hen it comes to cutting car-

bon emissions from steel

production, Italy is argu-

ably already ahead of the game. The

majority (more than 85 per cent) of

its steel is produced from electric arc

furnaces using recycled scrap steel

as feedstock – a much less energy

and carbon intensive method than

blast furnace steel production.

But for one of the country’s major

steel producers, this is not enough.

The ORI Martin Group has complet-

ed the most recent phase of its ongo-

ing effort to reduce emissions while

improving energy efciency across

its plants. The company recently be-

gan operating a large scale heat

pump in Brescia in its latest move to

further improve the plant’s energy

efciency and reduce carbon emis-

sions by a further 5000 t/year.

Brescia, a historic city in the region

of Lombardy between Milan and Ve-

rona, has a long history in demon-

strating its commitment to sustain-

ability and energy efciency. In 1972

it began developing an integrated

system for energy production, dis-

trict heating (DH) and heat recovery

from industries. Over the years the

expansion of the DH network, the

introduction of cogeneration plants

and waste to-energy technology has

seen the city gain international rec-

ognition as a good example of circu-

larity and efciency.

More recently, recognising the

need to play its part in tackling cli-

mate change, in 2021 Brescia issued

the City Charter for Climate Neu-

trality. It has set a target of reducing

per capita CO

emissions by 50 per

cent by 2030 compared to 2010. The

target does not take into account

emissions from the private produc-

tion, or industrial sector.

Yet industry has a big part to play.

Over the last decade or so, ORI Mar-

tin has been accelerating its activities

in support of the city’s sustainable

development and climate-neutral

ambition.

“The steel industry is one of the

biggest industrial emitters of CO

emissions. It accounts for more than

7 per cent of the world’s CO

emis-

sions. We have to decarbonise to be

in line with the EU’s pledge to de-

crease emissions by at least 55 per

cent by 2030, compared to 1990 lev-

els… ,” said Carolina De Miranda,

Sustainability Manager, ORI Martin

S.p.A. “This year we started our de-

carbonisation strategy to reduce our

Scope 1 and Scope 2 emissions by

30 per cent by 2030, compared to

2018. And we would like to use up

to 25 per cent renewable energy in

our process.”

Commenting on the Brescia site

specically, she added: “We are lo-

cated next to a residential area,

which has always pushed us to work

on sustainability. So we started to

work on sustainability a long time

ago, especially for this location. ”

The Brescia site has been a key

focus for the company. In 2016 it

began working with Turboden, a

Mitsubishi Heavy Industries com-

pany, to see how the steel plant

could contribute to the city’s drive

to improve energy efciency. It in-

vested €12 million in a project

called ‘I-Recovery’ to convey the

large amount of heat contained in

the fumes of the electric arc furnace

into a system to avoid it being wast-

ed to the atmosphere.

The heat is recovered by a waste

heat recovery steam generator that

generates steam, which is then used

to feed the district heating network

in winter, or converted into electrici-

ty in the summer months through a

2.5 MW Turboden turbine using an

Organic Rankine Cycle (ORC). Both

the heat and electricity are supplied

to local energy company A2A to

serve its customers. The system has

an annual heat recovery capacity of

52 GWh and has reduced CO

emis-

sions by 10 000 t/year.

In its ongoing mission to cut car-

bon emissions and improve energy

efciency still further, ORI Martin

again turned to Turboden to recover

even more heat from the process. A

project known as ‘Heat Leap’ was

launched in 2020 as part of the ‘Life’

programme funded by the EU. Oper-

ation of this €6.5 million project

started earlier this year.

Roberto de Miranda, Board Mem-

ber, ORI Martin, said: “We use a lot

of water in the process for cooling.

Normally we use a cooling tower to

cool down the water used to cool the

electrical furnace. Now we can send

the water to a large heat pump (LHP)

to recover even more heat.”

Thanks to the installation of the

LHP, the heat from the furnace

cooling water can be upgraded and

then re-utilised instead of being

wasted, i.e. dissipated through cool-

ing towers.

For this project, Turboden designed

and installed an innovative LHP sys-

tem. With a Coefcient-of-Perfor-

mance (COP) of 8.2, it elevates the

waste heat (using electrical energy)

coming from the low-temperature

thermal waste heat of the steel plant,

from about 70°C up to as much as

120°C, to transfer it to the local dis-

trict heating network. Turboden’s

LHP has a thermal output of up to 7

MWth and is capable of adapting its

operation to specic process condi-

tions, thereby maximising energy re-

covery from the steel plant.

It will also be able to regulate the

heat transfer temperature according

to the specic needs of the district

heating network, up to a maximum

of 120°C. According to the compa-

ny, this is an important innovation

compared to the maximum tempera-

tures achievable by conventional

heat pump technology.

It was a complex project. The over-

all architecture of the installation

was carefully studied before pro-

ceeding to any real work on site.

Overall installation drawings were

done, as well as detailed engineering

and computer-assisted design, espe-

cially on the different interfaces be-

tween sub-systems. Firstly, the LHP

was connected to the existing waste

heat recovery (WHR) system and

designed in such a way that it can

accommodate variations of the heat

source temperature, thus providing

constant temperature to the WHR in-

stalled downstream.

The LHP was assembled on site,

accounting for local constraints and

nal ne-tuning of connecting pipes.

The LHP was then thermally insulat-

ed to avoid heat losses, as well as to

ensure safe access for authorised

maintenance staff.

The LHP was installed sufciently

close to the WHR system to mini-

mise temperature drops, and all con-

necting pipes were thermally insu-

lated. Assembly was carried out

on-site. In addition to mechanical

and hydraulic works, the LHP in-

stallation included electrical works.

The heat pump at the steel works

can be split into its main different

components: a low-pressure com-

pressor skid, where the inlet pressure

is between 4 and 7 bar; a high-pres-

sure compressor skid, where the out-

let pressure is between 7 and 10 bar;

a condenser; and an evaporator.

Roberto Bertanzi, Product Devel-

opment Coordinator at Turboden

said: “The water needed to cool the

furnace used to be wasted but thanks

to the heat pump, it can be now heat-

ed from about 70°C to around 100°C

for feeding into the district heating

system. It works in parallel with the

system that recovers heat from the

furnace fumes.” He added: “It’s

quite a exible system; we use soft-

ware to optimise heat production in

summer and winter. This is a pio-

neering project.”

Bertanzi noted the growing use of

heat pumps throughout various in-

dustries due to their ability to pro-

vide both heating and cooling as

well as the pressing need for decar-

bonisation. “They are, for example,

needed in the food industry and dair-

ies,” he said. “They are also well

suited for carbon capture processes,

which need both heating and cooling

for the chemical processes used to

remove CO

.”

He concluded: “The heat pump

helps support decarbonisation of

heat. So every time you are produc-

ing heat, you have to ask: ‘Can I re-

cover heat somewhere else by us-

ing a heat pump to reach my target

temperature?’ It’s not just about

saving money; it’s about saving the

environment.”

ORI Martin’s steel

production plant in

Brescia, Italy, is a

good example of how

the sector can play its

part in cutting global

carbon emissions.

Junior Isles recently

visited the facility to

take a look.

Brescia steel factory pioneers

decarbonisation technology

THE ENERGY INDUSTRY TIMES - APRIL 2024

Technology Focus

Maximising heat recovery at

the ORI Martin steelworks in

Brescia, Italy

Photo courtesy: ORI Martin