Use of by-products from lignite combustion
The main PPC S.A. by-product is ash (flying and bottom ash) while gypsum is produced in considerable quantities in the desulphurization Units of Thermal Power Plants. The Company has already registered ash, which is also commercially marketed, in compliance with the requirements of the European REACH Regulation.
In 2019 approximately 3,463 thousand tons of fly ash and 144 thousand tons of bottom ash were produced from lignite combustion by the Company’s thermal power plants.
Fully in tune with the spirit and goals of circular economy, especially the trend to reduce waste by preventing its production (a top priority under European and national law), and as a key-objective of the National Strategy for Circular Economy (MoEE, December 2018), the utilization of ash from PPC lignite-fired power plants is a typical example of circular economy. Ash is widely used in various commercial applications (including but not limited to, the cement industry, road works, etc.) due to its pozolanic (i.e. stabilizing) and hydraulic properties.
Moreover, it can be mixed with gangue materials of excavations from Ptolemaida Mines, where it is used as is, without any treatment. Its pozolanic and hydraulic properties make ash eminently suitable for stabilizing soils for further use, as has been consistently demonstrated in practice and documented in scientific studies that mixing gangue materials with ash enhances the geotechnical stability of depot slopes, on the one hand, and the geochemical stability of gangue materials which are used to fill/rehabilitate excavation cavities and external depots, on the other hand.
Consequently, the exploitation of ash is, by definition, an example of waste prevention and of making good use of an available resource, which contributes to saving raw materials, improving competitiveness and creating added value to the material.
One very characteristic example of successful exploitation of ash, and what is more, in a large-scale project, is the Platanovryssi dam where the mortar consists in 80% of treated fly ash from Ptolemaida. It was a groundbreaking venture, not just for Greece, but for the international technical standards.
Re-use of cooling water and mine drainage water
In thermal power plant areas, water is extracted from various sources and for various uses as, for instance, in Cooling Towers. In order to adopt rational water management, PPC recycles and reuses significant amounts of water to reduce the overall volume required to meet needs. The rate of water recycling and reuse in power generation is 11.85% in lignite-fired plants and 54.73% in oil-fired plants. Cooling seawater is not taken into account in the former estimates of recycling rates.
In 2019, as in the past, in the areas of PPC mining operations, water (surface or underground) pumped for mine protection purposes and not used to meet mining needs, was supplied to neighbouring communities, mainly for irrigation purposes. Any surplus was redirected to surface water receivers (Soulou stream, irrigation canals or Heimaditida-Petres stream at West Macedonia Lignite Center) which helps to enhance water balance in respective areas, maintain ecosystem equilibrium and, in some cases, preserve the ecological flow (Soulou stream).
District heating
The provision of district heating is a sustainable management model as reflected in the targets of the National Strategy for Circular Economy to improve energy efficiency in production processes. At the same time, it achieves significant CO2 emission savings which would otherwise be generated from meeting heating demand.to name just a few, in 2020, approximately 548 GWh of thermal power were saved through district heating (542 GWh from PPC S.A. facilities and 6 GWh from Unit III of PPC Subsidiary Lignitiki Megalopolis S.A.).
Sound waste management contributes to operation efficiency and compliance with environmental legislation for the Corporation while minimizing the environmental impact on all receiving waters.
The Company always seeks to find ways to further reduce the amount of waste produced from its activities and strives to convert potential waste into useful materials.
In 2020, PPC had sixty-three (63) installations qualifying for the Electronic Register of Waste (ERW). Through the ERW environmentally licensed installations meet their obligation to submit an annual waste report.
Solid waste
PPC is entrusted with the management of solid waste (hazardous and non-hazardous) from power generation (Power Plants and Mines) in compliance with the legislation, with a view to environmental protection and sustainable development.
Said management is assigned by PPC to licensed (as per type of waste) companies of waste collection, transportation, management and use, in Greece or abroad, and to operators of alternative management systems approved by the National Recycling Organization as specified by law.
Liquid Waste
All PPC power plants are equipped with modern liquid water treatment systems in accordance with the stipulations of Approval Decisions of Environmental Terms for each facility and the Manual of Best Available Techniques for Large Combustion Installations.
At the same time, PPC takes all necessary measures to minimize leakages and ensure safe collection of waste lubricating oils and liquid fuels in suitable tanks.
Treated liquid water is disposed of either in natural surface water receivers in underground water depending on the location of the installation and the relevant approvals.
The Company systematically monitors the quantities and characteristics of produced effluents and regularly informs the responsible authorities, as decreed by law.