{"id":773,"date":"2026-02-17T16:37:52","date_gmt":"2026-02-17T16:37:52","guid":{"rendered":"https:\/\/heatpumpingtechnologies.org\/project59\/?post_type=case_studies&p=773"},"modified":"2026-02-17T16:37:52","modified_gmt":"2026-02-17T16:37:52","slug":"paper-pulp-drying-france","status":"publish","type":"case_studies","link":"https:\/\/heatpumpingtechnologies.org\/project59\/case-studies\/paper-pulp-drying-france\/","title":{"rendered":"Paper pulp drying, France"},"content":{"rendered":"
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TRANSPAC is the first industrial-scale transcritical high-temperature heat pump <\/strong>(HTHP) using a hydrofluoroolefin (HFO) refrigerant <\/strong>for drying applications. The 580 kWth HTHP demonstrator was installed at WEPA Greenfield in Ch\u00e2teau-Thierry, France, a paper-pulp production facility, as part of an innovation project led by EDF R&D<\/a> and Dalkia Groupe EDF <\/a>and co-financed by ADEME<\/a>.<\/p>\n<\/div>\n\n

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Heat pump demonstrator<\/h2>\n<\/div>\n\n
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The HTHP demonstrator was developed between 2017 and 2023 and has been in operation since April 2023, recovering waste heat for industrial process heating.<\/p>\n<\/div>\n\n

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The system operates with the HFO refrigerant R1234ze(E)<\/strong>, which has a critical temperature of 109.4 \u00b0C (see the T\u2013s diagram in the figure). Initial operating data confirms the expected performance at industrial scale. With a waste-heat source temperature of 70\u201380 \u00b0C<\/strong>, the unit heats the pulp dryer inlet air from 97 \u00b0C to 138 \u00b0C. <\/strong>Under these conditions, the measured COP ranges from 3.6 to 4.2<\/strong>, with an average COP of 4.0.<\/p>\n<\/div>\n\n

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The figure below shows the integration concept for waste-heat recovery and drying-air heating using the transcritical HTHP. The accompanying photos illustrate the containerized equipment arrangement and the piston compressor applied in the system.<\/p>\n<\/div>\n\n

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Figure: Concept for integrating the transcritical HTHP (Sources: Dalkia Groupe EDF (2024), EDF R&D (2024))<\/p>\n<\/div>\n\n

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The underlying TRANSPAC technology originated from a 30-kW prototype developed at EDF R&D and MINES ParisTech (France), with financial support from ADEME. EDF patented the concept (EP 2880 379 B1, WO 2014\/020255). The first-generation prototype used R32; a second-generation unit was subsequently developed using R1234ze(E) to preheat air up to approximately 150 \u00b0C (e.g., tunnel-drying applications) using waste heat at around 82 \u00b0C. Experimental testing confirmed technical feasibility.<\/p>\n<\/div>\n\n

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In the prototype stage, commercially available CO2<\/sub> components were adapted, including a semi-hermetic reciprocating compressor (Bock HGX2\/90), an electronic expansion valve (Danfoss CCM10), stainless steel\/aluminum finned heat exchangers as the gas cooler and evaporator, and synthetic POE lubricant. Efficiency enhancements were analyzed using an internal heat exchanger (+6% COP), parallel compression (+9% COP), and a combination of both (+12% COP).<\/p>\n<\/div>\n\n

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Benefits<\/h2>\n<\/div>\n\n
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By replacing heat previously supplied by a gas boiler, the transcritical high-temperature heat pump offsets approximately 5 GWh\/year of fossil heat<\/strong>. This corresponds to an annual reduction of roughly 1,000 t CO\u2082<\/strong>, based on an average COP of 4. Overall, the installation achieves an estimated ~75% reduction in energy use and CO\u2082 emissions for this heat demand. In addition, the specific CO\u2082 emissions are reported to be 16\u201320 times lower than those associated with natural-gas steam generation.<\/p>\n<\/div>\n\n

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Applications<\/h2>\n<\/div>\n\n
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With supply temperatures in the range of 105\u2013140 \u00b0C, the transcritical high temperature heat pump is applicable to many industrial sites with waste-heat sources between 60 \u00b0C and 90 \u00b0C. Typical target sectors include paper, food, chemicals, metallurgy, and textiles.<\/strong><\/p>\n<\/div>\n\n

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Drying applications include spray drying, evaporation, and distillation<\/strong>. Additional potential exists in starch production, wood pellets, tiles and bricks, technical nonwovens, pulp, and pet food.<\/p>\n<\/div>\n\n

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Key facts<\/h2>\n<\/div>\n\n
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Dryer type<\/td>Paper dryer<\/td><\/tr>
Drying product(s)<\/td>Pulp<\/td><\/tr>
Drying medium<\/td>Air<\/td><\/tr>
Operation<\/td>Continuous<\/td><\/tr>
Product conveying<\/td>Rolls<\/td><\/tr>
Heating medium temperature<\/td>120 to 140 \u00b0C (drying air)<\/td><\/tr>
Heat sources<\/td>Humid exhaust air (condensate) from paper pulp dryer<\/td><\/tr>
Heat pump capacity<\/td>580 kW<\/td><\/tr>
Flow temperature heat pump<\/td>155 \u00b0C<\/td><\/tr>
Refrigerant<\/td>R1234ze<\/td><\/tr>
Drying time<\/td>n.a.<\/td><\/tr>
Start of operation<\/td>April 2023<\/td><\/tr>
Capacity<\/td>n.a.<\/td><\/tr>
Dimensions<\/td>6.0 x 2.5 (L x H) (container installed outdoor)<\/td><\/tr>
Outlet condition drying medium<\/td>55 to 73 \u00b0C (condensate)<\/td><\/tr>
Direct heat recovery<\/td>Yes, fresh air preheating<\/td><\/tr>
Heat source for heat pump<\/td>Humid exhaust air (condensate), 60 to 88 \u00b0C<\/td><\/tr>
Challenges<\/td>Transcritical heat pump cycle, high temperatures, retrofit<\/td><\/tr>
Tracked parameters<\/td>Temperatures, COPs, specific energy consumption, specific air consumption, relative humidity<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n
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More information<\/h2>\n<\/div>\n\n
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This information was provided by Cordin Arpagaus<\/a>.<\/p>\n<\/div>\n\n

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It was extracted from:<\/p>\n<\/div>\n\n

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