Monday 30th July 2007
Instant Steam Feature Article
In what is believed to be a world first, UK scientists have invented a technology to generate superheated steam wherever it is needed, instantly and without the need for an external source of electricity – using a reactor that can be as small as a sugar cube. The key lies in the chemistry. Nina Morgan reports.
As chemical demonstrations go, it's an impressive trick. Chika Chukwuogo, a chemical engineer at the Oxfordshire UK-based company, Oxford Catalysts, squeezes the trigger of an ordinary HDPE spray bottle containing a mixture of methanol and peroxide. Out comes a cloud of high temperature steam.
The magic ingredient behind this chemical steam-in-a bottle is a small bed of powdered precious metal-based catalyst incorporated into a specially adapted nozzle mechanism. Squeezing the trigger causes the liquid fuel to pass over the catalyst and sets off the spontaneous and highly exothermic reaction:
CH3OH + 3H2O2 —> 5H2O + CO2 ΔH = -1006.5 KJ/mol methanol.
The reaction occurs very quickly – it takes just 1-2 seconds to produce steam – and it takes place at room temperature and atmospheric pressure. It releases only CO2 and high temperature steam. A reactor the size of a sugar cube can pump out up to 800°C steam at a rate of 7 litres per minute. And the larger the reactor, the higher the rate. A reactor just 2 cm high – roughly the height of a stack of 6 £1 coins – is capable of producing 70 litres of 650°C steam per minute.
Hot Stuff
Instant steam is not designed to generate the vast amounts of steam used in industry – BASF, for example used 53.8 million tonnes of steam in its operations worldwide in 2006. This is produced using waste heat or by cogeneration and requires a substantial capital investment (see Table 1). "Instead", explains Dave Wardle, Business Development Director at Oxford Catalysts, "the value of Instant Steam lies in creating truly portable steam that can be generated intermittently on demand." This, he notes, is an exciting area, with many potential applications. (see: ‘And That's Not All’ below)
One currently being explored in conjunction with OspreyDeepclean Ltd, a subsidiary of the Liverpool UK-based company Proventec plc, is for steam cleaning. The first potential use for the Instant Steam technology envisioned by OspreyDeepclean is in GumBusters, its steam-based technology for removing chewing gum from indoor and outdoor surfaces. GumBusters requires a minimum of 3kW of current to generate the steam used by each operator, and relies on generators carried on trolleys or in vans to produce the current. Instant Steam technology could make it possible to develop a backpack-based system to make GumBusters even more convenient and cost effective.
Another exciting prospect is the potential to apply Instant Steam to improve OspreyDeepclean's steam-based hospital disinfection systems. Research commissioned by the company and carried out by the Hospital Infection Protection Environmental Research (HIPER) Unit at University College London Hospitals in 2006 demonstrated that dry steam – or steam generated from small amounts of water compared to the volume of steam produced – applied at temperatures ranging from 150–180 °C could destroy bacteria, including antibiotic-resistant 'superbugs' such as MRSA and Clostridium difficile, in less than two seconds without the use of chemicals. OspreyDeepclean and HIPER plan to publish the results of this research soon. The company is also involved in establishing a new standard for steam disinfection.
"Steam – in combination with a specially developed range of tools and accessories to apply the steam to surfaces, and used in accordance with standard operating procedures – is an important part of our integrated approach to infection control," explains Thomas Stuecken, Managing Director of OspreyDeepclean and Chief Commercial Officer at Proventec. "The steam has to be extremely dry and at a high temperature. This is where Oxford Catalysts' technology scores over conventional technologies. Its use will make the system more portable and make it possible to place the steam where we need it, when we need it."
Although steam is already used for some cleaning applications in UK hospitals, and is widely used in Denmark, both for hospital cleaning and for combating sick-building syndrome, Stuecken believes its use can be greatly extended. "If we get the healthcare sector right, and if and when Oxford Catalysts develops their technology to meet our requirements, the opportunities are enormous", he says.
Wardle is similarly optimistic – and not just on the cleaning front. "This technology opens the door to new opportunities where the traditional method of making steam was considered inadequate or impractical", he says. "The design is very versatile and can be implemented to fit both small and large scale applications. We're always on the lookout for new ideas for uses."
| Traditional Steam | Oxford Catalysts' Instant Steam | |
| Start Up | Slow start up. | Instantaneous start up. |
| Energy | Energy required to vaporize water. | Self starting reaction. |
| Temperature and Pressure | High temperatures are only achievable by higher pressures, and thus, expensive vessels and associated systems. | Decouples the dependency of steam temperature on pressure. |
| Mobility and Portability | Usually requires an external power source, thus limiting its mobility and portability. | Requires only a rechargeable battery for temperature/flow control. |
| Gas Composition | CO, CO2, NOx and other gases emitted during fired boiler heating or at site of electrical energy production. | Approximately 15% (w/w) CO2 produced, depending on fuel concentration. |
| Size | Requires tank, boiler and superheater. | Only requires a fuel reservoir and a miniature reactor. |
And That's Not All
On the household front, Instant Steam created using a trigger bottle could form the basis of a new category of retail products where the heat from the steam is used to increase the efficacy of cleaning solutions or detergents used for degreasing. The steam alone could be used to kill weeds or strip paint or difficult wallpapers.
Instant Steam could also pave the way for the development of cheap and efficient sterilising systems, or form the basis for down hole steam generators to create localised heat for enhanced oil recovery.
It might also be used to drive small turbines to generate electricity in backup power systems. Or more speculatively, the steam could be used in turbine-powered environmentally friendly cars designed for urban use. With a slightly different fuel formulation combined with a more energetic catalyst, Instant Steam could even be used as a rocket propellant.
For more information about Oxford Catalysts's Instant Steam technology contact:
Dave Wardle, Business Development Director, Oxford Catalysts, 01235 841 700
To see a video of Instant Steam in action click here.
For more information about OspreyDeepclean steam cleaning technology contact:
Thomas Stuecken, Managing Director OspreyDeepclean and Chief Commercial Officer Proventec plc, 0151 706 0626
Nina Morgan is a freelance science writer based near Oxford. An article similar to this was featured in the 30th July 2007 publication of Chemistry & Industry.
