Enhanced solubility of foliar fertilizer via spray dryer: Process analysis and productivity optimization by response surface methodology

Abstract

Foliar fertilization is a highly efficient technique of applying needed plant nutrients. During pulverization in the field, the incompatibility between fertilizer and pesticides can cause clogging of the spray nozzles. So, this work aims to improve the solubility of foliar fertilizers to facilitate its application. The effect of airflow, inlet gas temperature, and feed solution flow rate over yield, productivity, solubility, and final moisture were evaluated. The powder solubility was improved because of the capillary effect caused by greater porosity, roughness, and particle agglomeration. The maximum productivity of 0.336 kg/h was obtained at 175 ºC, with a liquid feed of 0.82 L/h and an airflow rate of 1.95 m3/min.

Spraying Technology and Foliar Application Result in a Smooth Layer of the Spray: a Literature Review

“…10). Understanding the specifics of this phenomenon, such as the properties of the spray liquid (liquid viscosity and surface tension), the properties of the plant surface, solubility, pH solution, liquid molecular weight, plant canopy, type of the formulation adding to the spray liquid, droplet characteristics, nozzle type, and size, operating conditions, and weather conditions, is crucial to achieving the highest level of efficiency when applying foliar fertilizer (Alberto et al, 2022). Under the right conditions, the plant responses to the foliar application may be boosted during the spray liquid, resulting in the absorption and transport of the applied nutrients into plant organs.…”

Production of highly soluble foliar fertilizer in a spouted bed dryer

“…The commercial powder foliar fertilizer (PFF) used in this study was a source of micronutrients consisting of 16.5% S, 0.50% B, 1.00% Cu, 25.0% Mn, and 4.00% Zn, with acidity between 2.80 and 3.80. The same fertilizer was dried by Alberto et al (2022).…”

“…Initially, 0.5 g of fertilizer was weighed on the analytical balance and mixed with 25 mL of distilled water under agitation at 720 rpm (Brasil, 2016). The time needed to obtain a translucent/ transparent solution was recorded, which allowed us to visualize an internal vortex (Alberto et al, 2022).…”

“…They need to be dissolved in water by the farmer before being applied to the crops (Ferraz et al, 2021). Fertilizers and insecticides are frequently mixed for field application which can reduce solubility and clog spray nozzles (Alberto et al, 2022). Thus, making foliar fertilizers more soluble might add value to the product and decrease operational costs.…”

“…Although the industrial application of these techniques for drying pastes and solutions is widespread, studies involving fertilizers are limited. Alberto et al (2022) investigated the drying of an aqueous fertilizer solution using the spray drying technique. The product showed a reduction of 90.2% on the initial solubility time because of the capillary effects caused by the high porosity, roughness, and agglomeration of the particles.…”