva.

“CSEP typically represents a collection of 20 or 30 conventional columns operated with less complexity compared to traditional batch column operation. At the core of this innovative new technology is a valve with 20 or 30 ports that has a stationary component connected to feed and product tanks. In turn, it is coupled to a rotating component which is connected to the columns mounted on a rotating carousel.

“As for traditional chromatography processing, CSEP process is divided into steps such as adsorption, washing, desorption etc, and the valve co-ordinates the flow of fluids into and out of the columns. This arrangement of columns connected to the feed tanks through the rotating component of the valve and movement of the columns allows the productive use of all columns simultaneously.”

According to De Silva this cutting edge technology is only just starting to catch on in Australia. There are three dairy processing plants currently using the technology, now that it has proven itself, with the potential wider adoption beyond dairy.

“Chromatography is quite widely used in the pharmaceutical, chemical and water industry in the US, but it’s new in the food industry so we have to prove the concept is sound,” added De Silva.

“As with all new technology, there is a capital cost involved but there are considerable benefits to be derived from installing a CSEP system because it allows waste to be turned into functional products. There is the cost of the CSEP valve plus 20 to 30 columns depending on scale so it is not cheap. But it is usually used to extract components of high value so the future earning capacity once put in place needs to be taken into account,” said De Silva.

“With cheese processing, whey has been traditionally seen as a waste product. It was something that dairy processing companies got nothing for, or was a cost because they had to pay for its disposal. Now whey can be used for a variety of purposes such as protein supplements for body builders and it is also becoming popular with applications in the nutraceutical and cosmeceutical markets.”

The technology is not just applicable to the dairy processing market. For example, “in meat processing the blood from slaughtered animals currently goes into the waste stream but it is possible to use CSEP technology to take the blood and recover different proteins and fractions to produce all sorts of functional products,” said De Silva.

Additionally, the CSEP valve and its mode of connecting the column to the input and output tanks results in simple process control requirements and lower the operating costs compared to traditional batch chromatographic systems. This also enables the incorporation of complex chromatographic strategies to solve complex separation problems due its inherent flexibility. The CSEP technology is generally directly saleable and is capable of processing fluids over a very wide range of flow rates and hydraulic characteristics. CSEP technology utilises mild processing conditions compared to other forms of separation.

CSEP is also more efficient as a process. It is more flexible than traditional chromatography in that there’s no need to pre-clean material going through the system. Inputs and outputs are always flowing through the rotating element and because it’s continuous, operating costs are lower because less resin and water is needed. Upstream and downstream processing units can also be smaller because the process is not being done in large batches. A further advantage is that it can be linearly scaled up very easily.


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