Amid growing global concern about the overuse of plastic, Austria’s oil and gas group OMV and Austrian Airlines have partnered to turn the plastic cups the airline’s passengers have used into synthetic crude that could be later processed into fuels or other plastic products. OMV said on Friday that it had started to process used plastic disposable cups from Austrian Airlines into synthetic crude at a pilot plant that uses a process known as thermal cracking. OMV’s ReOil pilot plant heats the plastic to over 400 degrees Celsius,…