Pyrolysis of Almond Shells. Energy Applications of Fractions

Abstract

The pyrolysis of almond shells residues were studied in nitrogen atmosphere in a laboratory fixed bed reactor. The influence of the temperature (300−800 °C) and the heating rate (5−20 K min-1) on the composition and properties of the different fractions were analyzed. As the temperature was increased a decrease in the char yield and an increase in the gas yield was observed. The oil fraction yield passed through a maximum at temperatures between 400 and 500 °C. The decline at higher temperatures was likely due to the strong cracking, which increased the gas yield. The increase of the heating rate leads to a slight decrease of the char and oil yields and an increase of the gas yield. The production varied in the ranges between 21.5 and 47.3% for char, 31−51.5% for oil, and 11.4−47.5% for gas, with a maximum higher heating value of 29.0 MJ kg-1, 14.1 MJ kg-1, and 15.5 MJ N-1 m-3, respectively. The char had a high fixed-carbon content (>76%) as well as a high heating value, and therefore it could be used as solid fuel, precursor in the activated carbons manufacture (specific surface area BET until 121 m2 g-1), or to obtain category-A briquettes. Aliphatic and aromatic hydrocarbons and hydroxyl and carbonyl compounds were the majority components of the oil fraction, which suggests their use as a source of chemicals of industrial interest. Also, it can be used as liquid fuel. The gas composition was identified as hydrogen, carbon monoxide, methane, and carbon dioxide and can be used to heat the pyrolysis reactor or to generate heat/electricity in a gas-turbine/vapor-turbine combined cycle.

KARAKTERISTIK FISIK DAN KIMIA DARI PRODUK BIOINDUSTRI CANGKANG JAMBU METE (Anacardium occidentale) / Physical and Chemical Characteristics of Bioindustry Products of Cashewnuts Shell (Anacardium occidentale)

“…Persentase rendemen yang diperoleh juga sangat bergantung pada alat yang dipakai. GONZÁLEZ et al (2005) menunjukkan bahwa proses pirolisis pada temperatur 600 o C dapat menghasilkan cairan sebanyak 44.3% pada cangkang biji kenari. Hasil tersebut diperoleh lebih banyak dibanding hasil penelitian ini.…”

Study on the Comprehensive Utilization of Bitter Almond Shell

“…During the harvest period, the hull and kernel are the desirable products; the almond shell consists of 70% of the dry mass of a whole almond fruit. These nutshells can be collected on a community basis for reuse Gonzalez et al 2005;Izquierdo et al 2011; Meenakshi Sundaram and Sivakumar 2012;Pirayesh and Khazaeian 2012;Tiryaki et al 2014). Almond nutshells are abundant, inexpensive and readily available lignocellulosic materials, which contain a high content of carbon and other renewable chemicals.…”

“…Almond nutshells are abundant, inexpensive and readily available lignocellulosic materials, which contain a high content of carbon and other renewable chemicals. There have been many studies on converting almond shell into activated carbons (Gonzalez-Vilchez et al 1979; RodriguezReinoso et al 1982;Linares-Solano et al 1984;Rodriguez-Reinoso et al 1984;Torregrosa and Martin-Martinez 1991;Hayashi et al 2002;Toles and Marshall 2002;Gonzalez et al 2005 4994 Yuso et al 2014). Gonzalez et al (2009) carried out a study of the pyrolysis of various biomass residues including almond shell for the production of activated carbons.…”

Effects of the operating parameters on the production of bio-oil in the fast pyrolysis of Japanese larch

“…temperature, feed size, sweep gas velocity, atmosphere, heating rate, steam velocity, and initial moisture content) on the production of bio-oil [3][4][5][6][7][8]. However, most studies focused on pyrolysis in a fixed bed, which is difficult to apply on a large scale.…”