Zeolites for Reducing Drying Energy Usage

Moisture Sorption Isotherms of Broccoli Interpreted with the Flory-Huggins Free Volume Theory

In this work, the Flory Huggins Free Volume theory is used to interpret the sorption isotherms of broccoli from its composition and using physical properties of the components. This theory considers the mixing properties of water, biopolymers and solutes and has the potential to describe the sorption isotherms for varying product moisture...

On Dryer Energy Performance and Controllability: Generalized Modeling and Experimental Validation

This work presents an approach to compute dryer energy efficiency using air flowrate step responses and establish a link between drying energy efficiency and process controllability. The approach is based on the temperature drop between the dryer inlet and outlet air under adiabatic conditions and so decouples water evaporation from heat loss...

Synergistic process design: Reducing drying energy consumption by optimal adsorbent selection

This work analyzes the synergy between two complementary unit operations - adsorbent dehumidification and drying - and presents a mixed integer nonlinear programming approach to optimize energy performance in a two-stage system. Combined with active constraint analysis, the adsorbent properties that promote energy performance are derived....

Improving dryer energy efficiency and controllability simultaneously by process modification

This work establishes a relationship between dryer energy performance and controllability using energy balances and process resiliency analysis. It is shown that using the process gain matrix, the dryer energy efficiency can be reliably calculated with conditions for simultaneous controllability improvement established. By incorporating a drying...

Zeolites for reducing drying energy usage.

A Mixed Integer Formulation for Energy-efficient Multistage Adsorption Dryer Design

This work presents a mixed integer nonlinear programming (MINLP) formulation for the design of energy-efficient multistage adsorption dryers within constraints on product temperature and moisture content. Apart from optimizing temperatures and flows, the aim is to select the most efficient adsorbent per stage and product to air flow...

Reducing drying energy consumption by adsorbent property optimization in multistage systems

This work presents a mixed integer nonlinear programming method for the design of energy efficient multistage adsorption dryers within product temperature and moisture constraints. The aim is to find the adsorbent type and properties that minimize specific energy consumption. The results show that the adsorbents chosen in each stage have highest...

Improving dryer controllability & energy efficiency

This work shows from energy balances and process resiliency analysis, the relationship between dryer controllability and energy performance. It is shown that using the process gain matrix, the dryer temperature drop and hence, energy efficiency can be reliably calculated. Conditions necessary for simultaneous energy efficiency and...

On the controllability and energy sensitivity of heat-integrated desiccant adsorption dryers

This work studies the controllability of heat-integrated zeolite adsorption dryers. Mean product moisture content, temperature and vitamin C concentration (representative of product quality) are considered as controlled variables. Set-point tracking and disturbance rejection controllability metrics are considered in addition to energy...

Improving adsorption dryer energy efficiency by simultaneous optimization and heat integration

Conventionally, energy-saving techniques in drying technology are sequential in nature. First, the dryer is optimized without heat recovery and then, based on the obtained process conditions, heat recovery possibilities are explored. This work presents a methodology for energy-efficient adsorption dryer design that considers sensible and latent...

Optimizing energy efficiency in low temperature drying by zeolite adsorption and process integration

Drying is an energy intensive process, with low efficiencies, particularly at low drying temperatures required for heat-sensitive products. This work presents an energy efficient method for drying heat-sensitive products based on drying air dehumidification by zeolites and process integration. Two optimization approaches are considered:...

Model-Based Energy Efficiency Optimization of a Low-Temperature Adsorption Dryer

Low-temperature drying is important for heat-sensitive products, but at these temperatures conventional convective dryers have low energy efficiencies. To overcome this challenge, an energy efficiency optimization procedure is applied to a zeolite adsorption dryer subject to product quality. The procedure finds a trade-off between the improved...