May, 2025 || Volume 29 No.03
Volume 29(3) (2025)3-6
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1
Membrane desalination as one of the sustainable option for water needs of coastal India
CSIR Central Salt & Marine Chemicals Research Institute,
Ministry of S & T, Govt. of India; G.B. Marg, Bhavnagar 364002 (Gujarat), India
https://doi.org/10.71122/JIGU.29(3)2025.0014
ABSTRACT
India would move to water-starved country by 2030 (per capita availability ~ 1,000 m3/year) from water surplus (~6000 m3/year) in 1947. To make potable water available, desalination by membrane processes will play a major role. The desalination membrane research has been carried out since 1969 at CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar (Gujarat) with an aim to develop technology to meet the demand for clean water. The institute has given research priority on this membrane-based water desalination over the years, and now it has the capability on providing solutions as per the locational requirements. However, worldwide, a core environmental concern of desalination plants is the reject stream discharge from the plant. Zero-liquid-discharge process by rightful management of reject stream, is key towards achieving sustainable desalination.
2
Ocean energy technology development and demonstration activities by NIOT
Biren Pattanaik*, Anulekha Majumdar, Prasad Dudhgaonkar and Purnima Jalihal
Energy and Freshwater Group, National Institute of Ocean Technology, Narayanapuram, Pallikaranai, Chennai -600 100, Tamil Nadu, India.
https://doi.org/10.71122/JIGU.29(3)2025.0015
ABSTRACT
Today, the world faces several climate change-related issues due to pollution. The globe is seeing several alternate sources of renewable energy. Also, there is an acute energy crisis due to fast-depleting fossil fuel reserves on the earth, and there will be a time, when the known reserves will become extinct, or extraction from these reserves will become highly costly and technologically challenging, not forgetting the fact that this exploitation has led to adverse effects on the earth’s climate. While solar, wind, biomass, and other forms are already being tapped globally, renewable energy resources that can be harnessed from the vast oceans, have now become a focus of the scientific community worldwide. The oceans offer huge spaces where new technologies can be tried and tested without affecting human settlement or the environment. Many countries have already started working towards this. In India, this development is led by the National Institute of Ocean Technology (NIOT). Extensive efforts are being made at this institute to develop technologies related to the energy extraction from ocean waves, based on the oscillating water column principle, from ocean currents using principles of hydrokinetics, and from ocean thermal gradient along the sea depth using a rankine cycle. The floating wave energy devices like backwards bent ducted buoy and wave-powered navigational buoy, cross flow hydro kinetic turbine and Open cycle ocean thermal energy conversion (OTEC), are a few of the technologies that have been developed and demonstrated. The development consists of numerical analyses, laboratory studies and open sea trials. This paper briefly discusses these developmental activities and the status of the development of ocean energy by NIOT. It also discusses all these indigenously developed ocean energy conversion systems, their performance during the testing phase, and their challenges and opportunities in India.
3
High capacity offshore low-temperature thermal desalination plant: A new perspective
Ashwani Vishwanath*, Purnima Jalihal and Abhijeet Sajjan
National Institute of Ocean Technology (NIOT), Pallikaranai, Chennai-600100, India
https://doi.org/10.71122/JIGU.29(3)2025.0016
ABSTRACT
National Institute of Ocean Technology (NIOT) has been working on developing technologies to ameliorate the shortage of drinking water in island and other coastal areas. Towards this, various onshore desalination plants have been constructed and operated utilizing ocean thermal gradient. For high capacity ocean energy and desalination plant, going offshore is considered to be a viable option. This article discusses the experiences and work carried out for ocean thermal gradient based large capacity desalination plant. Offshore plants have their own complexities with regard to design of platform, moorings and sea water pipelines. These components were studied thoroughly and discussed in the article. The design philosophy and results have been presented for a design of 10 million liters per day (MLD) capacity desalination plant, mounted on semi-submersible platform moored in 1000 m water depth.
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Powering desalination with renewable energy
Energy & Fresh Water Division, National Institute of Ocean Technology, Chennai-600 100, Tamil Nadu, India
https://doi.org/10.71122/JIGU.29(3)2025.0017
ABSTRACT
Today, the world is facing two challenges, water stress and climate change, for which anthropogenic causes leading to greenhouse gas emissions, are considered responsible to a large extent. One of the ways to mitigate water stress is desalination. Today, renewable energies are being taken up rapidly to reduce greenhouse gas (GHG) emissions; however, newer forms of energy, like ocean energy, need to be taken up seriously to further augment the clean energy quantum. By coupling desalination with renewable energy, we can simultaneously reduce GHG emissions and alleviate the water stress. The paper discusses the possible hybridization strategies and challenges for the same. Each type of renewable, along with the suitable type of desalination method, needs more study, and complexities for constant powering for water generation need to be addressed.
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Membrane based desalination systems for seawater
E. Poonguzhali and S. Prabhakar*
Department of Chemical Engineering, College of Engineering and Technology,
SRM Institute of Science and Technology, Kattankulathur - 603 203 Chengalpattu District, Tamil Nadu, India
sivaprabha50@gmail.com
ABSTRACT
Desalination is a necessary supplement for the already existing natural resources to meet the growing demand of fresh water. It requires energy to separate the vast resources of seawater which contains around 3.5% of dissolved salts. Several technologies have been developed in recent years, besides the century old thermal desalination processes. This article provides an overview of the membrane technologies, particularly focusing on the most used Reverse Osmosis for seawater desalination.
6
Site feasibility for offshore wind farm development: A preliminary case study at Jakhau, Gujarat (India)
E. Sathish Kumar*, I. S. Judha Benhur, G. Dhinesh, K. Mullai Vendhan and S. V. S. Phani Kumar
Ocean Structures Department, National Institute of Ocean Technology, Chennai- 600100, India.
https://doi.org/10.71122/JIGU.29(3)2025.0019
ABSTRACT
Renewable and sustainable energy technologies have been adopted globally to meet increasing energy demands. Offshore wind farms are crucial for reducing greenhouse gas emissions and enhancing the availability of power supply. Planning offshore wind energy farm development, involves carefully considered multiple variables to identify the ideal project sites. This study assesses the feasibility of offshore wind farm development along the northern coast of Gujarat, India, which has been identified as an optimal zone for wind energy generation. This assessment was based on a long-term analysis of critical parameters, including wind speed, bathymetry and met-ocean conditions. The annual average wind speed in the study area is about 7m/s, making it feasible for offshore wind energy production. Bathymetric data show depth values ranging from 10 m to 23 m, suitable for monopile foundation structures, recommended for offshore turbines in shallow waters. The site experienced a maximum tidal fluctuation of 3 m, which affected the turbine design and placement. Wave patterns were analyzed to understand the local wave climate. This study incorporates these parameters into the site selection process, considering environmental sustainability, technical feasibility and cost-effectiveness. The results suggest that the identified location of the northern Gujarat coast provides a suitable environment for developing an offshore wind farm. This study gives valuable insights into the criteria required for the early planning stages of offshore wind projects. The findings show that the Jakhau, Gujarat has a good potential for offshore wind farm development.
7
Geothermal energy: A multi-utility energy source
Formerly Geological Survey of India, Nagpur-440006, (Maharashtra), India
https://doi.org/10.71122/JIGU.29(3)2025.0020
ABSTRACT
Geothermal energy is the anomalous heat content in the interior of the earth, reported mostly along the plate boundaries, fault zones, volcanic terrains and deep seated igneous injections. Geothermal system is mainly established due to deep circulation of water through conduit zones. Hot water springs and steam emission are the main manifestations of geothermal resources. The geological investigation and exploration by drilling, helps in the development of such resources. The temperature of hot springs may vary from 30 to 97°C on surface. This hot water content is used for generation of electricity, mostly in USA, Japan, New Zealand etc. Geothermal energy being a renewable natural resource with very less carbon emission, is an environment friendly energy source. Besides electricity generation, geothermal resources can be used for direct heat uses like refrigeration, greenhouse cultivation, aquaculture, tourist attraction, spa and bath centers. It is a renewable, 24x7 source of energy, useful to control the pollution and greenhouse effects.
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Oceanic perspectives on renewable energy conversion: A comprehensive review in the Indian context
S. Sandana Socratesa,b, V. Srirama,b* and V. Sundarb
Center of Excellence in Maritime Experiments to Maritime Experience (ME2ME)
Department of Ocean Engineering, Indian Institute of Technology, Madras-600036, Tamil Nadu (India)
https://doi.org/10.71122/JIGU.29(3)2025.0021
ABSTRACT
The demand for energy exploitation by natural means has currently become popular, which poses several issues related to global warming. The extraction of the abundance of energy from the marine environment that can cope with the ever-increasing demand is exciting and challenging for its sustainable aspects. The prominent forms of energy available in the sea are due to waves, tides, wind, and thermal gradients. Several existing research has focused on these challenging tasks for renewable energy conversion. This paper discusses the modern, innovative, renewable hybrid marine energy converters that are proposed and attempted globally, and also illustrates the relevance of these technologies in the Indian context. Further, the projects that have been explored on the Indian coast and the future potential that could be explored are also discussed.