Local variability of yield and physical properties of açaí waste and improvement of its energetic attributes by separation of lignocellulosic fibers and seeds

Abstract

The high degree of variability among suppliers and types of biomasses hinders their application in energy production. Investigation into this drawback is needed for the use of the waste produced from açaí depulping, which is widely available throughout the Amazonia. This work aimed to analyze the variability of the yield and physical properties of the açaí waste among different Amazonian producers located at Macapá, AP, Brazil. In addition, energetic attributes of different waste components, namely, seeds and lignocellulosic fibers, were compared to determine if they should be separated prior to burning or pyrolysis. The average yield (71.0%–95.0%), dry basis moisture content (66.6%–76.2%), and basic density (0.753 g cm−3 to 0.812 g cm−3) of açaí waste varied remarkably among the suppliers. Fibers and seeds depicted similar higher heating values (19.91 MJ kg−1 and 19.32 MJ kg−1) and fixed carbon (21.39% and 21.50%) and volatile matter (77.32% and 76.65%), while the ash content was slightly lower for seeds (1.29%–2.08%) in comparison to fibers (1.85%–2.63%). Thermogravimetric analysis revealed different initial degradation temperatures and mass loss rates for the seeds and fibers. It was concluded that the yield and physical properties of açaí waste varied remarkably among providers. A drying process should be carried out before açaí waste burning due to its high moisture content. The high basic density is an advantageous feature of açaí waste in the context of bioenergy. Separation of the components is recommended prior to pyrolysis to avoid heterogeneous charcoal.

Enhancement of the Amazonian Açaí Waste Fibers through Variations of Alkali Pretreatment Parameters

“…The main drawback of the açaí production chain is the enormous amounts of biomass wastes produced during depulping. The thin pulp covers the seed only superficially and the amount of waste generated varies from 71 % to 95 % of the processed fruit mass . They are accumulated in large leftover deposits or left near the commercial establishments, causing land and water pollution.…”

“…The thin pulp covers the seed only superficially and the amount of waste generated varies from 71 % to 95 % of the processed fruit mass. [6] They are accumulated in large leftover deposits or left near the commercial establishments, causing land and water pollution. One alternative destination for the lignocellulosic fibers that cover the waste seeds could be the production of high value-added products whereas the seeds could be used for energy purposes.…”

“…One alternative destination for the lignocellulosic fibers that cover the waste seeds could be the production of high value-added products whereas the seeds could be used for energy purposes. [6] Currently, the use of agroforestry wastes to produce biomaterials is a relevant topic due to their renewability and high availability. [7] Plant fibers are rich in cellulose and have a low density, are nonabrasive, noncombustible, nontoxic, economic, and have biodegradable properties.…”

The properties of the mesocarp fibers of patauá, a multiple-use palm from the Amazonia forest

“…The lower density in the treated patauá fibrous units may be advantageous if the matrix fills the unblocked piths increasing the strength of the composite [19]. The basic density of the raw patauá fibers is close to that found for similar açaí mesocarp fibers of 0.812 g.cm −3 [5].…”

“…The term Oenocarpus that names the genus concerns its most traditional use, the fruit juice commonly named wine (oinos = wine; karpos = fruit) for food [2]. The depulping process to obtain the wine is similar to the one used for the well-known açaí, after which a waste composed of the seeds covered by hard lignocellulosic fibers that can be easily removed by hand remains [5].…”