Can I use Likert scale to convert the qualitative data obtained from the literature to quantitative ones and do the comparison of alternatives using AHP ?
It is relatively common to use some form of content analysis to convert qualitative data to quantitative, but this more often involves counting the frequency of codes rather that Likert scoring. If you do the latter, you will almost certainly need to have two or more coders to assess the inter-rater reliability of their scoring.
I agree you could consider quantitative content analysis, which usually involves following a coding scheme and counting code occurrences. You might find relevant tips in the following piece.
Li, Y., & Zhang, S. (2022). Qualitative data analysis. In Y. Li & S. Zhang, Applied research methods in urban and regional planning (pp. 149–165). Springer International Publishing. https://doi.org/10.1007/978-3-030-93574-0_8
the likert scale is more on the quantitative type of research or quantitative part for mixed method. However, you can describe or discuss or make use of the likert scale in the discussion as supporting analysis where you can clearly give your prescriptions