How can we control NOx emission in thermal power plant?

Post-combustion control methods can reduce NOx emissions by neutralizing the NOx in the flue gas into nitrogen via chemical reactions with or without the use of a catalyst. These technologies have higher NOx reduction potential; however, they require higher capital and operating costs.

How do you control thermal NOx?

Techniques involving low-excess-air firing, staged-combustion, and flue gas recirculation are effective in controlling both fuel NOx and thermal NOx. The techniques of reduced air preheat and reduced firing rates (from normal operation) and water or steam injection are ef- fective only in controlling thermal NOx.

How can we reduce SOX and NOx in thermal power plant?

How to control Sox and NOx emission in Power Plant

  1. Switching the low sulphur fuel.
  2. Desulfurization the fuel.
  3. Utilizing a flue gas desulfurization ( FGD ) system.
  4. Combustion control techniques.

What other techniques are used for NOx emission control from power plants?

Data reflect that average NOx reductions for specific primary controls have ranged from 35% to 63% from 1995 emissions levels. The sec- ondary NOx control technologies applied on U.S. coal- fired utility boilers include reburning, selective noncata- lytic reduction (SNCR), and selective catalytic reduction (SCR).

IT IS INTERESTING:  How is light energy converted into chemical energy during photosynthesis quizlet?

How can NOx emission be controlled in a coal based power plant?

Primary measures for NOx control from coal-fired power plants include low NOx burners (LNBs), overfire air systems (OFA), fuel reburning, flue gas recirculation, fuel biasing, low excess air and combustion optimization.

Why is NOx harmful?

NOx can cause serious health damage to humans, including respiratory diseases. NOx is also responsible for smog and the typical brown cloud that covers larger cities and produces poor air quality. … NOx reacts with volatile organic compounds in the presence of sunlight and forms ground-level ozone.

What can cause high NOx emissions?

High NOx emissions can occur when an engine’s air-fuel mixture is too lean. This can happen when too much air is added to the fuel or when too little fuel is injected into the engine. In either case, this causes the mixture to burn hotter.

How can we reduce SOx emissions?

Approaches for Limiting Emissions

Since sulfur emissions are proportional to the sulfur content of the fuel, an effective means of reducing SOx emissions is to burn low-sulfur fuel such as natural gas, low-sulfur oil, or low-sulfur coal. Natural gas has the added advantage of emitting no particulate matter when burned.

How can we reduce coal emissions?

One method is carbon capture, which separates CO2 from emissions sources and recovers it in a concentrated stream. The CO2 can then be injected underground for permanent storage, or sequestration. Reuse and recycling can also reduce the environmental effects of coal production and use.

What is used to reduce SO2 emissions?

Reducing Pollution

IT IS INTERESTING:  Your question: Are electric water heaters silent?

Scientists have found different ways to reduce the amount of sulfur dioxide released from coal-burning power plants. One option is to use coal that contains less sulfur. Another option is to “wash” the coal to remove some of the sulfur.

How do you control NOx and SOx emissions?

NOx emission can be reduced by primary methods such as retard injection, fuel nozzle modification, change of compression ratio, water direct injection, water emulsification, exhaust gas recirculation (EGR) and secondary method such as selective catalytic reduction (SCR).

What is the difference between NOx and NO2?

The term ‘nitrogen oxides’ (NOx) is usually used to include two gases-nitric oxide (NO), which is a colourless, odourless gas and nitrogen dioxide (NO2), which is a reddish-brown gas with a pungent odour. Nitric oxide reacts with oxygene or ozone in the air to form nitrogen dioxide.

What are NOx emissions?

Nitrogen Oxides (NOx) Control Regulations. … Nitrogen Oxides are a family of poisonous, highly reactive gases. These gases form when fuel is burned at high temperatures. NOx pollution is emitted by automobiles, trucks and various non-road vehicles (e.g., construction equipment, boats, etc.)

Power generation