Improvement of Higher Heating Value and Hygroscopicity Reduction of Torrefied Rice Husk by Torrefaction and Circulating Gas in the System
Round 1
Reviewer 1 Report
The authors have demonstrated The Improvement of higher heating value and hygroscopicity reduction of torrefied rice husk by torrefaction and circulating gas in the system". Some questions in this manuscript have to be solved.
1. Seem some researchers already used the torrefaction process, please provide evidence novelty of this research.
2. On the schematic diagram of Figure 1, provide the temperature inlet and outlet T1-T4 beside the different experimental temperatures (200-320oC)
3. What is the authors want to explain with the statement on lines 255-256 the original heat value of the rice husk biomass sample increased from 15.65 (RH) to 23.69 (RH-T320, RT30) MJ/kg [31]” refer to the reference of 31?
4. Which one is wrong the figure 4 or the statement in lines 311 to 313? How about the EMC content related to this figure and what is the standard amount of the EMC
5. Does the author do the different experimental temperatures (200-320oC) without the torrefaction process, as a control and compared the result with the torrefaction process?
Author Response
Response to Reviewer 1 Comments
Point 1: Seem some researchers already used the torrefaction process, please provide evidence novelty of this research.
Response 1: This study aimed to enhance the thermal characteristics of rice husk biomass through torrefaction conducted in a fixed-bed reactor. A novel approach was employed by circulating the gas produced within the system instead of using traditional nitrogen. (in lines 10-12)
Point 2: On the schematic diagram of Figure 1, provide the temperature inlet and outlet T1-T4 beside the different experimental temperatures (200-320oC)
Response 2:
T1- used to control the infrared heater for the reactor.
T2-T4 is used to read time the temperature in the system.
Point 3: What is the authors want to explain with the statement on lines 255-256 the original heat value of the rice husk biomass sample increased from 15.65 (RH) to 23.69 (RH-T320, RT30) MJ/kg [31]” refer to the reference of 31?
Response 3: The torrefaction process improves the higher heating value of the rice husk biomass sample increased from 15.65 (RH) to 23.69 (RH-T320, RT30) MJ/kg [31], as a reference, the higher heating value by torrefaction microwave process.
Point 4: Which one is wrong the figure 4 or the statement in lines 311 to 313? How about the EMC content related to this figure and what is the standard amount of the EMC
Response 4: Equilibrium Moisture Content is an experiment to determine the hygroscopic value. Based on research at the laboratory at a temperature of 25 C and humidity of 55, and write a description of Figure 4 (in line 312-319).
Point 5: Does the author do the different experimental temperatures (200-320oC) without the torrefaction process, as a control and compared the result with the torrefaction process?
Response 5: The torrefaction process was conducted at 200 240 280 320 C and the temperature control infrared heater method was used according to the experimental plan. (in lines 132-157) with Torrefaction processes.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper discusses the interesting results on the biomass torrefaction. Thye torrefaction can significantly improve the properties of biomass for futher usage, and the goal of the paper meets the researchers' focuses. The paper is in scope of the Journal and can be published after some revision. Below, the author can find some issues to be revised before the publication.
1) I recommend the authors to check English. Some of sentences should be corrected to clarify the authors' statements. i.g. page 2 line 117-118.
2) Please add the results for the raw rice husk in Fiogures 2-4 to evaluate the effectiveness of the biomass torrefaction.
3) Page 7 lines 230-239. The description of the results does not match the Fig. 2. Authors stated that 93wt% of yield was obtained at 200 C for 30 min, but in Fig 2C this value is sufficiently lower. Please check it.
4) Authors repeate the torrefaction conditions too often in the Results and discussion section. It is enough to give the description once.
5) Some discussion on the influence of torrefaction temperature and residence time on the HHV and hydrophobicity are needed to be added. Please describe any chemical processes taking place during the torrefaction. What biomass components are destructed, what is the desrtuction mechanisms etc.?
Author Response
Response to Reviewer 2 Comments
Point 1: I recommend the authors to check English. Some of sentences should be corrected to clarify the authors' statements. i.g. page 2 line 117-118.
Response 1: Recheck english and writing sentences should be corrected to clarify. (line 111-118)
Point 2: Please add the results for the raw rice husk in Fiogures 2-4 to evaluate the effectiveness of the biomass torrefaction.
Response 2: Add results for the raw rice husk in Figure 2 (A,B,C)
Point 3: Page 7 lines 230-239. The description of the results does not match the Fig. 2. Authors stated that 93wt% of yield was obtained at 200 C for 30 min, but in Fig 2C this value is sufficiently lower. Please check it.
Response 3: Recheck again, and edit solid yield of 85.0 wt% (in line)
Point 4: Authors repeate the torrefaction conditions too often in the Results and discussion section. It is enough to give the description once.
Response 4: Check and adjust according to the reviewer.
Point 5: Some discussion on the influence of torrefaction temperature and residence time on the HHV and hydrophobicity are needed to be added. Please describe any chemical processes taking place during the torrefaction. What biomass components are destructed, what is the desrtuction mechanisms etc.?
Response 5: Check and adjust according to the reviewer, offer torrefactoin process. (in line 226-239)
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Refer to my review on points 1, 3, and 4 please the author provide a table of the higher heating value and hygroscopic value that the authors obtained compared to the other research.
Author Response
Comments and Suggestions for Authors: Refer to my review on points 1, 3, and 4 please the author provide a table of the higher heating value and hygroscopic value that the authors obtained compared to the other research.
Response 1: A novel approach was employed by circulating the gas produced within the system instead of using traditional nitrogen (in lines 11-12).
Response 3,4: And add data higher heating value in Figure 2 (lines 254-256), and hygroscopicity in Figure 3 (lines 266-269), and write an explanation and reference.
