Physicochemical Characteristics of Biofuel Briquettes Made from Pecan (Carya illinoensis) Pericarp Wastes of Different Particle Sizes

Abstract

Pecan nut (Carya illinoensis) pericarp is usually considered as a waste, with no or low value applications. Its potential as a densified solid biofuel has been evaluated, searching for alternatives to generating quality renewable energy and reducing polluting emissions in the atmosphere, based on particle size, that is an important feedstock property. Therefore, agro-industrial residues from the pecan nut harvest were collected, milled and sieved to four different granulometry: 1.6 mm (N° 12), 0.84 mm (N° 20), 0.42 mm (N° 40), and 0.25 mm (N° 60), used as raw material for biofuel briquette production. The carbon and oxygen functional groups in the base material were investigated by Fourier transform infrared spectroscopy (FTIR) and proximate analyses were performed following international standards, for determining the moisture content, volatile materials, fixed carbon, ash content, and calorific value. For the biofuel briquettes made from base material of different particle sizes, the physical characteristics (density, hardness, swelling, and impact resistance index) and energy potential (calorific value) were determined to define their quality as a biofuel. The physical transformation of the pecan pericarp wastes into briquettes improved its quality as a solid biofuel, with calorific values from around 17.00 MJ/kg for the base material to around 18.00 MJ/kg for briquettes, regardless of particle size. Briquettes from sieve number 40 had the highest density (1.25 g/cm3). Briquettes from sieve number 60 (finest particles) presented the greater hardness (99.85). The greatest susceptibility to swelling (0.31) was registered for briquettes with the largest particle size (sieve number 20). The IRI was 200 for all treatments.

Chemical and Energetic Characterization of the Wood of Prosopis laevigata: Chemical and Thermogravimetric Methods

“…The percentage of ash was measured according to norm ASTM D1102-84 [ 71 ], while volatile matter content was verified based on norm ASTM E872-82 [ 72 ]. Fixed carbon was calculated as the following difference: % fixed carbon = [100 − (% ash + % volatile matter)], based on calculations reported previously by Ngangyo-Heya et al [ 73 ].…”

Effect of pretreatment parameters and binder concentration on the densification of wood residue

“…The direct use of biomass for the generation of biofuels is restricted by some inherent characteristics of the material, such as its high volume, low density, hydrophilicity, high volatile content, high moisture content, low energy content, and heterogeneity 10 . Low‐density and bulky biomass demand large amounts of storage space and expensive transportation.…”

“…Physical grinding of wood usually depends on the size of fine particles, the shape of the different particles, specific surface area, energy and grinding method, grinding environment, and raw material properties 18 . The method of size reduction can be considered a change in fine size, form, and cellulose crystal lentils, all of which can be assigned to the mechanical properties of wood 10 . In the grinding process, the purpose is normally to split up the cell walls of the fiber in order to get the fine particles as against to particles in fiber forms 19 .…”

“…high volume, low density, hydrophilicity, high volatile content, high moisture content, low energy content, and heterogeneity. 10 Lowdensity and bulky biomass demand large amounts of storage space and expensive transportation.…”

“…18 The method of size reduction can be considered a change in fine size, form, and cellulose crystal lentils, all of which can be assigned to the mechanical properties of wood. 10 In the grinding process, the purpose is normally to split up the cell walls of the fiber in order to get the fine particles as against to particles in fiber forms. 19 The sieve and gauze are used to separate different-sized materials.…”