Some partial industrial ecosystems are currently in
operation. For example, a privately organized industrial
ecosystem model exists in Kalundborg, Denmark. The
Kalundborg industrial ecosystem consists of a network
of organizations composed of an electric power generating
plant, an oil refinery, a biotechnology production
plant, a plasterboard factory, a sulfuric acid producer,
cement producers, local agriculture and horticulture, and
district heating utilities [17]. Domestically, government
agencies have supported research and development of a
key element of industrial ecosystems called eco-industrial
parks where ecologically complementary organizations
are physically located in a regional area