The use of membrane technologies in boiler houses of heat and power enterprises Elena Kuvardina, Natalia Semicheva, Nikolay Kuvardin, Valery Tolmacheva and Vasily Amelin E3S Web Conf., 110 (2019) 02056 Published online: 09 August 2019 DOI: 10.1051/e3sconf/201911002056