A lithium silicate (Li
4SiO
4) absorbent has been developed as a new CO
2 absorbent at high temperatures, which emits CO
2 at temperatures above 993 K in pure CO
2 at 101 kPa. This temperature is approximately 200 K lower than that for well-known CaO. It was used in CH
4 steam reforming experiments and higher CH
4 conversion was observed for a mixture of a catalyst and an Li
4SiO
4 pellet, than for a catalyst alone, at around 873 K. In this study, the emission temperature and reproducibility of an Li
4SiO
4 pellet (5 mm, spherical) in N
2 was examined from the viewpoint of building a high-efficiency H
2 production system, since the CO
2 emission temperature is lower than that in pure CO
2. The pellet completely emitted CO
2 within 1 h at 873 K, and within 0.5 h at 923 K, and showed high reproducibility, exhibiting almost the same absorption property for 5 cycles.
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