It's so unfortunate, the sad thing is, most Africans (Nigerians) included, do not really know the economic situations of this countries, Economically, Brazil is not that better off than Ghana but they just assume anywhere is better than their current situation back home.
Unfortunately, it's almost too late by the time they realise this, they end up being stranded and not even able to feed themselves.
Even if they are granted Asylum, which I very much doubt, where is the employment in Brazil?!
It's widely documented that over half the population lives below the poverty line.
Trust me, they will soon realise it's a bad move. Feel for them though.

1 July 2014:  maintenance for Tier 4 applicants and their dependants

The required maintenance will increase for Tier 4 applicants and their dependants, for applications made on or after 1 July 2014.  The Home Office has explained that this early notice will allow applicants enough time to arrange any extra money now required.

At the same time, the maximum deduction from the required maintenance will increase from £1000 to £1020.  This deduction can only be applied for money paid to the Tier 4 sponsor for accommodation fees in university-managed housing.

The new monthly figures for Tier 4 applicants their dependants are as follows. In most cases, you will need to show up to 9 months’ worth of funds, so multiply the figure by 9.  If you have “established presence”, you can show up to 2 months’ worth of funds, so you would multiply the figure below by 2.

Please visit the site below for more info:

http://www.ukcisa.org.uk/studentnews/231/Changes-to-the-immigration-rules

All passengers flying into or out of the UK are being advised to ensure electronic and electrical devices in hand luggage are sufficiently charged to be switched on Extra security checks.
Passengers with uncharged devices face having to cancel or re book their flights.

Your HND qualification definitely meets the requirements but I am sorry to let you know that Nigerian Nationals are NOT eligible for the 2015 diversity immigrant visa programme. According to its official website.