Water wisdom

David H Koch assesses the prospects of membrane technology


Better known as one of the world’s most generous philanthropists, Koch Industries joint owner David H Koch has forged a strong link with the water industry

It’s not often that Utilities Middle East finds itself jostling for space on a meeting schedule that includes former US President George Bush and Dubai ruler HH Sheikh Mohammed Bin Rashid Al Maktoum, but then David H Koch is no ordinary interviewee.

As the joint owner and executive vice president of Koch Industries – one of the largest privately held companies in the US - Koch has interests in a number of verticals, not least the oil and gas and petrochemicals sectors, but it is soon obvious that the water industry is where his heart lies.

Koch developed his keen interest in membranes at the Massachusetts Institute of Technology (MIT) and after joining Koch Industries in 1970, took over as president of technology outfit Abcor, which eventually changed its name to Koch Membrane Systems (KMS) in 1981. It was this breadth of experience that led the International Desalination Association (IDA) to invite Koch to be the keynote speaker at last month’s World Congress, held in Dubai. In front of a cast of luminaries, which included a number of the GCC’s electricity and water ministers, the KMS president was unrestrained in his praise for the desalination sector and its importance with regard to future global stability.

In person, David Koch cuts an imposing figure, but his enthusiasm for the sector and affability are somewhat infectious. And when the interview turns to the new products being rolled out by his company in the water market, he seems clearly in his element.

On the new technologies front, Koch is keen to stress the merits of KMS’ newly re-engineered large-diameter seawater membrane, which was ably demonstrated with the presence of an 18-inch MegaMagnum element that took pride of place at the firm’s stand during IDA week.

“It’s a perfect example of the economies of scale, and large elements and larger housing in principle should cost less on a square-foot basis,” he explains. “I think that when we start getting large orders and volumes through, we can make these large elements a lower cost on the square-foot basis than the smaller elements. We’ve built a highly automated membrane manufacturing line, and we can push a lot of volume through it.”

Another benefit, says Koch, is that the housing weighs a third less than an equivalent number of 8-inch seawater housings at the same rated operating pressure. Furthermore, KMS is working on a configuration that will allow the company to assemble the housings together, which could reduce costs even further. “Depending on how the old 8-inch system was configured, you’re looking at savings of between 15-25%,” says Koch. “If you’re talking about a system that costs around US$30-50 million, that’s serious money.”

In addition, the use of large elements has the potential to lower facility footprints by as much as half, a point that is useful not only from a cost point of view, but also where systems are largely constrained by space, such as in urban areas, marine vessels or oil platforms. “I think that in order to be really successful in the large-element business, you have to offer the whole system; you can’t just sell the elements to the client and tell them to incorporate the products into their next project,” Koch explains. “Everything has to be integrated in a very systemic way.”

It’s no secret that demand for water in the Middle East is skyrocketing and the demands for the kind of systems that KMS manufactures are also rising steadily. The challenge is therefore on to look for different ways to improve existing technology, particularly as sustainability starts to play a more important role. Using less energy is clearly going to be a core requirement. So what technologies has KMS been examining?

“We’ve been doing analysis on a two-pass system; if you vary the performance of the seawater membrane, you can substantially reduce the pressure of the feedwater going to the first pass,” Koch indicates. “You then take the permeate that has a higher concentration of salt and feed it to a brackish water system. Depending on how you configure that, you can reduce the operating energy and, as a result, the cost.”

KMS’ automated manufacturing line has been designed to create membranes that have a wide range of properties, from high rejection and high pressure to low rejection and low pressure. “We can then dial in the properties of the membrane that our mathematical model predicts will give us the lowest operating cost,” observes Koch. “Generally speaking, reverse osmosis (RO) systems will operate more economically of the purity of the raw water going into the system is improved, so we’re also in the final stages of developing an ultrafiltration (UF) system that can more economically purify that water.”

While some observers have in the past claimed that RO technology may have reached its peak, Koch begs to differ. “I still think it’s possible to make up flat-sheet membranes that give you higher rejection with lower trans-membrane pressure – that would be wonderful,” he says. “Another area that I’m interested in is making seawater RO membranes out of hollow fibre, not flat sheet rolled into spirals.”

With recent advances in the textile industry enabling fibres to be spun at immense speed, with hundreds of fibres simultaneously, Koch thinks the scope for development is significant. A major factor here is that the cost of hollow textile fibres per foot is much lower than it is for UF membrane applications. “It’s just an engineering problem to make composite RO membrane in a hollow-fibre geometry; I think it ought to be possible to spin these RO hollow fibres at high speed and with great numbers simultaneously to gain a higher consistency and therefore a higher rejection,” the KMS president states. “That, I think, is the next great challenge in the membrane business.”

But KMS doesn’t see the drive for new technologies ending with just changes to the membrane. A holistic approach to system design, fouling and pre-treatment, and all the other variables that play a role in the membrane process, is likely to provide the best options, in terms of capital cost, to the end-user.

“There are still tremendous opportunities in the membrane bioreactor (MBR) area and all sorts of engineering modifications that can reduce the capital cost of MBR cartridges,” Koch explains. “We also have lots of ideas about reducing the amount of air used to scour the fouling off the membrane. We’re a long way from having optimisation of all the variables that go into the MBR field, which is probably the most under-developed area in RO desalination.” Koch also says that the biggest improvement on the UF side is the potential use of a fibre reinforced with a braid enabling it to be super-strong, thus solving breakage problems.

As the industry has grown, it has come in from some strong criticism from environmentalists about its effects on marine life and the harmful effects caused by brine discharge into the oceans. But Koch, like other company executives at IDA, is unequivocal in his assertion that the sector is doing its best to counter these accusations. “Modelling studies have shown that concentrated salt is very rapidly dissipated – if you go out a hundred metres away from the discharge pipe, salt concentration is reduced to the levels seen in the general body of the sea,” he argues. “I think it’s an inaccurate criticism and we need to use facts and data to disprove that as a serious concern. Long term, the general public will come to realise that that’s a criticism without any merit.”

Another major issue that is affecting the Middle East is that of privatisation, and Koch remains a strong advocate of the process as providing the greatest competitive benefits to the end-user. “The way it ought to work is that investment groups and companies like ours should build the plants, operate them and then sell the water over the fence to the municipality or industry,” he continues. “The more plants you build, the better you can operate them, and the cheaper the cost you can deliver to the municipality or client.”

Much of what Koch says highlights his appreciation of the value of cost to the client, and his confidence in the technologies that his company can provide. “I think the membranes have been proved to be theoretically the lowest-cost way to purify water,” he concludes.

“And as the industry gets bigger and bigger and more people invest in development projects, the cost of the systems will continue to decrease.”

KMS’s large-diameter MegaMagnum element
• Pressure vessel that houses 18-inch diameter, 60-inch length element
• The active membrane area has been increased by 12% to 3,500 square feet
• The housing is made from a glass-reinforced epoxy, which is stronger than previous vessels
• The new MegaMagnums will be available in Q1 2010


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