Drying of soybean grains with direct-fired furnace using wood chips: Performance, quality and polycyclic aromatic hydrocarbons

Abstract

The search for new technologies and options of activities to improve agricultural production systems are goals continuously desired by companies. Thus, the objective of this study was to evaluate the performance of soybean grain drying, using a furnace dryer automatically fed with eucalyptus chips, the quality of the grains before and after drying, as well as contamination by polycyclic aromatic hydrocarbons (PAHs). Twenty-seven samples were collected before drying and 27 samples were collected after drying, totaling 54 samples of around 1.0 kg each, at 5-minute intervals. The following experimental evaluations were carried out: dryerperformance, calorific value and fuel consumption; grainsmoisture content, germination, electrical conductivity, apparent specific mass, thousand-grain weight, color, oil acidity index and polycyclic aromatic hydrocarbons. The dryer showed an average efficiency of 75.61% for drying the grains. The average fuel consumption was 21.78 kg of chip per ton of dry grains. The specific energy consumption to remove 1.0 kg of water was 11,871.80 kJ. In general, drying did not compromise the final quality of soybeans. Soybeans showed the presence of two PAHs before drying and three more PAHs appeared after drying. Average concentrations were lower than the maximum values allowed by European Union Law No 835/2011. The drying conditions used for soybean grains influenced the low formation of PAHs.

Corn grains drying using direct-fired furnace with wood chips: Performance, quality and polycyclic aromatic hydrocarbons

“…Thus, in terms of energy, the closer to the exhaust temperature at room temperature, the greater the drying efficiency. Quequeto et al (2022) also obtained satisfactory results with 75.61% in the average performance of drying soybeans using direct-fire furnace.…”

“…There are several studies on the occurrence of PAHs in different types of products, including smoked meat sausages (Mirbod et al, 2022), corn grains (Resende et al, 2022;Silva et al, 2018;Lima et al, 2017), soybeans (Quequeto et al, 2022), grilled meat (Siddique et al, 2021), canola, sunflower and corn oils (Molle et al, 2017), infant milk and cereals (Rey-Salgueiro et al, 2009), yerba mate (Vieira et al, 2010), toasted bread (Rey-Salgueiro et al, 2008). For the children's scenario, if we use only B(a)P as a parameter for the evaluation of contamination, the mean values detected in this study would be in accordance with the European Union Law No.…”

Performance of industrial drying and soybean grains quality

“…The same author reports that, although almost 100% of the thermal energy contained in the fuel is transferred to the drying air in dryers with direct fire furnaces, the additional heat losses to the environment through radiation, conduction, and with the gases of exhaust reduce overall performance to 60% or less. Quequeto et al (2022b) also obtained satisfactory results with 75.61% in the average performance of drying soybeans using a direct-fire furnace.…”

Recent Advances in the Drying Process of Grains

“…Based on product quality enhancement, pulse-spouted vacuum microwaves and pulse-spouted microwave dryers outperformed the microwave vacuum dryers. Quequeto et al [22] studied the performance of soybean grain drying quality using an automatic furnace dryer fed with eucalyptus chips. After drying, the average moisture content of the grains decreased from 14.47 to 12.11%wb.…”

“…Drying of grain accounts for a large portion (27 to 70%) of industrial energy usage, depending on the final product of the process [21]. An efficient drying process is critical to the grain processing industries [22]. Currently, the drying operations must satisfy the demand of both grain farmers and processors.…”