Solar energy for process heating: A case study of select Indian industries

Abstract

The annual consumption of petroleum products in India was about 221 million metric tons in 2015. Of this, 84% was imported. The Indian industrial sector accounts for about 16%-20% of the total fuel consumption for thermal energy for different heating applications in the temperature range of 50°C-250°C. Solar collectors can meet these temperature requirements and offer the possibility to mitigate the consumption of oil. This study highlights the fact that conversion efficiency from solar energy is much higher for process heating than for electricity generation and that process heating applications constitute a significant share of industrial energy consumption. In this paper, a methodology has been developed to estimate the potential for integration of solar collectors for process heating. The methodology employs process operating temperatures to select the type of solar collectors. The size of the solar field is estimated taking into account the thermal heat loads, working fluid and temperatures of these processes, the efficiency of the chosen solar collectors, location-based solar irradiance and capacity utilization of the solar collectors. The proposed methodology has been validated with a software tool called System Advisor Model (SAM). The techno-economic analysis will indicate the viability of solar systems for integration in industries. Therefore, the consociated parameters on economic (capital cost, fuel oil savings, monetary benefits), financial (Payback periods, Rates of Returns) and environmental (Carbon savings) are estimated. Further, the methodology has been applied to select Indian industries to verify its potential quantitatively. The industries selected include Textile, Pulp & Paper, Dairy, Leather and Automobile. Processwise energy demands are considered while estimating the potential as the fuel requirement offset by solar energy in terms of absolute fuel oil savings, monetary benefits and carbon savings. The other economic and financial parameters mentioned above were estimated to verify the capability and present the market position of solar systems. Further, sensitivity analyses have been performed with respect to solar energy penetration and fuel oil prices to address the viability of integration of solar energy for process heating.

Time-Dependent Integration of Solar Thermal Technology in Industrial Processes

“…Among the total energy used in industry, 67% is contributed by heat energy. Suresh and Rao [41] reported that with current collector technologies, low-temperature heat demands are most suitable for the integration of solar heat. Solar energy has a significant industrial market in Malaysia given that 30% of the industrial process heat requires temperatures below 100 • C [42].…”

Energy Saving Potential of Industrial Solar Collectors in Southern Regions of Russia: The Case of Krasnodar Region

“…So, for example, processes such as various types of drying, cleaning, washing, heating water, pasteurization, and sterilization do not require temperatures above 250 • C, which can easily be achieved using various types of solar collectors. The second most common user of solar collectors is the textile industry, in which many production processes (such as cleaning, drying, washing, pressing) do not require high temperatures [15][16][17]. Depending on the required temperature level of the production process, various types of solar thermal collectors are used, from the most straightforward and cheapest air flat-plate collectors, suitable for temperatures up to 100 • C to the more complex Fresnel collector or parabolic trough collectors for temperatures up to 400 • C [14][15][16][17].…”

The Graphic Analytical Method of Flat Solar Collector Energetic and Optical Characteristics

“…The solar thermal collectors are usually broken down into three categories based on the heat transfer fluid (HTF) temperature. Low temperature solar collector (less than 100°C) consists of a flat plate and evacuated tube collectors (ETC), which are able to maintain the hot water and air for residential properties, high temperature collector (over 300°C) [2,3]. Such linear Fresnel collectors and parabolic ducts, are, by and large, designed for the steam generators vapor provision [4].…”