Solar-thermal driven drying technologies for large-scale industrial applications: State of the art, gaps, and opportunities

Research and Innovation (R&I) on Large-scale Industrial Solar-thermal driven Drying technologies (LISDs) is one of the strategies required to transition to a low-carbon energy future. The objective for this work is to guide future R&I on LISDs by defining the state of the art, gaps, and opportunities. To provide a high-level perspective on the current state of solar drying research, results are presented from an analysis of the content relevant to LISDs found in 45 solar drying Review Articles published in journals over the past 25 years. A conclusion is that most of the existing solar drying research is not focused on LISDs. To build-on these existing 45 solar drying Review Articles, results are presented from an analysis of 30 Original Research Articles with significant content relevant to LISDs published over the past 5 years. A gap is identified in coupling existing or slightly modified solar thermal collectors with existing or slightly modified industrial drying technologies to create indirect LISDs. To facilitate formulating new coupling strategies, the drying characteristics most relevant to this coupling are described and four fundamental classes of industrial dryer technologies are defined based on the underlying heat transfer mechanism, which then impacts the appropriate collector choice. At their most fundamental level, many of the technologies needed to couple solar collectors and industrial dryers to create novel indirect LISDs are not unique to indirect LISDs, but rather can be generalized across a wide range of Solar Heat for Industrial Processes (SHIP) applications, and integration issues are discussed at a more fundamental SHIP level. The technical and economic characteristics of 19 existing LISDs installations throughout the world are presented, and potential and emerging areas discussed.This work was supported in part with funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 731287 and by in-kind contributions from Orta Dogu Teknik Üniversitesi.Publisher's Versio

Decarbonization of industrial processes: technologies, applications and perspectives of low-temperature solar heat (80-150°C)

Low-temperature (80-150°C) solar collectors guarantee a very high efficiency (up to 60%) in the conversion of solar radiation into useful thermal energy. Moreover, solar thermal technologies are already reliable solutions, relatively cheap and widely available in the market. For that reason, solar collectors operating at low temperatures are among the most important sustainable technologies that can reduce the fossil fuel consumption of industrial processes and their corresponding carbon footprint. Unfortunately, Solar Heat for Industrial Processes (SHIP) is still mostly unused for several reasons, e.g., not easy identification of the appropriate applications (e.g., cleaning processes, drying, desalination) or lack of knowledge of the potential environmental and economic benefit of the use of SHIP technologies. For that reason, this work includes i) an overview of solar technologies for low/medium -temperature SHIP (80-150°C) ii) results obtained on the innovative design of the mirrors used in evacuated receiver tube by means of a variation in the shape of its internal reflector iii) estimation of CO2 saving using a solar field based on evacuated tube collector (ETC). The work also includes a comparison of the standard ETC solar plant with an ETC solar plant embedded with reflectors with innovative shape