Let’s just take the first step ”is the credo of Günther Schätzle, Head of Production Engineering and Logistics at CHT Germany in Tübingen, the German company of the worldwide group of specialty chemicals companies. In its rare After 20 years at CHT, a successful concept has consolidated for him: a sequential approach to new commissioning and flexible adjustments based on modular concepts in all areas – in other words: trying out what works step by step and making the most of the freedom to successfully meet the challenges. This approach proved successful again in a major project.
Legal requirements as a challenge
Chemical companies face complex and sometimes conflicting regulatory requirements when it comes to storing large amounts of various hazardous materials. Depending on the degree of risk and the amount stored, appropriately complex protective measures should be taken. In the case of different hazardous substances, it should always be checked if joint storage is allowed. The risk of fire and explosion must be carefully considered and taken into account in the fire protection concept. The approval process is demanding and lengthy.
For nearly 70 years, the CHT Group has been developing and producing chemicals for products and processes that are supplied to a wide variety of industries. The company’s headquarters in Dußlingen near Tübingen produces 50,000 tonnes of specialty chemicals annually for customers around the world. Several thousand tons of hazardous materials are stored on the site. The power plant is therefore subject to extended obligations under the major accident regulation and specific supervision by the authorities.
Construction projects against the usual procedure
As the products manufactured in the plant are becoming more complex and customer-specific, flexible and safe storage of a wide variety of hazardous substances is of utmost importance. At the same time, implementation of the storage rules for such substances is becoming increasingly complex. aggravating Added to this is the growing uncertainty of supply on the raw materials market. Logistics must therefore be efficient and flexible, and to this end, an on-site additional warehouse for hazardous materials was urgently needed.
In order to be able to cope with these tasks, Schätzle relied on a modular concept. In doing so, he chose not to take a typical industry approach – building another large open-rack warehouse. “Too inflexible, official obstacles and construction costs too high, project duration too long” was his conclusion. A large warehouse would have to be subdivided into separate fire zones according to the rules on shared storage. However, since the materials and quantities to be stocked can vary considerably in the course of day-to-day operations, classifying one off is a serious limitation. this size. However, memory modules can be delivered ready to plug in and set up immediately.
Five key key points for the project
In spring 2020, Schätzle brought in Denios, the specialist for the safe storage of hazardous materials. After a one-year technical and commercial planning phase, the two companies embarked on a joint project that included the supply of 30 storage modules and digital remote monitoring of system data. The five key points of the project were formulated together with a company specializing in industrial construction4: safety, flexibility, modularity, energy self-sufficiency, digitization.
The storage modules stand on a special concrete slab, designed as a watertight tub. Whole The structure with a floor, storage modules and a roof meets the requirements of all regulations, including those relating to the construction of plants in the 3rd earthquake zone, the highest category in Europe.
During the construction period, Denios has already delivered CHT’s first warehouse modules for uninterrupted interim storage. The final delivery of the remaining systems and final assembly went smoothly and quickly in early November 2021. 30 memory modules were configured over three weeks. A welding steel roof structure for the entire warehouse space was then constructed, electrical power was provided to all warehouse systems and a data network with an internal process control system, and a stationary fire extinguishing system was installed. The photovoltaic system on the roof ensures the energy-self-sufficient operation of the entire system.
Security and flexibility for all memory modules
The building permit process for the chemical warehouse was sped up by the fact that a general building supervision approval from the German Institute for Building Technology (DIBt) was available for each warehouse module. In this way, the warehouse of hazardous materials in conjunction with the water-legal approval of the general construction supervision for sewage tubs meets all the requirements of the official obtaining of a building permit. Each module is separately equipped with fire protection technology and assessed in accordance with legal requirements (including AwSV, TRGS 510) and properly dimensioned for local wind, snow and earthquake loads.
Two different types of modules are used in a modular chemical warehouse:
- An insulated warehouse of hazardous materials with fireproof insulation that must be set up with respect to the fire safety distance in the warehouse to protect adjacent installations and buildings from fire hazards.
- Fire-fighting warehouse (F 90 / REI 90), i.e. a warehouse for hazardous materials with a fire-resistant F 90 double-frame structure for fire protection on both sides. In the event of a fire inside, the outer support frame of the peace system provides the necessary support. If it is on fire outside, vice versa. The separation of the F-90 is designed to protect against each other
- Exposure to fire between the warehouse and neighboring objects and buildings. Safety distances are not required here.
Much more capacity on three levels
An insulated warehouse for hazardous materials offers significantly more capacity in three storage levels than a fire-fighting warehouse with two storage levels: 18 IBC or 60 barrels compared to 8 IBCs or 32 drums. However, due to the requirements of structural fire protection, a separate warehouse of hazardous materials may be installed only within safe distances, unless it borders on a separated fire-fighting area, such as a fire-fighting warehouse. To save space, the two different types of modules have been coordinated with each other economically and spatially, taking into account the fire protection distance, and arranged alternately. Schätzle draws his conclusions: “At first glance, it looks a bit chaotic that we have alternately arranged different memory module sizes. But that’s the whole trick. According to the regulations, more than twice as many pallets can be stored in the same area as if only one modular structure was used. “
Schätzle places particular emphasis on the additional flexibility of the new hazardous materials warehouse: “Each warehouse module provides a separate storage area in accordance with the Hazardous Materials Regulations. We can change the memory class to a module at any time. It is a very flexible concept that gives us the freedom we need to equip the warehouse with all storage classes that the TRGS 510 knows. “
In addition, each memory module is equipped with a Spillguard connect digital leak alert system, which transfers data to the cloud application via Narrowband IoT and makes it available for download to the user there. CHT converts the cloud data to MTP data format and uses it in its own process control system for condition monitoring. The entire system offers a high level of safety, which was convinced not only by TÜV. Also responsible approval authority for the construction project assessed the safety concept as future-proof for industry and approved the project particularly quickly.
Thanks to the large number of mutually separated storage modules, CHT can now respond immediately to any storage requirement. Quantity thresholds related to materials can be observed much better in smaller warehouses and adjustments due to changing requirements can be made much faster. “The benefits are absolutely convincing,” says Schätzle. From his point of view, the project is a model for the entire chemical industry and serves to secure locations in Europe. He has already received an offer for a second modular chemical warehouse. This concept should also be considered at other locations within the specialty chemicals group.