The replication potential of the selected sites will be exploited via replications studies, allowing local CO2OLHEAT virtual simulations. The studies will include on-site visits, analysis of available energy monitoring, benchmarking with potential WH2P alternatives (both technically and economically) as well as local grid flexibility potential assessment.
Şişecam already runs four WH2P systems via different technologies, different glass production processes, and at different locations. Therefore, Şişecam has significant expertise in WH2P and aims to enlarge it thanks to the CO2OLHEAT project. The selected reference plant is located in Ankara, Turkey.
CO2OLHEAT solution could recover the energy from melting furnace flue gases. The amount of available waste heat seems relevant – at 20-25 MWth. Potentially installed WHRU would valorise flue gases from the production furnace with temperature 450-580˚C and flow rate 90.000-120.000 Nm3/h. It is relevant to highlight that the flue gases must be conveyed back to the manufacturing plant at 180°C.
MYTILINEOS’ aluminium plant, “Aluminium of Greece” (AoG) is one of the strongest players in the Metallurgy sector in the European Union, with an annual production capacity that exceeds 190,000 tons of aluminium and 820,000 tons of alumina. The plant is located in Viotia, Greece. The holding furnaces of the foundry line are selected as the CO2OLHEAT replication site.
In total, the foundry line operates eight (8) holding furnaces in pairs, which perform batch operations. Periodic measurements on gas temperature and flow rate, performed by AoG analytical laboratory indicate the potential for the valorisation of waste heat streams, with further advantages of flue gas cooling. The flue gas flow rate and temperature at the foundry line fluctuate in the range of 10,000-20,000 Nm3/h and 120-500°C, respectively. The average heat recovery potential at each flue gas stream can be between 950 and 1200 kWth and the amount of recovered heat is strongly dependent on the operation capacity of each furnace.
MYTILINEOS has demonstrated practically its long-term commitment to sustainability by achieving a reduction of emissions per unit of revenue by more than 15% YoY, over the last four (4) years. On 18 February 2021, through a decision by the Board of Directors, MYTILINEOS became the first Greek company to make an ambitious commitment regarding the minimization of its carbon footprint, by setting clear targets:
For the Metallurgy Business Unit of MYTILINEOS the following targets have been set for 2030: reduction of the absolute emissions by 65% and, respectively, reduction of the relative emissions by 75% (as measured per ton of aluminium produced) by 2030.
The Metallurgy Business Unit aims to transform MYTILINEOS into a global leader in the field of “green metallurgy”. Within the course of the CO2OLHEAT project, MYTILINEOS aspires to further research the sCO2 potential for the Aluminium sector and understand whether the fluctuation of the temperature profile would affect the efficiency sCO2 unit.
CELSA aims to study the CO2OLHEAT cycle to recover the residual heat in the exhaust gases of the electric arc furnace (EAF) of steel plants. The replication will first take place in CELSA Barcelona, which is the largest company of the CELSA group, and generates the highest energy consumption of all the group’s subsidiaries. However, depending on the results in CELSA Barcelona, the replication could be carried out in all CELSA’s industrial steel plants in the EU.
The CO2OLHEAT WH2P solution could be located downstream of the Electric arc furnace (EAF) fume outlet, recovering waste heat through a HEX between the off gases and steam. This steam could then be fed to the CO2OLHEAT system. The temperature difference from which the residual heat can be extracted is relatively high, being TC=1.150˚C and TF=250˚C with off-gases flow around 104.200,00 m3/h.
ENGIE Laborelec supports several waste incineration plants in Belgium and Europe. A brand-new Flemish waste to energy plant located in Beringen will be used as a replication study for the CO2OLHEAT project.
The waste to energy plant has a waste incineration capacity of 200.000 ton of non-recyclable, non-toxic waste per year. The heat release from the combustion process is currently validated in a recuperation boiler. The produced steam capacity is 105 ton/hour at a pressure of 43,5 bara and a temperature of 410°C. The current steam turbine consists of three different pressure levels: HP-, MP- and a LP step followed by an aero condenser. Part of the produced steam (at a pressure of 43 bara and a temperature of 277°C) is injected in an industrial steam network that foresees in the steam demand of a neighbouring company. The maximum (brut) electrical generator capacity is ~25 MWel. The operational time of the waste incineration furnace is 24/7, and this during ~335 days a year.
The waste heat from the waste incineration furnace is to be seen as a very constant source of heat. The goal of the CO2OLHEAT replication study is to consider a replacement of the existing steam turbine plant with a sCO2 plant, in order to benchmark and understand benefits and performance of a sCO2 plant .
CO2OLHEAT technology is highly replicable in all EU waste incineration furnaces and this also for waste incineration plants with a highly fluctuating waste heat demand (for instance on a public or private heat network). The engineering of a compact sCO2 power block offers opportunities for the future to effectively integrate a power block on these waste incineration plants (that currently don’t have any form of electrical validation for the combustion heat). This might be possible due to the fact that sCO2 power blocks are more flexible, have a shorter ramp-up timing of the plant, and are more compact comparing to water/steam power blocks.
In the framework of the work related to the other sCO2-related projects, EDF has already capitalised on its extensive experience in sCO2 cycles for high power generation with conventional and renewable power plants as well as in cycles dedicated to heat recovery based on sCO2.
Within the CO2OLHEAT project, EDF proposes to study the replicability of the system developed on Gas Turbine Power Plants. Cycle optimisation is crucial for power generation sector replication. Retrofitting the existing combustion turbines to a combined cycle with a sCO2 bottoming cycle and a recovery boiler would increase the plant’s power by 100 MW of flexible capacity while increasing the plant’s efficiency by 38% to 55%.
The CO2OLHEAT plant would be an excellent way to decarbonise electricity production. It would offer a second life to existing combustion turbines and increase the electrical efficiency by 30%. It would also provide a new type of ultra-flexible combined cycle to compensate for the variability of a renewable park under development. From an economic point of view, the reuse of existing equipment as well as the increase in the number of call hours of the new plant (due to its higher efficiency) are promising levers to justify this retrofit. Finally, the EU fleet of GT of this type is large enough to allow a wide replication of this type of project.
The site envisaged for the replication of CO2OLHEAT system is located in the Paris region (Montereau Fault Yonne). The site was historically composed of two coal cycles and two fuel cycles for a total power of 750 MW. Following the desire to decarbonise electricity production, EDF closed these cycles in the 2000s and redeveloped the production site with two combustion turbines running on gas. The exhaust gases of one of them, a GT13E2 type combustion turbine with a power of 210 MW, will be considered to be valorised via the CO2OLHEAT cycle.
Creating a synergy with the SOLARSCO2OL project, a replication study will be conducted to study the integration of the CO2OLHEAT module in La Africana plant, and benchmark the CO2OLHEAT solution with SOLARSCO2OL cycle layout performances.