Comments on Abstract, title and references

● The aim of paper is predicting the performance of an industrial reactor by simulation to use computational fluid dynamics method. The abstract section clears this aim. ● It is clear and the study predicted the reactor conversion behaviour of several process variables such as pressure, temperature, velocity and concentration of components through the reactor used by computational fluid dynamics via simulation.
● The title of paper is informative and relevant ● The references of paper are often relevant. ● The references of paper are often recent. ● The references are corrected referenced. ● All the key studies are appropriate.

Comments on Introduction/ background

● The topic of this paper is a simulation of production of the vinyl chloride monomer by thermal cracking in a tubular reactor immersed in a furnace by using computational fluid dynamics method and this topic is clear in the abstract section. ● The question of this research is clearly outlined in the introduction section. ● The question of the research is justified that the most of the works on CFD aim to describe the phenomena occurring in the furnace, not approaching in more detail inside the reactor. The already known about the topic is CFD simulations of the furnace-reactor but are not approaching in more detail inside the reactor.

Comments on methodology

● The process of subject selection is clear. ● The variables such as pressure, temperature, concentration and velocity of the reactor did not defined and measured appropriately. ● The used method of this study is a CFD of reactor via simulation depend on the mathematical model under the assumptions and this method is often valid and reliable. ● The details of the methodology are not enough to replicate the study especially the CFD method.

Comments on data and results

● The data presented in an appropriate way. ● Tables and figures are relevant and clearly presented. ● Units, rounding, and number of decimals are appropriated. ● Titles, columns, and rows are labelled correctly and clearly. ● The Categories are grouped appropriately. ● The text in the results is added to the data. ● The statistically significant of the results are clear. ● The practically meaningful of the result is clear.

Comments on discussion and conclusions

● The results are discussed in good written and it appears clearly the reactor conversion behaviour of several process variables such as pressure, temperature, velocity and concentration of components by CFD. ● The conclusions answer the aims of the study. ● The conclusions supported by results with comparison with EDC plant in Brazil. ● The limitations of the study and the condition are appropriately and they give the opportunities to inform future research.

Overall

• The aim of this study is a computational fluid dynamics (CFD) to predict the performance of an industrial reactor via simulation and it is designed appropriate to answer this aim. • As a contribution of this work, a new treatment for the wall boundary condition was proposed and successfully implemented in order to eliminate the mesh in the tube wall. The heat transfer model used to represent the heat supplied by the furnace, implemented as a wall boundary condition, has been shown to be adequate for modelling the EDC cracking reactor with the advantage of low computational cost. • The already known on this topic is the CFD to describe the phenomena occurring in the furnace not approaching in more detail inside the reactor. • The major flaws of this article are methodology of CFD is not clear and the steps of solutions are required to more discussion. • The article is good written and it consistent within itself.

Overall statement or summary of the article and its findings in your own words

I have now completed my review of the paper. The paper presents the studying the production of the vinyl chloride monomer which it is commercially produced on a large scale by thermal cracking in a tubular reactor immersed in a furnace by using the computational fluid dynamics (CFD) to simulate and predict the performance of an industrial reactor. The references are often relevant and recently. The CFD of reactor via simulation depend on the mathematical model under the assumptions is valid and reliable. The results data are presented in an appropriate way, the statistically significant and the practically meaningful of the result are clear. The results are discussed in good written. The conclusions answer the aims of the study and it supported by results with comparison with EDC plant in Brazil. The limitations of the study and the condition are appropriately and they give the opportunities to inform future research. Finally, the paper is good written.

Overall strengths of the article and what impact it might have in your field

The overall strengths of this article are the following: 1. A new treatment for the wall boundary condition was proposed and successfully implemented in order to eliminate the mesh in the tube wall. 2. The heat transfer model used to represent the heat supplied by the furnace, implemented as a wall boundary condition, has been shown to be adequate for modelling the EDC cracking reactor with the advantage of low computational cost. 3. The study predicted the reactor conversion behaviour of several process variables such as pressure, temperature, velocity and concentration of components through the reactor used by computational fluid dynamics via simulation.
The impact it might have in my field are the following: ● The mathematical model of the tubular reactor at different variables. ● The CFD simulation of the reactor. ● The effects of various conditions on the reactor performance.

Specific comments on weaknesses of the article and what could be done to improve it

Major points in the article which needs clarification, refinement, reanalysis, rewrites and/or additional information and suggestions for what could be done to improve the article.

1. The methodology of CFD is required more discussions.
2. The steps of solutions of simulation are required to more clear.
3. The effects of different conditions on the design of reactor and production must be addition to the article.
4. Studying the effects of changing of reactor specifications.

Minor points like figures/tables not being mentioned in the text, a missing reference, typos, and other inconsistencies.

1. The figures and tables of the effects of different conditions on production must be addition to the article.
2. The discussions of results and conclusions must be supported with references .