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Garcia R.A.,Biobased and Other Animal Co Products Research Unit | Piazza G.J.,Biobased and Other Animal Co Products Research Unit
Applied Engineering in Agriculture | Year: 2015

Meat and bone meal (MBM), a product of the rendering industry, comprises a mixture of two particle types. The utility and value of MBM would increase if the two particle types could be separated economically. Past efforts at classification of MBM particles have achieved limited success. In the present research, a classification method originally developed for distiller's dried grains is applied with modifications to MBM. In this process, known in the literature as elusieving, a mixture of particles is screened into multiple fractions, and each fraction is processed separately using airstream classification units. In the present research, the MBM was treated with an anti-caking agent prior to processing. The screen opening sizes were chosen to isolate the smallest particles, which are very high in ash, and divide the remaining material into thirds. Each fraction was run through an air classification unit at multiple airspeeds, and the proximate compositions of the materials collected from the units were determined. These results were used to determine the optimal separation of particle types that would be achieved if each fraction were classified at the ideal airspeed. Unprocessed MBM with an ash content of 26.1%, dry basis, was fractionated into one stream with ash content reduced to 19.8% (42.0% of total mass) and another with ash content increased to 34.4% (58.0% of original mass). A concept named ash shift is defined and used to compare the separations produced by different methods. The ash shift results from elusieve processing (25.7%) are shown to be superior to the ash shift achievable through screening (7.4%) or airstream classification (17.7%) alone. The appropriateness and limitations of the elusieve process for classifying MBM particles are discussed. © 2015 American Society of Agricultural and Biological Engineers. Source


Garcia R.A.,Biobased and Other Animal Co Products Research Unit | Riner S.A.,Biobased and Other Animal Co Products Research Unit | Riner S.A.,Drexel University | Piazza G.J.,Biobased and Other Animal Co Products Research Unit
Industrial and Engineering Chemistry Research | Year: 2014

Reports of novel organic polymeric flocculants have become commonplace. The method used to test the effectiveness of these flocculants is most often the flocculation of a kaolin suspension in a jar test. The widely varying versions of this method that appear in the literature suffer from a range of weaknesses. The present research uses well-defined kaolin and confines testing to conditions in which the kaolin suspension is stable in the absence of a flocculant. The research examines all aspects of the conduct of the method, including clay dosing, mixing, settling time, and measurement to improve the sensitivity, reproducibility, and robustness of the method, and takes steps to avoid pitfalls that can reduce the validity of the method. Innovations include careful selection of the buffer system and instrument characteristics. Kaolin Clarification Effectiveness is introduced as a metric that gives a meaningful indication of the relative value of a novel flocculant while emphasizing the critical importance of test conditions. Together, the results form a set of recommended test conditions that should be useful for new flocculant research. © This article not subject to U.S. Copyright. Published 2013 by the American Chemical Society. Source


Garcia R.A.,Biobased and Other Animal Co Products Research Unit | Stein S.D.,Biobased and Other Animal Co Products Research Unit | Piazza G.J.,Biobased and Other Animal Co Products Research Unit
Applied Engineering in Agriculture | Year: 2014

Chicken blood is an attractive but problematic raw material for the production of biobased flocculants. Blood begins to degrade as soon as it is collected -it rapidly coagulates, and at longer time scales, the red blood cells lyse and microbial growth results in hydrogen sulfide production. This study investigated the extent to which these types of degradation can be limited by inexpensive chemical treatments, under non-sterile, non-refrigerated conditions. It is shown that while the anticoagulants potassium citrate and potassium oxalate are effective under refrigerated conditions, at ambient temperatures they can only prevent coagulation for about one day. The effectiveness of potassium EDTA, on the other hand, is not as temperature dependent and can prevent coagulation for at least four days at ambient temperature. Similarly, blood treated with oxalate or citrate produces dangerous amounts of hydrogen sulfide, but blood treated with EDTA produces significantly less of the toxic gas. Anticoagulated blood does undergo some red blood cell lysis under the conditions investigated, and a method for limiting this lysis is proposed. Finally, it is shown that chicken blood preserved with EDTA can be held in non-refrigerated, non-sterile conditions for at least four days without sacrificing the effectiveness of the flocculant made from the blood. © 2014 American Society of Agricultural and Biological Engineers. Source


Garcia R.A.,Biobased and Other Animal Co Products Research Unit | Clevenstine S.M.,Biobased and Other Animal Co Products Research Unit | Piazza G.J.,Biobased and Other Animal Co Products Research Unit
Food and Bioproducts Processing | Year: 2015

Hemoglobin from chicken blood has been shown to be a good substitute for synthetic polymeric flocculants. One stage of processing the blood entails lysis of the cells to release the hemoglobin; in the present study, the use of ultrasonic processing at this stage is investigated. Washed chicken blood cells are suspended in buffer and run continuously through a chamber attached to an ultrasonic probe. Calorimetry is used to measure acoustic power input to the liquid. Ultrasonic cell lysis is tested using chamber residence times of 75-300 ms, and the equipment's entire range of power inputs. The hemoglobin release kinetic parameters are determined and it is shown that above a particular level, increasing power input can actually result in a decreased rate constant. Ultrasonic processing can damage proteins, so reduction of hemoglobin's flocculant activity is considered. Using a sensitive assay involving suspensions of kaolin clay, no effect of ultrasonic processing on hemoglobin flocculant activity is detected. Although the conversion of electrical power to acoustic power is inefficient, the electric power required to release greater than 90% of the hemoglobin is shown to be minimal. © 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. Source

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