**4.6 Microbial fuel cell (MFC)**

Microbial fuel cells use microbes as a biocatalyst and changes directly the chemical energy deposited in chemical compounds into an energy current [3]. This alternative technology reduces sludge formation, refine odor, and remove aeration supplies, all at the rate of waste reaction for electricity creation. Its advantage is the direct conversion to electricity although it has low efficiency. Due to challenges such as more sophisticated ion exchange membranes [47], this method is not appropriate in Africa especially in sub-Saharan African countries.

## **4.7 Landfilling**

This is the technology in which biowastes are deposited and may be connected to biogas recovery and leachate processing system [3]. This method simple and cheap although may lead to environmental pollution and degradation if planning is not well done [3, 48]. This technology is appropriate in Africa since the technology is cheap, mature, and simple.

### **4.8 Agglomeration**

This is the technology of increasing energy density by converting small particle to large particles. This increases energy density and effectiveness in conversion processes such as combustion [49]. This involves the formation of pellets and briquettes from fine biowastes that can be usable household [50]. Its challenge is the use of high energy in compressing the materials. This technology is appropriate in Africa since the technology is simple, presence of binding materials in biowaste, presence of fine materials such as charcoal dust, and cheap. All countries in Africa can utilize it due to presence of fine materials especially during charcoal production.
