(638c) Ammonia’s Role in Enabling Widespread Renewable Power and Transport in Australia | AIChE

(638c) Ammonia’s Role in Enabling Widespread Renewable Power and Transport in Australia

The demand for H2, especially renewable H2, is rapidly growing in Asia and Europe, driven by favourable policies and the continued development of complementary H2 production and utilisation technologies. This represents a significant opportunity for Australia to become a renewable energy exporter, but the geographic mismatch between Australia’s large renewable energy resource and the end markets is a significant barrier to the realisation of this vision. H2transport is notoriously expensive and inefficient due to its low energy density and very low liquefaction temperature, and this problem is exacerbated with the large transport distances and long storage times required.

Liquid hydrogen carriers are emerging as an enabler of renewable energy export, and ammonia is the leading candidate due to its high hydrogen density (greater than liquid H2), existing production and transport infrastructure, and well-developed safety practices and standards. The only significant technical barrier which remains is the efficient utilisation of ammonia fuel at or near the point of use, either through direct NH3 fuel cells, combustion, and/or “cracking” to liberate high purity H2.

Direct utilisation and cracking need not be considered as completely separate technologies, however, as integration can give significant benefits with respect to economics (through sharing of components and real estate) and operational considerations. For example, waste heat from direct utilisation can be harnessed to provide the energy input to the endothermic cracking reaction, and unreacted NH3 and unrecovered H2 from the cracking reactor can be returned to the engine or fuel cell, allowing the cracking reactor to be optimised for H2 production over recovery, thereby reducing the size of the H2purification stage. Furthermore, direct utilisation need not be limited to small-scale generation in this ‘hub’ model: the use of ammonia in heavy vehicles and large transport engines (such as locomotives) has the potential to see decarbonisation of transport corridors where solar energy is abundant.

In support of this widespread adoption of renewable ammonia, we are working with our industry partners to better understand the combustion characteristics of NH3, to identify appropriate engine technologies, and design ignition and fuel systems for ammonia fuel. Ultimately, this will lead to demonstration of direct-fired ammonia systems in large-scale applications, paving the way for NH3to be used as a fuel for kW to MW stationary power generation.

We are also developing a cracking reactor which integrates catalytic NH3 cracking with hydrogen-selective, vanadium-based membranes. This system will produce high-purity H2 directly from NH3, at a rate of at least 5 kg H2 per day. Undertaken in collaboration with partners in the industrial gas and automotive sectors, this project will see the H2product compressed, distributed and dispensed into fuel cell vehicles to illustrate its fitness for purpose.

The poster will give an overview of the potential role for ammonia in Australia’s transport and electricity industries, and provide some insights into our initial progress towards a pilot-scale demonstration in Australia, in support of a range of renewable NH3 supply-side activities by a number of organisations.