Industrialisation of biogas

Kananelo Hlaeli

ROMA

Ever wondered what the ubiquitous wobbly species can do apart from just slipping smoothly through your fingers?

Using one environmental problem to combat another, Thato Mosaase, under the supervision of Dr Sissay Mekbib, solved one of the many problems most Basotho face – a lack of fuel.

This fifth year biotechnology student at the National University of Lesotho (NUL) is planning to develop a cheap resource that is often taken for granted, algae or bolele in Sesotho into biogas. 

“Bolele”, as many who have come across microalgae do not realise, is a group of diverse photosynthetic aquatic microorganisms that are very simple in structure.

What then accounts for freshwater algal blooms in our water bodies?

The application of fertilizers in agriculture and industrial effluent discharged into water bodies is rich in nutrients.

These micro and macronutrients facilitate the growth of microalgae.

Of the micronutrients disposed into water, iron is the most vital as it is necessary for photosynthetic electron transport chain. Iron, although useful, can hinder the growth of microalgae and production of biogas at high content.

Abattoir effluent was then identified as a potential source of nutrient supply for microalgae growth.

Interestingly, there is a real need for adequate industrial waste management strategies to dispose waste safely and economically using it as a source for other processing outputs like biofuel.

“Cultivation of microalgae as abattoir waste management will not only decrease pollution and bad odour, but it will also generate cheap and eco-friendly biofuel,” Mosaase said.

As the study progressed on the effect of iron on microbial activity and biogas production, sewage water microalgae samples were carefully collected from the National University of Lesotho (NUL) sewage pond system and these samples were controlled at different iron concentration levels and the results were amazing.

The concentration that favours microalgae growth is about 2mg/L of iron as indicated by this research, which means that iron rich effluent from abattoirs and other slaughter houses required to be diluted. The gas produced was high in volume and quality to be used as source of fuel for cooking and heating.

A conclusion drawn from this is that diluted abattoir effluents can be used as rich source of microalgae growth effluent which can be utilised as an alternative feedstock for the production of biofuel. This is important as the production of biofuel from microalgae is environmentally friendly and economical as the use of fossil fuels is increasingly polluting the environment by emission of green house gas and affecting health.

Mosaase believes that biofuel from microalgae will be affordable and its production will not pollute our air.

Fuel from crude oils requires lots of processing and causes lots of damage to the environment.

“We have been experiencing very harsh weather conditions lately and processing of biofuel from these natural sources will contribute positively in reducing the effect of green house gas chemicals that brings climate change,” Mosaase said.

It is no wonder then that finding a renewable energy that is not only affordable but safe is of grave concern. Algae come into play as a source of such energy, since it is readily available and grows rapidly. When enriched with adequate amounts of iron, it is wise to believe that algae could be the next reliable source of biofuel.

“Cooking gas (methane) is still a basic necessity in our country. It is used on a large scale as most people do not have electricity or other forms of fuel. Even those households that have electricity, having a gas cylinder always comes in handy especially when there is load shedding. Healthcare facilities in very remote parts of the country use gas refrigerators to store vaccines. Gas heaters are also used on cold winter days,” Mosaase said.

“This just shows how much we depend on biofuel on a daily basis, and finding a renewable energy source could be life changing.”

Although the feasibility of the production of biogas from microalgae is almost unquestionable, more research is needed with regard to increased biomass and biogas production.

This task brings hope that industrialisation of biogas production will succeed.