Biomass Residues in Brazil: Availability and Potential Uses

Abstract

Agroindustrial and forestry residues, which are by-products of key industrial and economical activities, stand out as potential raw materials for the production of renewable fuels, chemicals and energy. The use of wastes is advantageous as their availability is not hindered by a requirement for arable land for the production of food and feed. In addition, waste utilization prevents its accumulation, which is of great environmental concern due to its potential for contamination of rivers and underground water. In Brazil, the agroindustry of corn (13767400 ha), sugarcane (7080920 ha), rice (2890930 ha), cassava (1894460 ha), wheat (1853220 ha), citrus (930591 ha), coconut (283205 ha), and grass (140000 ha) collectively occupies an area of 28840726 ha (FAOSTAT, http://www. faostat.fao.org/site/567/default.aspx#ancor) and generates 597 million tons of residue per year. By itself, this scale of operation calls for new solutions aiming for the appropriate utilization of these valuable resources. However, innovative dealings must be environmentally and economically acceptable and, most importantly, have social meaning. Indeed, great social benefits could draw from novel yearround activities as alternatives for the typical seasonal jobs in agroindustry. Considering the production of biomass ethanol, the abundance of feedstock near the site of processing must be taken into account, as low-density biomass involves significant handling and transportation costs. Within this context, the crushed stalk of sugar cane (bagasse) and straw are obvious choices, although bagasse is often burned for the production of steam (heat) and power/electricity in sugar-ethanol mills and important amounts of straw are needed to keep the soil nutrients balance. Other agricultural by-products of importance in Brazil, such as corn straw, wheat straw, rice straw and rice hulls, grass and forestry materials and residues from citrus, coconut and cassava processing, also deserve attention as local feedstock for the development of new and profitable activities. As each type of feedstock demands the development of tailor-made technology, the diversity of the aforementioned raw materials could allow for new solutions for the production of chemicals, fuels and energy in accordance with the local availability of these materials.

Synthesis of the Prospective Anticancer Molecule Perillic Acid from Orange Essential Oil by the Yeast <i>Yarrowia lipolytica</i>

“…Orange essential oil is largely available due to a worldwide orange production of 70 million tons per year [27]. The orange-based industry (28 million tons/year) by itself generates residues amounting 50% of the raw processed fruit whereby the orange oil represents approximately 5% (on dry basis) [28] and can be obtained directly from the cold pressing citrus zests. In this scenario, the large availability of orange essential oil coupled to an environmentally friendly yeast based process to produce perillic acid could be extensively explored to establish a cost-effective synthesis of pharmaceutically valuable molecules.…”

Policies for Reintegrating Crop and Livestock Systems: A Comparative Analysis

“…Brazil's Agroenergy Plan of 2006-2011 provides further support for biofuels production by allocating more resources toward the generation of knowledge and technologies that can improve the competitiveness of biofuel production [82]. The production of sugarcane ethanol produces by-products that can be used as cattle feed; however, 88% of the bagasse produced from ethanol production is used for energy cogeneration in ethanol production plants [83].…”

The Protagonism of Biocatalysis in Green Chemistry and Its Environmental Benefits

“…Biogas should not be neglected due to its importance for heating and cooking. Considering that renewable feedstocks include different substrates, like vegetable oils, starch, sugars and lignocellulose, their use for the production of different fuels is expected both by chemical, thermochemical, or biochemical routes [9]. However, this section will only cover biochemical routes for the elaboration of biodiesel, lignocellulose ethanol, hydrogen and methane.…”

“…The enzymatic hydrolysis, using cellulases, has advantages because the minimal substrate modification (produced in the acid-based route), the superior conversion efficacy and the use of more environmentally friendly physic-chemical operating conditions [9]. Lignocellulose conversion into ethanol follows, at least, four steps: pretreatment, hydrolysis, fermentation, and distillation.…”

“…The exploitation of wastes from diverse sources is strategic, as their accessibility is not affected by the controversial competition between food and fuel. Moreover, utilization of waste prevents their accumulation, which helps protect the environment [9]. Green Chemistry Principles:…”