| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1710907 | Biosystems Engineering | 2015 | 8 Pages |
•KOH pretreatment for wheat straw including black liquor recycling was investigated.•Water and KOH consumption were reduced by 75% and 25% with recycling.•Pretreatment with black liquor recycling reached steady state after five batches.•Higher sugar and CH4 yields were obtained compared to raw straw treated with liquor.
A pretreatment process for wheat straw using potassium hydroxide (KOH) and recycled black liquor as a treatment reagent was developed and the minimum fresh chemical and water requirement were determined. Black liquor recycling in the pretreatment process resulted in a 75% reduction in fresh water use and 25% in KOH use, when compared to no recycling. It was found that after five batches of treatment, the concentrations of reducing sugar, chemical oxygen demand (COD), and K+ in black liquor, reached stable levels. During the pretreatment with black liquor recycling, 32–35% lignin was reduced in wheat straw. The pretreated straw showed reducing sugar yield of 336–366 mg g−1 [total solid (TS)] and methane yield of 290–303 mg g−1 [volatile solid (VS)] when subjected to enzymatic hydrolysis and anaerobic digestion, respectively.
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