THERMAL UTILISATION. of wastes. Incineration of sewage sludges Energy efficiency Closing of material cycles Cost reduction

Transcription

1 THERMAL UTILISATION of wastes Incineration of sewage sludges Energy efficiency Closing of material cycles Cost reduction

2 RELIABLE WASTE DISPOSAL: BASED ON EFFICIENT PLANT TECHNOLOGY GENDORF (Germany) Fluidised bed with closed air distribution base Capacity: Incineration medium: Reactor height: 10,000 t/a domestic, petrochemical and industrial sludges 9 m Bed temperature: 850 C Throughput: Thermal power: Air staging: Heat recovery: Steam power: Ashes discharge: 1.5 t/h drained sludges (50 % DS) 3 MW single-stage steam boiler 3.5 t/h (20 bar) overflow with fluid bed cooler GROSS- WILFERSDORF (Austria) Fluid bed with open nozzle bottom Capacity: Incineration medium: Reactor height: 16,000 t/a paper as well as tannery sludges and domestic sewage sludge 15 m Bed temperature: 820 C Freeboard temperature: 850 C Throughput: Thermal power: Air staging: Heat recovery: Thermo-oil boiler: Ashes discharge: 2.0 t/h mixed sludges (48 % DS) 2.4 MW two-stage thermo-oil boiler 2.2 MW continuous discharge of ashes/ contaminants

3 FLUIDISED BED TECHNOLOGY Fluidized bed technology has been established with Küttner for many years. The first successful installations for foundry sand regeneration were built in the 1990s. The adaption of existing know-how together with the handling of low-calorific fuels in the environmental field led to sludge incineration based on fluidized bed technology. Over 80 % of the thermal output from the fuel can be recovered and used within the process. After being used for drying the sewage sludge and preheating the air, the remaining thermal energy recovered from the incineration is available for further applications, such as: heating of sewage sludges upstream of the digestion tower utilization in district heating power generation process heat for industrial applications GROSS- WILFERSDORF 3D Concept - Reactor and Vessel The key issue in any plant design is the proper consideration and identification of the energy flow. Küttner designs and supplies process equipment worldwide. In close cooperation with our customers, we develop solutions from single components via subsystems up to turnkey plants. The development of individual solutions for effective energy utilization as well as minimization of material flows is a key issue. This approach applies to new conceptual designs as well as for implementation and adaption in existing infrastructure.

4 KÜTTNER-TECHNOLOGY Küttner Reactor Design I Reactor design I features the closed ceramic air distribution base. A so-called windbox situated below this base includes the burner which facilitates the start-up of the reactor. This layout is the best choice for all sludges with low amount of impurities. The bed height can be regulated via a lateral offtake. Reactor design I is perfectly suited for singlestage and two-stage incineration processes. Küttner Reactor Design II Reactor design II with its open air distribution base represents the best solution for sludges containing a high amount of impurities. Due to the barrier-free design of the air distribution base, impurities are transported to a central opening. Here they are extracted from the reactor and separated from bed material. This reactor design is perfectly suited for singlestage and two-stage incineration processes. Theoretical thermal power of an incineration line Mass flow sewage sludge incineration

5 SEWAGE SLUDGE 3D concept of an entire sewage sludge incineration line The treatment of wastes always shifts between the confl icting priorities of ecology, economy and social responsibility of the present generation towards the future ones. In the past, sewage sludge treatment in rural areas mainly focused on agricultural use, whereas incineration and landfi ll disposal prevailed in metropolitan areas. The agricultural use of sludges is only advantageous from a superfi cial point of view, based on its low-cost disposal for operators of waste-water treatment plants, and its use as fertilizer. The ecological aspect of sludges being a sink for heavy metals is completely ignored. The increasing fraction of waste water to be treated inevitably leads to further increasing amounts of sewage sludge. Additionally, sludges present increasing amounts of degradation resistant eco-toxic substances originating from domestic environments. These cover medicines, cosmetics, washing additives, as well as softening agents from plastics, fl ame retardants and, fi nally, residuals from domestic fi re places. These substances must be prevented from entering into rivers, streams and lakes as well as ground water. All this can only result in one sustainable key solution for the treatment of sewage sludge. The challenge reads: Finding an economic alternative which is harmless for air, water and ground while simultaneously ensuring high reliability to the operators of waste water treatment plants. The thermal disposal of sludges incorporating proven and tested processes, together with innovative approaches meets all requirements. This technology enables recycling of phosphorous by using the resulting ashes in order to produce a fertilizer, which then reenters the natural phosphorous cycle.

6 KÜTTNER ENERGY & ENVIRONMENT GMBH Subsidiary of Küttner GmbH & Co. KG A globally acting group of companies has developed from the engineering company once founded in 1949 by Dr. Carl Küttner. Nowadays, their main focus is on building turn-key plants for the iron & steel producing industry, foundry and NF (non-ferrous) industry, especially in the fi elds of process and smelting technology, materials handling as well as of energy and environmental technologies. Küttner Energy & Environment is one of the leading global players in developing and implementing innovative and sustainable energy and environmental technologies for effi cient energy use, reductions in environmental impacts and optimisiation of material cycles. Our scope of services comprises the design and engineering, construction, delivery, assembly, as well as the startup and commissioning of the entire plant including control system and data processing. Küttner systems can be found in almost all industrial sectors. Worldwide Küttner-Group personnel counts more than 650 employees, their owners themselves being active within the company. Küttner Energy & Environment GmbH Tel. +49 (0) kee@kuettner.com Alfredstr Essen Fax +49 (0) en 04/12