**Conventional and Advanced Exergy and Exergoeconomic Analysis of a Spray Drying System: A Case Study of an Instant Co** ff**ee Factory in Ecuador**

#### **Diana L. Tinoco-Caicedo 1,2,\*, Alexis Lozano-Medina 2 and Ana M. Blanco-Marigorta 2**


Received: 14 September 2020; Accepted: 23 October 2020; Published: 27 October 2020

**Abstract:** Instant co ffee is produced worldwide by spray drying co ffee extract on an industrial scale. This production process is energy intensive, 70% of the operational costs are due to energy requirements. This study aims to identify the potential for energy and cost improvements by performing a conventional and advanced exergy and exergoeconomic analysis to an industrial-scale spray drying process for the production of instant co ffee, using actual operational data. The study analyzed the steam generation unit, the air and co ffee extract preheater, the drying section, and the final post treatment process. The performance parameters such as exergetic e fficiency, exergoeconomic factor, and avoidable investment cost rate for each individual component were determined. The overall energy and exergy e fficiencies of the spray drying system are 67.6% and 30.6%, respectively. The highest rate of exergy destruction is located in the boiler, which amounts to 543 kW. However, the advanced exergoeconomic analysis shows that the highest exergy destruction cost rates are located in the spray dryer and the air heat exchanger (106.9 \$/h and 60.5 \$/h, respectively), of which 47.7% and 3.8%, respectively, are avoidable. Accordingly, any process improvement should focus on the exergoeconomic optimization of the spray dryer.

**Keywords:** advanced exergoeconomic analysis; spray dryer; exergy destruction cost rate
