fundamentally water emilio ghiazza · large desalination units with high thermal efficiency:...

LARGE DESALINATION UNITS WITH HIGH THERMAL EFFICIENCY:

FUNDAMENTALLY WATER

A VIABLE PATH TO REDUCTION OF ENERGY AND COST

Emilio Ghiazza

Water cost & Energy

FUNDAMENTALLY WATER 3

Water cost & Energy

THE COST OF WATER What’s the cost of water made of ?

mortgage of Investment cost cost of Fuel cost of Power cost of O&M

CAPEX

OPEX

$/m3


Water cost & Energy

THE COST OF WATER The key parameters

The unit costs can considerably change according to different situations. The following values are commonly used:

Plant 1500 ÷ 2000 $/(m3/day)

Power 0.03 ÷ 0.05 $/kWh

Fuel 2 ÷ 3 $/GJ


Water cost & Energy

THE OVERALL COST How’s the split between costs ?

On the basis of the previous unit costs, here’s a common situation of costs distribution:

FUNDAMENTALLY WATER

Water cost & Energy

REDUCING THE COST OF WATER Where do we have to act?

For an effective reduction of the cost of water, we must act on the two major cost components:

Energy cost 60%

Investment cost 33%

Energy consumption


Energy consumption

How can we correctly define the Energy Demand of a thermal desalination plant?

P.R. Energy for the process

Energy for the vacuum

Energy for the pumps

THERMAL

ELECTRIC

(thermal efficiency)

The Energy issue Avoiding common misbeliefs


Energy consumption

How can we correctly evaluate the Energy Demand of a thermal desalination plant?

Energy for the process

Energy for the vacuum

Energy for the pumps

THERMAL ENERGY

ELECTRIC ENERGY

ENERGY FROM FUEL

The Energy issue Avoiding common misbeliefs


Energy consumption

The Power Plant The Heat Rate of the Power Plant is the key factor to convert electrical energy into energy from fuel


Energy consumption

The Power Plant

A typical Combined Cycle Power Plant, when coupled with thermal desalination, shows an Heat Rate between

8,000 and 9,000 kJ/kWh, corresponding to a conversion efficiency between 40% and 45%.

Fuel

POSTExhaust FIRING

AirSTEAM

TURBINE

GAS HEATTURBINE RECOVERY

STEAMGENERATOR

THERMALFuel DESAL

A

A


Energy consumption

PRSpecific aux. electricalenergy consumption

(SW included)

Specific aux. thermalenergy consumption

Specific Process thermal energy consumption

Specific VS thermalenergy consumption

Total specific thermal energy

kg/2326kJ kWh/tkJ/kg

to aux.kJ/kg

to ProcesskJ/kgto VS kJ/kg

8.4 2.0 16.7 276.0 13.5 306.3

9.3 2.0 16.7 250.2 13.5 280.4

10.2 2.0 16.7 229.1 13.5 259.3

11.0 2.0 16.7 211.4 13.5 241.7

11.8 2.0 16.7 196.5 13.5 226.8

12.7 2.0 16.7 183.7 13.5 214.0

13.5 2.0 16.7 172.7 13.5 202.9

43%Power plant efficiency =

Specific energy demand: the MED Case

MED

MED/TVC


Energy consumption

PRSpecific aux. electricalenergy consumption

(SW included)

Specific aux. thermalenergy consumption

Specific Process thermal energy consumption

Specific VS thermalenergy consumption

Total specific thermal energy

kg/2326kJ kWh/tkJ/kg

to aux.kJ/kg

to ProcesskJ/kgto VS kJ/kg

9.0 4.7 39.3 258.4 8.5 306.3

10.0 4.7 39.3 232.6 8.5 280.4

11.0 4.7 39.3 211.5 8.5 259.3

12.0 4.7 39.3 193.8 8.5 241.7

13.0 4.7 39.3 178.9 8.5 226.8

14.0 4.7 39.3 166.1 8.5 214.0

15.0 4.7 39.3 155.1 8.5 202.9

43%

Power plant efficiency =

Specific energy demand: the MSF Case

MSF

MSF-A


Energy consumption

Specific energy demand • Particularly in the Gulf area, sea water temperatures can

reach extremely high values during summer (35÷40°C) • In MED and MED/TVC plants the maximum brine

temperature cannot exceed 70°C, and the discharge temperature is commonly around 10°C above the swt

• So the available flashing range is reduced to 20÷25°C, and as a consequence the max. number of effects and the corresponding max. P.R. is limited

• A MED/TVC with P.R. higher than 10 kg/2326kJ is hardly conceivable in this geographical region unless fed by steam at a pressure higher than MSF


Energy consumption

Specific energy demand

In MED and MED/TVC plants, high levels of thermal efficiency (P.R.) can be achieved only by using steam at relatively high pressure


Energy consumption


The use of steam at relatively high pressure turns into a much higher electric energy loss in the power plant. MSF-A units can reach high levels of thermal efficiency (P.R.) with steam at very low pressure, thus minimizing the electric energy loss in the power plant.


Energy consumption


High thermal efficiency



REDUCING THE COST OF WATER The most promising solution

According to what shown up to now, the most effective approach to a viable reduction of the cost of water is the design and construction of

LARGE MSF UNITS

EXTREMELY HIGH THERMAL EFFICIENCY

capable of



THE FUTURE OF MSF TECHNOLOGY

The most suitable technology

A new concept of MSF evaporator has been studied by to develop a reliable and efficient design reaching thermal efficiencies up to 14 kg of water per kg of reference steam, allowing at the same time a remarkable increase of single unit capacity (up to 100,000 m3/d).



• The basic principles of MSF type A were first presented at the Dubai IDA conference in 2009 by Dr. F. Alt, of PROCESS ENGINEERING LLC.

• They have been applied by to develop a reliable and robust detailed internal design allowing to reach performance ratios up to 14 kg/2326kJ in case of standard sea water quality and temperature.

• Such design has been already proposed by in the past years in several bids for large capacity installations.

THE BASIC CONCEPT



The new design – 20 MIGD / PR 14 THE FUTURE OF MSF TECHNOLOGY



THE INTERNATIONAL PATENT

Today holds an exclusivity agreement with PROCESS ENGINEERING LLC. for the proprietary use of the patent of MSF type A all over the world.



The new design – 2x20 MIGD / PR 14 THE FUTURE OF MSF TECHNOLOGY



Internationally certified

• Three independent reviews were conducted by International Consultants

Fichtner Parsons Brinckerhoff Lahmeyer Int.



Internationally certified

Money, Fuel and Environment



INVESTMENT COST • For very high values of

P.R., the investment cost of MSF-A can be nearly 20% less than the cost of MSF

• The difference in investment cost between MSF P.R.=10 and MSF-A P.R.=14 is only slightly above 10%

20%

12%



WATER AT A LOWER COST E + E + E

The benefits have to be considered in terms of: • Economic aspects

• Energetic aspects

• Environmental aspects



WATER AT A LOWER COST An Economical comparison

100000 14.0 11.5 15.8 5.9 1.4 0.99

Annual cost for CAPEX mortgage

Annual cost of fuel for

desalination

Annual cost of aux

consumption

Annual cost for O&M

Water cost

(M$/y) (M$/y) (M$/y) (M$/y) $/m3

100000 10.0 10.3 21.6 5.9 1.4 1.12

Total water(m3/d)

PRkg/2326kJ


WATER AT A LOWER COST An Energetic comparison

100000 14.0 209.680 19.582 35400

Thermal heat to desal

Desal Internal aux

cons.Fuel

(MW_th) (MW_el) barrels/Mm3

100000 10.0 286.592 19.582 46000

Total water(m3/d)

PRkg/2326kJ



WATER AT A LOWER COST An Environmental comparison

Emissions

kgCO2/m3

100000 10.0 17

Total water(m3/d)

PRkg/2326kJ

100000 14.0 13


Conclusions


SUMMARY (1) Conclusions

The cost of the water strongly depends on energy

The energy demand must be correctly defined and evaluated

Lower energy demand can be achieved by MSF-A by



MSF-A by is certified and patented

MSF-A by is eligible for commercial application

MSF-A by is the only way to reach P.R. up to 14



Water cost can be reduced Fuel can be reduced Carbon footprint can be

reduced

Via De Marini 1 - 16149 - Genoa (Italy)

For info and details:

Emilio Ghiazza

+39.010.60.96.361

[email protected]

www.fisiait.com

fundamentally water emilio ghiazza · large desalination units with high thermal efficiency:...

Documents