Combined Use of Solar and Biomass Energy for Sustainable and Cost-Effective Low-Temperature Drying of Food Processing Residues on Industrial-Scale

Özge Çepelioğullar Mutlu,Daniel Büchner,Steffi Theurich,Thomas Zeng

doi:10.3390/en14030561

Özge Çepelioğullar Mutlu, Daniel Büchner + Show 2 more

Open Access

https://doi.org/10.3390/en14030561

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Journal: Energies	Publication Date: Jan 22, 2021
Citations: 5	License type: CC BY 4.0

Affiliation: Deutsches Biomasseforschungszentrum

Abstract

In this study, a low-temperature drying plant based on renewable energies to dry food processing wastes is investigated. The demand-oriented heat supply is realized by a solar wall in combination with a biomass boiler. Due to the operational complexity of such a system with different sub-units and process parameters, steady-state simulations were performed in Aspen Plus to provide an insight into the process. Moreover, a time-resolved energetic evaluation was conducted to analyze the influence of varying capacity of the heat sources and operational strategy in addition to economic calculations. The simulations showed that an overall control strategy needs to consider the air properties as well as the flow rate of wet input material. In the reference case, the boiler must be operated at full load through the year to supply as much heat as possible. The revenue from the dried material was the most crucial parameter on the drying economics. Although the current plant configuration operating at 12 h per day and five days per week enable feasible results, the drying process can be more profitable by doubling the boiler capacity and increasing operational hours to 24 h per day and five days per week. The proposed plant can provide an environmentally friendly and cost-effective solution for the re-valorization of food-processing wastes into added-value compounds.

Highlights

The global population increase has caused a serious waste management problem, especially in food production and consumption [1,2,3]
The EU annually generates nearly 90 million tons of food waste, which is an important environmental challenge, in terms of resource efficiency and because food waste alone corresponds to about 8% of global greenhouse gas (GHG) emissions [2,4]
It can be possible to dry wet brewery spent grains (BSG) material continuously for ~6 h based on solar energy during the daytime, especially on hot summer days in July and August

Summary

Introduction

The global population increase has caused a serious waste management problem, especially in food production and consumption [1,2,3]. The EU annually generates nearly 90 million tons of food waste, which is an important environmental challenge, in terms of resource efficiency and because food waste alone corresponds to about 8% of global greenhouse gas (GHG) emissions [2,4]. In this regard, minimization of food waste plays a significant role to reduce GHG emissions, to balance future supply and demand more sustainably as well as to protect biodiversity and the resources (i.e., freshwater, soil, and energy) used at all stages of the food value chain [5]. As one of the most common industrial processes, can provide an alternative solution in this regard [9,10]

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