The large-scale application of hydrogen in a variety of human activity fields is a fundamentally new focus area, with its prospects still uncertain. As predicted by the leading analytical agencies, the global annual demand for hydrogen will grow from today’s 70 to 200 million tonnes by 2030.
The largest consumers of hydrogen are oil refining (accounting for 33 percent of the total demand), ammonia production (27 percent), methanol production (10 percent), and metallurgy (30 percent). The world’s hydrogen consumption more than tripled from 1975 to 2020.
The hydrogen topic is ambivalent, causing hydrogen energy lobbyists and critics to fight very hard. First and foremost, criticism concerns the possible use of hydrogen for residential heating and in motor vehicles for safety and efficiency reasons.
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At the same time, the use of hydrogen for industry decarbonisation (in steel making, cement, and fertiliser production), in the power sector, and as an alternative fuel for large-capacity cargo (especially water) transportation is recognised by the expert community as being expedient.
The main raw material for hydrogen production is natural gas, which is used in the steam methane reforming (SMR) process. Natural gas accounts for about three-quarters of the world’s annual hydrogen production.
Today, Nigeria is the continent’s leader in natural gas reserves and also has huge potential for hydrogen production development. Since more than 95 percent of the world’s hydrogen consumption is accounted for by the traditional industries that largely cover their own needs, there is no free hydrogen market at the moment.
At the same time, hydrogen is considered not only as a raw material or reagent for some industries but also as an energy vector going forward. Nigeria’s drive to create a competitive hydrogen market domestically shows great prospects for the country to take a leading position in the global hydrogen market.
The main processes of low-carbon hydrogen market formation in the world are associated with the replacement of captive hydrogen with a high carbon footprint. Presently, hydrogen is almost entirely utilised directly at the points of consumption.
The main problem with hydrogen storage and transportation is its low density (90.0 g/m3) under normal conditions, which makes it impossible to store hydrogen economically without certain physical and chemical effects related to energy inputs.
Hydrogen utilisation in the transportation and energy sectors requires a high degree of gas purification. Dense metallic membranes hold the record for permeability and selectivity.
They are capable of operating at high temperatures, which is an essential criterion for use, for example, in methane reforming technology. Best known among the metallic membranes for hydrogen separation and purification are membranes made of palladium alloys with other metals.
Palladium as well as group V metals (vanadium, niobium, and tantalum) have the property of transmitting only hydrogen atoms through them, which makes it possible to use those metals as a kind of filter to obtain ultrapure hydrogen.
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The essential preliminary step is hydrogen molecule decomposition into atoms, which will then go through the membrane. The only metal that enables that process to take place is palladium. Therefore, the separating membrane made of a palladium and vanadium alloy consists of three layers: the outer layer is palladium, ensuring dissociation of the hydrogen molecule into atoms, followed by a vanadium alloy layer ensuring the diffusion of hydrogen atoms, followed again by palladium. Hydrogen contacts palladium and “dissolves” in it to form hydrogen atoms from the molecule.
Atoms are much smaller than molecules and can easily penetrate through the membrane material. On the outer side of the third membrane layer (palladium again), hydrogen atoms form molecular hydrogen, which flies away from the membrane surface.
This is how ultrapure hydrogen is obtained. This type of membrane yields 30 to 50 percent more hydrogen than any other similar membrane at the same energy and time inputs, with high-purity hydrogen resulting downstream. Such products can be used effectively in the most demanding chemical industries, such as electronics, as well as in hydrogen-powered automobiles. Moreover, its purification costs will be significantly lower than those of the earlier purification systems.
Creating a competitive hydrogen market in Nigeria and going international requires some measures to be taken, including the development of a comprehensive hydrogen strategy, the creation of technological infrastructure, the implementation of global hydrogen standards, and the development of human resources and technological innovations that combine economic efficiency and mitigation of environmental risks.
Dmitry Izotov, Head of Palladium Center, Nornickel