No. The main cost is hotel costs, hall hire etc. Otherwise, hold your own conference in Cairo, offering accommodation in student residences outside of the academic year. Or investigate webinars.
I haven't heard of free conferences. I know that some funding agencies and academic institutions offer some grants (transportation/rent/conference fee - full or discount) for some researchers who fall under their bracket.
Free conferences are very rare, and they are usually sponsored by governments. In 2017, there was a free of registration charge energy conference in India, but, of course, the free is only the registration of the conference, while you have to pay for the accommodation, and travel. In that sense, you will not find an absolutely free of charge conferences.