Related by context. Frequent words. (Click for all words.) 61 fossil fuel 60 nonrenewable resources 60 fossil fuels 58 exhaustible 58 biodiesels 58 nonrenewable resource 56 nonpetroleum 56 gaseous fuels 56 Fossil fuels 55 petroleum byproducts 55 fluorocarbons 54 replenishable 54 Coal gasification 54 renewable feedstocks 53 hydro carbons 53 polluting fossil fuels 53 fuels 52 petroleum 52 biofuels 52 fracturing fluids 52 liquid fuels 52 diesel fuel 52 environmentally beneficial 52 Renewable fuels 52 petro diesel 51 biomass geothermal 51 bio fuels 51 Tar sands 51 finite resource 51 metal hydrides 51 lignocellulosic biomass 51 hydrocarbon fuels 51 petrochemical feedstocks 50 WVO 50 algal biomass 50 cellulose ethanol 50 fuel 50 potent greenhouse gas 50 biomass combustion 50 reciprocating engines 50 nonrenewable 50 alternative fuels 50 Burning fossil fuels 50 Methyl bromide 49 Carbon sequestration 49 biomass 49 biocrude 49 sugarcane bagasse 49 agricultural residues 49 energy 49 liquefied coal 49 biomass feedstock 49 Pyrolysis 49 oxidiser 49 Fischer Tropsch process 49 renewable 49 natural gas 49 backsheets 49 electrolyzers 49 biofuel 49 Sulfuric acid 48 Biobutanol 48 kerogen 48 sodium borohydride 48 petroleum distillates 48 reinjection 48 petrochemical feedstock 48 B# biodiesel [002] 48 reverse osmosis desalination 48 cellulosic feedstocks 48 desalinization plants 48 cellulosic feedstock 48 methane CH4 48 CO2 sequestration 48 petcoke 48 depletable 48 alternative energies 48 distillers dried grains 48 thermochemical 48 nitrogenous 48 biomass fuels 48 cellulosic materials 48 elemental sulfur 47 EROI 47 adipic acid 47 feedstocks 47 agrofuels 47 biofuel feedstocks 47 gaseous emissions 47 hydrogen 47 feedstock 47 digestate 47 inorganic fertilizers 47 gas 47 oil 47 decarbonization 47 biodiesel feedstock 47 crop residues 47 Liquefied petroleum gas 47 reactants 47 hydrocarbon liquids