Study on the Operation of the LUTsCO2 Test Loop with Pure CO2 and CO2 + SO2 Mixture Through Dynamic Modeling

Study on the Operation of the LUTsCO2 Test Loop with Pure CO2 and CO2 + SO2 Mixture Through Dynamic Modeling

Within the framework of the Horizon 2020 DESOLINATION (DEmonstration of concentrated SOLar power coupled wIth advaNced desAlinaTion system in the gulf regION) project, CO2-based mixtures will be used as the working fluid of the power cycle coupled with the desalination plant. Desalination technologies require temperatures above 50℃, therefore a fluid with a critical temperature above 70 ℃ is required to perform the compression step in the liquid phase, minimizing compression work and increasing cycle efficiency. Blending CO2 with other fluids, such as SO2, leads to an increase in the critical temperature of the mixture and makes it suitable for transcritical cycles in concentrated solar power applications, while preserving the advantages of pure CO2 over steam cycles. Throughout the DESOLINATION project, CO2 blends will be tested in the LUTsCO2 test loop to provide validation data for the design of heat exchangers. In this work, the adaptation of the test loop to the CO2 blend is investigated. A dynamic model of the test loop is built in MATLAB-Simulink, which allows each component to be modeled independently and to realize a closed-loop cycle model coupled with a controller and real gas property tables. Steady-state simulations of the system are performed and the dynamic model of each component is verified with the design values. As a result, the study highlights the key performance and fluid dynamic differences which arise from the use of a CO2 blend instead of pure CO2.

Keywords:

  • CO2 mixtures
  • Transcritical refrigeration cycle
  • Dynamic model
  • Simulink
Authors:

Giuseppe Petruccelli Lappeenranta-Lahti University of Technology LUT, Lappeenranta, Finland

Teemu Turunen-Saaresti Lappeenranta-Lahti University of Technology LUT, Lappeenranta, Finland

Aki Grönman Lappeenranta-Lahti University of Technology LUT, Lappeenranta, Finland

Afonso Lugo Lappeenranta-Lahti University of Technology LUT, Lappeenranta, Finland

Techno-Economic Analysis of Brine Treatment by Multi-Crystallization Separation Process for Zero Liquid Discharge

Techno-Economic Analysis of Brine Treatment by Multi-Crystallization Separation Process for Zero Liquid Discharge

This study analyses the concept of a novel multi-crystallization system to achieve zero liquid discharge (ZLD) for desalination plants using an innovative heat recovery system consisting of a heat transfer fluid and a compressor to reduce energy consumption. The main focus is to recover water and separately extract salts from seawater brines with high purity, including calcite, anhydrite, sodium chloride, and epsomite, which can be sold to the cement industry. The system is compared with a conventional brine treatment system. The energy demand and economic feasibility of both systems are assessed to evaluate profitability at a scale of 1000 kg/h. The results estimate that the utilization of a heat recovery fluid reduces energy consumption from 690 kWhth/ton of feed brine to 125.90 kWhth/ton equaling a total electric consumption of 60.72 kWhe/ton. The system can recover 99.2% of water and reduce brine discharge mass by 98.9%. The system can recover 53.8% of calcite at near 100% purity, 96.4% of anhydrite at 97.7% purity, 91.6% of NaCl at near 100% purity, and 71.1% of epsomite at 40.7% purity. Resource recovery accounts for additional revenues, with halite and water accounting respectively for 69.85% and 29.52% of the income. The contribution of calcite and anhydrite to revenue is very low due to their low production. The levelized cost of water (LCOW) of the multi-crystallization system is 13.79 USD/m3 as opposed to 7.85 USD/m3 for the conventional ZLD system. The economic analyses estimate that the conventional ZLD system can achieve payback after 7.69 years. The high electricity cost, which accounts for 68.7% of the annual expenses, can be produced from renewable sources.
Authors:
School of Water, Energy and Environment, Cranfield University, Bedford, Bedfordshire MK43 0AL, UK
Prof. Dr. Kumar Patchigoll School of Water, Energy and Environment, Cranfield University, Bedford, Bedfordshire MK43 0AL, UK
World Utilities Congress 2022 | Abu Dhabi

World Utilities Congress 2022 | Abu Dhabi

Our project partner Aalborg CSP received a very warm welcome at the World Utilities Congress, from May 9-11, 2022 and an excellent response from attendees, with around 150 visits to its stand presenting the DESOLINATION project.

Hosted by the Abu Dhabi National Energy Company (TAQA), and organised by dmg events, the World Utilities Congress is the global meeting place for senior local, regional and international utilities professionals to connect with governments, policy makers and industry leaders, to discuss trends and to explore technologies and innovations that influence future demand for energy and water.

Press release: DESOLINATION presented in the French Plein Soleil Webzine!

Press release: DESOLINATION presented in the French Plein Soleil Webzine!

Plein Soleil, a leading French digital magazine focused on renewable energy in buildings, has featured our innovative project DESOLINATION. We invite you to visit their website to read the full press release and learn more about this exciting venture.

DESOLINATION, an evocative neologism, represents a pioneering €10 million European project involving 19 partners from 12 EU countries. The initiative aims to develop a unique and efficient coupling of concentrated solar power and seawater desalination techniques. The first pilot plant will be deployed in Saudi Arabia, signalling a major step forward in sustainable water production.

Commencing on 1 June 2021, and running through May 2025, the Horizon 2020 DESOLINATION project will introduce groundbreaking technologies to enhance both independent and coupled systems of solar power and desalination. The final demonstration system will be a 2 MW power plant in Saudi Arabia, combining these two promising technologies to achieve unprecedented efficiencies.

Affordable, Low-Carbon Solar Freshwater

Focusing on the Gulf Cooperation Council (GCC) region, DESOLINATION will test and deploy its prototype at King Saud University in Riyadh, Saudi Arabia. Leveraging high solar resources and significant demand for desalinated water, the prototype aims to deliver renewable electricity at low costs (<€90/MWh) and affordable freshwater (<€0.9/m3). Additionally, the system will substantially reduce CO2 emissions compared to traditional desalination methods: 30% reduction compared to direct osmosis systems, 40% compared to reverse osmosis, and 70% compared to thermal desalination.

DESOLINATION will innovate in various domains. On the solar power front, CO2 blends will drive more efficient and cost-effective power cycles with controllable parameters. In water desalination, direct osmosis will be developed and linked to membrane distillation, utilising waste heat from the power cycle to produce freshwater. This unique combination will enable the disruptive coupled system to achieve high efficiency in converting waste heat to freshwater.

Throughout the project, EU and GCC countries will collaborate to deliver a high-level technological demonstrator. DESOLINATION brings together some of the world’s leading experts in concentrated solar power, CO2 energy cycle design, desalination processes, separation membranes, and system integration to meet the project’s objectives and ensure strong market uptake post-completion. The project includes 19 partners from 9 EU countries and 3 GCC countries, comprising 13 top universities and research centres and 6 industrial and SME partners.

Visit Plein Soleil’s website to read the full press release and discover more about the innovative DESOLINATION project.