Although I don't know the plant, I would suggest to follow pulping procedures as they are used for banana leafs etc., e.g., https://www.tandfonline.com/doi/full/10.1080/15440478.2014.984060?casa_token=I0BpD71ZSC8AAAAA%3AFMBzmesd_zkOc1gV3NoP8ytFYhr7i_Pw7pjpejzDgLtJrGwpi8HGOx0rM1RcpzUCvTgt-KnwgPxT8A