TY - JOUR
T1 - Increasing the Selectivity for Sulfur Formation in Biological Gas Desulfurization
AU - De Rink, Rieks
AU - Klok, Johannes B.M.
AU - Van Heeringen, Gijs J.
AU - Sorokin, Dimitry Y.
AU - Ter Heijne, Annemiek
AU - Zeijlmaker, Remco
AU - Mos, Yvonne M.
AU - De Wilde, Vinnie
AU - Keesman, Karel J.
AU - Buisman, Cees J.N.
PY - 2019/4/16
Y1 - 2019/4/16
N2 -
In the biotechnological desulfurization process under haloalkaline conditions, dihydrogen sulfide (H
2
S) is removed from sour gas and oxidized to elemental sulfur (S
8
) by sulfide-oxidizing bacteria. Besides S
8
, the byproducts sulfate (SO
4
2-
) and thiosulfate (S
2
O
3
2-
) are formed, which consume caustic and form a waste stream. The aim of this study was to increase selectivity toward S
8
by a new process line-up for biological gas desulfurization, applying two bioreactors with different substrate conditions (i.e., sulfidic and microaerophilic), instead of one (i.e., microaerophilic). A 111-day continuous test, mimicking full scale operation, demonstrated that S
8
formation was 96.6% on a molar H
2
S supply basis; selectivity for SO
4
2-
and S
2
O
3
2-
were 1.4 and 2.0% respectively. The selectivity for S
8
formation in a control experiment with the conventional 1-bioreactor line-up was 75.6 mol %. At start-up, the new process line-up immediately achieved lower SO
4
2-
and S
2
O
3
2-
formations compared to the 1-bioreactor line-up. When the microbial community adapted over time, it was observed that SO
4
2-
formation further decreased. In addition, chemical formation of S
2
O
3
2-
was reduced due to biologically mediated removal of sulfide from the process solution in the anaerobic bioreactor. The increased selectivity for S
8
formation will result in 90% reduction in caustic consumption and waste stream formation compared to the 1-bioreactor line-up.
AB -
In the biotechnological desulfurization process under haloalkaline conditions, dihydrogen sulfide (H
2
S) is removed from sour gas and oxidized to elemental sulfur (S
8
) by sulfide-oxidizing bacteria. Besides S
8
, the byproducts sulfate (SO
4
2-
) and thiosulfate (S
2
O
3
2-
) are formed, which consume caustic and form a waste stream. The aim of this study was to increase selectivity toward S
8
by a new process line-up for biological gas desulfurization, applying two bioreactors with different substrate conditions (i.e., sulfidic and microaerophilic), instead of one (i.e., microaerophilic). A 111-day continuous test, mimicking full scale operation, demonstrated that S
8
formation was 96.6% on a molar H
2
S supply basis; selectivity for SO
4
2-
and S
2
O
3
2-
were 1.4 and 2.0% respectively. The selectivity for S
8
formation in a control experiment with the conventional 1-bioreactor line-up was 75.6 mol %. At start-up, the new process line-up immediately achieved lower SO
4
2-
and S
2
O
3
2-
formations compared to the 1-bioreactor line-up. When the microbial community adapted over time, it was observed that SO
4
2-
formation further decreased. In addition, chemical formation of S
2
O
3
2-
was reduced due to biologically mediated removal of sulfide from the process solution in the anaerobic bioreactor. The increased selectivity for S
8
formation will result in 90% reduction in caustic consumption and waste stream formation compared to the 1-bioreactor line-up.
U2 - 10.1021/acs.est.8b06749
DO - 10.1021/acs.est.8b06749
M3 - Article
C2 - 30882225
AN - SCOPUS:85064330517
SN - 0013-936X
VL - 53
SP - 4519
EP - 4527
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 8
ER -