Presentation on theme: "Controlling boiler emissions in an industrial cluster-A case study Prof. H S Syed Asst. Prof. of Env. Engg L. D. College of Engg, Ahmedabad November, 2011."— Presentation transcript:
Controlling boiler emissions in an industrial cluster-A case study Prof. H S Syed Asst. Prof. of Env. Engg L. D. College of Engg, Ahmedabad November, 2011
Chimney, the stack attached to the boiler house. A symbol of progress and development in the past Now, a symbol of pollution and hence a concern
Heat requirements in the industry are satisfied by steam generated at boiler house. Boiler House - an important source of air pollution. Different types of boilers, of different capacities using different types of fuel with different operating conditions are in use.
Case Study: Narol Industrial cluster of textile process houses was identified as a major source of pollution by Supreme Court appointed Environmental Pollution Control Authority(EPCA) – Bhurelal Committee. Also identified by GPCB as major air polluter with reference to CEPI (Comprehensive Environmental Pollution Index ) score of MOEF.
Environmental Engg Department, L D College of Enginering, Ahmedabad was approached by Ahmedabad Textile Process Association (ATPA) to study the problem and provide a solution to pollution.
Case Study: Narol Industrial cluster of textile process houses 122 Process Houses 91 having Steam Boilers and Thermic Fluid Heaters 87 have been surveyed and data collected
Broad Classification Of Boilers Based On Steam Generation Capacity 2 Ton/hr35 5 – 7.5 Ton/hr35 10 Ton/hr14 10 Ton/hr3
The Different Fuels Used In The Boiler
The common fuels used are wood for 2 Ton/hr and lignite for 5 Ton/hr capacity boilers. The Proximate Analysis Of The Fuel
The common air pollutants encountered: PM, SO 2 & NO x The air pollutants namely particulate matter (PM), SO 2 and NO x primarily depend on the fuel used as well as on the operating conditions and procedures adopted.
Based on the proximate analysis stoichometry calculation for pollutants (50% Excess Air) Parameters LigniteSaw Dust PM, mg/m 3 10, SO 2, ppm500--
Out of selected units were monitored for air pollution parameters. The Measured Concentration Of Pollutants
The present scenario: About pollutant control equipments/ systems; Practically all boilers are equipped with multi cyclones Not designed appropriately Offers only % removal of PM
2 Ton/hr: No economizer or pre-heaters are installed to control temperature 5 Ton/hr: Economizer or pre – heaters are installed for heat recovery and hence temperature control Bag filters are installed at practically all the units. Under compulsion and directions of Bhurelal committee and GPCB
The boilers with steam generation capacity 5 Ton/hr, mostly use lignite as fuel. Lignite generates PM and SO 2. Wood generates PM However, no system is installed to control SO 2 in the flue gas.
The multi cyclones and bag filters installed are not appropriately designed and hence are neither adequate nor efficient Result is gross non - compliance of the emission standards.
Environmental Engineering Department of L.D. College, Ahmedabad has proposed/ developed the scheme Design Approach: For 2 Ton/hr capacity wood/saw dust as fuel Multi cyclone – Venturi Scrubber– Cyclone separator-Demistifer For 5 Ton/hr capacity lignite as fuel Multi cyclone – Bag Filter – Packed bed Alkali wet Scrubber
1 Venturi Scrubber 7. Filter Cloth 2 Cyclonic Separator 8. Mesh Pad Type Demister 3 ID fan 9. Alkali storage tank (powder / lye) 4Stack 10. Feeder 5Filter neutsch 11. Mixing tank 6Alkali Recirculatin Pump 12. Pump (Alkali Solution) : The Proposed Air Pollution Control System for 2 TPH Lignite based Boiler
The Proposed Air Pollution Control System 5 Ton/hr capacity: Lignite as Fuel FurnacePre Air Heater Multi Cyclone Bag House Cyclone ID Fan Alkaline Wet Scrubber Stack Bypass
The Expected Results: When installed as per the design and operated as directed the emissions norms will be satisfied.