Modified Fuzzy FMEA Application in the Reduction of Defective Poultry Products

Failure mode and effects analysis (FMEA) consists of the famous qualitative management methods used for improvements in management processes. This paper aims to determine the factors of defective products in the processing of poultry products in the industry. The causes of problems have been analyzed by systematic brainstorming of specialist consensus in the evaluation of problems to achieve unanimity on the violence level. The FMEA method uses the risk priority number (RPN), which indicates the priorities of risk problems and can evaluate three components: severity, occurrence and detection. Sometimes, this risk assessment leads to the wrong priorities. Therefore, we propose fuzzy FMEA methods for priority ranking of RPN and efficiently reducing poultry product defects, which are established based on fuzzy systems followed by comparison with conventional FMEA. The results indicate that the fuzzy FMEA method can efficiently and feasibly reduce poultry product defects

Noncatalytic Esterification for Biodiesel Production.

Noncatalytic esterfication of fatty acids is an alternative process for biodiesel production. This thesis showed the possibility of conducting the esterification of oleic acid under subcritical ethanol conditions with an acceptable yield. A yield of around 75% was obtained at 230 oC, 5.5 MPa with an hour of reaction. The molar ratio of ethanol to oleic acid was found to have an optimal point, which is 3:1 within the range studied of 1:1 to 10:1. Water was shown to inhibit the reaction. The stainless steel reactor walls do not have a significant catalytic effect on the reaction. This thesis also demonstrates the possibility of biodiesel production from micro-algae without drying and extraction by using the concept of a two-step noncatalytic process involving hydrolysis followed by esterification. This thesis also examined the esterification kinetics at both phenomenological and mechanistic levels. The phenomenological models (simple power-law kinetics and fatty acid catalyzed kinetics) provide a reasonable prediction of conversion with a small number of parameters. The simple power-law kinetics model with few parameters was able to fit experimental data from esterification. The model provides an acceptable conversion prediction within the parameter studied. The fatty acid catalyzed kinetics model used experimental data from both esterification and hydrolysis (reverse path of esterification) to estimate the values of its 6 parameters. This model gives a reasonable prediction for a wider range. The mechanistic model was developed to study how the reaction proceeds. The study showed that esterification is mainly catalyzed by protons, which came from the dissociation of oleic acid.Ph.D.Chemical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/89765/1/tanawanp_1.pd

Mechanistic Modeling of Hydrolysis and Esterification for Biofuel Processes

We have elucidated the mechanism for ethyl oleate hydrolysis in high temperature water and its reverse reaction, oleic acid esterification in near- and supercritical ethanol in the absence of any other added compounds. Both reactions are acid catalyzed. H⁺ (from dissociation of water and oleic acid) and oleic acid serve as catalysts for hydrolysis and H⁺ alone is the catalyst for esterification. The rate equation arising from the proposed mechanism provided a good fit of experimental conversion data for both hydrolysis and esterification. The rate equation accurately predicted the influence of pH on hydrolysis for acidic and near-neutral conditions. The mechanistic model exhibits the ability to make quantitatively accurate predictions within and outside the original parameter space, especially for a multicomponent system. Sensitivity analysis shows that the values of the dissociation constant of oleic acid in ethanol, water, and ethanol–water systems strongly influence the predicted conversions. There is a need for experimental measurement of p<i>K</i>_a for fatty acids in both water and alcohols at elevated temperatures