The present study is an observational study of bibliographical character and international scope where the time frame has been the period 2015-2021. The study units were the scientific articles directly related to the processes of CLC in the capture of CO2, with racs and bagasse of sugar cane, published in any scientific journal of a period indexed in the Scopus database, carrying out a generic search strategy to recover the largest possible number of references published in each autonomous community during the study period.
The following search criteria were used for this purpose: 'chemical looping combustion', 'carbon dioxide capture', 'manganese-based 'and 'oxygen carrier'.
Then each of the documents recovered was manually reviewed, excluding those that did not correspond to the CLC and CO2 capture, based on the information contained in the title, abstract and affiliation data.
In each of the records obtained, the following variable quantity were collected: title of the journal, year of publication, surnames and initials of the first and last author, institution or place of work of the signatory primer and autonomous community.
Subsequently the articles were basified the following sources; Energy and fuels, Applied energy, biofuel, International Yearbook of Green Energy and Gas, Yearbook of Chemical Engineering, Biotechnology for Biofuels, Energy and Energy Technology, Research in Industrial and Engineering Chemistry.
In cases where more than one institution was mentioned, the item was assigned to the one in the first place and documents that have few research matches were rejected, as illustrated in Figure 1.
By means of the criteria of use, 475 papers were recovered in the six-year period 2015-2021, excluding 2162 because their affiliation did not correspond to centers institutions directly related to documents related to the CLC and CO2 capture. In total, 212 documents were selected, and 10 different authors were identified as shown in Figure 2.
In Figure 3, the various percentages of the analysis of the documents by area of study are indicated, in Energy 125 journals were found (25.5%), in Chemical Engineering 107 journals were found (21,8%), in Environmental Science 81 (16,5%), In Chemistry 74 (15,1%),in Engineering 71 (14.5%), Physics and Astronomy 12 (2,4%),in Materials Sciences 10 (2.0%), in Biochemistry, Genetics and Molecular Biology 5 (1.0%), Agricultural and Biological Sciences 2 (0, 4%), and in other documents 4 (0,6 %).
When analyzing the documents by year, between the period of 2015 and 2021 the first five years there were more publications, being in the 2015 and 2020 where they disseminated 40 and 44 articles respectively reaching the highest points. In the year 2019 there is a decrease in the number of publications to 26, but without minimizing its importance, that even by 2021 there are already 9 articles related to the processes of CLC and CO2 capture (Figure 4).
We identified 23 studies related to Energy and Fuels between 2015 and 2020, being the maximum relevant investigate source, while in the area of Chemical, Industrial and Engineering Research, only 6 sources were found, as shown in Figure 5.
When searching the documents according to affiliation it was determined that in the country of China is where a greater number of publications have been published finding 71 investigations being the Chalmer University of Technology of China where they have carried out the largest number of studies. In the case of South America, 3 scientific journals disseminated in the country of Brazil were identified, being in the Institute of Energy and Fuels where they have studied in greater depth, determining that studies related to the process of manganese transporters is little investigated (Figure 6). Considering that the country of China has the largest number of studies, the most relevant authors are Abad, A; Linfelt, A and Adanez, J, as shown in Figure 7. To complement this analysis, it was determined that China, the United States and Spain are the countries where this study has the greatest relevance while in Iran there are only 7 publications during the period 2015 and 2021 (Figure 8).
Finally, we investigated the types of research carried out during the period of this bibliometric study, finding 170 articles (80.2%),24 reviews (11.3%), 10 documents of book chapters (4,7%), conference articles 7 (3,3 %) and 1 retracted (0,5%) as shown in Figure 9.
In the following active map of the CLC process, CO2 capture, with rac biomass from sugarcane. At the national and international level, it was detected, from the correlation when using the carbon dioxide word in most cases, the grouping when publishing of several authors. The green dot carbon dioxide), the largest, is in relation to each author publishing a large number of articles. Twenty-four articles have been considered in this study that, in addition, is not closed, marked on the active map with a different color (Figure 10). For a greater understanding of the identification of the networks academics, has proceeded to establish the results through Vos’s viewer identify the groupings or cluster.
One of the most widely used methods for CO2 capture developments with sugarcane races has been chemical reactors, CLC (Figure 11). To indirect combustion with solid oxygen transporters (Chemical Looping Combustion - CLC), is an energy efficient alternative for capturing CO2, as it is a technology with inherent separation of CO2 through the use of solid oxygen conveyors ‐ TOs (metal oxides). [11]
Whereas CLC technology uses oxygen transporters, which are basically metal oxides of copper, nickel, manganese, iron or cobalt, based on an inert species acting as a porous matrix, gives surface area and mechanical resistance to the transporter in the capture of CO2, figure 12 illustrates that this process and is broadly related to this reaction[12].