Novel Agglomeration Strategy for Elemental Sulfur Produced during Biological Gas Desulfurization

Annemerel R. Mol, Derek J.M. Meuwissen, Sebastian D. Pruim, Chenyu Zhou, Vincent Van Vught, Johannes B.M. Klok, Cees J.N. Buisman, Renata D. Van Der Weijden*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

7 Citations (Scopus)


This article presents a novel crystal agglomeration strategy for elemental sulfur (S) produced during biological desulfurization (BD). A key element is the nucleophilic dissolution of S by sulfide (HS-) to polysulfides (Sx2-), which was enhanced by a sulfide-rich, anoxic reactor. This study demonstrates that with enhanced Sx2- formation, crystal agglomerates are formed with a uniform size (14.7 ± 3.1 μm). In contrast, with minimal Sx2- formation, particle size fluctuates markedly (5.6 ± 5.9 μm) due to the presence of agglomerates and single crystals. Microscopic analysis showed that the uniformly sized agglomerates had an irregular structure, whereas the loose particles and agglomerates were more defined and bipyramidal. The irregular agglomerates are explained by dissolution of S by (poly)sulfides, which likely changed the crystal surface structure and disrupted crystal growth. Furthermore, S from Sx2- appeared to form at least 5× faster than from HS- based on the average Sx2- chain length of x ≈ 5, thereby stimulating particle agglomeration. In addition, microscopy suggested that S crystal growth proceeded via amorphous S globules. Our findings imply that the crystallization product is controlled by the balance between dissolution and formation of S. This new insight has a strong potential to prevent poor S settleability in BD.

Original languageEnglish
Pages (from-to)27913-27923
Number of pages11
JournalACS Omega
Issue number42
Publication statusPublished - 26 Oct 2021


Dive into the research topics of 'Novel Agglomeration Strategy for Elemental Sulfur Produced during Biological Gas Desulfurization'. Together they form a unique fingerprint.

Cite this