Problem solving for ammonia solutions
19 May 2020
An EU Directive covering the carriage of dangerous goods created a significant UK problem for the supply of ammonia solution. Temporary fixes will come to an end in February 2022. Chief Executive, Peter Newport, explains how the Chemical Business Association (CBA) and its member companies tackled the issue.
A standard IBC
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When the International Carriage of Dangerous Goods by Road (ADR) regulations almost halved the percentage concentration of Ammonia solution that could be legally carried by road, from 35% to 19%, several specialist sectors of the chemical supply chain faced serious issues.
Ammonia solution in the higher concentration is used for a number of specialist applications. It is a key chemical component in the recycling of catalytic converters, the approval process for many pharmaceutical products, in the disposal of military ammunition, and in dealing with slurry in the oil and gas sector.
The UK adopted the revised provisions of the ADR in 2000 but agreed to allow deliveries at the higher concentration to continue through the use of Multi-Lateral Agreements (MLAs). MLAs offered an interim solution that ensured supplies could continue.
They are authored by one party and have to be counter-signed by at least one other party in order to operate. The expiry date for MLAs can vary, but they normally last for five years unless they are extended due to the advent of new regulations.
MLAs provided the industry with some breathing space in order to tackle the precise requirements of the ADR regulations. The ADR regulations contained three key requirements in relation to the carriage of ammonia solution:
(1) It specified three types of Intermediate Bulk Containers (IBCs) that could be used to carry ammonia solution (Types 31H1, 31H2, 31HZ1).
(2) The IBC must be fitted with a device to allow venting during carriage and the venting device had to be sited in the vapour space under maximum filling conditions.
(3) The IBC(s) must be carried on an open vehicle (this includes curtain-sided vehicle). Carriage through the Channel Tunnel was specifically excluded.
These requirements are valid until 31 January 2022 for carriage of ammonia solution in territories that continue to remain contracted to the ADR agreement.
The central challenge within these provisions was the creation of a venting device that would conform to ADR’s requirements. The first step was to review a range of IBC models to establish if any conformed or could be adapted to meet the ADR’s provisions. It quickly became apparent that a simple solution of this kind was not available. The main stumbling block was the vapour pressure restriction imposed by the ADR.
Other problems involved the size and construction of IBCs. Supply chain companies required an IBC capacity of 1,000 litres. In addition, the use of plastic to form the containers was limited to five years and it was not economically viable to construct a more robust plastic container.
It became clear that a new design for an IBC would have to be developed. CBA therefore contacted Thielmann, a German company recognised as one of the world’s leading manufacturers of stainless steel containers and offering tailor-made in-house solutions to meet a range of design requirements.
The specification provided to Thielmann by CBA and a group of interested member companies was for a 1,100-litre cylindrical stainless steel IBC suitable for a liquid (Packing Group II) with a specific gravity not exceeding 1.00 and able to withstand hydraulic pressures of 550kpa. This specification was agreed, and development work began.
A prototype IBC was produced in a conical shape, with 2.5mm thick sidewalls, a convex head, two-inch camlock filling aperture, a butterfly outlet valve, and a pressure-relief valve. In January 2018, testing the prototype began. It successfully passed all its tests apart from the hydraulic pressure test. Over 510kpa, the base cone distorted forcing the valve handle onto the base plate causing the valve assembly to leak so the required pressure could not be maintained.
The redesigned IBC for ammonia solutions
Several possible solutions were considered, including making a hole in the base plate to allow the handle to move and making the walls of the IBC thicker. For different reasons, these solutions were not appropriate.
The design team then recalculated the ADR formula suggesting that the hydraulic pressure the IBC had to withstand was 550kpa. Research showed that the actual hydraulic pressure was 460kpa. The UK Department for Transport subsequently agreed this revised calculation.
In August 2018, the new IBC was retested and maintained its integrity at 460kpa for ten minutes. The results of the full range of testing procedures were:
• Vibration test - 3.95Hertz for 60 minutes
• Bottom lift test - 1,816.02kg load with 75% fork penetration
• Top lift test - 2,997.57kg load for 5 minutes
• Stacking test - 5,101.30kg load for 5 minutes
• Leakproofness test - 20kPa for 10 minutes
• Hydraulic pressure test - 65kPa, 200kPa, 350kPa and 460kPa (ten minutes each)
• Drop test - 98% water filled IBC dropped from 1.2metres
This example of the industry creating an innovative and effective solution to a significant regulatory issue was brought to a successful conclusion with the issue of the new IBC’s Vehicle Certification Agency in September 2018, the Department for Transport’s authorisation issued in April 2019, and the beginning of the final roll out phase in January 2020.
What is the ADR?
The ADR is a European agreement covering the transnational carriage of dangerous goods by road. It establishes specific conditions of carriage for nine separate classes of dangerous goods – from gases to flammable liquids and from oxidising substances, corrosive materials, and toxic substances. A distinguishing four-digit UN number is allocated to each hazard class along with an explanatory pictogram that must be displayed on the vehicle carrying the dangerous goods.
ADR is derived from the French ‘Accord européen relatif au transport international des marchandises Dangereuses par Route’. From 1 January 2021, the treaty is to be renamed the Agreement concerning the International Carriage of Dangerous Goods by Road.
CBA represents the UK’s independent chemical supply chain. Its membership includes distributors, traders, warehouse operators, along with logistics and transport companies. CBA’s members, the majority of which are SMEs, are the main industry interface with thousands of UK downstream chemical users.
CBA member companies employ more than 8,700 people. They distribute, pack, and blend over 4 million tonnes of chemicals each year with a market value of almost three billion euros. In addition, CBA’s logistics member companies handle more than four million tonnes of chemicals annually.
About the author:
Peter Newport is the Chief Executive of the Chemical Business Association. Peter is a key industry advocate to governmental and regulatory authorities in the UK and Europe. He is also a board member and current Treasurer of the European Association for Chemical Distributors (Fecc) and a board member of the International Chemical Trade Association (ICTA).
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