What is the ruling on the 23,0 Egyptian pounds remaining from selling the project and repaying the loan after taking 100,0 Egyptian pounds (half of which was a benevolent loan and half a partnership) from a person who bears the interest on his employment loan?

Usury (riba) is one of the gravest major sins, and your friend must repent from the usurious loan. You are not obligated to help him pay off the usurious interest, nor is he obligated to pay it off in the first place. Rather, he is only obligated to repay the principal amount of the loan. The loan does not affect the validity of the partnership between you if it fulfills its conditions. The profit between you is according to your agreement, and it is permissible to waive a share of the profit or part of it.