Bulgaria Exports of coke, semi-coke of coal, of lignite, of peat; retort carbon to Romania was US$13.01 Thousand during 2021, according to the United Nations COMTRADE database on international trade. Bulgaria Exports of coke, semi-coke of coal, of lignite, of peat; retort carbon to Romania - data, historical chart and statistics - was last updated on May of 2024.