Waste Heat – Present Situation
- Industrial Processes use Oil, Gas , Coal or electricity for Heating
- Furnaces, heaters, Boilers, reformers, reactors, kilns etc. reject 30 to 40% heat to the atmosphere through Exhaust Flue gas.
- Higher temperature exhaust gases ( >300 Deg C) are already used in the process for pre heating, or co generation using CHP technologies
- How ever exhaust gases below 300 Deg C are not used due to low efficiency of conventional Rankine cycle and non availability of sustainable technology
Barriers To Waste Heat Recovery
Technological Barriers
- Technology is available for high temperature recovery using conventional HRSG ( heat recovery steam generators) and Steam turbine Generators using Rankine cycle
- Rankine cycle is not suitable for Low temperature heat recovery
Financial Barriers
- ORC technology for Low grade heat recovery is available in Europe and other parts of the world. But the systems are Too expensive to adapt
- Pay back period is too long
- Economically not feasible due to the subisidised electricity tariffs
Risk Reward Imbalance
- Any new technology, users would initially perceive high risk
- If the economic benefit due to the technology is not sustainable due to High Capital expenditure, there is no motivation to take the RISK
What IS ORC SYSTEM?
- ORC Stands for Organic Rankine Cycle.
- ORC systems use Organic Fluid in place of water.
- In a ORC system Organic Fluid vapor will drive the Turbine in place of Steam ( Rankine Cycle).
- ORC systems can work on Low temperature Heat resources.
- ORC systems are best suited for Low temperature Heat Recovery.
ORC Power systems – FEATURES
- Organic fluids have low specific consumption of vapor in the Turbine expander.
- Plants work on Closed Loop control and automation.
- Suitable for remote monitoring and control.
- Very Low maintenance and operating cost.
- Faster supply Construction period ( maximum 6 to 9 months).
- Faster Pay back period ( less than 3 years)
ORC SYSTEMS – AVAILABILITY
High Temperature ORC systems
- Temperature Range : 70 Deg C to 170 Deg C
- Power range : 10 KW to 1000 KW
- ORC Fluids : R245 Fa, R134, 3M Fluids
- System efficiency : up to 14%
Low Temperature ORC systems
- Temperature Range : 170 Deg C 70 300 Deg C
- Power range : 250 KW to 10 MW
- ORC Fluids : Cyclo pentane, hexane, n-heptane, Tolune
- System efficiency : up to 25%
Sources for Waste Heat Recovery
- Gas Turbine Exhaust Gases 550 Deg C
- Diesel generator set Exhaust Gases 450 Deg C
- Cement Kiln – PH exhaust Gases 320 Deg C
- Cement Kiln – Cooler Exhaust Gases 350 Deg C
- Steel Reheat Furnace 400 Deg C HRSG Exhaust Gases 140 Deg C
- Boiler Exhaust Gases 180 Deg C
- Oil Fired Furnaces ( petroleum & Chemicals) 150 Deg C
- Engine Jacket Cooling water 90 Deg C
Potential for ORC Power systems
- 50 M3/ Hr Hot water available at 140 Deg C can generate 280 Kwe Gross power
- 200 Tons / Hr Hot water at 90 Deg C can generate 500 Kwe power
- 150 Tons/ hr Hot Flue Gas at 300 Deg C can generate 1000 Kwe Gross power
Innovative Business Models
Project is Offered by FIRST ESCO through innovative business models
BOT Model
20% investment by Mahindra Sanyo and 80% Funding by FIRST ESCO. Monthly EMI payment by Customer. At the end of the period Plant is handed over to the customer.
PPA Model
100% Funding by FIRST ESCO, Customer signs a Power purchase agreement. At the end of the period plant is sold to Customer at nominal price.
