Opportunities for Organic

Rankine cycles (ORCs) in

the Process Industries

T.P. Handayani

A.P. Harvey

D.A. Reay

R. Law

Sustainable Thermal Energy Management in the Process Industries International Conference

(SusTEM2011)

25-26 October 2011, Newcastle upon Tyne, United Kingdom

Author background

1st year MPhil Student at School of Chemical

Engineering and Advanced Materials, Newcastle

University

Working on EPSRC funded OPTITHERM project:

OPTImising THermal Energy Recovery, utilisation and

Management

Overall aim to produce an Organic Rankine cycle

(ORC) Expert System software package

Presentation Outline

1. Introduction

2. Working fluids in ORCs

3. Configurations of ORC machines

4. ORC Manufacturer

5. Proposed decision tree

6. Conclusions

Presentation Outline

1. Introduction

2. Working fluids in ORCs

3. Configurations and applications of

ORC machines

4. ORC Manufacturer

5. Proposed decision tree

6. Conclusions

Introduction : Low grade waste heat

Low grade heat (> 100oC) released to

environment create thermal pollution

Steam Rankine cycle economical to

recover high grade waste heat (> 350oC)

Introduction : What is an ORC ?

Moran, M.J. et al,

What is an ORC ?

Similiar to steam cycle but utilizes

an Organic fluid instead of water

Mario Gaia, 2011

Mario Gaia, 2011

Introduction : How does it work ?

Pump

Condenser

Turbine

Evaporator

Saturated Liquid

Saturated Vapour Saturated Vapour

W power

Saturated Liquid

Work

Waste heat

Introduction: When to use ORCs?

Mario Gaia, 2011

Introduction: When to use ORCs ?

Low grade waste

heat < 350oC

Direct

use

possibility

?

Heat

exchanger

recovery

possibility

?

Refrigeran

t required

on site ?

40-60 K

lift useful

?

Electrical

demand ?

Waste

heat

temperatu

re >100 C

Export heat ?

Pipe and duct

work?

Heat exchanger

network Absorption “chiller” Heat pump ORC

Yes Yes

Yes Yes

Yes

Yes

No No No

No

No

Objective : To show when to use an ORC in the process

industry

Presentation Outline

1. Introduction

2. Working fluids in ORCs

3. Configurations and applications of

ORC machines

4. ORC Manufacturer

5. Proposed decision tree

6. Conclusions

Introduction: Working fluids in ORCs

Chen et al Recommended

in ORCs

Why?

-Reduce droplets in outlet

turbine

- No superheat needed

-Low critical temperature

compared to water

Key rule to select the

working fluid:

Choose the temperature

closest to the waste heat

source

Chen et al, 2010

Presentation Outline

1. Introduction

2. Working fluids in ORCs

3. Configurations and applications of

ORC machines

4. ORC Manufacturer

5. Proposed decision tree

6. Conclusions

Configurations of ORCs

1. Conventional ORC

2. Dual Source ORC

3. Regenerative ORC

4. Recuperative ORC

Configuration of ORC

1. Conventional ORC

2. Dual Source ORC

3. Regenerative ORC

4. Recuperative ORC

Conventional ORC –

ORCs in the Cement Industry

Waste Heat source: grate cooler and

clinker cooler (375000 lb/hr, 250oC to

275oC)

Method of waste heat extraction:

Direct method (waste heat direct connected

to evaporator)

Indirect method (using oil thermal loop e.g

Mobilterm 254)

- Working fluid : Pentane, Siloxane, Toluene (closest

critical temperature to waste heat)

- Net power output : 0.5 to 3 MW

Conventional ORC –

ORCs in the Cement Industry - 2

Heidelberger Zement ORC (Legmann, 2002)

Conventional ORC

Conventional

ORC Indirect

method

Conventional ORC –

ORCs in the Refinery Industry

Process Waste Heat

source

Source

temperature

(oC)

Average ORCs

system size (kW)

Atmospheric Distillation L, C 150 1794

Vacuum Distillation L, C 150 1947

Fluid Catalytic Cracking L, C 150 732

Hydrocracking L, C 146 1685

Hydrogen Plant G 150 3559

Catalytic Reforming L, C 137 4700

Hydrotreating L, C 121 1031

Hydrofening L, C 121 1087

Waste heat source in “West Coast” oil refinery

(Drake, 1985)

Working fluids : R113

L = liquid; C = condensable vapor, G = Gas Potential for ORC

Possible Heat source

Conventional ORC –

ORC in the Refinery Industry

Rose, R. K, 1979

Conventional

ORC

Working fluid: Fluorocarbon (banned now)

Bypass valve to take full

evaporator load if there is problem

in turbine

Conventional ORC –

ORC in the Refinery Industry

Working fluid: R113

Drake, R. 1985

Parallel utilization of ORC

(each ORC provide 750 –

1500 kW)

First

ORC

Second

ORC

Conventional ORC –

ORC in the Refinery Industry

Working fluid: R113

Drake, R. 1985

Parallel utilization of ORC

(each ORC provide 750 –

1500 kW)

Configurations of ORCs

1. Conventional ORC

2. Dual Source ORC

3. Regenerative ORC

4. Recuperative ORC

Dual source ORC –

in the Cement Industry

Dual source ORC (Wang et al, 2009)

First

Source : Preheater

exhaust

(340oC)

Second

Source: clinker

cooler exhaust

(320oC)

Working fluid: R123

(Dichlorotrifluoroetha

ne)

When to use dual

source ORC ?

If there are several

heat sources

available

Dual source ORC –

in the Cement Industry

Dual source ORC (Wang et al, 2009)

Dual source ORC –

ORCs in the Food Industry

Waste heat :

- Foul gas from the fryer (120oC)

- Effluent gas stream from the heat

exchanger to the stack (140oC)

Working fluid : R245fa

Dual source ORC –

Waste heat source in food industry

Anneke et al, 2011

First heat

source

Second heat source

Dual source ORC –

ORCs in the Food Industry

From foul gas

120 oC

From heat exchanger

exhaust

140 oC

Anneke et al, 2011

Configurations of ORCs

1. Conventional ORC

2. Dual Source ORC

3. Regenerative ORC

4. Recuperative ORC

What is Regenerative ORC ?

Regenerative ORC is one that uses a

feed water heater to recover the outlet

turbine vapour

Objective (Mago et al, 2008):

To increase the thermal efficiency

To decrease the irreversibility

To increase the second law efficiency

Comparison Conventional ORC and

Regenerative ORC

Moran, M.J. et Pump

Condenser

Turbine

Evaporator

Pump

Condenser

HP Turbine

Evaporator

Feed water

heater

Pump Moran et al, 2008

Conventional ORC Regenerative ORC

Lp Turbine

The waste heat: furnace flue gas waste heat (398oC – 454oC)

Working fluid : Toluene (critical temperature 320oC)

Configurations of ORCs

1. Conventional ORC

2. Dual Source ORC

3. Regenerative ORC

4. Recuperative ORC

What is recuperative ORC?

Recuperative ORC is one that uses a

recuperator employing the turbine outlet

vapor to heat up the working fluid going

to the boiler (Hjartarson, 2009)

Why use a recuperator:

To reduce the heat load in the evaporator

To increase the thermal efficiency

Recuperative ORC –

ORCs in chemical industry

Waste heat: Furnace (220OC – 400oC)

Tested three types of ORC

in Elkem ferrosilicon plant.

Configuration with one

recuperator produced

maximum power compared

to basic and two

recuperator types

(Hjartarson, 2009)

ORC configuration - Summary

ORC

type

Conventional Dual Source Regenerative Recuperative

What ?

Why ?

When ?

Where ?

1 heat source

Pump,

Evaporator,

Condensor,

Turbine

Generator

2 heat source,

Pump,

Evaporator,

Condensor,

Turbine

Generator

1 heat source,

Pump, Evaporator,

Condensor,

Turbine,

Feed water heater

Generator

1 heat source,

Pump, Evaporator,

Condensor,

Turbine,

Recuperator

Generator

To convert

waste heat to

electrical power

To produce more

power, To increase

thermal efficiency,

to reduce

irreversibility

To produce more

power, To increase

thermal efficiency,

to reduce

irreversibility

To produce more

power, To increase

thermal efficiency,

to reduce

irreversibility

Waste heat

>100 C

electrical power

2 Waste heat

source >100 C

If thermal

efficiency low

If thermal

efficiency low

Most industrial

plant (Cement,

Refinery)

Cement, food

industry

Glass industry

Chemical

Presentation Outline

1. Introduction

2. Working fluids in ORCs

3. Configurations and applications of

ORC machines

4. ORC Manufacturer

5. Proposed decision tree

6. Conclusions

Some ORC manufacturers

Manufacturer Application Power range

Turboden Biomass CHP applications and industrial

waste heat recovery

400 kW – 2 MW

ORMAT Geothermal and solar power

applications

250 kW – 20 MW

Tri-O-Gen: Exhaust gas and biogas flare

applications

160 kW

Electratherm Biomass and industrial applications

50 kW

Infinity turbine Biomass and industrial applications

10 – 50 kW

Adoratec Biomass CHP applications 300-2400kWe

GMK Biomass and industrial applications 0.5 - 2 MW

3 -8 MW

Calnetix (GE

energy)

Waste heat 125 kW

Presentation Outline

1. Introduction

2. Working fluids in ORCs

3. Configurations and applications of

ORC machines

4. ORC Manufacturer

5. Proposed decision tree

6. Conclusions

Proposed decision tree

Waste Heat

Temperature

Working fluid temperature

near to waste heat

temperature? Increase the evaporator pressure

and decrease the condenser

pressure

Check the quality of vapour

in outlet turbine

If the quality of

vapour in turbine

outlet < 90%

Superheat ed

the vapor in

turbine inlet

using steam

generator

Improve the quality of

vapor in turbine outlet

Reheat the vapor

from first turbine

before enter the

second turbine

Regenerative

open feed water

heater

Dual

Source

ORC

Recuperative

ORC

Increase the

efficiency ?

Two heat

source ?

Stop

No

No

No

Yes

No

Yes

Conclusions

Based on the literature surveyed here:

The waste heat temperature range for genuine industrial use

of ORCs is 100oC - 350oC.

Conventional ORCs commonly used in industrial application

ORC configuration can use either a direct or indirect

approach.

ORCs have been successfully used to generate electricity

from low-grade waste streams

In some cases dual heat source ORCs should be integrated

Regenerative and Recuperative ORCs are potential to

increase the thermal efficiency

Acknowledgement

EPSRC project entitled OPTITHERM:

OPTImising THermal Energy, Recovery,

utilisation and Management in the

process industries (project no.

EP/G061467/1)

Partner universities

Other industrial partners

Thank you for your attention