Water plays a fundamental role in modern industries worldwide, serving as an indispensable resource across various sectors. This article explores water’s diverse industrial applications and identifies the sector that accounts for its most significant use.
Understanding Industrial Water Use
Industrial water use encompasses all water withdrawn by industries for a wide array of processes, extending beyond just manufacturing. This includes water employed in the production of goods, the generation of energy, and the maintenance of industrial facilities. Water’s unique properties make it fundamental for industrial operations. It functions as an effective solvent, useful in chemical processes and product formulations.
Water also acts as an efficient coolant, absorbing and dissipating excess heat generated by machinery and processes, thereby preventing equipment damage and ensuring operational stability. Additionally, it serves as a transport medium for materials, such as in slurry pipelines or for washing and rinsing products. Industries also use water for creating steam, which can be a direct energy source or used to drive turbines for electricity generation. The volume of water withdrawn by industries varies significantly depending on the specific processes and products involved.
The Foremost Industrial Water Application
Thermoelectric power generation is the primary industrial water use. These power plants, which include facilities fueled by coal, natural gas, oil, and nuclear energy, generate electricity by heating water to produce steam. This steam then drives turbines, which power generators to produce electricity. Once the steam has passed through the turbines, it must be cooled and condensed back into liquid water to complete the cycle and maintain efficiency.
This cooling process is where the substantial water demand arises. Power plants withdraw large volumes of water, typically from nearby rivers, lakes, or oceans, to absorb heat from the steam in components called condensers. While a significant portion of this water is returned to its source, often at a warmer temperature, a considerable amount is lost through evaporation during the cooling process, particularly in cooling towers. Thermoelectric power generation accounts for approximately 40% of total water withdrawals in the United States, highlighting its dominance in industrial water use.
For instance, in 2021, the U.S. electric power sector’s water withdrawal intensity was about 11,595 gallons per megawatthour (gal/MWh) of electricity generated. While these plants withdraw immense quantities of water, only about 2.5% of the withdrawn freshwater is consumed through evaporation. Most is returned to the environment, though its temperature can be elevated. The reliance on water for cooling makes thermoelectric power generation the leading industrial water user globally.
Other Significant Industrial Uses
Beyond thermoelectric power generation, various other industrial sectors rely on water for their operations, each with distinct applications. Manufacturing industries, for example, use water as a direct ingredient in products such as beverages, pharmaceuticals, and certain chemicals. Water also serves as a solvent for cleaning, washing, and rinsing equipment and products, ensuring quality and hygiene. The chemical industry uses water extensively for cooling various reactions, with over 90% of its water use dedicated to this purpose.
The mining sector utilizes water for mineral processing, separating desired minerals from raw ore. Water is also employed for dust control on mining sites to improve air quality and for slurry transport, moving finely crushed materials through pipelines. In industrial-scale agriculture, distinct from crop irrigation, water is used in large food processing plants for washing, cooking, and preparing food products. Water is also used for general cleaning and sanitation throughout industrial facilities, maintaining cleanliness and preventing contamination.
Industrial Water Lifecycle
The journey of water through an industrial facility typically begins with withdrawal from a source, such as surface water bodies, groundwater, or municipal supplies. Before use, this raw water often undergoes treatment to meet the specific quality requirements of industrial processes, such as demineralization for sensitive machinery or purification for product formulation. The required grade of water can vary significantly, from potable water for food production to ultrapure water for electronics manufacturing.
Once used, industrial water follows one of two primary paths: discharge or reuse. Discharged water, often called effluent or wastewater, undergoes treatment to remove pollutants and ensure it meets regulatory standards before being returned to the environment. Many industries also implement recirculation and recycling practices, where water is treated and re-entered into the industrial process. This approach minimizes fresh water intake, reduces wastewater volume, and helps conserve water resources and mitigate environmental impacts.