If Ph Was Controlled During Fermentation Case Study

Response: “After sealing the bottle with a butyl rubber stopper and an aluminum crimp, the bottle was purged with pure nitrogen (for 10 min) to obtain anaerobic conditions.” This explanation is added to the revised manuscript. (Page 8, line 13-15)

Comment 14: Page 8: Explain if pH was controlled during fermentation. In any case, do a reference in the result section to the pH at the end of fermentation
Response: The pH was not directly controlled during the fermentation. In the line with typical studies conducted for ABE production, the medium was supplemented with buffer (50 g/L KH2PO4, 50 g/L K2HPO4, 220 g/L C2H3O2NH4) as an approach to control the pH changes during the fermentation. In addition, it has been reported that lignocellulosic
Comment 16: Page 11, line 17. …10.8% lignin…Acid soluble lignin? Acid insoluble lignin? Explain what type of lignin.
Response: This sentence is about acid insoluble lignin. “10.8% lignin” is corrected to “10.8% acid insoluble lignin” (Page 11, line 6).

Comment 17: Page 11, line 60: How was glucan removal determined?
Response: The glucan removal was calculated based on the amount of glucan before and after the pretreatment. For instance, using the pretreatment at 180 °C for 90 min, 100 g untreated SSB, containing 37.1 g glucan (wt% of glucan in untreated SSB), was pretreated to 43.4 g pretreated solid containing 27 g glucan (=43.4 g × glucan fraction of 62.5%). Therefore, the pretreatment resulted in removing 10.1 g glucan from 37.1 g glucan corresponding to 27% glucan removal.
Appreciating the comment, the definition of glucan removal, “, i.e., the reduction in the amount of glucan after the pretreatment,”, is added to the revised manuscript. (Page 11, line 23; Page 12,
Comment 1: This reviewer suggests that the authors should provide an analysis on the production cost based on unit mass of end products, taking subsequent separation and purification costs into account.
Response: Thank you for the comment. The techno-economic evaluation needs simulation and a preliminary process design and then economical evaluation. In the continuation of this work, we plan to do that.

Comment 2: Also, since the recycled acetone will not be pure, the pretreatment using recycled acetone should be tested to see the feasibility of the proposal.
Response:
After evaporation, only acetone together with some water is recovered; the solids, catalyst (sulfuric acid), and other stuff cannot be evaporated. Then 50 % v/v acetone-water solution can be made by adding the necessary water. In principle, as there are no more volatile components in the system, except acetone and water, we did not have any reason to redo the experiment with the recovered acetone. We will check it in the continuation of this