There is no reason to even use FontAwesome in anyway for this. Just do what you said, which is create the images you want to use as icons (ex. images/icon-new.png) and insert them as plain images like so...
<li class="element_fade_in">
<img src="images/icon-new.png class="icon-wrench">
<h5>Airdrop</h5>
<p>We tackle business problems with intelligence. We use cutting-edge tech and cutting-edge thinking to bring.</p>
</li>
then use the CSS class (icon-wrench for the example given) you used to position it properly and change sizes.