Biomass and bioenergy potential of cassava waste in Nigeria: Estimations based partly on rural-level garri processing case studies

Published Date
Renewable and Sustainable Energy Reviews
May 2017, Vol.72:625–638, doi:10.1016/j.rser.2017.01.031

Author 

• C.G. Ozoegwu ^a,,,
• C. Eze ^b
• C.O. Onwosi ^c
• C.A. Mgbemene ^a
• P.A. Ozor ^a

• aDepartment of Mechanical Engineering, University of Nigeria, Nsukka, Nigeria
• bDepartment of Mechanical Engineering, Nnamdi Azikiwe University, Awka, Nigeria
• cDepartment of Microbiology, University of Nigeria, Nsukka, Nigeria

Received 5 November 2015. Revised 22 November 2016. Accepted 8 January 2017. Available online 20 January 2017. 

Highlights

• •
  The Nigerian culture of processing cassava into food is X-rayed to highlight the sources of cassava non-food biomass(CnFB).
• •
  Factors for transforming cassava harvest data to CnFB are established using statistical regression analysis.
• •
  Mass of cassava wastes associated with food processing is about   of the harvested mass.
• •
  The unrecorded data history of CnFB generation is about the same as the recorded data history cassava tuber production.
• •
  The relevance of CnFB in the Nigeria energy policy are discussed with emphasis on renewable energy integration in the national energy mix, emission reduction and distributed generation.

Abstract

Advocating production of bio-energy from agricultural crop wastes has double benefits of minimizing land usage and threat to food security. These benefits are specially needed now that issues of greenhouse emissions, deforestation and human over population of the world dominate international discuss. Cassava being a major food crop in Africa, its waste constitutes the major candidate for bio-energy production thus motivating the aim to review its history, production, food value, economic value and bio-energy value. Cassava waste is noted to be suitable feedstock for bio-fuel production from the 1st Generation, 2nd Generation and integrated processes unlike the other Nigerian crop residues that are mainly suitable for the not-yet-viable 2nd Generation bio-fuel production. A procedure for estimating cassava non-food biomass(CnFB) from harvest data is established. The procedure entails use of statistical sampling and regression analysis to establish scaling factors for transforming the data to CnFB. A real case study reflected very accurate and statistically significant error indices. For example, the factor for converting mass of harvested cassava for food production to waste is   (R² = 0.9875 and t-Test = 0.0896) while the factor for estimating mass of peels alone is   (R² = 0.9951 and t-Test = 0.1680). The other factors for converting mass of dewatered cassava pulp to waste were established for the case study community as follows;  Kg per bag (R² = 0.9611 and t-Test = 0.0665),   kg per bag (R² = 0.9865 and t-Test = 0.1944) and   (R² = 0.9464 and t-Test = 0.2539). The factors and literature data were used to make long-term projections of CnFB potential of Nigeria. The implications of the projections to the programs of the Nigeria Energy Policy - which pertain to renewable energy integration in the national energy mix, emission reduction and rural electrification via distributed generation - were discussed.

Keywords

Biomass

Bio-energy

Cassava

Renewable energy

---

 Table 1

Table 1.

 Table 2

Table 2.

Fig. 1.

 Table 3

Table 3.

Fig. 2.

Fig. 3.

Fig. 4.

Fig. 5.

Fig. 6.

Fig. 7.

 Table 4

Table 4.

 Table 5

Table 5.

 Table 6

Table 6.

 Table 7

Table 7.

Fig. 8.

Fig. 9.

• ⁎ 
  Corresponding author.

© 2017 Elsevier Ltd. All rights reserved.

For further details log on website :
http://www.sciencedirect.com/science/article/pii/S1364032117300321