CATALYST HANDLİNG SERVİCE

Catalyst vacuuming
Unregenerated catalysts are prone to exothermic reactions on contact with ambient oxygen, which may occur after the opening of a reactor. In order to prevent uncontrolled reactions and for the purposes of primary explosion protection, the vessel is filled with an inert gas (nitrogen) before it is opened, so that the catalyst can be removed in safety. If, because of the nature of the plant, vacuum removal of the catalyst is necessary, enclosed mobile vacuum units equipped with nitrogen recirculation are used for safety reasons. In collaboration with specialised manufacturers, STH (Silver Teknik Heavy Industries) Service has developed vacuum units for pyrophoric catalysts. Safe technology permits working with unregenerated catalysts without danger while, at the same time, handling the contact gently.

Mechanical work
As a specialist service provider, STH Service performs mechanical work under both inert and normal atmospheric conditions. Our spectrum ranges from repairs to the complete replacement of internals. Appropriately trained personnel and equipment are available for the dismantling and assembly of internals. Welding work on internals using all known welding techniques are carried out by appropriately trained welders. This service guarantees efficient time planning for plant conversions. The different trades employed are coordinated by STH Service and, in this way, the shutdown duration is optimised.

Reactor loading
Continual optimisation processes required in the production, combined with increased quality requirements for the finished product, demand improved loading techniques for catalytic reactors. The good condition of reactor internals and exact catalyst loading according to specifications has a positive effect on your production results. Before the loading, our reactor specialists check the condition of all internal components and do not commence the loading process until the result is positive. Different loading methods, such as sock loading or dense loading techniques, can be applied according to the characteristics of the reactor. STH Service is licensed for all known dense loading techniques.

Regeneration of catalysts
 When an analysis of the removed catalyst has been carried out, the results with regard to residual activity and mechanical condition determine the possibility and the nature of its re-utilisation. In order, to prepare catalysts for repeated use, a professional external regeneration has to be carried out by specialised companies. For safety reasons, the remaining volatile hydrocarbons are first burnt off under controlled input of oxygen. In a second cleaning step, the remaining carbon components are then burnt off and the catalyst is fractioned in order to separate the quantity which can be re-utilised. A subsequent analysis confirms the suitability of this material for re-utilisation in the production process. The regeneration can be carried out in turnaround, i.e. during a shutdown, or the regenerated catalyst may serve as a spare batch for the next catalyst replacement. SILVER TEKNIK help you with the selection of suitable and approved partner companies and can organise the logistics required.

N2 Works
The reactors are flooded with nitrogen in order to avoid chemical and thermal reactions during the works in the reactor. Economic systems are used, the nitrogen feed is regulated and controlled according to requirements and the purity of the gas is over 99%. Flushing the reactors with hot nitrogen is an environmental friendly preparation of the catalyst handling. Hydrocarbon deposits are evaporated from the catalyst mass and the reactors are fully dried out. After incidents in catalytic plants, hot stripping is used to relieve the product. The controlled rapid cooling of the reactor takes place in an integrated closed circulation system with liquid nitrogen. The use of this procedure means a considerable reduction in shutdown times, thus making decisive reduction to the costs .

Unloading of used Catalyst
Initially, the used catalyst is removed from the reactors. Depending on the type of reactor, the material can be removed using emptying facilities on the reactor. The other options is gently vacuuming the used catalyst through the reactor head with high-performance vacuum units, which are equipped with N2 cooling and recirculation. The catalyst is packed in Unauthorized containers and processed directly on-site.

Loading of new Catalyst
Depending on the specification, we load the reactors by ‘’Sock Loading’’ or ‘’Dense Loading’’. With ‘’Sock Loading’’, catalysts and ceramic balls are controlled by using a special loading sock and filled in a way that prevents damage. The continual shortening of the loading hose prevents a free falling of the Catalyst. With ‘’Dense Loading’’, a rotation system effectuates an even distribution of the catalyst in the reactor during the filling process. The high catalyst density achieved as a result prevents channelling and hot spots. SILVER TEKNIK offers all ‘’Dense Loading’’ processes known on the market, for the loading of catalyst, molecular sieve,activated carbon and other bulk goods. For primary reformers and cracking furnaces, the ‘’Unidense’’process is used.