At a time when the energy transition is becoming a strategic imperative for industry, the recovery of waste heat is emerging as an essential lever.

Accessible, quick to implement and cost-effective, waste heat recovery enables industrial sites to immediately reduce their fossil fuel consumption and CO₂ emissions, whilst boosting their competitiveness. However, each site has its own specific potential, and solutions must be tailored to the site and its technical, economic and organisational constraints.

It is with this aim of providing practical support to manufacturers that the ALLICE Alliance is today publishing a report featuring seven case studies illustrating a variety of long-standing projects, highlighting the robustness of these solutions, which have been tried and tested in the field.
 
Manufacturers and solution providers share their collaborations and case studies on specific projects involving the recovery and utilisation of waste heat across a range of sectors. The case studies particularly highlight the longevity of the installations, with operating periods ranging from 2 to 10 years.

Each fact sheet presents:

• the scope of the project and the process concerned,
• the decision-making criteria that guided the choice of solution,
• the progress of the project (timeline, funding),
• as well as the results achieved in terms of energy savings.

Electrification is a key driver of decarbonisation for the industrial sector, particularly in France, where the electricity mix is largely decarbonised. Solutions exist and are ready to be implemented. However, despite this significant potential, projects are still struggling to get off the ground.

To help overcome these barriers, the ALLICE Alliance has published five project factsheets which analyse lessons learnt from electrification initiatives in a range of energy-intensive sectors: metallurgy, textiles, construction, glass, and tiles and bricks. To facilitate the roll-out of electrification, each project is analysed in terms of its replicability.

Having published a forward-looking public report in 2022 on the potential for electrification of industrial thermal processes, the ALLICE Alliance is publishing project factsheets in 2025 aimed at making electrification initiatives within the industrial sector concrete and replicable.
These factsheets aim to demonstrate that electrification is feasible in a wide variety of scenarios, even within energy-intensive sectors.

French and European industry faces a two-fold environmental challenge: decarbonising its thermal energy use, which remains heavily reliant on fossil-fuel-generated heat, and reducing its water consumption, which is subject to significant constraints due to climate conditions and regulations.A cross-analysis of industrial water abstraction and waste heat sources shows that several sectors lie at the intersection of these two challenges. The chemicals and agri-food sectors thus account for more than 50 per cent of both waste heat sources and industrial water abstraction. These are closely followed by the paper and board sector, non-metallic materials (glass, cement, terracotta, etc.) and the metallurgy sector, each accounting for around 10 per cent of their respective categories.

This context, together with the observation that a significant proportion of waste heat sources also contain water, has led to the central question of this study: in what scenarios does the combined recovery of heat and water appear to be worthwhile?

This key question therefore raises a number of related issues concerning the feasibility, cost-effectiveness and competitiveness of these solutions in the industrial sector.

• The study aims, as a first step, to analyse the key components required to implement this type of project (equipment, studies, technologies, etc.) in order to identify the obstacles, barriers and opportunities from a technical, technological and regulatory perspective.
• The study then goes on to examine the key factors determining the environmental and financial impact of projects: it thus identifies three sets of factors that significantly influence profitability, and sets out favourable ranges for each of them. These may include contextual factors such as the number of operating hours per year, the reference price of heat or local water pressure, as well as factors relating to the characteristics of the waste heat stream in question (temperature, water content, etc.)
• Based on the conclusions drawn from the previous sections, the study provides an analysis and quantification of the potential of industrial sectors and sub-sectors, taking into account the key processes involved and the available sources of waste heat.

In order to illustrate and challenge the findings, the study presents a case study based on previous examples. The cases analysed confirm the technical feasibility of combined heat and water recovery, in line with the sectors identified as relevant.

The LIFE ZEUS project, implemented by MONIN (a French syrup manufacturer) at its Bourges site, demonstrates the industrial feasibility of water recycling in an agri-food context: the expected water savings are set to exceed 60 per cent of the site’s annual consumption, by reusing the entire 38,000 m³ of wastewater discharged each year.

Energy efficiency is a key driver of industrial decarbonisation, but investment remains insufficient to meet emissions reduction targets.

This situation can be partly explained by an incomplete assessment of projects, which is often limited solely to energy savings and reductions in CO₂ emissions, without taking into account their contribution to industrial performance and competitiveness.

However, energy efficiency projects also generate numerous non-energy benefits (NEBs) — such as reduced maintenance costs, improved productivity or comfort — which are still rarely factored into investment decisions, due to a lack of data, suitable methods and the expertise required to quantify them.

Against this backdrop, the study carried out by ALLICE aims to raise awareness of BNE amongst its members and to identify the barriers and drivers to its integration into investment decisions.

The study will focus on identifying and characterising BNE, applying the MBENEFITS methodology to two real-world industrial cases (Cooperl and Thyssenkrupp), and formulating best practices and recommendations to better capitalise on these benefits in energy efficiency projects.

Decarbonising high-temperature industrial thermal processes is a major challenge for the energy transition in high-emission sectors such as metallurgy, the construction materials industry and the chemical industry. These processes, which often require temperatures in excess of 1000 °C, are difficult to fully electrify in the short to medium term. In this context, the integration of decarbonised gaseous fuels appears to be a complementary and pragmatic means of reducing greenhouse gas emissions.

Decarbonised gaseous fuels – biomethane, biogas, synthetic methane, low-carbon hydrogen, biopropane, renewable dimethyl ether (rDME), decarbonised ammonia or syngas – are characterised by a reduced carbon footprint throughout their entire life cycle. Integrating these gases into existing thermal processes raises complex issues regarding technical feasibility, safety, compatibility with equipment, and economic viability, affecting burners, gas installations, furnaces and regulatory compliance.

The study is divided into two parts: the first part aims to analyse the technical challenges associated with the use of these gases in high-temperature combustion processes, whilst the second part examines their economic impacts through sector-specific case studies.

The objectives are: 

1. Assessing the adaptability of existing burners to the integration of low-carbon gaseous fuels
2. Identify innovative or emerging burner technologies suitable for these gases
3. To analyse the conditions for industrial implementation, taking into account technical, economic, regulatory and safety aspects
4. Quantifying the economic impacts (CAPEX, OPEX, energy costs, carbon costs)   

The study resulted in the production of four complementary deliverables:

• A technical analysis report on the technical feasibility of burner hybridisation
• An economic analysis report presenting the results of technical and economic modelling for three sector-specific case studies
• The Excel tool implementing the case studies for economic analysis
• A benchmark of burners compatible with carbon-free gases, listing existing and developing solutions, their levels of maturity and their areas of application

Electric furnaces are a key driver of decarbonisation in industry, with technological maturity continuing to advance. They offer significant advantages in terms of reducing CO₂ and pollutant emissions, energy efficiency, operational flexibility and maintenance.

However, the roll-out of high-temperature electric furnaces remains hampered by a number of major obstacles: high capital costs, the need to adapt industrial processes, and the lack of a stable economic framework to underpin long-term projects.

The study aims to identify solutions for the electrification of high-temperature furnaces and to analyse the conditions for their industrial deployment.

It covers an overview of fossil-fuel-based technologies and their electric alternatives across several key sectors (steel, metallurgy, cement, glass and ceramics), an analysis of the European and global markets, and the identification of drivers for development, particularly the challenges associated with connecting to the electricity grid.

The success of the roll-out depends on the coordinated involvement of all stakeholders in the ecosystem: public authorities, industry, trade associations, furnace manufacturers, engineering consultancies and energy suppliers, with targeted support for pioneering projects.

Three main technologies are analysed — arc, resistance and induction furnaces — the maturity of which varies depending on their application, but which offer significant potential for decarbonisation. Technological advances and the standardisation of solutions are essential to reduce costs, safeguard investments and help achieve the climate targets set out in the SNBC.

This study focuses on the decarbonisation of drying and firing processes. It follows on from a previous ALLICE study of the same name. Three types of decarbonisation solutions are examined: energy efficiency, electrification, and renewable and recovered energy. The aim of the study is to examine the application of these different solutions across three case studies and to compare the results up to 2050 in terms of energy, economic and environmental impacts.

The applications studied are glass annealing arches, metallurgical tempering furnaces and starch drying.

An initial energy-efficiency solution is being implemented for these three scenarios. It is regarded as a prerequisite for the use of low-carbon energy. Indeed, it is generally accepted that the widespread adoption of low-carbon energy sources will only be possible if energy consumption is reduced. Next, several alternative energy solutions are examined for each scenario: hybridisation, electrification, solar power, geothermal energy, hydrogen and biomass.

Overall, two trends emerge from all the case studies.

Firstly, energy efficiency is consistently among the most economically viable solutions.
Secondly, electrification is invariably one of the solutions that delivers the greatest reduction in CO₂ emissions. However, it is often the solution that generates the fewest savings.

This study shows that, taken together, these solutions enable significant reductions in GHG emissions. To achieve further reductions in GHG emissions associated with certain processes or specific cases, CCUS (Carbon Capture, Utilisation and Storage) solutions may be necessary. Finally, it is important to consider the other environmental impacts of these processes, particularly with regard to water.

Energy recovery from polluted flue gases is relevant to a significant number of industrial operators that generate waste heat, particularly in the food and drink industry (ovens, deep-fryers, cooking, drying), the materials industry (lime, tiles and bricks, insulation, glass) and the metals and engineering sectors (paint lines, smelting, heat treatment).

This study provides an overview of the current state of the art in flue gas treatment solutions on their own, as well as treatment solutions that incorporate heat recovery.

The report focuses on seven heat exchanger technologies, the advantages and disadvantages of which have been summarised in technical data sheets. Some of these have already been analysed in ALLICE’s previous work, whilst three of them are the subject of new data sheets for an in-depth assessment:

• Cascade of heat exchangers with flue gas treatment
• Glass heat exchanger for acid fumes
• Polymer heat exchanger for low-temperature polluted flue gases

In order to enrich these fact sheets with data drawn from the actual operation of flue gas treatment systems, the study incorporates three case studies:

• Flue gas treatment and heat recovery at an oil and natural gas refinery
• Flue gas treatment with heat recovery in the brick and tile industry
• Flue gas treatment with heat recovery at a waste incineration plant

In 2021, ALLICE carried out an initial technical study on very high-temperature heat pumps (VHT heat pumps) for industry. This study provides an overview of the current state of the art in existing solutions and analyses in detail three heat pump technologies considered particularly relevant to the industrial sector. To build on this analysis, ALLICE launched three new studies in 2024 aimed at identifying the barriers and drivers to the deployment of these technologies.

The third study complements the other two by identifying the key factors (barriers, constraints and drivers) influencing the deployment of heat pumps at industrial sites, from technical, practical, economic and regulatory perspectives.

In particular, a modelling tool has been developed to illustrate the study’s findings, highlighting the impact of various parameters on the performance of heat pump projects. This tool helps to anticipate favourable or unfavourable configurations based on technical and economic criteria, and is made available to members.

In 2021, ALLICE carried out an initial technical study on very high-temperature heat pumps (VHT heat pumps) for industry. This study provides an overview of the current state of the art in existing solutions and analyses in detail three heat pump technologies considered particularly relevant to the industrial sector. To build on this analysis, ALLICE launched three new studies in 2024 aimed at identifying the barriers and drivers to the deployment of these technologies.

This second study updates the 2021 research on high-temperature heat pumps (THT) by incorporating the latest technological advances (R&D; and feedback from practical experience). It focuses on three alternative technologies:- Helium-based heat pumps with Stirling engines

– Thermoacoustic heat pumps

– Coupling a ‘conventional’ high-temperature heat pump with mechanical vapour compression (MVC)

The study also lists demonstrators and pilot projects in Europe.

This is followed by Section 3, which focuses on the integration of heat pump technology in industry.