JSW Group: Innovations in coking coal and methane emission reduction

By JSW Group 

Jastrzębska Spółka Węglowa S.A. is the largest producer of high-quality hard coking coal in the European Union and one of the leading producers of coke used in steel smelting. It is located in Silesia, in the southern part of Poland. The production and sale of coking coal, coke and hydrocarbons constitute the JSW Group's core activity.

Coking coal, also known as metallurgical coal, has been identified as one of the 30 critical raw materials for the European Union, signifying strategic economic importance and entailing a high supply risk for the European industry.

Coking coal is an essential ingredient in the production of steel - a key component for the development of an innovative economy and modern infrastructure. It is important to know that there are currently no alternative and economically viable steelmaking technologies without the use of coking coal.

Coking coal extracted from JSW's mines is used in Central Europe by local steel mills belonging to international steel producers. The high quality coke produced by the JSW Group is also sold on the global market. The main customers of JSW Group's products are in Poland, Germany, Austria, the Czech Republic, Slovakia, Italy and India.

Aiming to meet the Fit for 55 guidelines, JSW S.A. is participating in the MASTERMINE project. The project is being carried out at the KWK 'Pniówek' site. The involvement of the Polish partners in the project (JSW S.A. and GIG) will focus on the development of an intelligent methane drainage network system.

The European Union's requirements regarding the limitation of methane emissions from coal mines into the Earth's atmosphere force the initiation of innovation aimed at increasing the efficiency of methane drainage. This applies to both the environmental areas of mining operations and isolated post-exploitation workings in coal mines. The highest percentage of emitted methane in mines is the volumetric flow of methane released into the operational areas. Following closely is the value of methane emissions from the surroundings of isolated post-exploitation workings to actively ventilated excavations. This situation is attributed to the increasing methane content in the extracted and surrounding coal seams, along with the growing concentration of mining activities in Polish coal mines. The rise in the absolute methane content in the total operational areas directly translates into the value of the methane flow into isolated workings after the completion of exploitation.

Developed at the Central Mining Institute, models of methane release over the 15 consecutive years following the completion of longwall extraction allow for the prediction of values for the recoverable volumes of desorbed methane into workings. Often, the overlapping exploitation of successive seams in a deposit section enables the development of a gas model for forecasting methane release, covering the isolated space of workings.

In post-exploitation workings over a 15-year period, degassing occurs from depressurized underburden and overburden layers within depressurization zones, creating reproducible volumes of emitted methane over time.

In the nodes of the ventilation network outlining post-exploitation workings, the existing field of aerodynamic potentials enables conducting methane drainage, both from behind insulating barriers and through openings directed from actively ventilated workings to depressurization zones.

The volume of mine gases, including methane, undergoes gas transformations in response to changes in volume and pressure conditions resulting from atmospheric pressure variations. Under conditions of atmospheric pressure changes, there is a decrease or increase in the volume and pressure of mine gas with methane.

The current lack of regulations governing the capture of methane from isolated post-exploitation workings during atmospheric pressure decreases leads to methane migration from workings, especially in the vicinity of insulating barriers, into actively ventilated mine workings.

The design of a methane capture regulation system for post-exploitation workings will enable smooth control of the captured methane flow, limiting the migration of methane from workings to active workings around insulating barriers, especially during periods of atmospheric pressure decreases. The implementation of a regulation system for methane capture from post-exploitation workings will significantly reduce the magnitude of methane emissions from workings into active mine workings, achieving the fundamental goal of developing this regulation system by reducing the absolute ventilation methane content in coal mines.