RITE-WAKAMATSU LABORATORY in Mitsui Mining Co., Ltd.

1 Development of methane recovery system:

(1)Biogas methane 60% carbon dioxide 40% as feedstock was purified for methane recovery by Pressure-Swing-Adsorption system. Achievement of 95% methane concentration of 90% recovery was better than 90% methane concentration of target. Recovery test of higher concentration will be continued.

2 Demonstration of adsorbent activation process:

(1)Scaled up vertical retort of 20litter carbon,5kg was tested for activation of the carbon and 1,300m2/g of surface area larger than that of target was obtained.

3 Demonstration of adsorbent forming process:

(1)Practical 100 and 150mm mold adsorbent for fuel tank of natural gas automobile were molded by press-molded and by cold isostatic pressing mold with water.

(2)Continuous molding tests of 50 and 70mm were conducted. Some cracks of the mold were obserbed after drying. Problem of cracks will be solved by adjusting molding condition.

4 Development of methane storage system:

(1)Town gas storage test showed decreasing adsorption capacity along with repeating adsorption and desorption cycle because of heavy hydrocarbon component. It could not be solved yet.

(2)In case of biogas, adsorption capacity was stable even in the existense of carbon dioxide and hydrogen sulfide.

5 Development of the high performance methane adsorbent:

(1)Density of the adsorbent was improved from 0.3-0.4g/cm³ to twice as 0.5-0.7g/cm³ same as mold type. It was achieved by finely milled adsorbent and pressed in vacuum. Adsorption capacity at 10 atomspheric pressure increased from about 35v/v to about 60v/v. But,adsorption capacity at 35 atomspheric pressure was about 130-140v/v and it was lower than 150v/v of target.

(2)Chemical reforming of adsorbent surface was not yet effective but the experimental will be conducted with acid washing.