How the water industry can improve energy management with new performance insights.
by Bavo Symens
October 11, 2018

Clean water is one of the most essential requirements for human health, environmental sustainability and economic development. Due to population growth, urbanization and climate change, this vital resource has become more scarce than ever in many communities around the world. In order to meet the increasing demand, there is a growing need for societies to shift toward a more circular economy, but it comes at a cost. Instead of automatically discharging wastewater, many experts believe it needs to be captured, treated and distributed back to the consumer.

Water reuse and wastewater treatment are intrinsically energy intensive, due to the need to move large volumes of water using pumps and electric motors, and then treating the water to meet stringent regulatory requirements. In conventional wastewater treatment plants (WWTPs) aeration is one of the biggest energy consumers for treating wastewater. Other significant energy consumers include filtration and disinfection processes depending on application.

To cope with increasing energy consumption and to reduce the carbon footprint in water industries, novel technologies need to be implemented. Innovative technologies in water reuse facilities often come with drawbacks like increased complexity and reliance on instrumentation. These challenges in energy management are not unique to the water industry. They are also of critical concern in other industries including the chemical, food and beverage, metals and mining, pharmaceutical, and oil and gas.

calculated hydraulic headImage 1. Calculated hydraulic head as a function of flow (Images courtesy of TrendMiner)

Energy management has become more important in recent years due to established regulations to reduce greenhouse gas emissions on an international, national and local scale. To achieve these goals and to comply with regulations, the oil and gas industry in particular is rapidly adopting the International Organization for Standardization (ISO) 50001 standard to improve energy performance and to make climate part of their corporate strategy. Most companies have formalized their energy management programs and use automation and control technologies to help minimize energy costs. It is clear, however, that many companies need to take their efforts to the next level by monitoring and optimizing energy use in real time and leveraging Industrial Internet of Things (IIoT)-generated data.

For many years process data has been retained and maintained within corporate histories. All of this data can be unlocked and leveraged for continuous improvement of processes and to lower the carbon footprint. To some extent, data analytics has been used by major companies for their larger on-site energy issues, but this requires significant resources.

Interestingly, these time-consuming, centrally led, data modeling projects are less suited for process-related optimization projects that require subject matter expertise. In recent years, new tools have become available that place advanced analytics in the hands of subject matter experts, including process and field engineers. These tools enable such experts to solve energy process-related cases independently and positively contribute to corporate goals for reducing carbon footprints.

Energy Management 4.0

Global interest in Industry 4.0 has accelerated digital transformation in the process manufacturing industry, including those that are water-related. Many companies have engaged in technology pilots to explore options for reducing costs, to increase overall equipment effectiveness (OEE) and to help conform to enforced regulations.

Anaerobic membrane bioreactors (AnMBR) are used in WWTPs to separate and treat sludge from wastewater, generating biogas as a byproduct. This technology can drastically reduce the energy consumption in large plants by generating renewable energy on-site. Microbial electrical systems can be used to generate electricity while treating wastewater with microbial fuel cells (MFC), for instance, but this is still in its early stages of development.

Aeration is a key consumer in wastewater facilities, and a lot of research has been conducted in an effort to optimize these processes. To give some examples, membrane aerated biofilm reactors are an emerging technology in which oxygen is transferred much more efficiently. Optimizing the configuration and hydrodynamics in large bioreactors can provide better mixing. Better mixing consequently leads to less energy consumption for aeration and can even result in less production of strong greenhouse gases like nitrous oxides and methane.

comparing resultsImage 2. Comparing results of energy measures to reference year 2013 at Covestro, Antwerp.

Disinfection and filtration processes can contribute significantly to the total energy consumption. This depends largely on the level of water quality standards required for the application. Novel technologies like ultraviolet (UV) treatment using LEDs can reduce the energy consumption. Also, improved membrane technologies like ultrafiltration and reverse osmosis are gaining more attention for reducing the energy impact of the system.

One of the best ways to leverage these new innovations is to apply advanced industrial analytics to production data, generated by sensors. Every piece of data provides unique opportunities for improving energy efficiency.

Since data is only as valuable as the solutions it unlocks, understanding its potential is key. Complex optimization problems are frequently tackled by a limited group of data scientists who use the data for building and validating mathematical models.