Chemical Modification - Processing Additives

Session Chair

• Ida Chen, The Dow Chemical Company

Session Description

The session will feature presentations on “processing additives”, such as foam control agents, rheology modifiers, or additives on the boiling process, to name some examples. The basic idea is that during a product manufacturing process or a chemical process, the additives can be added into it to reduce the foaming issue, reduce the viscosity of the product, lower processing temperature or pressure. Speakers will present the impact of those additives on the process phenomena, yield, conversion, and more.

*All session and speaker information is subject to change pending finalization

Schedule:

Abstracts:

Effects of Surfactants on Flotation Separation Performance

Fan Shi, AECOM/National Energy Technology Lab., US Department of Energy

Flotation is a continuous, efficient, inexpensive, and well-developed commercial process. It has been widely applied in a variety of industrial processes, including mineral processing, and oily water treatment. Gas bubbles are generated within a solid-liquid or liquid-liquid suspension during flotation process. Based on the hydrophobicity of the surface, hydrophobic particles/immiscible droplets attach easily to gas bubbles and rise to the froth layer on top of the liquid surface. Finally, the floated solid particles, or immiscible liquid droplets, are skimmed off to achieve the separation.

In this study, we have investigated the effects of surfactants on the enrichment of rare earth elements (REEs) from coal and coal by-products, and the cleanup of oily sea water. The effectiveness of surfactants, i.e., frother, depressant, and collector, can strongly influence the flotation process. Different types of frothers and collectors were studied at varying flotation conditions. The properties of particle size, temperature, and pH were also studied. The discussion will focus on the performance of these surfactants and the efficiency of separation at those operating conditions.

Predicting the Effectiveness of Glidants Used to Improve the Flowability of Cohesive Pharmaceutical Powders

Maxx Capece, AbbVie Inc.

This work focuses on understanding and predicting the flowability of pharmaceutical powders. Because well-flowing powders are critical to the successful manufacturing of tablets and capsules, this topic is of upmost importance in the area of drug product development. Special attention will be given to the role played by flow additives such as nano-sized silicon dioxide which are commonly known as glidants. Fundamental aspects such as inter-particle cohesion will be discussed with an emphasis on the relationship between material properties, particle-scale interactions, and bulk-scale behavior. Examples of success and failure experienced in practical application will be given to exemplify the complexity and difficulty in applying theoretical aspects to predicting powder flow behavior.

Development of a New Anti-Foamer for Food Processing

Steve King, The Dow Chemical Company

In food processing, uncontrolled foaming media can result in a significant loss in production capacity, due to inefficient mixing or pumping, clogged process lines, overflows which result in spills, and product waste. Mechanical methods of foam management often have limited effectiveness. The addition of foam control agents is considered to be more practical and is more widely employed to minimize production losses due to foaming. A foam control agent can include a defoamer and an antifoamer. An antifoamer is designed to prevent foam, whereas a defoamer eliminates existing foam.

Potatoes have a dry substance content of about 25 % which consists mostly of starch, crude fibers and proteins. During processing of potatoes, foam is generated because foam active substances (starch and protein) are extracted by water during transport, washing, peeling and cutting. Like potatoes, sugar beets have a dry substance content of about 25% and also contain saponin, a bio-surfactant, which can cause foaming during processing. In the case of sugar beet processing, some of the foam generated by saponin can be stabilized by sugars. As a result a foam control agent which is useful for potato processing may not be useful for sugar beet processing.

One class of foam control agents used for food processing include block copolymers composed of ethylene oxide, propylene oxide, and/or butylene oxide. These types of products are believed to be effective since at increased temperatures, they are insoluble in solution, thereby causing an increase in the surface tension of the system, which results in foam collapse. Another class of foam control agents for food applications include polydimethylsiloxane (PDMS) materials. PDMS polymers are effective because they have low surface tensions, and are also highly insoluble in water. However, growing customer demand for solutions based on renewable materials has spurred the development of new more bio-based foam control agents. In this presentation, several new classes of materials which are, at least in part, bio-based and showed excellent antifoaming properties for sugar beet or potato processing will be discussed.