Biogas is the mixture of gas produced by methanogenic bacteria while acting upon biodegradable materials in an anaerobic condition. This gas is primarily composed of 60 to 70% methane (CH4) and 30 to 40% carbon dioxide (CO2), with smaller amounts of hydrogen sulphide (H2S) and ammonia (NH3). Biogas is somewhat lighter than air and has an ignition temperature of approximately 700° C (diesel oil 350° C; petrol and propane about 500° C). Like any other fuel, biogas can be used for household and industrial purposes which include cooking, lighting, refrigeration, use in biogas-fueled internal combustion engines and electricity generation. Nigeria has continued to face enormous energy crisis due to her overdependence of fuels from fossil origin with their attendant problems of environmental degradation, global warming and climate change phenomenon. The need for alternative and sustainable renewable energy from locally available resources therefore cannot be neglected in the quest for human survival and national development. With the past and anticipated energy challenges ascribed the nation, there is need for huge investment into biogas generation from the several millions of tons of wastes and biomass generated in the country annually most of which ends up as nuisance in the environment.


Biofertilizers are preparations containing latent cells of efficient microorganisms which help crop plants’ uptake of nutrients by their interactions in the rhizosphere when applied through seed or soil. Digestate biofertilizers comprises microbial biomass, semi-degraded organic matter and inorganic compounds, and therefore can be used as soil conditioners on farmlands. Anaerobic digestates are particularly highly useful as biofertilizers due to their richness in nutrients coupled with great potentials to increase both the microbial and nutrient status of soil especially nutrient-depleted ones when applied. Application of these digestates as biofertilizer could equally enhance plant growth and general wellbeing especially in Nigeria and the rest of Sub-Saharan Africa which is already bedevilled with issues ranging from soil nutrient depletion, toxicity to soil microorganisms to leaching of nutrients and pollution is on the increase due to over-dependence on the use of inorganic chemical fertilizers. Therefore, biofertilizers are important in the provision of ecological benefits including the improvement of soil quality, food quality and safety, human and animal health as well as environmental quality enhancement.