Effects of Pyrolysis Temperature on the Composition of Liquid Smoke Derived From Oil Palm Empty Fruit Bunches

Abstract

Oil palm empty fruit bunches (OPEFB) contain cellulose, hemicellulose, and lignin that can be pyrolyzed to produce liquid smoke. This study characterizes the composition of liquid smoke compounds from OPEFB pyrolyzed at various temperatures. OPEFB pyrolysis was performed using slow-reactor pyrolysis at temperatures of 300°C, 320°C, 340°C, 380°C, and 420°C. The composition of the chemical compounds in the liquid smoke was then analyzed using gas chromatography-mass spectrometry (GC-MS), and the concentrations of phenol and acetic acid were analyzed using spectrophotometry and high-performance liquid chromatography (HPLC), respectively. The results show that pyrolysis temperature affects the composition of liquid smoke compounds. The GC-MS analysis shows that liquid smoke contains more than 15 chemical compounds, including acetic acid, pyridine, benzene, benzenesulfonic acid, phenol, and toluene. Acetic acid and phenol dominate the composition of the liquid smoke. The HPLC analysis shows that the concentration of acetic acid in liquid smoke produced at the pyrolysis temperatures of 300°C, 320°C, 340°C, 380°C, and 420°C was 10.727 g/L, 17.994 g/L, 17.423 g/L, and 13.269 g/L, respectively. The highest phenol content was obtained at a temperature pyrolisis of 340°C.

Characteristic of Liquid Smoke Produced From Slow Pyrolysis of Cacao Pod Shells (Theobroma Cacao L)

“…Three kilograms of cacao shells were fed into a stainless-steel pyrolysis reactor (60 cm height, 40 cm diameter and 5 kg capacity) and processed at 300 o C, 340 o C, 380 o C, and 400 o C. The complete pyrolysis method has been identified in previous research [11]. The temperature and volume changes during pyrolysis were observed every five minutes.…”

“…There are also a few other compounds such as hydrocarbon (2-cyclopenten, cyclopenten), furan (2-furanmethanol, 2-furanmethanol, 3furanmethanol) and ketone (2-cyclopenten-1-one, [9] showed that the pyrolysis of durian shells at 300 o C, 340 o C and 380 o C results in 18, 14 and 21 compounds, respectively, such as phenol, carboxylic acid, furan and lactone. These characteristics were found from GC-MS testing on liquid smoke that resulted from various raw materials such as oil palm fruit bunches [11], oil palm shells [6], durian shells [10] and rice hulls [13,14].…”

“…This was likely due to lignin decomposition at 300-450 o C. A temperature of 400 o C (near the maximum temperature for lignin degradation) results in even higher phenol concentration. The research showed that liquid smoke resulting from the pyrolysis of oil palm fruit bunches at 420 o C contains 1.71% phenol [11]. The amount and quality of the resulting phenol depends on the amount of lignin content in the raw material as well as on the pyrolysis temperature [27].…”

“…In the past few years, liquid smoke has been developed from various biomass waste, such as oil palm shells [4][5][6][7][8], durian peel waste [9,10], oil palm empty fruit bunches [11], sawdust [12] and rice hulls [13,14]. The resulting liquid smoke is used as a preservative in wood and food products.…”

“…Hemicellulose degradation forms several carbonyl and acetic acid compounds as well as producing colours, while lignin degradation produces phenolic compounds that act as bacterial and flavouring agents [18,19]. There are several available studies about the content of liquid smoke produced by various types of biomass, such as oil palm fruit bunches [11], oil palm shells [4][5][6][7][8] and durian shells [9,10]. However, there is little literature about the characterization of liquid smoke from cacao pod shells.…”