Low-NOx emissions control: major power plants of Hong Kong select ENVEA
Hong Kong has been facing two air pollution issues, namely local street-level pollution, and regional smog problem, caused by a combination of pollutants from motor vehicles, marine vessels, industry and power plants both in Hong Kong and in the Pearl River Delta (PRD) region. Nitrogen oxides (NOx), sulphur dioxide (SO2) and respirable suspended particulates (RSP) continue to be the three major air pollutants in Hong Kong.
Combustion of coal for electricity generation inevitably leads to emission of Nitrogen Oxides (NOx) and other air pollutants. To improve the air quality, the HK Special Administrative Region (SAR) Government has been tightening emission allowances from the power plants and set extremely strict limits in terms of industrial emissions for new projects of thermal electric power stations. That includes a 5 mg/Nm3 limit value for NOx, as well as continuing to apply European standards EN 15267 (QAL 1-2-3).
Facing this challenge, Black Point and Lamma Power Stations have retrofitted advanced pollutant abatement facilities in some of their older electricity generation units and have built extensions.
These are using low NOx combustion combined cycles technology paired with DeNOx treatment systems that have been implemented by major engineering companies that are Siemens and Mitsubishi Hitachi Power Systems, Ltd.
In order to comply with the new low NOx regulations and continuously monitor the emissions limit values, QAL 1 certified last generation equipment have been required.
As a consequence, ENVEA has been chosen by the integrators to equip both power plants with CEMS monitoring solutions based on MIR 9000H and MIR 9000 CLD gas monitors, holding the lowest NOx range on the market certified QAL1. The system on Lamma Island (Unit 10) implemented end of 2019 has been intensively tested and approved as fully compliant (QAL 2) by the local authorities in the first quarter of 2020.
The low NOx combustion system retrofit projects not only significantly reduced the NOx emissions level of the two power generation units, but also enhanced their combustion efficiency when burning coal of different grades.
These projects showcase the winning strategy of Hong Kong that pursues of a very low emission energy production plan, with the possibility of a total removal of coal power plants in the years to come.