Material Insights · Understanding the Material World

Organic Rankine, Kalina and sCO2 cycles: Impact and additionality

Fuel-free, water-free power riding on existing hosts

What this tab covers The impact and additionality lens: direct emission cuts, side benefits for water and air, and the risk of prolonging the life of a polluting host plant.

ORC power is fuel-free and water-free, avoiding about 0.46 t CO2 per MWh (calculated) at the Riyadh plant; it mainly rides on existing fossil or industrial hosts but also enables geothermal and biomass power.

Direct Scope 1 and Scope 2 abatement

Favourable

Riyadh Cement's 13 MW ORC is expected to avoid about 37,000 t CO2 a year from nearly 80 GWh, about 0.46 t per MWh (calculated). Turboden lists 21 cement-sector plants with more than 115 MW combined. In biomass, Turboden had 300 ORC installations with over 397 MW by 2018, where ORC is the power block rather than a recovery add-on.25

Riyadh CO2 avoided about 37,000 t/yr2 Implied factor about 0.46 t CO2/MWh (calculated)2 Turboden cement plants 21, more than 115 MW2 Turboden biomass ORCs (2018) 300, over 397 MW5

Water and air synergy

Favourable

ORCs are normally air-cooled and need no boiler feedwater treatment, which Turboden presents as water-free electricity; this is a clear advantage over steam WHR in arid regions. Recovery lowers stack temperature, reducing thermal plume, but does nothing for particulates unless combined with filters. Kalina uses ammonia, which needs leak control.38

Avoided lock-in

Mixed

Most ORC recovery hosts are cement kilns, gas compressor stations and engines. Adding power from their waste heat improves their economics slightly and could delay replacement, but the effect is small relative to the host's fuel costs. Where ORC serves geothermal or sustainable biomass, it supports clean generation directly.26

Sources

  1. Turboden commissions 13MW waste heat power plant at Riyadh Cement CemNet (International Cement Review), 2026
  2. Enhancing energy security and sustainability in cement plants through Turboden ORC technology Turboden (press review), 2026
  3. Turboden reflects on 300th biomass ORC milestone Bioenergy International, 2018
  4. Ormat Technologies signs a new power purchase agreement with Great River Energy (dated) Ormat Technologies (press release), 2008
  5. Heat recovery from Diesel engines: a thermodynamic comparison between Kalina and ORC cycles, Applied Thermal Engineering 30(2-3), 212-219 IAEA INIS record of journal article (Politecnico di Milano, University of Brescia), 2010