Analytical Pyrolysis Study of Peanut Shells using TG-MS Technique and Characterization for the Waste Peanut Shell Ash

Abstract

ABSTRACT:As an agricultural waste produced from the processing of peanut, the yield of peanut shells in China is quite abundant. Although numerous studies on the pyrolysis of peanut shells have been carried out, most of them were focused on the dynamics models for predicting kinetics parameter of biomass, and rarely on the evolution of gaseous products in pyrolysis. This study carried out a set of experiments on the pyrolysis of peanut shells under different heating rates in order to fill the knowledge gap. Besides, there is also a lack of information available concerning the characterization of resulting peanut shell ash. Thus, the aim of this study is to investigate the pyrolysis behaviors of peanut shells thoroughly and to characterize the properties of peanut shell ash that serves as predictors for its applications. The results show that the decomposition of peanut shells follows a stepwise mechanism, and the activation energy calculated by FlynnWall-Ozawa method varies from 58.3 to 88.6 kJ·mol -1 . Compared with low heating rate, fast heating rate at low temperatures is more suitable for biogas production. Chemical and phase analysis shows that peanut shell ash has a high SiO 2 content except for other oxides (K 2 O, CaO, MgO, Al 2 O 3 , etc.) that quite suitable in glass production, implying its potential for glass production and as a mineral admixture in concrete. Released volatile matters in pyrolysis create many pores in carbonaceous materials, thus low-cost adsorbents can be produced from these carbon residues.

Evolved gas analysis of cassava (Manihot esculenta) industrial waste

“…Usando la técnica TG/MS, la literatura reporta la cinética de pirólisis y la formación de productos de residuos de semillas de uva, semillas de cereza y cáscara de almendras [12], tallos de tabaco [13], aserrín de pino [14] y cáscara de maní [15], entre otros [16]. Varios estudios de la pirólisis de residuos industriales de yuca se han publicado, incluyendo el uso de reactores tubulares de lecho fijo [9], [17], reactores de lecho fluidizado [18], [19], reactores de caída libre [20] y balanza termogravimétrica [7], [21]; sin embargo, se cuenta con muy poca información que analice los gases producidos en la pirolisis de los residuos industriales de yuca.…”

“…Ésta aparece como producto de reacciones de deshidratación de la celulosa y hemicelulosa [16]. De forma similar, se detecta la formación de CO2 (m/z = 22 y 44) producto de la descomposición de la celulosa, hemicelulosa y lignina; este es uno de los productos que presenta un perfil de Fuente: Autores gases a lo largo de todo el rango de temperatura de la pirólisis, siendo este aporte más significativo a temperaturas elevadas [15]. La relación m/z = 30 se asocia principalmente a la presencia de formaldehído y la relación m/z = 58 a un conjunto de compuestos entre los cuales se encuentran isobutano, propanal, acetona y propanol; estos se deben principalmente a la degradación de la celulosa [16].…”

Devolatilization of African Palm (Elaeis guineensis) Husk studied by TG-MS

“…Methane production (m/z = 12 y 14) at low temperatures is the result of the decomposition of extractive materials and oil that remains in the husk and thermal degradation of hemicellulose and cellulose. Lignin decomposition and production of methane is sustained in all the temperature range, being increased at high temperatures (T. Yao, Xu, & Liang, 2016). Relation m/z = 30 is related to the presence of formaldehyde, while m/z = 32 represents the presence of methanol (Malika, Jacques, Fatima, & Mohammed, 2016).…”

Mass spectrometry characterization of evolved gases from catalytic pyrolysis of cassava starch residues

“…Nevertheless, in the decomposition of CIW presence of hydrogen was not observed. At the first stage of the pyrolysis at low temperatures, evolved gases are the result of the hemicellulose decomposition, while lignin decomposition is presented in the whole temperature range, increased in higher temperatures [18]. Relation m/e = 30 is associated with formaldehyde production, m/e = 58 corresponds mainly to isobutene, propanaldehyde, acetone, and propanol produced by cellulose decomposition [9].…”

“…Other advantages are the operation pressure near atmospheric conditions, no need for hydrogen supply, and the possibility of increase bio-oil yield and quality [19]. The behavior of several kinds of biomass by thermogravimetric analysis has been described extensively in previous studies, nevertheless, the distribution of the specific products as a function of time or process temperature in the literature is scarce [4,9,12,13,18]. In order to obtain the identification and quantification of the products of the devolatizationthermal decomposition processes, thermogravimetric analysis (TGA) coupled with mass spectrometry (MS) can be used [7,12].…”