1. Introduction
Cotton is the main supply of natural fibers for textile industries
and one of the largest sources of agro-industrial residues that can
be utilized to produce fuels and chemicals (Howard et al., 2004;
Ojumu et al., 2003). In 2014, the total world production of refined
cotton fibers was 25.9 million ton, with Brazil and India, the largest
world producers, contributing with 1.5 and 6.7 million ton, respectively.
The world total area destined to cotton production was 34.4
million hectares across 80 countries, being China, India, United
States, Pakistan and Brazil the most important contributors to
these very impressive numbers (USDA, 2014).
The high total world production capacity of cotton fibers also
equates to the production of high amounts of cotton gin residues