ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Co-production of hydrogen-rich gas and porous carbon by partial gasification of coal char

Jianbo Zhang, Guorong Zhang, Meng Qi, Haoquan Hu, and Xiaoxun Ma

Northwest University, Xi’an, China

E-mail: jbzhang@nwu.edu.cn

Abstract: An industrial coal char from coal pyrolysis was used for simultaneous preparation of hydrogen-rich gas and porous carbon by catalytic steam gasification. The effects of K₂CO₃ as a catalyst under varying steam flow rates, reaction temperatures, mass ratios of CC:K₂CO₃ and reaction times were investigated on hydrogen output and textural properties of the produced porous carbons. The suitability of CaO and the packing pattern were also examined for CO₂ capture, thereby promoting hydrogen content in the outlet gas. The results show that in a single operating system and process, stable and consistent hydrogen-rich gas and porous carbon can be simultaneously produced by partial or incomplete gasification. At the optimized gasification conditions, hydrogen output can be up to 3.2–3.5 mmol/(min•g_CC). H₂ and CO₂ were the dominant species sharing around 65% and 30% of the produced gas (dry basis), respectively, while only small CO and CH₄ fractions were observed. The surface area and total pore volume of the produced porous carbon can reach up to 812 m²/g and 0.473 cm³/g, respectively. The maximum hydrogen content of 95 vol.% (dry basis) can be achieved at the initial stage with some additional CaO by using either homogeneous or heterogeneous configuration.

Keywords: Hydrogen ; Porous carbon ; Coal char ; Steam gasification ; K₂CO₃ 

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-017-0278-5

Chemical Papers 72 (2) 273–287 (2018)