Rumela Bhadra

Flowability properties of commercial distillers dried grains with solubles (DDGS).

ABSTRACT Distillers dried grains with solubles (DDGS), the major coproduct from the corn-based fuel ethanol industry, is primarily used as livestock feed. Due to high protein, fiber, and energy contents, there is a high demand for DDGS. Flowability of DDGS is often hindered due the phenomenon of caking. Shipping and handling of DDGS has thus become a major issue due to bridge formation between the DDGS particles. The objective of this investigation was to measure flowability characteristics of DDGS samples from five ethanol plants in the north central region of the United States. Carr and Jenike tests were performed and the resulting data were mathematically compared with a previously developed empirical model. The largest particles had an average geometric mean diameter (GMD) of 1.19 mm, while the lowest particle size had an average GMD of 0.5 mm. Soluble solid levels were ≈10.5–14.8% (db). The effective angle of friction (δ) was 43.00–57.00°. Additionally, a few parameters exhibited fairly high linear c...

Cross-Sectional Staining and Surface Properties of DDGS Particles and Their Influence on Flowability

ABSTRACT With the U.S. fuel ethanol industry projected to grow during the next several years, supplies of distillers dried grains with solubles (DDGS) are anticipated to continue to grow as well. DDGS is used primarily as livestock feed. Much of the DDGS must be shipped, often over large distances, outside the Corn Belt (which is where most of the corn-based ethanol plants are currently located). Stickiness and caking among particles is a common issue for DDGS, and it often leads to flowability problems. To address this, the objective of this study was to understand the cross-sectional and surface natures of DDGS particles from five ethanol plants, and how they interact with DDGS properties. This study examined the distribution patterns of chemical components within cross-sections, within section edges (i.e., surface layers), and on surfaces using standard staining techniques; chemical composition was determined using standard protocols; and physical and flowability properties were also determined. Crude ...

Physical and Chemical Characterization of Fuel Ethanol Coproducts Relevant to Value-Added Uses

ABSTRACT One of the fastest growing industries in the United States is the fuel ethanol industry. In terms of ethanol production capability, the industry has grown by more than 600% since the year 2000. The major coproducts from corn-based ethanol include distillers dried grains with solubles (DDGS) and carbon dioxide. DDGS is used as a livestock feed because it contains high quantities of protein, fiber, amino acids, and other nutrients. The goal of this study was to quantify various chemical and physical properties of DDGS, distillers wet grains (DWG), and distillers dried grain (DDG) from several plants in South Dakota. Chemical properties of the DDGS included crude ash (5.0–21.93%), neutral detergent fiber (NDF) (26.32–43.50%), acid detergent fiber (ADF) (10.82–20.05%), crude fiber (CF) (8.14–12.82%), crude protein (27.4–31.7%), crude fat (7.4–11.6%), and total starch (9.19–14.04%). Physical properties of the DDGS included moisture content (3.54–8.21%), Aw (0.42–0.53), bulk density (467.7–509.38 kg/m3...

Drying characteristics of distillers wet grains under varying condensed distillers solubles and drying temperature levels

Distillers dried grains with solubles (DDGS) has been shown to be an excellent livestock feed ingredient, and it is produced by the fuel ethanol industry, which is primarily located in the Midwest United States. There is a growing need to transport DDGS over long distances via rail, but this can often be hampered by poor flowability when unloading. DDGS is formed by combining condensed distillers solubles (CDS) with distillers wet grain (DWG) and then drying at high temperatures. It is hypothesized that drying conditions can affect resulting DDGS chemical, physical, and flow properties, but there is currently little quantified information about drying behavior of these coproducts. Thus, the objective of this study was to investigate the moisture desorption patterns of DWG for three CDS addition levels (10%, 15%, and 20% wet basis (wb)) at three drying temperatures (100C, 200C, and 300C), to thus produce DDGS. Several mathematical models (Page, Newton, Pilosof, Henderson-Pabis, and others) were used to fit the observed moisture data over time. A new comprehensive model was developed for moisture ratio versus time (the best fit had R 2 = 0.91, SEM = 0.17) using a modified Page model which accounted for varying CDS and temperature levels. The developed model will be useful to predict moisture content values of DDGS for various drying times, CDS addition levels, and drying temperatures, and will thus be a benefit to industrial processing conditions.

Drying Kinetics of Distillers Wet Grains (DWG) Under Varying Condensed Distillers Solubles (CDS) and Temperature Levels

ABSTRACT Distillers dried grains with solubles (DDGS) is a widely used animal feed. But transportation of DDGS is often troublesome because of its stickiness. DDGS is formed by combining condensed distillers solubles (CDS) with distillers wet grains (DWG) and then drying. As a first step toward understanding drying behavior, this studys objective was to investigate batch-drying kinetic behavior of DWG with three CDS addition levels (10, 15, and 20% wb) and three drying-temperature levels (100, 200, and 300°C). Multiple nonlinear mathematical models were used to fit experimental drying data for moisture content versus drying rate. A new comprehensive model was developed (R2 = 0.89, SEM = 18.60) from a modified Chen and Douglas model to incorporate CDS and drying-temperature terms. Drying temperature affected drying rate more significantly than did changes in CDS level; thus, drying temperature was the main effect and CDS was a subeffect. Increasing the drying temperature increased the drying rate signific...

Measurement of Sticky Point Temperature of Coffee Powder with a Rheometer

Sticky point temperature is a parameter that quantifies stickiness of food and biological powders. It is traditionally measured using glass instruments. In this study, a new methodology was developed to measure sticky point temperature using a rheometer, and it was successfully used to determine sticky point temperature for coffee powder samples. The behavior of coffee sticky point temperature as a function of moisture content (%, dry basis) was observed to be non-linear, but after 16% (dry basis) moisture content, there were no changes in sticky point temperature with further increases in moisture content. An exponential prediction model for sticky point temperature = f (moisture content) was achieved with an R2 value greater than 0.93; a power law regression model also fitted well, with an R2 value of 0.97. Rheometry was shown to be a viable and convenient means to determine sticky point temperature for various coffee powders.

Effects of Varying CDS levels and Drying and Cooling Temperatures on Flowability Properties of DDGS

Demand for alternative fuels and the need to reduce dependence on fossil fuels, have triggered the growth of corn-based ethanol production, and this is expected to rise in future years. Transportation of the co-product distillers dried grains with solubles (DDGS) from this industry occurs under various environmental conditions. It is often problematic, since caking between the particles can lead to flow problems. In this study we have prepared DDGS by combining condensed distillers solubles (CDS) with distillers wet grains (DWG) and then drying. We investigated the effects of CDS (10, 15, and 20% wb), drying temperature (100, 200, and 300°C), and cooling temperature (-12, 25 35°C) levels on the flowability of the resulting DDGS. Statistical analyses of the resulting data found significant differences among the cooling temperature levels for angle of repose, total flow and flood indices, dispersibility, water activity, and protein dispersibility index. Additionally, significant interaction effects between CDS, drying temperature, and cooling temperature levels for angle of repose, total flow and flood indices, dispersibility, and protein dispersibility index were observed as well. Response surface regression on selected dimensionless flowability parameters was also applied. However, multivariate PLS regression yielded better results (R2 > 0.8) than response surface plots. Understanding the effects of drying and cooling temperature as well as CDS levels can help to improve the industrial processing of DDGS and improve storage and transportation.

Measurement and Comparison of Glass Transition and Sticky Point Temperatures of Distillers Dried Grains with Solubles (DDGS) with Varying Condensed Distillers Solubles (CDS) and Drying Temperature Levels

ABSTRACT Distillers dried grains with solubles (DDGS) is the main coproduct of the U.S. fuel ethanol industry and has significantly impacted the livestock feed markets in recent years. Particle agglomeration and subsequent flowability problems during storage and transport are often a hindrance, a nuisance, and expensive. This paper aims at characterizing the glass transition (Tg) and sticky point (Ts) temperatures of DDGS samples prepared with varying condensed distillers solubles (CDS) levels (10, 15, and 20%, wb), drying temperatures (100, 200, and 300°C), and moisture contents (0, 10, and 20%, db), and it discusses implications on DDGS flowability behavior. Distillers wet grains were combined with specified levels of CDS and dried in a convection-style laboratory oven to produce DDGS. Subsequently, predetermined amounts of water were added to the DDGS to achieve desired moisture content levels. To determine Tg (°C), a differential scanning calorimeter was used, whereas Ts (°C) was determined through a ...

Artificial Neural Network Modeling of Distillers Dried Grains with Solubles (DDGS) Flowability with Varying Process and Storage Parameters

ABSTRACT Neural network (NN) modeling techniques were used to predict flowability behavior of distillers dried grains with solubles (DDGS) prepared with varying levels of condensed distillers solubles (10, 15, and 20%, wb), drying temperatures (100, 200, and 300°C), cooling temperatures (–12, 25, and 35°C), and storage times (0 and 1 month). Response variables were selected based on our previous research results and included aerated bulk density, Hausner ratio, angle of repose, total flowability index, and Jenike flow index. Various NN models were developed using multiple input variables in order to predict single-response and multiple-response variables simultaneously. The NN models were compared based on R2, mean square error, and coefficient of variation obtained. In order to achieve results with higher R2 and lower error, the number of neurons in each hidden layer, the step size, the momentum learning rate, and the number of hidden layers were varied. Results indicate that for all the response variabl...

Optimization and Modeling of Flow Characteristics of Low-Oil DDGS Using Regression Techniques

Citation: R. Bhadra, R. P. K. Ambrose, M. E. Casada, S. Simsek, K. Siliveru. (2017). Optimization and Modeling of Flow Characteristics of Low-Oil DDGS Using Regression Techniques. Transactions of the ASABE. 60(1): 249-258. (doi: 10.13031/trans.11928)