b, c, *
The development of cleaner and renewable energy sources are needed in order to reduce fossil fuel
dependence and mitigate global warming by reducing greenhouse gas emissions. Solar dryers are
considered as clean technologies and optimal use of these can minimize the use of non-renewable energy,
and can play an important role in the world's future. Drying for forest products is one of the most
attractive and cost effective application of solar energy because it may be possible to improve forest
residues in proﬁtable biomass as biofuel. In this study, a solar greenhouse dryer was used in drying
experiments of wood chips of Pinus pinaster in the south of Spain. The environmental conditions were
under autumn season with an average daily solar radiation of 13.74 MJ/(m
d) during the 15 days of the
experiment. The experiment analyzed the drying process under indoor conditions of several piles of
wood chips which was compared to the same shaped piles under open sun drying. The results were
mathematically modelled to show the advantages of the Solar Greenhouse Dryer for both, to reach the
10% of relative humidity and fewer days were dedicated for this. Thus, these analyses reveal that the Solar
Greenhouse Dryer is a useful and vital technology for the improvement of wood chips as biofuel, it
reduces moisture, and it can be applied in many countries because of the fact that it only uses solar
energy; it is a renewable energy resource which is both free and clean.
Cleaner technologies using renewable energies is essential
nowadays for reducing the dependence of fossil fuels (Ba
nos et al.,
2011) and its negative impact to the environment (Cama et al.,
2013). Bioenergy has been regarded as a promising substitute for
fossil fuels (Mizsey and Racz, 2010), mainly due to its renewable
and carbon neutral nature (Nguyen et al., 2013). Biomass is one of
the main types of renewable energy sources (Manzano-Agugliaro
et al., 2013). In addition to producing energy, it contributes to
local economic growth and overall sustainable development (Long
et al., 2013). On the other hand, the biomass residues would appear
to be an interesting source of renewable energy (Callej
et al., 2011). In Spain biomass, wind and hydropower are the
main sources of renewable energy (Montoya et al., 2014). So, in the
* Corresponding author. Department of Engineering, University of Almeria,
CEIA3, 04120 Almeria, Spain.
E-mail address: [email protected] (F. Manzano-Agugliaro).
0959-6526/© 2016 Elsevier Ltd. All rights reserved.
Journal of Cleaner Production 135 (2016) 1233e1241
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Journal of Cleaner Production
journal homepage: www.elsevier.com/locate/jclepro
© 2016 Elsevier Ltd. All rights reserved.