Hydrogen Station Explosion – Aftermath

The hydrogen station at Kjørbo is centrally located in Sandvika outside of Oslo, by two of the busiest roads in Norway with 80 000 cars passing daily. It is in Bærum municipality, and Akershus county. It exploded on Monday 2019-06-10. Since then, a number of interesting – some might say alarming – facts have emerged.

The station was a joint venture between X-Uno, Nel and Nippon Gases (formerly Praxair), announced on 2016-04-01. It uses Nel technology for on-site hydrogen production from electrolysis. The station is co-located with Powerhouse Kjørbo, an energy-positive office building, that uses solar panels that can supply upward of 200 000 kWh each year, twice the amount of the building’s annual energy consumption. Some of this excess energy was to be used to produce hydrogen.

The project had a total budget of NOK 28.4 million, of which NOK 5.7 million was support from the Akershus County Council and NOK 7.7 million was from the Norwegian public enterprise, Enova, responsible for the promotion of environmentally friendly production and consumption of energy. Other project partners included consulting firm Asplan Viak and Bærum Municipality.

Nel is an electrolysis technology company that has expanded into the hydrogen market. Its roots going back to technology developed by
Norsk Hydro in 1927. It is the world’s largest electrolyzer manufacturer with more than 3500 units delivered in over 80 countries. It is also a world leading manufacturer of hydrogen fuelling stations; approximately 50 stations delivered to 9 countries.

Safety Assessment

Bærum municipality has clearly stated that they did not have the competence to say whether the station was safe or not. They pointed out that the operator Uno-X sent its risk analysis to the Directorate for Civil Protection and Emergency Planning (DSB), relying on the authority to intervene if they saw the station as a security risk.

But DSB did not assess the analysis. Neither do they need to do so with anyone who stores or produces hydrogen in Norway. It emerges from DSB’s overview of hydrogen facilities in Norway, that the limit for having to get approval from the professional authority is actually set so high that it does not apply to anyone.

A total of 5 tonnes of hydrogen can be stored before it is subject to major accident regulations. Then another regulation on the storage of hazardous chemicals enters, which requires consent from DSB. That said, 100 grams of hydrogen can cause a serious situation if it is handled incorrectly, and less than one kilogram can lead to a fatal accident.

The 5 tonne limit is taken directly from Seveso, the relevant EU directive, which has been placed in the Norwegian major accident regulations. DSB is nevertheless free to demand that organizations obtain approval even if they are below the limit. However, DSB must argue that the risk dictates it, and then make a decision. It was not done at the hydrogen filling station in Sandvika. DSB is now also asking whether the limit of 5 tonnes of hydrogen is reasonable.

The amount of hydrogen stored when it exploded in the Uno-X station in Sandvika is uncertain, but in the safety analysis, the company estimates that they would store up to 100 kilograms during the first 1-2 years.

Leakage without Alarm

Perhaps the most disturbing fact emerging is that there was a hydrogen leak for an estimated 2.5 hours, that did not set off any alarms before the station exploded.

Nel installed the technology at the station and has admitted their responsibility for the explosion.

They are now reacting to the accident with a four point action plan. First, with a verified plug solution, they intend to inspect all high pressure storage units in Europe, and to check and re-torque all plugs. This should prevent the same circumstances arising in the future.

Second, they are updating their routines for assembly of high pressure storage units. This includes the introduction of a new safety system, and routines that follow an aerospace standard. This includes torque verification, double witness and documentation/marking.

Third, there is a need for improved leak detection, since it is estimated that hydrogen leaked from the tank for 2.5 hours, without this being detected. Thus, no alarm sounded before the tank exploded. Initially, this will involve a software update to increase leak detection frequency. However, they will also consider additional detection hardware and/ or modifications to the existing equipment.

Fourth, ignition control measures will have to be implemented. These are site dependent. A smooth surface, without gravel, should surround any high pressure storage unit. Additional ventilation may also be required, along with greater use of EX-equipment. That is, electrical equipment specifically designed for hazardous locations. This type of equipment should be specially designed and tested to ensure it does not initiate an explosion, including – but not restricted to – those due to arcing contacts or high surface temperature of equipment.

Incorrect Assembly of Equipment

The safety consulting company Gexcon, along with SINTEF and Bureau Veritas, is responsible for investigating the accident. They have found that a plug in one of the hydrogen tanks was mounted incorrectly and that this is why hydrogen leaked into the air and formed a cloud that eventually exploded.

On Friday, 2019-06-28, Nel, the company manufacturing the hydrogen distribution equipment, and who has taken responsibility for the explosion, explained how the incorrect assembly took place. Their presentation – which appears to be part public relations information about the company and part explanation for the incident – is here.

  1. Materials OK
    1. Magnetic particle inspection
    2. Penetrant testing
    3. Verification of materials
  2. Design OK
    1. 1 000 000 cycle accelerated test
  3. Assembly NOT OK
    1. Bolt analysis
    2. Physical gap
    3. Opening torque
  1. Starting condition.
    1. Green bolts torqued properly
    2. Blue bolts not torqued properly
  2. Red sealing fails.
    1. Starting with small leak on red sealing area
    2. Small leak wears red sealing out and escalates
    3. Large leak exceeding capacity of leak bore, causing pressure increases inside blue sealing area
  3. Bushing with Plug lifts and the blue seal fails.
    1. Insufficient pretension of bolts leads to lift of the plug and blue sealings fail immediately
    2. Spread of Hydrogen leaks out in uncontrolled way

There are two main candidates for ignition that are probably impossible to distinguish between. These are: 1. Self-ignition by static electricity mixed with optimum amount of oxygen and hydrogen led to ignition. 2. Gravel on the substrate at the tank, which lay at the very bottom in one corner. Wind acting on the gravel may have caused friction which led to ignition.

An additional report is expected to be released at the end of august 2019.

V2: The content was updated 2019-06-30 at 17:30.

Hydrogen Station Explosion

2019-06-10, the Uno-X hydrogen station at Sandvika, near Oslo, Norway, was destroyed in an explosion. The explosion led to the activation of airbags in two nearby cars. (Photo: NRK)

An explosion, most likely in a single hydrogen tank, occurred at the Uno-X hydrogen station at Sandvika, near Oslo, on 2019-06-10. When writing this post, the cause of the explosion was not known.

While no one appears to have been directly injured in the explosion, two people driving in the vicinity were injured when their airbags activated because of air pressure from the explosion.

The explosion resulted in the closing, in both directions, of two major highways. European Highway 16 (E16) is the major east-west connection between Bergen and the Swedish border. The E18 connects southern Norway with Oslo.

For those interested in robotics, a LUF 60 wireless remote controlled mobile firefighting support machine, was actively used to suppress the fire that followed after the explosion. More importantly, it was used to cool other unexploded hydrogen tanks, to prevent them from exploding. In addition, a platform lift with water canon assisted with this task. These two vehicles allowed firefighters to keep their distance.

Norway’s other two hydrogen stations, one in Skedsmo, another Oslo suburb, and the other in Bergen, have now been closed.

According to Norwegian Hydrogen Forum as of 2018-12-31 there were 148 hydrogen cars registered in Norway: 57 Toyota Mirais, 27 Hyundai Nexos, and 64 Hyundai iX35s. In addition to this there are 5 buses and 1 truck. In contrast, as of the same date there were 200 192 plug in electric vehicles, plus 96 022 hybrid vehicles.

In another post titled Methane vs Electricity, a significantly flawed study from the Munich-based IFO Institute for Economic Research, was examined, along with its support for methane based, hydrogen vehicles.

With this explosion, hydrogen supporters in Norway will have lost much of the little good will that hydrogen fuel cells have built up. It has probably resulted in the last nail being put into the hydrogen car coffin.

Methane vs Electricity

The Solar (and battery) powered Sion EV, to be made by Sono Motors at the former Saab car plant at Trollhatten, Sweden. A more environmentally friendly choice than a methane powered vehicle. (Photo Sono Motors)

A study from the Munich-based IFO Institute for Economic Research, claims that battery electric cars are dirtier than those that are diesel powered. It proposes methane based, hydrogen vehicles. This study is significantly flawed.

For inforation about the report see: http://www.cesifo-group.de/ifoHome/presse/Pressemitteilungen/Pressemitteilungen-Archiv/2019/Q2/pm_20190417_sd08-Elektroautos.html

IFO is an acronym from Information and Forschung (research). As one of Germany’s largest economic think-tanks, it analyses economic policy and is widely known for its monthly IFO Business Climate Index for Germany. Its research output is significant: about a quarter of the articles published by German research institutes in international journals in economics in 2006 were from IFO researchers. Unfortunately, I have been unable to find more recent data to support this claim. According to the Frankfurter Allgemeine Zeitung ranking, it is also Germany’s most influential economics research institute.

Part of the problem is the recycling of disproved research. The claim promoted by ICE (internal combustion engine) automakers and the fossil fuel industry, is that electric vehicles are worse for the environment because they are powered by dirty electricity.

Studies looking at overall emissions based on electricity generation have debunked this and showed that electric cars are cleaner and becoming cleaner as renewable energy is becoming an increasingly more important part of the electric grid. Previous studies have shown that EVs are cleaner than diesel no matter which European grid electricity is used.

The new twist in the new report, is that EVs use significant amounts of energy in the mining and processing of lithium, cobalt, and manganese, which are critical raw materials for the production of EV batteries.

The major error here, is an assumption that EV batteries become hazardous waste after 150 000 km or ten years. This is untrue. First, 150 000 km is shorter than the warranty period for an EV battery, which is generally 160 000 km.

There are requirements in place throughout Europe for the recycling of batteries. Even in a depleted state, they are valuable because lithium is a scarce resourse. Lthium ion batteries are not considered hazardous waste, although lead acid batteries are, because of the lead.

Cobalt and manganese are also recycled.

The study also concludes that methane-powered gasoline engines or hydrogen motors could cut CO2 emissions by a third and possibly eliminate the need for diesel motors. Again the conclusions are not matched by the facts.

Most hydrogen is produced using steam-methane reforming, a production process in which high-temperature steam (700°C–1,000°C) is used to produce hydrogen from a methane source, such as natural gas. Methane reacts with steam under 3–25 bar pressure in the presence of a catalyst to produce hydrogen, carbon monoxide, and a relatively small amount of carbon dioxide. Steam reforming is endothermic, heat must be supplied to the process for the reaction to proceed.

This is followed by a water-gas shift reaction, where carbon monoxide and steam are reacted using a catalyst to produce carbon dioxide and more hydrogen. In a final process step called pressure-swing adsorption, carbon dioxide and other impurities are removed from the gas stream, leaving essentially pure hydrogen. Steam reforming can also be used to produce hydrogen from other fuels, such as ethanol or propane.

Steam-methane reforming reaction
CH4 + H2O (+ heat) → CO + 3H2

Water-gas shift reaction
CO + H2O → CO2 + H2 (+ small amount of heat)

The production of 1 ton of hydrogen produced 19 tons of CO2.

Hydrogen can be produced through other processes, including the partial oxidation of methane, and the electrolysis of water. Neither is in significant use.

While Germany currently uses more coal power than most of Europe, it is cleaning up more quickly than most. By 2030, 2/3 of its energy will be provided by renewables. This was not considered in the study.

Other mistakes arise from using the flawed NEDC driving cycle. This gives unrealistically optimistic numbers for diesel emissions, and unrealistically pessimistic numbers for electrical emissions.

One of the most significant mistakes involves the comparison of the full production and lifecycle emissions of an electric vehicle, including the emission from the electricity uses, versus those for a diesel vehicle. Unfortunately, the study does not account for all the energy used to produce the diesel and supply it to the cars.

The German auto industry has under-reporting diesel emissions, going so far as to install cheat devises on vehicles. These emissions have caused thousands of deaths, something that billions in fines cannot compensate.

Fossil fuel extraction requires large amounts of energy, machinery and in many cases has detrimental effects on the environment. A Canadian favourite, tar sands oil, requires strip-mining tar mixed with sand, this has to be liquified and cleaned for transportation. Then there are transportation costs including tanker grounding, railcar derailments and pipeline leaks, all resulting in massive environmental damage, including ground water contamination.