The woman, 47 from Almassora, may have fallen behind on her mortgage and was led to desperate measures after not being able to negotiate with the lender, thinkSPAIN reported.
Her friends said the bank was about to foreclose on her mortgage.
She was heard screaming "you've taken everything from me, I've lost everything because of you" before pouring the liquid on herself on Sunday, thinkSPAIN said.
She is separated from her spouse, has three dependent children and is likely a lottery-ticket seller, thinkSPAIN said.
The woman was taken to the hospital where she was listed in critical condition after suffering burns to 48 percent of her body.