Production of liquid fuels from oil shale requires significant amount of water. Although abundant in Estonia, water is a scarce resource in many parts of the world, where oil shale recourses are available. Therefore we have put a lot of effort into reducing the water consumption of Enefit280 technology.
The retorting process of the Enefit280 technology is essentially water free. Water is however used in many other steps in the liquid fuels production life-cycle, like for example oil upgrading, power production, ash handling.
Water requirement of Enefit shale oil industry in Estonia (bbl / bbls SCO)
There are many ways to decrease water use in those areas of the process.
- Ash removal in Estonia uses hydro pulp transportation system, where water is constantly recycled in the system by means of transportation pipes, canals and settling ponds. For all future projects Enefit plans to use dry ash removal systems with minimal water use for dust prevention. Estimated water usage of this system is ~0,26 bbl per bbl of oil.
- In Estonia turbine cooling is done by means of open river cooling. For future projects Enefit plans to utilize other cooling schemes for reducing cooling water needs, e.g. air cooling (zero water usage) or closed circuit water cooling with cooling towers (estimated water usage 2,99 bbl per bbl of oil) depending upon the specific location.