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.
How the water industry can improve energy management with new performance insights.
TrendMiner
10/11/2018
Image 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.
Image 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.
For instance, computational fluid dynamics (CFD) modeling is gaining much more traction in the water industry. Another strategy is to empower subject matter experts such as process, operation and maintenance engineers, who have deep knowledge about the production process itself. If they can quickly access, search and analyze the historical time series data, they will be able to answer relevant questions for their day-to-day jobs, without having to rely on data scientists. Hypothesis generating and hypothesis testing using descriptive, discovery, diagnostic and even predictive analytics has proven its value already in many other industries.
Image 3. Production rate as a function of energy consumption
Using specific formulas and calculated tags, various energy consumers are monitored and controlled. Through monitoring the performance against the reference year, it is shown that the energy consumption is effectively decreased year over year, meeting their corporate goals. More importantly, with a growing knowledge and insight into the production process, Covestro is continuously improving overall performance.
Diagnostic analytics can help the process engineers troubleshoot and gain more insight into processes. Comparing different regeneration cycles in ion-exchangers can help the investigation into the effect of multiple process parameters on performance. By overlaying multiple runs, hypotheses can be tested with historical data. An example of this is the monitoring and quantification of the effect of feed composition, temperature, or pH on the quality of the biogas production in AnMBR systems. Visualizing the relevant data in the correct way helps engineers to gain new insights.
For instance, Evides, a Dutch water company, found that a significant amount of energy could be saved by using a redundant reverse osmosis skid to deliver the same production rate. This became clear after preprocessing and filtering the relevant data of a reverse osmosis unit at an industrial WWTP in Antwerp, Image 3.