Dairy

WHEY DEMINERALIZATION PROCESSES

In the dairy industry, whey is obtained from the manufacturing of cheese and casein. There is a high demand for demineralized whey for many applications in human and cattle feed: these include instant formula (baby food; min. 90 % demin.), confectionary, baking, meats, etc. Depending on the use for the end product, the demineralization process has tbe tailored taking intaccount the complete composition of the raw whey: this includes the ash profile and the equivalent acid content. Thus, the optimum demineralization processes will be different for wheys produced from two types of cheese, even if these belong to the same cheese category.

In the case of cheese whey, there are two main grades of whey:

• Sweet whey with a titrable acidity below 0.16 % or a pH above 6.0, from cooked cheeses

• Acid whey with a titrable acidity above 0.4 % or a pH below 4.0, from soft, fermented, and cottage cheeses.

In manufacturing, the whey obtained after coagulation with HCl or H2SO4 has a titrable acidity between 0.4 and 0.45 %.

With more than 20 operating systems worldwide, Eurodia / Ameridia has a unique expertise in whey demineralization processes, either internally developed or licensed form close partners. In accordance with our general process development philosophy, the optimum process for each dairy customer might combine several technologies adapted to its specific product: these include electrodialysis reversal (EDR), ion exchange resins (IER), and nanofiltration (NF). For instance, nanofiltration is not attractive if used alone for any demineralization rates above 35 % because of the high losses of lactose and divalent ions: therefore, NF could be useful as a pretreatment or postreatment step. Similarly, ion exchange resins are not economically attractive when used alone because of the high volume of effluents, the high running cots, and the heavy pollution load. For more details about the use of nanofiltration only to demineralize whey, please go also to the Technologies Section/ Nanofiltration of this website.

Following, are some general guidelines for the expected optimized overall demineralization process for sweet whey:

SWEET WHEY DEMINERALIZATION

Method to be used depends on the required demineralization rate:

Eurodia's design principles for a whey demineralization plant:

• Achieve the demineralized whey specifications with the lowest operating costs and the most cost effective investment.

• Maintain the quality of the valuable product (proteins) by avoiding microbiological development and thermal shocks (by operating at acidic pH as much as possible).

• Keep the dry solid and valuable product yields as high as possible.

• Reduce the volume of waste effluent as well as the pollution load.

• Design the demineralization process taking into account the downstream process steps (i.e. evaporation, standardization, spray drying…) to optimize their operating and capital costs.

• Optimize the choices of technology, materials, and instruments.

• Look for easy maintenance.

• Design to meet FDA and 3A requirements.

EXAMPLE

6 % DS SWEET WHEY DEMINERALIZATION FOR INSTANT FORMULA RUNNING COSTS in €/kg DS

WHEY DEMINERALIZATION PERMANENT IMPROVEMENT OF TECHNOLOGY

1.ELECTRODIALYSIS

• Proprietary spacers specifically designed to dramatically reduce the internal leakage.

• Thus :

• Minimizes valuable products losses

• Lowers pollution load even after 10,000 hours of operation

• Improves the current efficiency and the power consumption

• Reduces the water consumption.

• Large range of spacers available to adapt the technology to the product

• Different thicknesses depending on of DS content and viscosity

• Different materials (all FDA approved grade) to operate at temperatures as high as 60°C

• Different types of netting to optimize flows and lower pressure drops.

• Proprietary ion exchange membranes (NEOSEPTAâ) manufactured by TOKUYAMA CORPORATION

• Longest membrane life

• All components are Food Grade

• Organic fouling resistant

• Metallic or graphite long lasting electrodes designed to operate in the current reversal mode (edr)

2. ION EXCHANGE RESINS AND COLUMNS

• Specific ion exchange resins developed by RESINDION (MITSUBISHI CHEMICAL GROUP)

• Strong cation gel type with high DVB content to improve the selectivity of resins when used as softeners before ED (SODIUM PROCESS® patented by the SAFIR Company).

• Adsorption of protein and complexed salts is dramatically reduced.

• Strong anion resins of special grade to be used with the above-mentioned strong cation resins in mixed beds (density, granulometry, swelling)

• Weak cation resins (carboxylic) adaped to reduce the divalent cations and adjust the pH.

• Weak anion resins with low swelling, no adsorption of proteins, and high capacity for phosphorous removal.

• Technology of IER columns

• Proprietary distributors

• Cost effective regarding feed distribution and chemicals (regenerants) consumption

• Adapted to resins swelling (if low).

• Easy to move when increasing resins volume for capacity increase

• Allowance for 100 % resin bed expansion.

3. EASY MAINTENANCE AND OPTIMIZED HYDRAULIC PIPING

• ED stacks can easily be handled, disassembled and reassembled for on-site maintenance (in less than 2 hours per stack).

• Rod electrodes that can be replaced within a few minutes (while hours are necessary for flat electrodes).

• Easy access to all key components (pumps, valves, instruments).

• Selection of reliable instruments for non-stop operation.

• Short hydraulic piping for both ED and IER to optimize brine, chemicals, water and energy consumption.

• Specifically designed valve manifolds are installed to avoid any risk of streams contamination (feed/product, product/chemicals etc...)

• The on-line factor of our demineralization plants is usually higher than 96 -98%.

EXAMPLE

SWEET WHEY DEMINERALIZATION FOR INSTANT FORMULA

Table 1

Raw material composition, sweet whey analysis

Table 2

Raw material composition, standard sweet whey