Technologies for utilization of industrial excess heat: Potentials for energy recovery and CO2 emission reduction

Abstract

Industrial excess heat is a large untapped resource, for which there is potential for external use, which would create benefits for industry and society. Use of excess heat can provide a way to reduce the use of primary energy and to contribute to global CO 2 mitigation. The aim of this paper is to present different measures for the recovery and utilization of industrial excess heat and to investigate how the development of the future energy market can affect which heat utilization measure would contribute the most to global CO 2 emissions mitigation. Excess heat recovery is put into a context by applying some of the excess heat recovery measures to the untapped excess heat potential in Gävleborg County in Sweden. Two different cases for excess heat recovery are studied: heat delivery to a district heating system and heat-driven electricity generation. To investigate the impact of excess heat recovery on global CO 2 emissions, six consistent future energy market scenarios were used. Approximately 0.8 TWh/year of industrial excess heat in Gävleborg County is not used today. The results show that with the proposed recovery measures approximately 91 GWh/year of district heating, or 25 GWh/year of electricity, could be supplied from this heat. Electricity generation would result in reduced global CO 2 emissions in all of the analyzed scenarios, while heat delivery to a DH system based on combined heat and power production from biomass would result in increased global CO 2 emissions when the CO 2 emission charge is low.

Industrial excess heat use: Systems analysis and CO2 emissions reduction

“…For a through description of the energy market scenarios, see Table 2. The model, and hence the results, is based on the heat potential derived from a questionnaire in Gävleborg County presented in Broberg Viklund and Johansson [3]. Table 4 A brief summary of EMS-1 to EMS-6.…”

“…The heat could be found in different energy carriers (water, flue gases, air and heat in materials) and the temperature of the heat ranged from 45 -1600°C. [3] The manner in which the excess heat is used will affect the system, e.g. the CO2 emissions.…”

“…the CO2 emissions. Though the purpose is not to fully reflect this county, the study is based on the industrial excess heat potential in water, flue gases, and air in Gävleborg County as presented in [3], and summarized in Table 1. However, it is assumed in this study that the potential is the actual potential available at the point of use for the heat use technologies in this study, that is, the recovered heat that has been exchanged to a suitable medium.…”

“…The energy system and the consequences for excess heat use were studied using energy systems modeling. This study is based on a study presented in Broberg Viklund and Johansson [3] where a questionnaire was sent to producing companies classified as firms holding high environmental impact (according to the classification in [22]) in Gävleborg County, Sweden in spring of 2012 [3]. The energy use in Gävleborg County adds up to approximately 20 TWh (in 2011) [23], which results in direct CO2 emissions totaled approximately 1580 kton [24].…”

“…Efficient use of resources can be from both internal and external improvements, and there are several options for utilization of these unused heat resources [3][4][5][6]. It is important to first reduce the amount of excess heat from industrial processes.…”