The present invention relates to the absorption type-removal/concentration apparatus which can remove and condense carbon dioxide by separating carbon dioxide contained in air to be processed from the air to be processed by making use of a difference in enthalpy between air to be processed and air to be reproduced.
Conventionally, as to the apparatus which can separate and remove a gaseous material to be removed from air to be processed in a concentrated state and at low temperature, for example, as disclosed in Japanese Patent Publication No. 5795423, the absorption type removal/concentration apparatus which can secure a material recovery rate of the apparatus by humidifying the low-temperature reproduced air using a breathable adsorption rotor which holds an amine support solid absorbent while suppressing a renewable energy is well-known.
Currently, the chemicals absorbing method by amine solution is known as one of the separation and collection technologies of carbon dioxide. Since immense energy is required in order that amine solution may separate carbon dioxide from the amine solution which absorbed carbon dioxide (the amine solution is heated to reproduce), reduction of renewal energy is desired. As one of solutions, development of a solid absorbent is progressing. Using the solid absorbent can reduce the excessive energy about required heating and cooling of moisture, which is necessary to be a solution system at the time of reproduction of amine solution.
As disclosed in Public utility foundation legal entity, Research Institute of Innovative Technology for the Earth, “Carbon dioxide collection-management-technique highly advanced enterprise Result report” (2010), the absorption process of the carbon dioxide using amine solution is indicated generally by the following formulas.
Primary Amine (R—NH2)2R—NH2+CO2<=>R—NH3++R—NH—COO−  [1]R—NH2+CO2+H2O<=>R—NH3++HCO3−  [2a]R—NH—COO−+H2O<=>R—NH2+HCO3− secondary amine (R1R2—NH)  [2b]2R1R2—NH+CO2<=>R1R2—NH++R1R2-N—COO−  [3]R1R2—NH+CO2+H2O<=>R1R2—NH2++HCO3−  [4a]R1R2—N—COO−+H2O<=>R1R2—NH+HCO3−  [4b]
If carbon dioxide absorption liquid can perform carbon dioxide absorption by the second indicated processes of [2a], [2b], [4a] and [4b], since heat of reaction becomes small rather than that of the reaction indicated by the process of [1] or [3], there is a merit that energy of desorption reproduction can be lessened. That is, in a case where an amine support solid absorbent is used, for example, the reactions will occur as indicated by the processes of [2a], [2b], [4a], and [4b] under the low-temperature condition that 15° C. of absorption Centigrade (let all temperature be “Centigrade” henceforth) and 45° C. of desorption are set. However, since these reactions progress under the condition of existence of water, coexistence of moisture (hygroscopic moisture) is indispensable.
Since the third class amine does not have NH combination, the reaction indicated above does not occur and the amine does not perform the absorption desorption of carbon dioxide under the low-temperature conditions, for example, such as 15° C. of absorption and 45° C. of desorption.
Also, in view of that an amine system carbon dioxide absorbent has problems of smell by oxidative decomposition and heat deterioration, it is important to make reproduction temperature low in order to reduce the smell and the deterioration.