Can he pay money for kafaarat al-yameen because nowadays it is more beneficial than food?
Question

                Is it permissible for me to give money that is equivalent to the value of the food required for kafaarat al-yameen (expiation for breaking an oath)? Nowadays money is more useful, and one cannot find ten poor people at the same time.
Praise be to Allah.Giving money for kafaarat 
    yameen or kafaarat al-zihar (expiation for divorcing one’s wife by zihaar, 
    which is a jaahili form of divorce in which the husband says to his wife, 
    “You are to me as my mother’s back”) or for breaking one’s fast in Ramadaan 
    by having intercourse, instead of giving food, is not sufficient, even if 
    one thinks that money is more useful. Rather the person has to give food of 
    the type that he gives to his own family, whether it be wheat, dates, 
    barley, rice or whatever, because this expiation is an act of worship that 
    must be done in the manner enjoined by sharee’ah. There are many poor people 
    who will accept this food. The person who is obliged to offer expiation does 
    not have to distribute this food all at the same time, rather he may do it 
    in the way that is easiest for him. 

    From Fataawa al-Lajnah al-Daa’imah, 23/8 

    If a person cannot find ten poor people, or it is difficult 
    for him to give the expiation himself, then some charities can give the 
    kafaarah on behalf of people and give it to those who are entitled to it. 

    So he could pay the equivalent amount to a trustworthy 
    charity to distribute the kafaarah on his behalf. 

    And Allaah knows best.