Patent UA-106433-C2 (UA)
Title: Method and plant for isolation of carbon dioxide from flue gas
Inventor: KUCHMA OLEH IHOROVYCH
IPC: B01D53/62
Filed: 2013-01-30
Abstract: The invention relates to the field of thermal energy and can be used in the design of processes of purification of flue gas and heat and power plants for isolation from flue gases of carbon dioxide and production of liquefied carbon dioxide. A method of isolation of carbon dioxide from flue gas includes cooling the flue gases, absorption by a repeatedly circulating absorbent, desorbing absorbed carbon dioxide from rich absorbent, cooling the absorbent, drying desorbed carbon dioxide and its supply to a consumer. As an absorbent in the absorption process, a solution of monoethanolamine (MEA) is used, absorption occurs in the countercurrent when the flue gases move upwards and the absorbent moves downwards, absorption with the repeatedly circulating absorbent is conducted while continuously monitoring the temperature and concentration with adjustment of the amount of flue gases. The absorbent solution saturated by carbon dioxide is divided into two flows, one of which is first heated and then fed to the desorber, the second flow is cooled and fed to the desorber, drying desorbed carbon dioxide is carried out in multi-step manner and thereafter it is subject to liquefaction and supplied to the consumer in liquefied state, and the regenerated absorbent is subject to cooling and fed again to the absorption. A plant for isolation of carbon dioxide comprises a heat exchanger with a body fitted with a pipe, an absorber equipped with a chimney connected to the absorber via a heat exchanger, a collection tank of absorbent, one circulating pump, a dehumidifier, a desorber and a cooler. The plant further comprises a storage tank of the absorbent solution, a compressor, at least six heat exchangers, wherein five of them are of plate type, and one vane and two circulation pumps. The cooler is made in the form of a freezer of chilling machine. The heat exchangers, absorber, absorbent collection tank, desorber, cooler, solution storage tank and compressor have separate bodies and functionally connected by pipes, wherein the absorber body is vertical. The heat exchanger connected to the gas duct is made as a contact economizer. The circulation pumps are made in the form of a circulation pump of absorption, a circulation feed pump and a circulation desorption pump. The solution storage tank is equipped with sensors for determination of fluid parameters by sensors and control valves at outlet connected thereto and connected by pipes to the absorber and desorber, which through the dryer is connected to the compressor. The dryer is multistage, whose stages comprise a shell-tube heat exchanger – condenser, a drip pocket of vapor-gas mixture, as well as a unit of silica drying and an evaporator, and a shell-tube heat exchanger – refrigerator of the solution is connected by its outlet to the absorber. The invention enables to produce liquefied carbon dioxide of high concentration in the final product. In addition, this technology meets the modern environmental standards, using this method the plant completely regenerates used water, absorbent and has minimal heat and energy loss and emissions into the air.