【Major Industrial Equipment in the Chemical Industry】062 – Largest Single Seawater Desalination Evaporation Module
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The past decade has been a period of rapid development for China’s chemical industry, marked by the emergence of many new processes, products, and equipment. There has also been significant progress in China’s chemical processing equipment, which has contributed to the swift advancement of the petrochemical sector. Here, we have compiled some of the achievements and breakthroughs made by Chinese equipment manufacturers in terms of larger-scale production and increased use of domestic equipment. We invite everyone to share their insights and engage in discussions, to cheer for Made in China and to support the development of chemical processing equipment! *********************************** At the end of 2013, Zhongze Heavy Industry was tasked with manufacturing 4 modules of the core MED desalination evaporators for a desalination project in Kuwait. Each evaporator weighed over 2,700 tons, was more than 50 meters long, over 30 meters wide, and more than 10 meters high. These evaporators consisted of condensers, condensation sections, and evaporation sections internally, with a total of over 400,000 heat exchange tubes – making them the largest single desalination evaporator in the world to date. With 4 units involved, the entire production and manufacturing process took over a year. The goods were loaded at Zhongze Heavy Industry’s roll-on/roll-off terminal and shipped to the site in Kuwait. The successful completion of this project represents yet another milestone achievement for our company.
More people are welcome to participate in the relevant discussions. Click on the blue link to access it: The 【HaiChuan Equipment Guessing Game】 series is being updated continuously in 2022; all Hai friends are invited to join actively! https://bbs.hcbbs.com/thread-2079686-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum) Summary post on the series 【Major Equipment in the Chemical Equipment Industry】 https://bbs.hcbbs.com/thread-3312079-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum) Summary post discussing the components of cracking furnace equipment for 【Ethylene Cracking】 https://bbs.hcbbs.com/thread-3308724-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum)
【Major Chemical Equipment in a Global Powerhouse】075 – Large-scale seawater desalination evaporation module for the Abu Dhabi Oil Flexibility Project https://bbs.hcbbs.com/thread-3319305-1-1.html (Source: Hua Hai Chuan Liu – Haichuan Chemical Forum Website)
What are the benefits of making devices super-large? Should it be to reduce investment or to reduce energy consumption? :Q
All of them help reduce the investment per unit and energy consumption
Among them, thermal and membrane desalination technologies are the main methods currently used for large-scale industrial applications. Thermal methods can mainly be divided into multi-stage flash (MSF), multi-effect evaporation (MED), and vacuum distillation (VC). In the 1990s, the primary technology for seawater desalination was multi-stage flash distillation, especially in the Middle East**; however, MSF later faced significant competition from multi-effect evaporation and membrane technologies. Membrane desalination and water purification technologies, represented by RO technology, do not require large amounts of thermal energy, making them suitable for saltwater desalination on a large, medium, or small scale. For the zero-discharge treatment of high-salt wastewater, direct evaporation crystallization can achieve zero discharge, but it is extremely costly and energy-intensive, as well as wasteful of resources. Membrane technology can be used to further concentrate high-salt wastewater into ultra-high-salt wastewater; the fresh water component can be reused directly, while the concentrated ultra-high-salt wastewater can be subjected to evaporation and crystallization to achieve zero discharge. This approach significantly reduces energy consumption while making rational use of some of the water resources. However, membrane technology has certain requirements regarding the quality of the feed water. Therefore, high-salt wastewater must undergo pretreatment (such as chemical softening, filtration, ion exchange, etc.), which effectively reduces membrane fouling and improves both the service life of the membranes and the quality of the effluent.
There are two mature seawater desalination technologies: thermal desalination and reverse osmosis (RO) desalination. Both are used in the Middle East; Saudi Arabia operates the world’s largest desalination plant, which produces 640,000 cubic meters per day. Since the 1960s, water authorities in the Middle East have used thermal desalination as the primary process for producing drinking water. However, the high energy requirement of thermal desalination has shifted attention to less energy-intensive seawater desalination technologies, such as reverse osmosis (RO). Globally, 70% of thermal desalination plants have switched to RO desalination, but in the Middle East, only 50% of the desalinated water is treated in this way, as the membranes used in RO processes have not yet been fully customized for high-salinity seawater from the Red Sea and Gulf. Another limitation is that the high temperatures in this region affect the operating capacity of the RO membrane units. Most current research on this technology focuses on developing new high-throughput membranes that can operate at low pressures and high temperatures while resisting fouling. However, given the high salinity of the waters in the Gulf of Persia and the Arabian Sea, researchers need to pay further attention to the development of pretreatment processes.
Several new desalination technologies are currently being developed to reduce consumption and to create sustainable desalination processes based on renewable energy. Adsorption desalination (AD) is considered one of the most energy-efficient processes. A research team at King Abdullah University of Science and Technology (KAUST) conducted a successful pilot project, and the first industrial-scale AD test has been approved for construction in Saudi Arabia. AD can use direct solar energy or industrial waste heat to desalinate high-salinity water, but its initial capital cost remains an issue that needs to be addressed through modeling and investigation of its payback period. Membrane distillation (MD) is a heat-driven, low-energy process that uses hydrophobic microporous membranes to separate fresh water through liquid-gas equilibrium. This method is based on a combination of traditional distillation and membrane technology involving heat and mass transfer. Preliminary studies indicate that at higher fluxes, hydrophobic membranes can produce high-quality water even when the temperature gradient between the hot and cold streams is as low as 10°C. However, several major obstacles, including the low permeation flux and low thermal efficiency of MD modules, hinder their large-scale commercialization. More research is needed to develop new MD membranes with high throughput, in order to increase the permeation flux and thermal efficiency by utilizing industrial waste heat or by combining it with direct use of solar energy. The forward osmosis (FO) process can be used directly or indirectly to make the desalination process more energy-efficient. The indirect FO seawater desalination process uses a low-salinity feed solution (such as wastewater) to dilute high-salinity seawater and produce partially desalinated water that can be used for irrigation. Ongoing research shows that the fouling on the membrane surface is low, while pollutants such as micropollutants, natural organic substances, trace metals, and nutrients from the feedwater can be completely removed. However, there are still many aspects that need to be explored before applying this technology to commercial production in the Middle East. The development of high-throughput FO membranes will be a breakthrough for scaling up the process and achieving commercialization. As the demand for freshwater in the Middle East grows, the future of seawater desalination will depend on the combination of existing and emerging technologies. Researchers need to focus on the combination of forward osmosis (FO), membrane distillation (MD), and adsorption desalination (AD), as well as conventional desalination processes such as thermal desalination and reverse osmosis. This combination will help develop seawater desalination technologies powered by energy-efficient and renewable sources. In addition to developing energy-efficient and environmentally friendly seawater desalination technologies, good water resource planning and management are crucial. Reclaimed water technology holds great potential to increase the utilization of treated domestic and industrial wastewater, thereby generating an adequate supply of fresh water.
We welcome more people to participate in these discussions in order to support China’s chemical industry and praise its equipment manufacturing sector. Click on the blue link to access it: The 【Haichuan Equipment Guessing Game】 series is being updated continuously in 2022; we invite all our friends to join actively! https://bbs.hcbbs.com/thread-2079686-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum) Summary post on the series 【Major Equipment in the Chemical Equipment Industry】 https://bbs.hcbbs.com/thread-3312079-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum) Summary post discussing the components of cracking furnace equipment for 【Ethylene Cracking】 https://bbs.hcbbs.com/thread-3308724-1-1.html (Source: Huahai Chuanliu – Haichuan Chemical Industry Forum)