Hazards: learning from experience

New industries continue to emerge and develop, bringing with them new hazards. These can generate unforeseen safety risks and environmental impacts, as new technology introduces new ways of causing failures. Organisations also still fail to address even the foreseeable risks, as the lessons from many of the accidents experienced in more established industries are not learnt. It is important that we improve our understanding of all these risks, in areas such as nanotechnology, food technology, clean coal power supply, oil sands, next generation biofuels, renewable energy, nuclear power and decommissioning, and LNG supply.

The text above is part of the introduction to the IChemE “Hazards XXI” – Process safety and environmental protection symposium, scheduled for 9-12 November this year (Link). Last week IChemE advised that it will be publishing the out-of-print HSE accident reports on-line, so that we do not forget the lessons from such accidents as the Grangemouth BP Oil Refinery fires and explosion (1987), the explosion and fires at the Texaco refinery, Milford Haven (1994) and the Abbeystead water pumping station explosion (1994). Many plants, still operating today, pre-date the technology and knowledge in use when these accidents happened.

It is important that such reports are made easily available for the current generation of designers to be aware of history, and learn from the harshest of our experiences. In the USA the CSB (Chemical Safety Board: (Link)) is striving to publicise the findings of its accident investigations. The CSB approach (in contrast to that of the HSE in the UK, where their reports are apparently ‘out-of-print’) is to spend money and produce brilliant animations on video (available free of charge) to show just how simply the accidents they investigate happened, and therefore could have been prevented. The overall message I found from these is that good housekeeping is critically important on any process plant. One consistent example quoted is the failure of a tank high level alarm. This is obviously not seen as “sufficient reason to shut the plant down” by busy production staff: but so often the lack of attention to repairing such an alarm is symptomatic that there are other plant problems, and this leads to an event that automatically shuts operations off, permanently. Safety alarms (high level alarms) need to be able to operate automatically, just as experiences gained from accident reports need to be published and available.

Hima-Sella report that they have completed the design and installation of its first TOPS solution (Tank Overfill Protection System) for the Mayflower oil terminals in Plymouth, and presented TOPS at the recent Tank Storage Association (TSA) conference in Coventry. So if your new process and tank storage systems designers missed the Coventry meeting, as I did, maybe a trip to Manchester in November would be useful.

The Energy Event 2009

At the Energy Event last week, Atlas Copco were able to present a TUV endorsement of the nett zero energy consumption of their latest air compressor system, under certain atmospheric conditions. As a component in an energy management system, the extra heat is recovered from the 55-750kW ZR range of compressors in terms of hot water supplies from the cooling systems used by the compressors, balancing the work done in compressing the air by liberating the latent heat of the moisture in the air supply, in hot humid conditions. So for industries that can benefit from hot water supplies, ie food and beverage, pulp and paper, chemicals and power plants, the incorporation of this style of energy recovery compressor in the overall energy management system can lead to more efficient plant operations (Link).

A similar process input of otherwise wasted heat energy was on offer from Thermal Energy International, the new owners of the GEM venturi steam trap company. The GEM stand showed the TEI Flu-Ace, which is a flue gas energy recovery and pollution control system. The heat energy in the hot flue gases from a typical boiler, plus the latent heat within the water vapour in these hot gases, is recovered within the Flu-Ace unit, and the resulting hot water output stream can be used for process water heating. GEM also claim that the particulate removal in flue gases is 98% of particles over 1 micron. A recent Flu-Ace installation at a hospital site in Northern Ireland not only provided the benefits of energy recovery, but would avoid the cost of installing a tall flue gas discharge chimney to disperse these particulates from the boiler plant effluent (Link).

Several simpler systems were on offer for energy savings in any typical UK company. Magnatech offer passive permanent magnet systems to attach externally, directly onto a gas or oil fuel line, near the burner. The result is a higher fuel burn temperature, leading to faster boiler heating and less fuel used. Fuel savings of a minimum of 6% have been verified by the EU Tritech project: plus, for the real skeptics, Magnatech offer a full refund if you are not convinced after monitoring the results (Link).

A different approach was presented by Active Energy and PowerPerfector. Simply put, the power supplies in the UK average 242Vac: but most equipment is designed to work at a voltage of 220Vac. Using a step down transformer on the incoming supply will shave off the extra 10%, and thereby lead to energy cost savings of around 10% on your bill, as well as reduce the stress on your equipment by not running it at the upper end of the rated voltage (Link).

Sentridge Control are a West Midlands based ABB Drives Alliance partner, and presented a really effective demonstration of the power wastage from the use of a damper in an air flow control system: use of a variable speed drive immediately showed the 50% energy saving available when the air flow was reduced. Several of the Sentridge application examples are now available on Processingtalk http://www.processingtalk.com/news/esj/esj000.html.

Carbon Capture and LNG

Carbon (CO2) capture and hard water were discussed last week, and this has resulted in several new releases on the topics, as listed in the newsletter. The CO2 Capture Project, based in Illinois, has just issued a report entitled ‘A Technical Basis for Carbon Dioxide Storage’, explaining how to assess and manage industrial-scale CO2 geological storage (CGS) projects. Specifically in relation to ground water, a well chosen site for such CO2 storage is quoted as being at greater than 800m depth, with functional barriers that provide isolation from drinking water and the near-surface environment, as well as between geological storage intervals. More background can be found in the Enviro-talk pages on Processingtalk, (Link).
The CCP article reminds us that the Intergovernmental Panel on Climate Change believes CCS could contribute 15-55 per cent of the cumulative mitigation effort until 2100, while the International Energy Agency found that the cost of containing climate change would be 70 per cent higher without CCS.

So, I would like to raise a different aspect to this topic, to hopefully get some further feedback. I am a real fan of the LNG projects that are springing up around the world: but one article I consulted recently over CCS commented that most existing expertise in CO2 separation systems had been developed from the requirement to remove the CO2 and moisture from natural gas before it is liquefied, ie at the well. But instead of storing or re-injecting this CO2, it was quoted that the separated gas is “typically released back into the atmosphere”. Admittedly the levels of CO2 are lower than in combustion processes, between 5-10%, but we should not just throw captured CO2 back into the atmosphere. This would be an obvious place to look to avoid some CO2 emissions: does such CO2 release actually happen anywhere?

It certainly is not the case in Norway, as you would expect: the modern facilities of the Snohvit LNG project (led by Statoil) receives gas containing between 5% and 8% carbon dioxide from the offshore field: this is separated out at the processing and liquefaction facility and then returned via a separate 160km pipeline for storage/sequestration beneath the seabed (2,600m below the sea bed on the edge of the original gas reservoir source, in the 45m to 75m thick Tubasen sandstone formation) thus preventing undue (CO2) pollution and allowing Norway to adhere to the Kyoto treaty (Link).