TITLE:
Design and Testing of a Solar Torrefaction Unit to Produce Charcoal
AUTHORS:
Rajaram Swaminathan, Frans Nelongo Pandeni Nandjembo
KEYWORDS:
Torrefaction, Charcoal Production, Solar Parabolic Trough, Design, Testing
JOURNAL NAME:
Journal of Sustainable Bioenergy Systems,
Vol.6 No.3,
August
10,
2016
ABSTRACT: With increasing crude oil prices, fuels like kerosene and cooking gas have become unaffordable
for many ordinary people in developing countries. For millions of Africans who need heat energy
to cook their food, biomass like wood remains the easiest and cheapest source of fuel. Charcoal
remains the most popular choice compared to wood since it can cook food much faster with very
little smoke. Torrefaction of biomass is a mild form of pyrolysis at temperatures typically between
200℃ and 300℃ to produce charcoal. Torrefaction changes biomass properties to provide a much
better fuel quality for combustion applications. A simple parabolic trough solar collector to produce
charcoal by torrefaction process using solar energy has been designed from first principles.
The device was fabricated and various locally available wood species were tested. The yield was
found to be 21% to 35% with a production time of 90 minutes. The paper details the design procedure
and the test results.