Mapping potentials of low-grade industrial waste heat in Northern China

•The industrial waste heat (IWH) that can be used for heating in northern China reaches 100 million ton standard coal equivalents (Mtce, 2.93 EJ).•We set out three levels of low-grade industrial waste heat (IWH) investigation.•The potential heat resources inside industry are mapped in a Chinese province.•The amount of waste heat in steel mills and cement factories throughout Hebei province reaches 44268 MW and 2155 MW.•Higher recognition of industrial waste heat is needed in future Chinese district heating systems.

Low-grade industrial waste heat has drawn great attention in China. A new regulation concerning low-grade industrial waste heat (IWH) use has been issued by the NDRC (National Development and Reform Commission) and the Ministry of Housing and Urban-Rural Development. Among the four major tasks mentioned, the most important is investigating IWH. However, there is little official data on the amount of waste heat in China. This paper presents a three-level method of IWH investigation. Meanwhile, the information needed at each level is summed up and heating area in northern China is taken as a case. A series of means are adopted, such as official statistics analysis, literature investigation, field test and so on. Results reveal the drastic situation of energy waste, and the great potential for energy conservation through the use of IWH. Approximately, 100 Mtce (2.93 EJ) potential of waste heat in industry can be recovered during heating season in whole northern China with 3.04 billion m3 of water saving. Questionnaire inquiry covers 11 cities in Hebei, a typical industrial province. The feasibility and benefit of waste heat to district heating (DH) were verified in a case in Qianxi county. But usually waste heat doesn't distribute according to residential heat demand, as details are necessary when we regard it as potential heat source in any level. Moreover, it is recommended that policy makers should attach importance to data statistics, technology evaluation and stimulating market mechanism for proposed aim on waste heat.