Thermogravimetric Kinetics of Selected Energy Crops Pyrolysis

Round 1

Reviewer 1 Report

I read carefully the manuscript entitled ‘Pyrolysis Kinetics of Selected Energy Crops submitted to Energies. Authors have compared pyrolysis kinetics by selecting three types of energy crops namely Miscanthus giganteus, Sida hermaphrodita and Sorghum Moench. They have checked three different heating rates and checked the performance using TGA and DTG curves. The kinetic parameters were investigated using the non-linear regression assuming that thermal decomposition proceeds via three parallel independent reactions of n-th order. The concept is novel and suitable to publish in Energies however, there are many lacking points, need substantial major revision before to publish. 1) Title need to modify which can describe whole research work. 2) In abstract authors should put the obtained result values. Add one or two sentences describing the importance of research work. Add one or two energy cropsname in keywords. 3) Line no 29-30 sentence give suitable reference; ln. 30 ‘energy’ elaborate this. Ln. 36 mentions not only liquid but also gaseous fuels. Ln no 39 no need of this sentence. 4) In this manuscript there are many many paragraphs which is not good author should make very few paragraphs throughout the manuscript. The Unit style should be similar everywhere and firstly describe the full form somewhere before using abbreviation. The table no and Fig no are not correct which indicate carelessness of Authors should avoid such kind of mistakes. 5) In the introduction section, write the novelty of the work and the problem statement clearly. 6) Importance of selected crops used in this study detailed explanation is missing. 7) In Material and Methods section Source of energy crops give details. In Analytical methods section give detailed methodologies only citing reference is not sufficient 8) Statistical analysis of the results should be provided in the materials and methods section. Its important for all experimental work Report these values in the results and discussion. 9) Ln 153 change ‘present’ to ‘represent’. Fig 1 need to redraw so that readers can easily differentiate the results. 10) One comparative table which can compare obtained results with literature is highly recommended. 11) The conclusion of the study is not discussed with the specific output obtained from the study, it could be modified with precise outcomes with a take home message. 12) Write the practical applications and future research perspectives of this work before conclusions 13) Overall the manuscript well written however there are, many English and grammar mistakes are present author should check the manuscript by native English Speaker to improve the quality of the manuscript.

Author Response

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Reviewer 2 Report

This manuscript compared pyrolysis kinetics of three types of energy crops: Miscanthus giganteus, Sida hermaphrodita and Sorghum Moench by TGA and DTG. Activation energy and pre-exponential factor were estimated by Friedman and Ozawa-Flynn-Wall methods. However, there are some comments need to be addressed before further proceeding. 

 

 

1. The authors need to revise the grammar and English style so that it is easy to understand. 
2. While the authors were trying to develop kinetic models for the pyrolysis, explanations should be given to the mass transfer issue too. For example, the char or tar may cover on the biomass feedstock surface and may affect the kinetic. 
3. Figure 3 is not clear, please redraw the colors, symbols, labels and legends.
4. There are two Figure 2. Please check!
5. In Line 323, it mentioned Figure 5. Where is Figure 5?
6. The author used peak deconvolution to separate the peaks of lignin, hemicellulose and cellulose. However, can the author perform the TGA analysis on the separated lignin, hemicellulose and cellulose alone to further verify the conclusion?

Author Response

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Reviewer 3 Report

In this article, the authors studied pyrolysis kinetics of three energy crops. Although, similar studies have been reported previously in the literature, the authors attempt to fit TGA data using various models for three specific energy crops are novel. The results found in the paper are adequate. The introduction could be improved by comparing introducing difference among the models and kinetics study previously performed for other materials e.g., https://doi.org/10.1002/ep.12907. 

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Reviewer 4 Report

In this paper, the kinetics of pyrolysis of three different feedstock was investigated applying both the isoconversional method and non-linear regression methods. The results were properly described and only minor aspects, listed below, require to be revised before the publication on Energy.

1. The results of TGA analysis revealed different decomposition peaks for the three feedstocks, which was ascribed to their different composition. In order to assure an easier comprehension of the results, the authors should provide a table with the composition and the relative content of hemicellulose, cellulose and lignin in the feedstock.
2. It is suggested to split Eq. 8 into three separate equations.
3. The quality of Fig. 1, 2 and 3 should be improved as well as the discussion of the results related to Fig. 1 and 2.
4. Did you try to perform an analysis on the gaseous stream exiting from TGA analyser (for example, via mass spectrometer)?
5. Figure 5 (line 323) is absent in the text. Is it an error?

Author Response

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Round 2

Reviewer 2 Report

The authors have addressed my comments and improved the quality of the paper. I suggest it to be accepted in its current form.