Chlorophyll does not change into fresh blood in the body
Very little or no chlorophyll is absorbed through our digestive wall and into the bloodstream. Chlorophyll is broken down into different end products during the digestion process, which starts in the mouth. Simply put, there is not a chance for it to be converted into fresh blood.
As chlorophyll breaks down, its phytol tail—part of chlorophyll's structure— is freed, but only about 1% of the ingested chlorophyll phytol is absorbed by humans. Furthermore, studies show that only a very small portion of the non-phytol portion of the chlorophyll molecule is absorbed. You can see the two studies at these links: "Absorption of chlorophyll phytol in normal man and in patients with Refsum's disease" and "Absorption of phytol from dietary chlorophyll in the rat."
It is also thought that the fact chlorophyll is a fat-soluble pigment accounts for its poor absorbency in the body.