Periodic Reporting for period 1 - HERMES (Highly Efficient Super Critical ZERO eMission Energy System)
Reporting period: 2022-11-01 to 2024-04-30
Gas Turbine engines (GT) are a vital part of the backbone of EU power generation and will continue to hold a major role in centralized and decentralized energy supply. They have numerous advantages for power generation, i.e. efficiency, reliability, unique ability to vary power outputs rapidly to stabilize the electrical grid and balancing demand with greatly variable supply. Although emissions from gas turbines are relatively low, still they have an influence on the environment. Therefore, a breakthrough is needed to advance GT technology to the Green Deal level.
HERMES project presents an unique system based on the supercritical gas turbine which while generating power and heat does not produce any net greenhouse gas. Furthermore, the efficiency of the cycle is about two times higher comparing to the systems being currently in use. The main features of the HERMES concept are (i) a gas turbine working on renewable fuel with direct oxy-combustion process and using supercritical fluid as a major component of the energy carrier, (ii) a novel cost-effective small-scale methanol synthesis process exploiting decentralized carbon capture and storage (CCUS) and (iii) a dynamic simulation tools based on the machine learning algorithms to provide optimized fuel production and energy supply. The HERMES system, next to power and heat generation for domestic purposes, it is applicable to energy intensive industries (e.g. cement, steel, ceramics, glass), for decentralized electricity and heat production at neighborhood level (contributing to net zero energy communities, large building complexes, critical infrastructures -e.g. hospitals - etc.) and (parts of the system) for transportation.
The key objective of HERMES is to develop and assess the performance of a closed-loop renewable energy system based on a directly fired supercritical gas turbine engine operating on a variety of liquid/gaseous renewable fuels (here, methanol and hydrogen are used as a representatives) to provide electricity (and heat) with an efficiency above 65%, with net-zero greenhouse gas emissions and no emission of other pollutants.
HERMES project presents an unique system based on the supercritical gas turbine which while generating power and heat does not produce any net greenhouse gas. Furthermore, the efficiency of the cycle is about two times higher comparing to the systems being currently in use. The main features of the HERMES concept are (i) a gas turbine working on renewable fuel with direct oxy-combustion process and using supercritical fluid as a major component of the energy carrier, (ii) a novel cost-effective small-scale methanol synthesis process exploiting decentralized carbon capture and storage (CCUS) and (iii) a dynamic simulation tools based on the machine learning algorithms to provide optimized fuel production and energy supply. The HERMES system, next to power and heat generation for domestic purposes, it is applicable to energy intensive industries (e.g. cement, steel, ceramics, glass), for decentralized electricity and heat production at neighborhood level (contributing to net zero energy communities, large building complexes, critical infrastructures -e.g. hospitals - etc.) and (parts of the system) for transportation.
The key objective of HERMES is to develop and assess the performance of a closed-loop renewable energy system based on a directly fired supercritical gas turbine engine operating on a variety of liquid/gaseous renewable fuels (here, methanol and hydrogen are used as a representatives) to provide electricity (and heat) with an efficiency above 65%, with net-zero greenhouse gas emissions and no emission of other pollutants.
Various renewable fuels were explored and analyzed based on their production processes and how well they align with the HERMES combustion system. Both electrofuels and biofuels were studied, providing a portfolio of alternatives. The review of literature highlighted potential challenges, such as high-pressure requirements, CO2 dilution and low laminar flame speed. A classification table was created to suggest fuel mixtures that could improve desirable properties and mitigate problematic ones.
Furthermore, an extensive literature review was conducted on the potential of sorption-enhanced methanol synthesis. Cu-based catalysts and zeolites as water sorbents to enhance methanol production efficiency were considered. The methanol synthesis route using a fluidized bed reactor with a commercial Cu-based catalyst and zeolite 3A as a water adsorbent was validated at TRL1-3 under 3 bar(a) pressure. Testing within a temperature range of 200-250°C showed that temperatures above 200°C activate the catalyst, while temperatures below 250°C maximize water adsorption and methanol yield. Further, adsorption experiments on sodium mordenite (MOR), zeolite 3A, and zeolite 4A confirmed zeolite 3A as the best sorbent for sorption-enhanced methanol production from CO2 due to its superior water selectivity and reduced dimethyl ether (DME) formation.
For the development of a highly efficient supercritical gas turbine operating on renewable fuels with zero-emissions, an experimental campaign on methanol injection under high and moderate pressures was done. The results show that injectors, when operating at high pressures could be subject of cavitation and erosion. This was not observed for the moderate pressure injection. Furthermore, the effect of an increased pressure in the combustion chamber on the laminar burning velocity (LBV) was investigated. The research was performed at atmospheric conditions (i.e. with air) and with CO2 environment. The effect of pressure and equivalence ratio on the combustion process revealed that with pressure increase the LBV decreases, whereas the increase in equivalence ration gives an opposite effect. Finally, a preliminary ignition tests at combustion research unit (CRU) with an optical access the flame and at 150bar pressure were performed. The operation concept of the CRU was confirmed and validated.
In parallel line of investigation, a semi-detailed kinetic mechanism for combustion process were evaluated and implemented to the LES numerical code. The numerical schemes were validated against available literature data for supercritical and transcritical combustion and with using a spray-flame. It was concluded that the results are satisfactory and the numerical simulations can be applied for further development of the supercritical combustors.
Finally, to design a supercritical compressor, a 1D code has been developed. It is currently in use to optimize the design.
Furthermore, an extensive literature review was conducted on the potential of sorption-enhanced methanol synthesis. Cu-based catalysts and zeolites as water sorbents to enhance methanol production efficiency were considered. The methanol synthesis route using a fluidized bed reactor with a commercial Cu-based catalyst and zeolite 3A as a water adsorbent was validated at TRL1-3 under 3 bar(a) pressure. Testing within a temperature range of 200-250°C showed that temperatures above 200°C activate the catalyst, while temperatures below 250°C maximize water adsorption and methanol yield. Further, adsorption experiments on sodium mordenite (MOR), zeolite 3A, and zeolite 4A confirmed zeolite 3A as the best sorbent for sorption-enhanced methanol production from CO2 due to its superior water selectivity and reduced dimethyl ether (DME) formation.
For the development of a highly efficient supercritical gas turbine operating on renewable fuels with zero-emissions, an experimental campaign on methanol injection under high and moderate pressures was done. The results show that injectors, when operating at high pressures could be subject of cavitation and erosion. This was not observed for the moderate pressure injection. Furthermore, the effect of an increased pressure in the combustion chamber on the laminar burning velocity (LBV) was investigated. The research was performed at atmospheric conditions (i.e. with air) and with CO2 environment. The effect of pressure and equivalence ratio on the combustion process revealed that with pressure increase the LBV decreases, whereas the increase in equivalence ration gives an opposite effect. Finally, a preliminary ignition tests at combustion research unit (CRU) with an optical access the flame and at 150bar pressure were performed. The operation concept of the CRU was confirmed and validated.
In parallel line of investigation, a semi-detailed kinetic mechanism for combustion process were evaluated and implemented to the LES numerical code. The numerical schemes were validated against available literature data for supercritical and transcritical combustion and with using a spray-flame. It was concluded that the results are satisfactory and the numerical simulations can be applied for further development of the supercritical combustors.
Finally, to design a supercritical compressor, a 1D code has been developed. It is currently in use to optimize the design.
Most of the results were not yet published. Some experiments and numerical computations still need to be conducted to get the full picture about the interacting phenomena. However, first conference presentations obtained a major attention from the scientific community. This resulted in two poster prizes.