Chemical composition and calorific value of elephant grass varieties and other feedstocks intended for direct combustion

Abstract

Perennial grasses display several positive attributes as suitable energy crops for use as a solid fuel for direct combustion, such as high annual production of dry matter per unit area, perennity and high harvest flexibility. This study aimed to characterize the chemical composition and calorific value of 18 elephant grass (EG) varieties (Pennisetum purpureum Schum.) and 10 other potential bioenergy feedstocks intended for direct combustion. Samples were obtained from 6‐month‐old EG and sorghum and 3‐year‐old eucalyptus, Mimosa caesalpiniaefolia, and bamboo plants. Sugarcane bagasse and straw, rice husk, corn stover, coconut husk, and fiber samples were also evaluated. The elemental composition, lower heating value (LHV), and cellulose (CEL), hemicellulose (HCEL), lignin (LIG) and ash contents (% dry matter) were analyzed. The results indicated that the EG genotypes showed significant differences when compared with other evaluated biomasses, but showed no differences among themselves. The EG varieties showed a mean LHV (16.7 MJ/kg) superior to that of rice husk, sugarcane bagasse, and sorghum and similar to that of sugarcane straw, coconut fiber, and corn stover. The EG varieties showed a mean ash content (4.74%) inferior to that of rice husk, sugarcane bagasse, coconut fiber, and sorghum; a mean CEL content (36.0%) similar to that of sugarcane straw, coconut fiber, corn stover, sorghum, and Mimosa caesalpinifolia; HCEL; a mean HCEL content (30.3%) superior to that of rice husk, bamboo, eucalyptus, M. caesalpinifolia, coconut husk, and fiber; and a mean LIG content (8.80%) superior to that of corn stover and similar to that of sorghum, sugarcane bagasse, and straw biomass. The significant capacity of EG to accumulate dry matter was associated with the biomass quality attributes (LHV and CEL, HCEL, LIG, and ash contents), thereby making it an excellent alternative to lignocellulosic feedstock for direct combustion.

Characterization of bovine ruminal content focusing on energetic potential use and valorization opportunities

“…The measured calorific value of RM is directly related to its lignin, hemicellulose, and cellulose content (see Table 2 ). RM owns a low calorific value (CV) of 15.5 MJ/kg, meanwhile, that is similar to other biomass, such as flax straw (18.2 MJ/kg), wheat straw (17.9 MJ/kg), oat straw (17.5 MJ/kg), barley straw (17.9 MJ/kg), rice husk (15.5 MJ/kg), elephant grass variety (16–18 MJ/kg), and sugarcane bagasse (16 MJ/kg) [ 38 , 39 ]. CHONS measured values in RM are similar to the abovementioned biomasses within a range lower than 5%.…”

“…The cellulose content in RC has the highest percentage value, followed by hemicellulose and lignin. Probably the action of microorganisms is responsible for these values, which makes RC a useful material for anaerobic digestion and fermentation processes [ [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] ].…”

Conversão de energia por genótipos de cana-energia em Alagoas

“…O poder calorífico superior (PCS, MJ kg -1 ) foi determinado bimestralmente para cada genótipo utilizando a matéria seca, nas três repetições. Para determinação do PCS foi utilizado um calorímetro (IKA C2000), seguindo método MB-2850(ABNT, 1990Marafon et al, 2021).…”

Cold alkaline extraction of Elephant grass for optimal subsequent extraction of hemicelluloses and energy production

“…Industrially, Elephant grass has been used to obtain chemicals such as cellulose and xylanase [35], monosaccharides and ethanol [36], xylitol and ethanol [37], hemicelluloses [38,39], lignin nanoparticles [40], cellulose pulp [32,41], and corrosion inhibitor extracts [42]. Also, it has been used to obtain fuels such as ethanol [33,34,[43][44][45] or methane [24,[46][47][48], pyrolysis products [34,[49][50][51][52], thermal and electrical energy [17,24,[53][54][55][56][57][58], and densified solid biofuels [19]. These uses testify to the high potential of Elephant grass for energy production and have fostered research into genetic breeding methods for improving its properties as a raw material and optimizing its use [24,53,[59][60][61].…”