Netherlands

Achieving net-zero emissions requires major changes across a nation’s economy energy and land systems particularly due to sectors where emissions are difficult to eliminate. Here we adapt two global scenarios from the International Energy Agency—the net-zero emissions by 2050 and the Stated Policies Scenario—using an integrated numerical economic-energy model tailored to Australia. We explore how emissions may evolve by sector and identify key technologies for decarbonisation. Our results show that a rapid shift to near-zero emissions electricity is central to reducing costs and enabling wider emissions reductions. From 2030 onwards carbon removal through land management and engineered solutions such as direct air capture and bioenergy with carbon capture and storage becomes critical. Australia is also well-positioned to become a global supplier of clean energy such as hydrogen made using renewable electricity helping reduce emissions beyond its borders.

Liquid hydrogen (LH2) is a promising candidate for zero emission aviation but its cryogenic properties make the refuelling process fundamentally different from that of conventional jet fuels. Although previous studies have addressed LH2 storage and system integration detailed modelling of the refuelling process remains limited. This paper presents the first part of a two-part study focused on simulation of the refuelling process for an LH2-powered commercial aircraft. An existing tank model is substantially modified to more accurately capture relevant physical phenomena including heat transfer and droplet dynamics during top-fill spray injection. Newly available experimental data on LH2 no-vent filling enables direct validation of the model under conditions that match the experimental setup. A sensitivity analysis identifies the most influential parameters that affect model precision including loss coefficient droplet diameter radiative heat ingress and vent-closing pressure. The validated model forms the basis for Part 2 of this study in which it is applied to a representative LH2-powered commercial aircraft to simulate refuelling times quantify venting losses and assess the impact of key operational settings. These results support the design of efficient LH2 refuelling systems for future aircraft and airport infrastructure.

Hydrogen will play a critical role in decarbonizing diverse economic sectors. However given limited sustainable resources and the energy-intensive nature of its production prioritizing its applications will be essential. Here we analyse approximately 2000 (low-carbon) hydrogen projects worldwide encompassing operational and planned initiatives until 2043 quantifying their greenhouse gas (GHG) emissions and mitigation potential from a life cycle perspective. Our results demonstrate the variability in GHG emissions of hydrogen applications depending on the geographical location and hydrogen source used. The most climate-effective hydrogen applications include steel-making biofuels and ammonia while hydrogen use for road transport power generation and domestic heating should be discouraged as more favourable alternatives exist. Planned low-carbon hydrogen projects could generate 110 MtH2 yr−1 emit approximately 0.4 GtCO2e yr−1 and potentially reduce net life cycle GHG emissions by 0.2–1.1 GtCO2e yr−1 by 2043 depending on the substituted product or service. Addressing the current hydrogen implementation gap and prioritizing climate-effective applications are crucial for meeting decarbonization goals.

Fluidized bed systems play a crucial role in industrial processes such as combustion and gasification. In the Iron Power Cycle fluidized bed systems are essential for enabling the reduction of combusted iron back to iron making them a critical component in the regeneration step of the cycle. This study investigates the impact of operating gas velocity on conversion by performing reduction experiments at three distinct fluidization numbers (us/umf): 16 (bubbling regime) 55 (transition region) and 100 (fully turbulent regime). Experiments were conducted to determine the appropriate velocities for each regime ensuring optimal fluidization conditions across reduction temperatures ranging from 500 to 700 ⚬C. The results reveal that conversion rates increase significantly with gas velocities. At 500 ⚬C operating at approximately six times higher velocity leads to a sixfold improvement in conversion when using iron-oxide particles with a Sauter mean diameter of 61 µm. However while enhanced velocities improve reaction efficiency challenges remain at elevated temperatures (T ≥ 500 ⚬C) where iron undergoes defluidization when exposed to hydrogen. Once defluidization occurs refluidization proves impossible with either hydrogen or nitrogen raising concerns about process stability. These insights highlight the potential for optimizing fluidized bed reduction through velocity control while also underscoring the need for additional measures to mitigate unstable fluidization during high-temperature iron oxide reduction.