In one of the stages of the gelatin production process, a highly concentrated solution of gel is cooled and extruded to form gelatin noodles, which are then laid on a drying belt. Gelatin is a molecular colloid that is not porous under these drying conditions, and as a consequence, water migration occurs solely by diffusive processes. To achieve a commercial standard of dryness, the dependence of the diffusion coefficient as a function of temperature is used. This set of circumstances favors the appearance of sharp concentration gradients inside the gel. In a numerical simulation of the drying process these characteristics create difficult conditions for use of the traditional methods for solution of time-dependent partial differential equation models. This paper evaluates an implementation of the boundary element method to determine surface conditions of the gelatin particle
In this study, the production of fatty acid ethyl esters (FAEE) from macauba pulp oil and pressurized ethanol was investigated. The experiments were conducted without the addition of catalyst, at 20 MPa, to determine the effect of temperature (200 to 300 °C) and the oil to ethanol mass ratio (1:1 and 1:2) on the FAEE content and different residence times (10 to 45 min). The effect of the addition of n-hexane to the oil (20 wt%) as a co-solvent was also evaluated. The use of high temperatures (275 and 300 °C) resulted in high FAEE content (∼90%). Increasing the amount of ethanol in the reaction medium contributed to the formation of esters only at operating temperatures of 200 to 250 °C. It was also observed that with the addition of co-solvent (in the oil) it was possible to obtain high amounts of FAEE in a shorter reaction time. In addition, a low content of unreacted compounds (∼8.0%) and the conversion of ∼90 and 99% of the free fatty acids and triglycerides were observed, respectively.
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