Patent ID: 8754002

Claim:
A method of fabricating medium-high temperature CO 2 sorbents made of alkali metal promoted calcium aluminate carbonates, comprising steps of: (a) mixing a source of Ca ions and Al(NO 3 ) 3 .9H 2 O to obtain an acid solution, wherein said source of calcium ions is selected from a group consisting of CaCl 2 , Ca(NO 3 ) 2 and Ca(CH 3 COO) 2 .xH 2 O and x is a value between 0 and 1; and wherein a mole ratio of said source of calcium ions to said Al(NO 3 ) 3 .9H 2 O is between 1:1 and 30:1 in said acid solution; (b) mixing NaOH and a carbonate to obtain an alkali solution, wherein said alkali solution has 1.6 mole of NaOH; and wherein said carbonate is selected from a group consisting of Li 2 CO 3 , Na 2 CO 3 and K 2 CO 3 ; (c) mixing said acid solution and said alkali solution to obtain a mixed solution and staying still said mixed solution; and (d) after staying still said mixed solution, filtering said mixed solution to remove impurities and drying said mixed solution to be sintered in an oven to obtain a CO 2 sorbent, wherein, according to said carbonate used in step (b), said CO 2 sorbent thus obtained is selected from a group consisting of Li—Ca—Al—CO 3 , Na—Ca—Al—CO 3 and K—Ca—Al—CO 3 .