Bioenergy production in Central America: Integration of sweet sorghum into sugar mills

Abstract

Central America Sweet sorghum Electricity Ethanol Sugar millsThis paper aims to evaluate the potential for electricity and ethanol production in Central America using sweet sorghum as an energy crop. Three scenarios were built to analyse sweet sorghum production in terms of the land where it can be cultivated: cropland, sugarcane land in fallow and land in continuous production (intercropping system). The land under permanent crops was not considered for this evaluation. We propose the integration of sweet sorghum into Central American sugar mills, by using the existing machinery to process it. The short growing period of sweet sorghum would allow the Combined Heat and Power (CHP) plants and distilleries to operate outside the sugarcane crushing season using sorghum bagasse and molasses as raw materials. This production could be performed 1 month before, and 1 month after the sugarcane season.Results indicate that by growing sweet sorghum on 5% of Central America's cropland, sorghum could supply around 10% of region's electricity demand. Thus, Central America could increase its CHP share of electricity supply from 4.4% to 5.6%. The increase in renewable electricity production would allow countries such as Guatemala, Honduras and Nicaragua to reduce fossil fuel bills by USD$ 13, 10 and 20 million, respectively.The ethanol produced from sweet sorghum during off-season can help to implement and maintain a sustainable ethanol program in the region that does not only depend on sugarcane. Sweet sorghum would allow distilleries to easily supply the ethanol required to implement an E5 or ED3 program. Central America could produce about 387 million liters of ethanol by growing sweet sorghum on 5% of its cropland. This ethanol production would help the region to reduce fossil fuel bills by USD$ 517 million by using ethanol-gasoline blends or USD$ 463 million by using ethanol-diesel blends.

Sorghum: A Multipurpose Bioenergy Crop

“…It can be a supplementary feedstock to the sugar mills operating with the distilleries in the off season (2 mo), development of average revenue of US$3 million for a crushing rate of 6500 t d −1 can be achieved in dryland situations. Several studies have highlighted the potential of sweet sorghum for ethanol production (Srinivasarao et al, 2009), and it was reported as a viable feedstock for electricity production (Cutz et al, 2013).…”

Short Rotation Wood Crops in Latin American: A Review on Status and Potential Uses as Biofuel

“…Renewable energy is a potential solution to increasing global energy demand, climatic change, and ecological challenges [19], but must be environmentally, socially, and economically sustainable if its benefits are to be fully recognized [18]. However, despite the advantages of renewable energy, some Latin American countries are still highly dependent on fossil fuels (from 40%-80% of total energy demand) or other forms of energy production, mainly hydroelectric power (11%) [6,7].…”

“…Biomass as a renewable energy resource is important, however, some authors have pointed out that this energy must be used smartly [26,27]. Cooking and heating in developing countries, such as in Central America [7], utilizes one-third of the biomass produced around the world [18]. Meanwhile, developed countries utilize biomass in industrial applications, such as in the heating, power, and road transportation sectors, and for heating purposes in the private sector [1].…”

“…Although SRWCs are extensively implemented in many regions of the world [14], their use has been expanded very little in Latin America [7,[15][16][17]. However, Latin America has an extension from Mexico to the southern part of Chile, where there are diverse habitats and climates, therefore different SRWCs are going to vary in how well they perform in these environments.…”

Reviews of Science for Science Librarians: Second-generation Biofuels Feedstock: Crop Wastes, Energy Grasses, and Forest Byproducts

“…Sweet sorghum, which was mentioned five times, is a variant of grain sorghum that contains a much higher percentage of sugars and is often processed much like sugar cane (Cutz et al 2013). Like sugar cane, however, it also has problematic bagasse.…”