Short CommunicationLower pressure heating steam is practical for the distributed dry dilute sulfuric acid pretreatment

- Lower pressure heating steam was practical for dry dilute acid pretreatment.
- Lower inhibitors generated in pretreatment using lower pressure heating steam.
- High SSF performance was obtained for corn stover pretreated by lower pressure steam.
- Lower pressure heating steam caused shorter mixing time during pretreatment.

Most studies paid more attention to the pretreatment temperature and the resulted pretreatment efficiency, while ignored the heating media and their scalability to an industry scale. This study aimed to use a relative low pressure heating steam easily provided by steam boiler to meet the requirement of distributed dry dilute acid pretreatment. The results showed that the physical properties of the pretreated corn stover were maintained stable using the steam pressure varying from 1.5, 1.7, 1.9 to 2.1 MPa. Enzymatic hydrolysis and high solids loading simultaneous saccharification and fermentation (SSF) results were also satisfying. CFD simulation indicated that the high injection velocity of the low pressure steam resulted in a high steam holdup and made the mixing time of steam and solid corn stover during pretreatment much shorter in comparison with the higher pressure steam. This study provides a design basis for the boiler requirement in distributed pretreatment concept.

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