Innovative and flexible single screw press for the oil extraction of Calophyllum seeds

Abstract

The oil extraction of Calophyllum seeds using a conventional single screw press leads to an inferior yield and is perceived to be less efficient as well as difficult to operate. An innovative and flexible single screw press was, therefore, designed and investigated in this study to solve these problems. Moreover, the effects of the seeds’ moisture content, pressing temperature and seeds’ feed rate on the oil yield and quality were identified to determine the optimal oil extraction performance from the Calophyllum seeds. The study found that the seeds’ moisture content, pressing temperature and seeds’ feed rate generally affected the oil yield. The yield indeed improved as the pressing temperature and the seeds’ feed rate increased respectively from 45 to 75°C and 1.5 to 5 kg·h<sup>–1</sup>. The oil yield also ameliorated as the seeds’ moisture content rose from 1.7 to 12.8%, but it was optimal when the seeds’ moisture content was 5.5%. The best oil yield of 80.6% was, thus, obtained with the seeds’ moisture content of 5.5%, a pressing temperature of 75°C and the seeds’ feed rate of 5 kg per h. Although the quality of the crude oil was poor with a high viscosity (³ 94 mm<sup>2</sup>·s<sup>–1</sup>) and high acid value (³ 48 mg KOH/g), its density, saponification and iodine values were acceptable. After the oil refining process by degumming and neutralisation, its quality improved and met the Indonesian Biofuel Standards, except for its viscosity.

Optimisation of concurrent Calophyllum oil-resin extraction and separation

“…The increment of the n-hexane-to-methanol ratio from 2 : 1 to 2.5 : 1 might have increased the oil yield due to a decrease in polarity, even though the stirring speed used was lower (400 vs 800 rpm). https://doi.org/10.17221/67/2020-RAE Compared to the highest oil yield obtained in a study by Indartono et al (2019), the optimal oil yield in the present research is twice that achieved with a screw press (65 vs. 33%).…”

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“…The operating conditions of the screw press also have a substantial impact on the efficiency of oil pressing. These conditions are considered in the papers (Indartono et al, 2019;Bogaert et al, 2020; Eseoha & Akubuo, 2021): seed properties, temperature, seed feed rate, screw rotation speed, and screw profile, which can determine the degree of filling of the screw shaft, pressure increase and friction. Thus, the effect of pressure on pressing efficiency can be investigated by applying different seed moisture content and operating modes (conditions) during the oil pressing process with a screw press, and different screw configurations.…”

“…However, when using simplified technological schemes, it is possible to squeeze oil directly from purified oil-containing seeds. The main technological schemes (Alonge & Jackson, 2019) and various types of modern single-screw press designs (Indartono et al, 2019;Fakayode & Ajav, 2019;Pedretti et al, 2019), single-screw and twin-screw extrusion presses (Romero-Guzmán et al, 2020; Evon et al, 2021), which are used in agricultural processing plants and oil pressing enterprises, are described and widely investigated in the processing of various oilseeds. The development of screw presses and extrusion presses in various fields of technology is associated with using continuous production methods and the ability to convert extrusion presses to meet any industry requirements (Choton et al, 2020).…”

Modelling of dewatering wood pulp in a screw press using statistical and multivariate analysis

“…Screw presses are widely used in mechanical pressing to remove liquid from a variety of suspensions. They are used in food processing industries, especially oil extraction (Bredeson 1983;Indartono et al 2019), water treatment (Fangueiro et al 2008), paper industry (Meyer et al 2018), and more recently, in lignocellulosic biomass pretreatment (Yan et al 2014). Screw presses are similar to conventional extruders but with a perforated barrel allowing water to be drained and collected as a filtrate.…”