by Charles Kusi Minkah-Premo
An article in the August 2015 edition of the Environmental Progress & Sustainable Energy journal assesses Africa’s promising hydrogen energy potential (HEP) from biomass.
Africa’s long-standing issues with electricity generation and access have been well documented. With Northern Africa and South Africa accounting for 30% and 45% respectively of the total electricity generation in Africa, Sub-Saharan Africa (SSA) —excluding South Africa— generates only 25%. The alarm bells start ringing when you consider the fact that 80% of Africa’s population resides in SSA and a whopping 67% of people living in this region lack access to electricity.
In recent years, though, African countries have been making efforts to include renewable and sustainable energy sources such as solar, wind, and biomass in their energy mix. However, trying to imagine a future where hydrogen energy plays a key role in Africa’s energy sector most likely hinges on the continent efficiently utilizing its biomass resources — forest products and residue, agricultural residue, energy crops, and municipal solid waste. This is especially true given that Africa holds 17% of the world’s total forest area.
Hydrogen as an energy source is the dream for renewable energy advocates. It has the highest specific content among all conventional fuels and produces almost no pollution —burning hydrogen produces water as a by-product. In addition, it can be produced from all primary energy sources given that most of our fuel sources today are hydrocarbons and in theory, anywhere that has electricity (Africa falls short here) and water. Hydrogen can be produced from biomass through gasification and pyrolysis — both thermochemical processes. Both processes involve the decomposition of organic materials at extremely high temperatures to form carbon monoxide, carbon dioxide, and hydrogen. The carbon monoxide then reacts with water to form carbon dioxide and more hydrogen—via what is known as a water-gas shift reaction—. The hydrogen produced is then separated and purified. [http://energy.gov/eere/fuelcells/hydrogen-production-biomass-gasification]
The authors posit an interesting model to assess Africa’s HEP from fuel wood and agricultural residue. It is important to note here that the model —and article for that matter— is not intended to assess the feasibility of implementing hydrogen energy technologies (HET) in Africa. A key finding from the model suggests that Africa has the potential to produce a total of approximately 350,000 GWh of hydrogen energy from just 30% of fuel wood and agricultural residue —one of the model’s assumptions— annually. A fraction of this yield from these biomass resources can displace 100% of the current annual electricity consumption in West Africa. No matter how you look at it, these findings are monumental in terms of what it could mean for the future of Africa’s energy sector. At present though, Africa as a whole is a long way from fulfilling this prospect. A major reason being that obtaining hydrogen from the gasification and pyrolysis of biomass requires a huge electrical generating capacity (to begin with) to power these processes. [http://auto.howstuffworks.com/fuel-efficiency/fuel-economy/hydrogen-economy.htm]
Although the majority of African countries have an abundance of biomass resources at their disposal, most simply do not have the electrical generating capacity to undertake these renewable hydrogen production methods today and in the mid-term.
HETs have all the potential to become the go-to energy and fuel source of the future and also revolutionize Africa’s energy landscape once issues with their production, transportation and storage are overcome. Given that hydrogen energy is still a relatively young prospect in the energy sector, the energy form itself and its associated technologies still very much require substantial R&D before HETs can become more marketable and pave the way for countries to consider Hydrogen economies.
I bet that once the costs of HETs become lower and the industry goes through enough technological breakthroughs, Africa would also begin to realize and take advantage of its HEP, in the same manner that solar energy is now diffusing quickly across the continent. It could open doors for another African technological leapfrog.
Amuzu-Sefordzi, B., Huang, J., Sowa, D. M.A. and Baddoo, T. D. (2016), Biomass-derived hydrogen energy potential in Africa. Environ. Prog. Sustainable Energy, 35: 289–297. doi:10.1002/ep.12212. February 5 2016
Renewable Energy World (http://www.renewableenergyworld.com/hydrogen/tech.html)