WATER AND OIL -THE SHELL STORY

Not all burn the water...

"Energy and water are interconnected. The energy industry needs water for drilling, flooding wells, refining crude and producing biofuels. Water is also used as steam to drive electricity turbines in power generation. At the same time, the purification, distribution and treatment of water and waste water require energy.

Demand for fresh water is growing. Yet access to fresh water supplies is becoming more restricted for many people. In some regions, freshwater reserves are being used up or polluted faster than they can be replenished.  And the world’s water resources will come under even greater stress between now and 2050 as populations grow and become wealthier.

At Shell we have water management plans at our operations to help us monitor and reduce our water use in water-stressed areas. Growing crops to make bio-fuels, for example, can be water intensive.

But sourcing the raw materials in countries like Brazil, where high rainfall reduces the need for artificial irrigation, can make a difference.

Shell is investing in Brazilian sugar-cane ethanol through Raízen, our joint venture with Cosan.

In its processing mills Raízen uses a system that recycles 90% of the water used to convert sugar cane into ethanol.

Elsewhere we use advanced technology to help reduce our water use.

Our Pearl GTL plant in Qatar, for example, turns natural gas to liquid products and is designed to take no fresh water from its arid surroundings.

In Oman we are using reed beds to clean water produced with oil.

This saves the energy needed to pump water back into the ground.

At the SAPREF refinery (Shell interest 37.5%) in South Africa we use recycled household water, and at our Clyde refinery (Shell interest 100%) in Australia we have launched a campaign to conserve water.

In the Netherlands, the Schoonebeek (Shell interest 30%) project will reuse municipal wastewater to make steam.

Looking to the future

The pressure on water and energy will continue to grow in the coming decades driven by rising prosperity and rapid urbanization.

To improve the measurement of water use in industry, in 2011 we worked with the World Business Council for Sustainable Development (WBCSD) and the University of Utrecht to develop a new methodology.

Now we can estimate more accurately the amount of water needed to generate energy from different sources – including oil, gas, coal, nuclear and biofuels – using different technologies and in different locations.

The findings were published in early 2012 in a peer-reviewed academic journal. We are sharing our data with the wider business sector and the International Energy Agency.

Water is a resource that is hard to come by in Qatar’s desert climate. The Pearl GTL plant produces more water than gas-to-liquids products.

The chemical reaction that occurs when synthesis gas is passed over catalysts in a gas-to-liquids (GTL) plant produces water as well as the building blocks for GTL products.

“The amount of water that Pearl GTL produces makes it possible to run the plant without drawing on Qatar’s scarce natural fresh water resources or on seawater,” says Rob Overtoom, Technology Manager on the Pearl GTL project.

Over the longer term Shell aims to use every drop of this water as part of our approach to not discharge any liquids from the plant. Pearl GTL’s industrial water processing plant is the world’s largest for the recovering, treating and re-using of industrial process water. With a capacity to treat 280,000 barrels of water a day, Pearl GTL’s water treatment plant is comparable to a plant for a town of 140,000 people.

After cleaning the industrial water by removing trace metals, hydrocarbons and any particles, most water is used for cooling by evaporation and for steam systems. Some of it is used for maintaining bushes, shrubs and trees at the plant.

Petroleum Development Oman (PDO, Shell share 34%) operates in some locations where waer is extremely scarce, yet it produces nearly five barrels of water for every barrel of oil. At the Nimr oil field, around 250,000 m3 of contaminated water is brought to the surface together with the oil. The water must be disposed of and this adds to the cost of production.

In 2008, PDO engaged German company Bauer Resources to build the world's biggest commercial reed-bed sewage treatment plant, covering 235 hectares. Since its start-up in 2010 the plant has been cleaning about 47,000m³ of water each day. This approach has the potential to make water available for use by locals.

The plant uses micro-organisms to clean contaminants, removing oil and leaving salt, which can be processed to industrial salt. Biomass is also produced and can be used as an energy source." 

Courtesy:Shell Global