Browsing by Author "Garg, Kapil"

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    A comprehensive review of pre-and post-treatment approaches to achieve sustainable desalination for different water streams
    (Elsevier, 2023-09-09) Poirier, Kristofer; Lotfi, Mohsen; Garg, Kapil; Patchigolla, Kumar; Anthony, Edward J.; Faisal, Nadimul Haque; Mulgundmath, Vinay; Sahith, Jai Krishna; Jadhawar, Prashant; Koh, Liam; Morosuk, Tatiana; Al Mhanna, Najah
    Desalination is an energy intensive process requiring adequate pre- and post- treatment. The novelty of this paper is that it jointly reviews the technologies for pre-treatment, desalination and post-treatment and bridges the gap between them while comparing the treatment methods needed depending on the type of feed water including seawater, brackish water, municipal and industrial wastewater. Those different streams show wide variability, sometimes containing organics, oil or scaling precursors which require adequate treatment. Nowadays, membrane pre-treatment methods have become promising alternatives to conventional pre-treatment techniques thanks to their flexibility. Hybrid desalination technologies have shown great potential in reducing energy consumption. Moreover, desalination plants produce large quantities of brines which require post-treatment to reduce environmental impacts. Current research on post-treatment is looking into recovering salts, metals and potable water from brines to achieve zero liquid discharge (ZLD). Thermal-based ZLD technologies are capable of extracting those resources while membrane-based ZLD methods are mostly limited to pre-concentration and water recovery due to fouling issues. Several studies have shown that ZLD systems can lower the cost of water and increase profitability if crystals and water are recovered and sold for additional revenue.
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    ItemOpen Access
    Thermodynamics analysis of a novel absorption heat transformer-driven combined refrigeration and desalination system
    (Elsevier, 2022-12-21) Beniwal, Ravi; Garg, Kapil; Tyagi, Himanshu
    Preservation of food and medicines below sub-zero temperatures is the need of the present times. To achieve the required temperature using renewable energy, a waste heat-driven vapour absorption refrigeration system can be implemented. Majority of the available waste heat is available in the low temperature range i.e. between 60–80 °C, which cannot be directly used to provide refrigeration. Therefore, an absorption heat transformer (AHT) is coupled with the VARS (Vapour absorption refrigeration system) system which increases temperature of this waste heat, and the upgraded heat is utilized to produce required refrigeration effect. Further, the rectifiers’ waste heat of the absorption system will be used to power humidification-dehumidification (HDH) desalination cycle. Although all these three components (AHT, VARS, and HDH) have been studied individually, but they have never been combined altogether. This paper presents a mathematical model for the proposed system and its validation against published available literature. The performance parameters such as coefficient of performance, gain output ratio and refrigeration effect of the system is evaluated at different evaporator and desorber temperatures. For 300 kW waste heat at 80 °C, evaporator (VARS) temperature of −10 °C, the system reported 70 kW of refrigeration effect is provided with 20 kg/hr of distillate production rate. An exergy destruction of 82.64 kW has been reported for total input exergy of 142.2 kW, for refrigeration capacity of 157 kW.