Once upon a time, the acquisition and disposal of water in the refinery and petrochemical sectors used to be a relatively minor issue. ‘If it is cheaper to buy water from a municipality and dispose of salty water in an injection well, then that is what an oil company will do,’ said Edward Godeaux, a Technical Director with Siemens Water Technologies.
Now, a combination of legislation, growing demand and increasing scarcity is making it more important to find new sources and reuse water in as many ways as possible. And to do that, desalination is expected to play a key role. ‘I am very optimistic about the future of desalination,’ said Henri Inselberg, Vice President, Sales and Contracts, for IDE Technologies Ltd. ‘You can clean water up, or find new sources. The only new source left is seawater.’
There are two main technologies used to desalinate water: membrane and thermal. The most common membrane technology is reverse osmosis (RO), which pressurises seawater across a membrane that limits the transmission of ions, creating a pure water stream. Thermal systems heat seawater in vacuum conditions, causing the water to evaporate and subsequently condense as pure water. There are many regional producers of desalination equipment in the Middle East and Asia, but the international market is dominated by a small number of major manufacturers, including Siemens and Veolia of Europe, GE and Aquatech in the US, and IDE in Israel.
Reusing refinery water
Refineries use large amounts of water to desalt crude, to fill up the steam boilers used to crack oil, and in cooling towers to condense hydrocarbon fractions. ‘How much water you use depends on each facility,’ said Tom Schultz, an Oil and Gas Market Director for Siemens Water Technologies. ‘A 100 000 bpd refinery might use between 100 000 to 200 000 bpd of water.’
Generally, half of a refinery’s water usage is lost as steam, but the remaining half represents both a challenge and an opportunity.
Swimming up stream
According to Global Water Intelligence, the world spends approximately US$ 10 billion annually to add 6 million m3/d of new desalination capacity. Every year, hundreds of smaller desalination plants (under 10 000 m3/d) are installed around the world by regional firms. In addition, approximately 50 projects ranging from 10 000 - 500 000 m3/d are commissioned. Approximately 70% of the larger projects are in the Middle East, and the rest scattered throughout Asia, the Former Soviet Union and North America.
Although it is difficult to accurately estimate, oil and gas accounts for approximately 10 - 20% of that market. Industry participants see oil and gas taking on a more significant role within the desalination sector, however, as water needs in the upstream sector become more important.
In the next decade, breakthrough advances are expected to benefit desalination. ‘It’s the golden age of technology,’ said Sharma. ‘Global consolidation within desalination has created a few mega companies and there is little opportunity for investment in the mainstream. This is driving tremendous money into emerging technology entities that are uncovering new, creative, and, most importantly, cost effective methods of treating water. For instance, we are seeing nanotechnology being applied to membranes to reduce fouling, and all sorts of energy efficiencies. The amount of energy per m3 has dropped more in the last five years than it has in the last 25.’
And with increasing water scarcity, stricter regulations and a growing world population, there is little doubt that the future of desalination is bright. ‘I’m very optimistic that the market will grow,’ said Sharma. ‘It’s been very easily adapted in rich areas like the Middle East, and when I look at the needs for India and China, the potential is mind boggling.’
The full article can be found in the October issue of Hydrocarbon Engineering.
Gordon Cope, Contributing Editor
Read the article online at: https://www.hydrocarbonengineering.com/gas-processing/05102010/desalination_and_the_petroleum_industry/