All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
The blood that is spilled out is impure, and there is no difference of opinion in regard to the prohibition of selling it.
Abu Juhayfah, may Allah be pleased with him, narrated, “The Messenger of Allah forbade the price of blood, and the price of a dog...”
The Fiqh Academy of the Muslim World League has resolved at its eleventh session held in Makkah (13-20 Rajab 1409 AH) that, “It is not permissible to take a compensation for blood or to sell blood because blood is among the prohibitions stated in the text of the Quran along with the meat of dead animals and pork; so it is not permissible to sell it and take a compensation for it.”
Therefore, it is not permissible for you to sell blood, even if with the intention of getting rid of its price by giving it in charity to the poor and needy.
A permissible objective does not justify the unlawful means, as has been determined by the scholars.
Allah knows best.