Paguthan
Description
Paguthan is a Combined Cycle Gas Turbine (CCGT) station designed to use both natural gas and liquid fuels (naphtha and high-speed diesel). The modular design of the station consists of three gas turbines, three heat-recovery steam generators and one steam turbine. The total installed capacity is 655MW.
Natural gas is delivered by pipeline from the Gandhar gas field. These pipelines are owned by the Gas Authority of India Ltd. Naphtha, from the Indian Oil Corporation Ltd is delivered by rail to a siding and then by a 7km underground pipeline to the station. High-Speed Diesel is delivered to site by road tankers.
Operation
During the year, the station was operated at a reduced load in view of the customers' decision not to take power generated from Naphtha fuel. For the whole year about 16.71% of the approved capacity was put into generation.
Also during the year, management efforts to augment additional gas to the power station led to the signing of gas supply contracts and about 2.3MCMD of gas is expected to be delivered by July 2002. This is likely to bring a major improvement in terms of efficient use of energy resources besides lower NOx emissions.
Environmental Management System
Paguthan achieved ISO 14001 certification in November 1999 and was successfully re-certified during 2000 - 2001. The last surveillance audit, carried out during December 2001, resulted in just one minor finding. This has now been rectified.
Environmental targets for 2002 include improving environmental culture and waste management on-site. A recycling initiative, improved contingency plans, water conservation, documentation procedures and contractor performance monitoring have also been targeted.
Air emissions
The gas turbines are equipped with dry low-NOx burners to minimise NOx emissions when burning gas. Water injection is employed when using liquid fuels. The station is required to operate below a NOx emission limit of 50ppm when firing natural gas and below 100ppm when firing liquid fuels and gas/liquid mixture. Continuous stack monitoring is performed with the online stack emission-monitoring instrument (CEMS) fitted to the main stack of each unit.
Four ambient air-quality monitoring stations have been set up and the data collection is done fortnightly. In addition, complete air and water discharge compliance is monitored through an external-monitoring agency approved by the local government. Meteorological data collection equipment has been set up at the station laboratory to collect weather data.
Water
Water is abstracted from the river Narmada, 24km away from station.
The effluents generated from water usage on site constitute mainly cooling tower blow-down (approx. 90% of total effluents), some of which is recycled for plant horticulture. Water effluents are ultimately discharged to a dry stream called Linda Nallah, which drains to the seasonal river Bhukhi and consents are in place for this discharge route. For the combined effluent there are discharge limits for pH, suspended and dissolved solids.
An Effluent Treatment Plant is available to handle any effluent, generated from centrifuges. The final Naphtha / HSD-rich oily waste is recycled back to the naphtha storage tanks.
Waste
Non-hazardous controlled waste is segregated at source and stored in a purpose built industrial waste storage area. Contracts have been placed to reuse and recycle these non-hazardous wastes where possible e.g. scrap metal, broken drums, wooden and packaging waste and air filters.
