Reverse osmosis filtration reduces energy consumption to your powder production
Water removal is integral to any powder production line. Milk and whey consist mainly of water, and turning them into powder requires every drop of water to be removed. Any remaining moisture or humidity can spoil the finished product.
For this reason, evaporators and dryers play a pivotal role in powder production. But these units are highly energy-intensive to operate. Indeed, evaporation and – especially – drying consume more energy than any other food or beverage production process.
The good news is there is an effective and straightforward way to reduce energy consumption from evaporation and drying. In fact, you can save money in three different ways with this one valuble solution: reverse osmosis filtration.
1. Reduce your energy costs
The first way is to add a filtration step before your evaporation and drying installation. The more you can pre-concentrate your product by reverse osmosis filtration, which uses less energy than an evaporator or spray dryer, the less energy your process will consume in the evaporation and drying phase.
Filtering a liquid feed product through a reverse osmosis membrane will concentrate the product to between 20 and 30 percent total whey solids – or 35 percent skim milk solids – compared to the 12 percent total solids that is the typical input for many evaporation setups. This substantial reduction in liquid content leaves less work for the energy-intensive evaporator and spray dryer to do.
“The energy efficiency savings can be very appreciable,” says Claus Jakobsen, General Sales Manager for Tetra Pak Filtration Solutions. “We calculate that in a typical production scenario, a high-capacity powder plant can expect to reduce its daily electricity costs by more than €1,200. This equates to an annual saving of €425,000 per year.”
Our specialists can calculate the exact reduction in energy use you can expect, and the total cost of ownership of the filtration unit, so you can measure precisely how much you can save. But in all cases the savings are likely to be considerable.
2. Lower investment cost by choosing smaller units
Adding a reverse osmosis step to your process creates a second way to save money. By reducing the capacity requirement of the evaporator and dryer, reverse osmosis allows you to choose smaller units when upgrading your line. Instead of maximising your evaporator or dryer, you may be able to consider a mid-sized unit. The result: a lower investment cost for you.
3. Recover and reuse water
There is also a third benefit that is often overlooked. Using reverse osmosis, condensate water can be recovered from evaporators and dryers for reprocessing and reuse, making the evaporation and drying process even more cost-efficient.
After collection, condensate water is treated using reverse osmosis filtration. The process removes impurities, creating a new water source for use in rinsing, cleaning-in-place or even upstream in the production process, depending on the purification level selected, Claus Jakobsen says:
“Based on working with largest customers, we estimate that a typical large powder line can recover and reuse around six hundred cubic metres of condensate daily. That equals an Olympic swimming pool almost every four days.”
Collecting and reusing process water reduces daily water consumption by an estimated €300 per day at a typical powder plant. Over an entire year, this generates a cost saving of more than €100,000. On top of that, closing the loop with reverse osmosis also reduces wastewater treatment or discharge costs by an estimated €1,200 per day, or €420,000 per year.
“Assuming a total cost of ownership for a reverse osmosis filtration solution of €436,000, this means that investing in this technology will pay for itself through lower wastewater treatment and disposal costs in just over one year,” Jakobsen comments.
Add in the decrease in mains water consumption and lower electricity bills, and the payback period on your investment falls to less than six months.