How is the Coking production process defined?

Coking refers to the process of heating coal in the absence of air (oxygen) to a temperature above 600°C to remove volatile components from the raw coal, leaving a hard, solid and porous material with a high carbon content, called "coke". Coke is almost entirely composed of hydrocarbons. Coke is mainly used to produce cast iron (iron and steel) in blast furnaces, which remains its main use today.

 

Coking, a high-polluting industry

Coking process has historically been a very polluting process especially with the evolution of sulfur and nitrogen oxides from the coke ovens. In Europe and the United States, only a few coking plants remain in operation and the emissions, by-products and waste from these plants are very closely controlled. However, in some developing countries, coking remains an important source of pollutants.

China supplies over 80% of the world’s demand

As a result, China has recently imposed some of the most stringent regulations in the world on this industry. Since there was no prior smoke treatment system in place and because the coke industry cannot afford a long shutdown period for the modernisation of the pollution containment system, a different solution had to be found.

Multiple gas emission

The main pollutant emissions resulting from coking are mainly SO2, NOx and dust with a small amount of HCl in some cases.

 

What SOLVAir® dry scrubber system can do for coking plants?

SOLVAir® efficiency is no longer to be proven

SOLVAir® provide high efficiency in pollutant removal. Find below the possible results: 

  • SO2 emission concentration <30 mg/Nm3

  • NOx emission concentration < 150 mg/Nm3

  • Dust emission concentration < 15 mg/Nm3

A quick start-up for a fast compliance

SOLVAir® can be installed in only 4 months and with minimal downtime for final tie-in and is working across a large range of temperatures, from quite low (<100C) to very high  (>300°C). The large temperature range of Coking Industry isn’t a challenge for SOLVAir®, it even complements the final DeNOx step which requires flue gas temperatures over 180°C to maximize efficiency. There is no reheating needed.

 

Key benefits for the Coking Industry

A cost effective process

Producing coke is a batch process where the pollutant levels range widely. With SOLVAir® Dry Sorbent Injection process (DSI) the adsorbent quantity is quickly and automatically adjusted according to the amount of pollutants in the flue gas assuring compliance throughout the batch, ensuring economic efficiency.

Energy recovery, no water discharge

Once the coke oven flue gases have been cleaned, they are sent back to the original coke oven chimney. With a clean combustion gas, energy recovery is possible by creating new value from a waste stream. Also, since the process is completely dry, unlike other technologies, no water is used and therefore no wastewater is generated.