I think this is what you want. It only uses enough memory to hold the data from one element number. It assumes the file is already sorted by element number and not just sorted ascii-betically. The data will be sorted on column 1 and then on column 9.

use strict;
open (INFILE, "<filename") or die "could not open file";
open (OUTFILE, ">outfilename") or die "could not open outfile";

my $line = <INFILE>;
my @record = split " ", $line;
ELEMENT: while (defined $line) {
    my $element = $record[0];
    my @array;  
    push @array, [$line, $record[8]];
    while (1) {
        $line = <INFILE>;
        @record = split  " ", $line;
        if ($element == $record[0]) {
            push @array, [$line, $record[8]];
        }
        else {
            #sort using psudo-Schwartzian Transform
            @array = map {$_->[0]} 
                sort {$a->[1] <=> $b->[1]} 
                @array;
            print OUTFILE @array;
            next ELEMENT;
        }
    }
}
[download]

--

flounder