QUALITY THROUGH EXPERTISE. MultiTherm. Direct Thermal Oxidation of gaseous and liquid streams containing organic pollutants

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1 QUALITY THROUGH EXPERTISE Direct Thermal Oxidation of gaseous and liquid streams containing organic pollutants

2 CTP Especially in the pharmaceutical, chemical and petrochemical industries waste streams occur that can contain highly concentrated waste gases and waste waters. For oxidation of these highly concentrated waste gas and liquid streams CTP has developed the concept of the. Already more than 15 years ago CTP realised the first systems for the removal of liquid waste. Increased requirements, growing operating experience and inventive talent paved the way for ever more effective and optimized systems. CTP has not only developed nozzle systems for an optimized distribution of waste gases and liquids in the combustion chamber but also a series of variable nozzle lances which operate at fluctuating flow rates without the need of flow compensation of the waste gas streams. CTP s creative solutions together with long-time experience, an excellent project management and a quality-orientated manufacturing are of considerable value to our customers. 2 Different streams Explosive waste gas streams with declaration of zones Low contaminated waste gases or waters Liquid waste as a combustible Waste gases with or without oxygen

3 Unique advantages of the CTP-system Residue-free combustion Well-proven multifunctional burner also available in LowNOx design Selection and arrangement of the injection lances in an optimally dimensioned combustion chamber for the respective pollutant Special nozzle technologies Universal applicability Hydrocarbon compounds Organic nitrogen compounds and ammonia Halogenated hydrocarbons Organic sulphur compounds and hydrogen sulphides (+ CS2) Hydrogen Ultrasonic spray nozzels with modular nozzle design Waste gases or liquids containing hazardous substances are injected by special nozzels into a combustion chamber which is adapted to the respective pollutants. For waste gases or liquids creating flames the nozzels are arranged in the multifunctional CTP burner, for low calorific source streams the nozzels are positioned at the front wall of the combustion chamber to ensure an optimum mixing with the burner flame. The injection of the combustion air through the burner is essential for the mixing quality of the combustion air and the pollutants. All parameters of the air supply such as the direction of the swirl or the power of the swirl are adjustable durning operation via slides and valves. As a waste gas cleaning process the combustion is appropriate for all oxidizable pollutants. Hydrocarbons oxidize at temperatures between 750 C and 1000 C to carbon dioxide (CO2) and water (H2O). Depending on the type of pollutant, however, undesirable oxidation by-products such as SO2, HCl, NOx, SiO2 and others can occur which have to be removed by further procedural steps when exceeding the permissible legal emission limits. The purified gases are either re-cooled by a flue gas quench or directed to the stack via a downstream heat recovery. 3

4 The system CTP is part of a combination process. This process consists in general of a thermal oxidation and one or more upstream or downstream processes adapted to the specific application. Typical system combinations Liquid and/or gaseous hydrocarbon compounds and organic nitrogen compounds SCR/ Dioxin Removal Liquid and/or gaseous haloenic hydrocarbon compounds or sulphur compounds Quench/ Scrubber SCR/ Dioxin Removal The process The flow chart below shows, as an example, a typical design of a thermal oxidation system. The first cleaning stage, which consists of the system, guarantees the complete oxidation of the pollutants. The waste heat is recoverd in the downstream steam generator and waste gas heat exchanger (economizer) and thus is then available in the production plant. In the downstream flue gas quench/scrubber stage undesirable oxidation by-products such as HCL, SO2 oder SO3 are removed. In the last cleaning stage, which consists of preheating, reduction agent, injection and SCR catalyst, nitric oxides (NOx) are converted to water and atmospheric nitrogen (N2). After the extraction of the waste heat of the SCR unit the waste gas is exhausted via an induced draft fan through the stack. 4

5 Heat recovery in form of a steam generator or a thermal oil heater improves the efficiency of the complete system significantly. For the steam generation fire tube boilers are used which can be dimensioned for medium to high steam pressures. Downstream economizers additionally increase the efficiency of the system. The thermal oil heating takes place in conventional tube bundle heat exchangers. SCR/Dioxin removal Nitrogen oxides and dioxines can be purified together, if necessary, in a catalyst. The type of catalyst, its geometry and dotation are chosen for each specific case. As the special SCR catalyst provides a NOx cleaning even at low temperatures, it is a good solution for a particularly economical operation of the system. Quench/ Wet scrubber The hot flue gas from the combustion is cooled to absorbent temperature in the quench to absorbent temperature. In the downstream scrubber the inorganic flue gas contents such as halogenated compounds and sulphur compounds are washed out. The wet emission control may vary according to contents and contaminants in compliance with the requirements of emission limits and the requirements of the downstream system in the design of a two- or multi-level system. 5

6 The key components The burner system CTP s multifuel burner for liquid and gaseous combustibles also serves as supporting burner for a self-sufficient operation. Separately draggable lances with functional spray nozzle caps for waste gases and liquids can be built into the center of the burner. Through adaptable swirls inside of the burner the turbulence in the combustion chamber can be adjusted depending on the requirements. Injection lances and nozzels CTP offers different nozzles which fit perfectly to the respective requirement: gas nozzles with optimized spray devices for low primary pressures with reduced consumption of resources, or variable gas nozzles which guarantee a safe and flashback-free operation at fluctuating flows. Ultrasonic nozzles for liquids guarantee a complete oxidation because of an optimal distribution and a steady flame. All nozzles are equipped with a flame shaping head which determines the geometry of the flame. The combustion chamber Geometry, size and deisgn of the combustion chamber are constantly adapted by CTP to the respective requirements. For insulation ceramic fibre materials, refractory concrete or refractory stones are used. A ventilated external insulation keeps the steel wall at an elevated temperature. The dimensioning of the insulation body is carried out taking the dew point of the flue gas into account. Controlled systems and safety technology The number of the independent safety features required depends mainly on the determined zone definition of the substance stream. For combustions, static dry or wet flame arresters and dynamic flash-back protection are used. As an innovative new development CTP offers dynamic control lances which reliably inhibit a flashback because of the high outgoing speed and the integrated cooling circuit. 6

7 Control system The control system includes control, safety-related monitoring and control of the system components. A sophisticated control concept allows an automated system operation even under changing load conditions without human intervention. This control system can also be integrated into the external system-in-use of the customer. The user interface visualizes the processes of the system in diagrams which are clear and intuitive to use. All measurements, alarms and events are stored in databases and are available at an interface for data recording by the customer. Integrated options SNCR The reduction agent, urea or also ammonia water is passed through a separate part of the combustion chamber and reacts with the existent nitrogen oxides. The suitable placement of the reagent injection lances and a controlled dosage of the reduction agent amount make it possible to achieve a comparatively high degree of NOx reduction. Zero heat-loss combustion chamber In order to prevent as much as possible heat losses at the combustion chamber a multi-layered design of the external insulation is used. The inner shell keeps the steel wall at a higher temperature, so that at no point a condensation of flue gas components occurs. The outer shell largely prevents a heat loss to the environment. Between the shells the ambient air circulates by means of natural draft. The air, preheated by the axcess heat, is fed directly to the combustion chamber. 7

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