Waste Heat Recovery
In the last years, the high prices of energy and the need to reduce CO2 emissions increased the importance of heat recovery applications for industrial processes. Our ORC technology, highly reliable and safe, is particularly suitable for heat recovery applications. It allows to transform the recovered heat into electricity, which, unlike heat, is always useful.
How it works (video)
Advantages of ORC in Heat Recovery Applications
Compared to other competing technologies (i.e. steam turbines), the main advantages obtained from the ORC technology are the following :
- High cycle efficiency (especially if used in cogeneration plants)
- Very high turbine efficiency (up to 90%)
- Low mechanical stress of the turbine, thanks to the low peripheral speed
- Low RPM of the turbine allowing the direct drive of the electric generator without reduction gear
- No erosion of the turbine blades, thanks to the absence of moisture in the vapour nozzles
- Very long operational life of the machine due to the characteristics of the working fluid that, unlike steam, is non eroding and non corroding for valve seats, tubing and turbine blades
- No water treatment system as in steam plants is necessary
There are also other relevant advantages, such as simple start-stop procedures, quiet operation, minimum maintenance requirements and good partial load performance.
In 1996 Turboden realized its first heat recovery plant in an iron foundry in Brescia. Since then, Turboden has been involved in ORC turbogenerators projects in different industrial processes, such as cement industries, glass industries, steel industries, waste incinerators, minings. Turboden ORC units can produce electricity also by recovering heat from combined cycles, reciprocating engines, internal combustion engines, gas turbines, gas compressor stations.
In 2010 an innovative project was installed in Russia for heat recovery from the associated gas coming from Oil Extraction through controlled combustion (instead of flaring). The plant generates both heat and power: the hot water is used to warm up the extracted oil; the electric power is used in the extraction station. The ORC turbogenerator produces 1,800 kW of electric power.
A further project was installed in Russia, Moscow region: this heat recovery ORC unit is coupled with five MTU engines, 2 MWe each. The exhaust gas of these engines will be conveyed with thermal oil to the ORC module.
Turboden was also awarded an order for a 4 MW ORC unit for heat recovery in cement industry in Slovakia. The plant produces 4 MW recovering waste heat from the kiln and clinker cooler exhaust gas. The recovered heat conveys to the ORC by two different loops using thermal oil and water. This project represents another step of Turboden’s growth in the cement industry, coming after the successful startup of the 2 MW Ait Baha plant for Italcementi in December 2010.
In February 2013, Turboden started-up its first application in steel industry: a heat recovery system for power generation, in Singapore. The ORC is a 700 kW unit that recovers waste heat from a billet reheating furnace.
Furthermore, one of the latest innovative projects is a new 3 MW ORC unit, that uses part of the saturated steam produced by recovering heat of the exhaust gasses from the EAF (Electric Arc Furnace), in Germany. This plant is part of the H-REII DEMO Project (Heat Recovery in Energy Intensive Industries), that the DG Environment of the European Commission decided to co-finance under the LIFE+ program for its technological innovation and environmental value.
You can find a detailed list of our heat recovery units in the References section.
Is it suitable for you?
Typical industrial applications are found in the following areas:
- Cement industry
- Glass industry
- Steel industry
- Non ferrous furnaces
- Internal combustion engines and gas turbines
Generally, the turbogenerators for heat recovery applications have a power ranging from 200 kWel to 15 MWel; for this group of plants, Turboden, if required, can act as Main Contractor, supplying also complementary items for the ORC plants. You can see our standard products for heat recovery in the Products section.
Small Combined Cycles
Internal combustion engines are another interesting source for heat recovery. The addition of an ORC to recover the energy of downstream exhaust gas of a gas turbine is a way to obtain an efficient and reliable Combined Cycle system at small scale. The same result can be obtained with a reciprocating engine + ORC (either with a Diesel or a gas engine). In that case the ORC added power is indicatively from 8% to 12% of the primary engine (turbine or motor). The fuel for the combined cycle can be fossil fuel (mainly natural gas), vegetable oil, biogas or syngas. In addition, the ORC turbogenerator can be vertically integrated as downstream component to engines fuelled by medium-large size gasifiers, thus increasing the overall efficiency of the plant.
The production of electric energy from vegetable oil and biodiesel, benefits from renewable energy incentives (in Italy, for instance, there are Green Certificate incentives) and the profitability of the investment is highly appealing for investors. The spreading of new energy crops (i.e. jatropha) which seems to give excellent yields also in dry land areas should give a further boost to the projects of electric energy production from biofuels and reduces the utilization of oils used by the food industry. Moreover, biogas-fuelled internal-combustion engines are widely used in agriculture and farms. They range from 200kWel to 15MWel and are fuelled by urban landfill gas or biogas from digestors.Back to top