▁Kingdom , ▁Portugal , ▁Germany , ▁Brazil , ▁Argentina , ▁Japan ▁and ▁China ▁were ▁reported ▁to ▁have ▁tested ▁and ▁used ▁veget able ▁o ils ▁as ▁dies el ▁fu els ▁during ▁this ▁time . ▁Some ▁oper ational ▁problems ▁were ▁reported ▁due ▁to ▁the ▁high ▁vis cos ity ▁of ▁veget able ▁o ils ▁compared ▁to ▁pet role um ▁dies el ▁fuel , ▁which ▁results ▁in ▁poor ▁atom ization ▁of ▁the ▁fuel ▁in ▁the ▁fuel ▁sp ray ▁and ▁often ▁leads ▁to ▁depos its ▁and ▁c oking ▁of ▁the ▁inject ors , ▁comb ust ion ▁chamber ▁and ▁val ves . ▁Att empt s ▁to ▁overcome ▁these ▁problems ▁included ▁he ating ▁of ▁the ▁veget able ▁oil , ▁bl ending ▁it ▁with ▁pet role um - der ived ▁dies el ▁fuel ▁or ▁eth an ol , ▁py ro ly s is ▁and ▁crack ing ▁of ▁the ▁o ils . ▁ ▁On ▁ 3 1 ▁August ▁ 1 9 3 7 , ▁G . ▁Ch av anne ▁of ▁the ▁University ▁of ▁Br uss els ▁( Bel g ium ) ▁was ▁granted ▁a ▁pat ent ▁for ▁a ▁" Pro cedure ▁for ▁the ▁transformation ▁of ▁veget able ▁o ils ▁for ▁their ▁uses ▁as ▁fu els " ▁( fr . ▁" Proc édé ▁de ▁Trans formation ▁d ’ H u iles ▁V ég ét ales ▁en ▁Vue ▁de ▁Le ur ▁Util isation ▁comme ▁Car bur ants ") ▁Belg ian ▁Pat ent ▁ 4 2 2 , 8 7 7 . ▁This ▁pat ent ▁described ▁the ▁alco hol ysis ▁( o ften ▁referred ▁to