Minimizing freshwater withdrawals in production processes
22 Mar 2022
Growing water scarcity and increasing costs and regulation require manufacturers to reduce their freshwater withdrawals and wastewater discharge. GEA helps customers tackle these challenges with solutions that minimize water usage within individual process steps and enable its reuse in plants and plant processes.
Freshwater withdrawals constitute water taken from ground or surface water sources. As global population and water demand increase, freshwater is more likely to be extracted beyond the rate at which aquifers are replenished, leading to water stressed conditions. Industry also competes for freshwater – often requiring large volumes and generating significant amounts of wastewater too, due to cleaning processes. With deep engineering and process expertise across multiple industries, GEA is well-positioned to help customers meet even the most ambitious water targets.
“Water stress is the biggest crisis no one is talking about. Its consequences are in plain sight in the form of food insecurity, conflict and migration and financial instability.”– Dr. Andrew Steer, President and CEO, World Resources Institute
– Dr. Andrew Steer, President and CEO, World Resources Institute
GEA solutions promote circular use of water
Reusing industrial wastewater, or effluent, is the most effective way to limit water withdrawals and minimize discharge to sewers. Depending on its original use and end use, effluent must fulfil specific safety and hygiene standards before it is recycled.
GEA offers key technologies that are shaping the discourse and pushing boundaries when it comes to water recovery and treatment in industrial processes. Our customers, which span diverse industries around the globe, are realizing impressive water stewardship results – in some cases achieving water-neutrality across their production and plants. Key GEA solutions in this area include:
- membrane filtration
- centrifugal separation
- evaporation
- crystallization
- product recovery & automated clean-in-place (CIP) systems
Water recovery and reuse in production processes
Milk is approximately 85 percent water. That means dairy processors have the potential to reuse millions of liters of water annually. Using a GEA reverse osmosis unit, condensate can be collected from an evaporation plant and the resulting water returned to the process. This greatly reduces freshwater withdrawals, minimizes manufacturing and disposal costs and mitigates CO2 emissions.
Located in Gandhinagar, India, AmulFed is Asia’s largest skim milk powder plant. It is also a near zero-water discharge facility. This feat is the result of three sets of GEA reverse osmosis polisher units which treat the condensate from an evaporation plant. From there, the water is reused for product cooling and plant cleaning, which eliminates the use of 420 million liters of freshwater annually.
A type of membrane filtration, reverse osmosis (RO) is commonly used in dairy and food processing to concentrate solids, recover water and for “polishing.” The additional polishing step purifies the condensate resulting from the evaporation process. From there, it is suitable for watering green space or for use as toilet water. With further heat- or UV light treatment, effluent is safe to use in product-contact operations (e.g., final flushing, rinsing cans, cleaning tanks and pipework) and even as an ingredient in finished products.
In chemical processing, manufactures may use evaporation to separate water vapor from their waste stream. After condensing, it is usable as process water. To ensure it meets quality requirements, membrane treatment, stripping or distillation are generally required. In Europe, GEA customers in the medium-density fiberboard (MDF) industry are recycling 100 percent of their condensed wastewater with GEA evaporation technology. And while the energy consumption of evaporation is significant, it can be substantially reduced with thermal or mechanical vapor recompression (MVR).
In other water-intensive processes, such as industrial recycling, materials recovery facilities can integrate a GEA sludge Decanter, which allows them to return wash water back to the process cycle. This step reduces disposal costs freshwater usage and averts potentially harmful chemicals from entering the environment.
Zero-liquid discharge for recovering water and by-products
Zero-liquid discharge (ZLD) is a process that more industries are adopting, particularly in regions where water shortages are acute. The process is commonly employed in the production of chemicals, oil and gas, power generation, mining and in water treatment plants. The benefits of ZLD are that it:
- eliminates wastewater discharges
- allows for reuse of process water, reducing freshwater withdrawals
- enables the recovery of by-products
- meets strict water reclamation & wastewater disposal regulations
GEA offers thermal and non-thermal zero liquid discharge systems which utilize crystallization technology to treat liquid effluent. Depending on requirements, GEA can provide membrane separation, decanter centrifugation, evaporation, crystallization, drying and energy recovery in this context. Our ZLD technology is successfully employed within a wastewater treatment plant at a power plant in Ciudad Juárez, Mexico. The ZLD wastewater plant converts salt-laden wastewater into pure water for internal recycling. The process leaves behind minimal dry solids for disposal, thanks to a GEA decanter centrifuge for final dewatering.
Superior cleaning requires less water, not more
GEA product recovery and CIP systems also play an important role in minimizing freshwater usage and wastewater disposals. Product recovery, in particular pigging systems, clear process pipes of product which reduces the amount of water and chemical required during cleaning processes. For processes where storage tanks, silos or intermediate containers (IBC) are required, the removal of residues is paramount to safety and product quality. Here GEA Cleaning Technology is used across nearly all industries, ensuring product safety and hygiene and the efficient use of water and cleaning agents.
For juice producer innocent, GEA designed and installed a unique automated CIP system that minimizes the required cleaning surface area of the process piping for the company’s first carbon neutral plant, in Rotterdam, the Netherlands. The solution leverages pioneering technology from Fluidor which cleans pipes with an air tornado instead of water. The integration of this system with GEA’s automated CIP system, allows innocent to recover 98 percent of the juice from the process phase.
Another contributor to this impressive freshwater reduction is the use of citric acid rather than freshwater as a seal flushing liquid. The low-acidity and pH level of the citric acid naturally prevents bacterial growth. And by installing condensers, innocent consumes 45 percent less water than was initially estimated.
GEA innovation pipeline focused on water
As part of our sustainability targets, we commit that by 2030, 100 percent of GEA solutions will come with the option to be operated without additional freshwater intake, particularly during the cleaning process. In addition to our existing portfolio, we continue to improve our machines. In 2022, we will launch two significant innovations focused on safeguarding fresh water. These include:
- a “smart” solution combining GEA membrane filtration technology and an intelligent, sensor-based flushing process: enabling up to 50% reduction of freshwater consumption during CIP compared to conventional membrane filtration solutions
- a GEA Centrifuge Water Saving Unit that manages and reduces cooling water consumption during separation by reusing process water: enables annual freshwater savings of up to 1.3 million liters
Path to net-zero emissions critical to global water security
We know that climate change exacerbates the availability and quality of water around the world. Therefore, reducing global greenhouse gas emissions must be part the solution when it comes to safeguarding global water resources. Here too, industry can take the lead by setting, and working as quickly as possible, to achieve net-zero targets. The good news is manufacturing – and the engineering behind it – can play a significant role here too. For its part, GEA is committed to achieving net-zero across its operations by 2040.
