650
120000 100000 140000 160000 200000 180000 220000
TM2500 (50 Hz) 6B.03 9E.04
600
TM2500 (50 Hz) 6B.03 9E.04
550
9HA.01 7F.04
9HA.01 7F.04
500
450
400
0 20000 40000 60000 80000
350
300
250
0 5 10
15
20 25
30 35
40
45
50
55
60
65 70
75
0 5 10
15
20 25
30 35
40
45
50
55
60
65 70
75
Ammonia content (vol%)
Hydrogen content (vol%)
hydrogen or ammonia, show a maximum CO 2 emissions intensity of around 1.4%, which corresponds to an overall emissions reduction of approximately 15%. In contrast, hydrogen-enriched fuel blends result in significantly larger reductions in CO₂ emissions intensity, with emissions cut by almost 50% at high hydrogen content. Fuel gas requirements Figure 4 shows the amount of fuel blends with hydrogen required to maintain a fixed GT load, which is 90% of the rated capacity for all GE GTs in this study. As the hydrogen content increases in the fuel gas, the fuel gas requirements exhibit an almost quadratic growth trend. For GE and Siemens GTs, using hydrogen-enriched fuel gas blends increases the fuel gas flow by a maximum ratio of 2.1:1. This ratio implies a large actual volume flow rate of fuel gas to the GT, which, for existing facilities, might be difficult to accommodate. Ammonia-rich fuel gas blends require a lower fuel gas flow rate, reaching a maximum ratio of 2.0:1, slightly smaller than the case of hydrogen enriched fuel gas blends. Table 2 shows a summary of all simulation results comparing the performance of the GTs using hydrogen and ammonia fuel blends. Effect on GT combustion temperature A critical variable when adding hydrogen and ammonia into the fuel gas mixture is the GT combustion temperature. This directly Figure 4 Fuel requirements vs hydrogen content in fuel gas for GE GTs
GTs. As expected, the CO 2 emissions intensity decreases with increasing hydrogen content in the GT fuel blend. This raises a key question: how consistent are these reductions across turbine size and configuration? The simulation results show that smaller gas turbines tend to have higher CO 2 intensity compared to larger GT models. This is because the efficiency of a small GT is lower, so it consumes more fuel per unit of power produced. The CO 2 emissions intensities and fuel blend consumption for ammonia and fuel gas blends were investigated using the Petro-SIM models. The simulation results are shown in Figure 3 . It is important to note that publicly available operational data for ammonia firing in commercial gas turbines remains limited, as most current work is focused on modelling, pilot studies, and early-stage demonstrations. However, manufacturers and recent studies indicate that such operation is feasible with appropriate modifications to turbine and combustion systems (Pashchenko, 2024). A comparison of the results shown in the figures is summarised in Table 1 . Siemens and GE GTs, assuming a maximum composition of 75% for either hydrogen or ammonia, show a maximum reduction in CO 2 emissions intensity of around 3% for ammonia-enriched fuel blends. This is attributed to the higher heating value of ammonia, which reduces hydrocarbons in the fuel blend to reach the required power. A similar trend is observed from the analysis of results with Siemens and Mitsubishi GTs. Mitsubishi GTs, which can handle up to 30 vol% of either Figure 3 CO 2 emissions intensity vs ammonia content in fuel gas for GE GTs
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