**5. Economic feasibility of using Sclerocarya birrea to produce biodiesel**

The future outlook of the Sclerocarya birrea biodiesel fuel is bright on the basis of abun‐ dance and minimal conflict with food security. As discussed in section 2, Sclerocarya birrea plant is abundant in Botswana and an almost negligible fraction is utilised for purposes that use the fruit pulp and juice, discarding the seed as a byproduct. Thousands of tons of the fruits are left to rot annually as an untapped resource. The major economic factor to consider with respect to the input costs of biodiesel production is the feedstock, which is about 80% of the total operating cost [37]. Other important costs relate to the geographical area of the feedstock, variability in crop production from season to season, labor and production inputs including methanol and catalyst. These costs depend on the prices of the biomass used and the size and type of the production plant. Other important factors that would determine the production cost of birrea biodiesel are the yield and value of the byproducts of the biodiesel production process, such as oilseed cake (a protein-rich animal feed) and glycerine (used in the production of soap and as a pharmaceutical medium). Since birrea nut oil has not been studied as a potential feedstock for production of biodiesel, precise production costs are yet to be established.

This study aims to establish the technical properties of the biodiesel as a suitable fuel for the compression ignition engine, thereby providing a basis upon which socio economic feasibili‐ ty analysis can be done to further the research. Factors including actual yield of birrea fruits per hectare and associated production and logistics costs will need investigation.

Production of biodiesel from sclerocarya birrea will however have other obvious social im‐ pacts. It will provide a source of income and employment for many families. Thousands of rural people who are largely unemployed would earn income from the gathering and proc‐ essing of the raw material into biodiesel. Thus the logistics of harvesting the raw material is deemed simple and cost-effective. Furthermore, the fact that sclerocarya birrea tree thrives and produces abundantly under natural (unoptimised) conditions implies a substantial re‐ duction in overall costs of producing biodiesel from this plant species. Optimising growing conditions, if desired, may increase the yield.

Although birrea fruit production is seasonal under natural conditions (follows the rain sea‐ son), nut availability for oil extraction can be perennial. When the hard woody seed has been extracted from the fruit skin and pulp and allowed to dry, it can stay for more than a year with no damage to the nut in its cavity. Thus there are two options for keeping this raw material inventory. One option is to keep hard seeds and only crack them when oil extrac‐ tion is about to commence. This eliminates (or largely minimises) inventory holding costs on the delicate seed bearing the oil. The other option is to crack all the seeds and keep in stock the oil bearing nuts, but this requires special preservation facilities which come at a cost.

On the basis of abundance and the results discussed in this chapter, Sclerocarya birrea bio‐ diesel is recommended for production in Botswana.

**Acknowledgements**

**Ret Time**

15 14.546 1765470999

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**Appendix 1**

**Peak #**

The authors acknowledge support of the University of Botswana, and the Ministry of Wild‐

 10.649 89593610 Methyl tetradecanoate ester 10.759 248711863 Tridecanoic acid methyl ester ester 12.297 11762782 1.2-benzenedicarboxylic acid,bis(2-methyl propyl) ester ester 12.561 154502042 9-Hexadecenoic acid,methyl ester ester 12.848 5773983254 Hexadecanoic acid methyl ester ester 12.972 1472336051 decanoic acid methyl ester ester 13.046 1625971299 Pyradazin-3(2H)-one ketone 13.12 1385277087 Pentadecanoic acid methyl ester ester 13.25 4284563596 Heptadecanoic acid methyl ester ester 13.569 31847458 Heneicosanoic acid methyl ester ester 13.838 206216774 Octadecanoic acid methyl ester ester 13.902 94186693 Tetradecanoic acid methyl ester ester 13.97 102294655 Eicosanoic acid methyl ester ester 14.038 278766060 9,12octadecadienoic acid(Z,Z)-methyl ester ester

 15.203 769700914 2-Fluorobenzylamine amine 15.25 1604733504 4-Biphenylol 3,3-dinitro Biphenyl 15.337 1731581422 Ethyl oleate ester 15.436 966708117 2-chloroethyl oleate ester 15.494 484782015 9-octadecenoic acid methyl ester ester 15.522 428166076 12-octadecenoic acid methyl ester ester

**Area Compound Name Compound**

Sclerocarya Birrea Biodiesel as an Alternative Fuel for Compression Ignition Engines

Isopropyl Linoleate ester

**Type**

http://dx.doi.org/10.5772/54215

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life, Tourism and Environment who granted a research permit for this work.

Chemical composition of sclerocarya birrea biodiesel at 70% match factor.
