WATER AND WASTEWATER MANAGEMENT
The process of water and wastewater management at the ORLEN Group has for years focused on the optimisation and efficiency of water withdrawal and consumption.
The effectiveness of our responsible management of water resources and investments in state of the art technologies is demonstrated by the developments seen at the Płock refinery over the last 40 years, where steady growth of production and crude oil processing was accompanied by a gradual decrease in the water consumption and wastewater discharge volumes.
Technology in statistics
Water and wastewatermanagement
PKN ORLEN uses 27.7 million cubic metres of water a year, with 900 million cubic metres of water circulating in its systems annually.
Water is essential for the operation of the production plant in Płock. It isused for:
- power generation;
- technical safety.
Water for power generation and cooling purposes is sourced from the Vistula, where as all water for technical safety purposes is produced from wastewater treated on the plant premises, which is an element of a semi-closed loopwater system.
Cooling water is abstracted from the Vistula and thent reated to remove impurities. This water, called processwater, is directed to cooling water towers, where it is added to the water circulating in the closed-loop system between the cooling water towers and the production units. Coolingwater needs to be refilled to make up for its losses (of about 2% of the total amount of the cooled water) caused by partial evaporation during water cooling processes occurring in the cooling towers.
Water for technical safety purposes is water produced from treated wastewater and subjected to a final purification process. Water for fire-fighting purposes is directed to the Company's fire hydrant network to be used in case of fire. A part of this water is directed to the utility water hydrant network and isused for other technical purposes at the plant.
The plant also produces drinking water for its own use from water drawn from the Company’s owned wells located in the area of Biała Stara and treated on the premises of the production plant.
Upgrade of pump units - objectives and results
Efficient water and wastewatermanagement
Measures taken to reduce water consumption by the production plant:
- Wastewater redirected to be used to produce water for utility and fire protection purposes
- Closed cycle cooling systems - minimising water losses
- Efficient use of cooling water through its recirculation in closed cycle cooling systems
- Reuse of water used in desalination of cooling water towers by directing it to the utilyty and fire protection water system
- Minimising losses in the water treatment process
- Recovery, treatment and reuse of condensates
- Reuse water from pressure tests of tanks by diverting it to the network
Approximately 3.5 million cubic metres of wastewater per year is recycled to produce water for fire protection purposes at the plant.
Upgrade of pump units - results
Energy saving measures include:
1. Operation of pumps with frequency inverters.
2. The inverter can control any of the power supply units available at the pumping station. The leading parameter for the operation of an inverter is the pressure in an operating manifold.
3. Pumping water through three manifolds instead of one.
4. Each meter of pumping height means some 10.5 kW of additional power consumption. If a single pipeline is in operation, linear losses grow in line with the increase in flow velocity, resulting in an increase in the pumping height and thus in higher power consumption.
5. Maintaining a low water level in the tower tanks reduces the pumping height and thus mitigates power consumption growth.
6. The purchase of a new inverter improved the control efficiency by a few per cent. Effect: reduction of electricity consumption by 3,000,000 kWh a year.