Related by context. Frequent words. (Click for all words.) 66 environmentally friendly 65 environmentally sound 61 ecologically sound 60 environmentally sustainable 59 environmentally responsible 58 ecologically friendly 56 environmentally damaging 56 environmentally harmful 55 economical 54 ecofriendly 54 environmentally 53 eco friendly 52 nonpolluting 50 nontoxic 50 environmentally preferable 50 efficient 50 ecologically sustainable 49 biomass 49 desalinization 49 fossil fuels 49 environmentally friendlier 49 organic solvents 49 sustainable 48 biodegradable 47 Gasification 47 renewable 47 biocide 47 alternative energies 47 biobased 47 environmentally conscious 47 bio degradable 47 environmental impacts 47 proton exchange 46 economically viable 46 economically feasible 46 degradable 46 gasification 46 polluting 46 ecologically 46 bioremediation 46 Fischer Tropsch 46 coal gasification 45 cellulosic biomass 45 renewable energy 45 environmentally sensitive 45 biobutanol 45 environmentally destructive 45 nanomaterials 45 geo thermal 45 biodegradable plastics 44 feedstocks 44 bio fuels 44 syngas 44 feedstock 44 nanomaterial 44 thorium 44 cleaner 44 Lithium ion 44 Cellulosic ethanol 44 biogas 44 hydrogen 44 commercially viable 44 biomass fuels 44 alternative fuels 44 supercritical 43 cleaner greener 43 Thorium 43 oxidant 43 fossil fuel 43 pollute 43 liquid fuels 43 synthetic fertilizers 43 crop residues 43 Eco friendly 43 internal combustion engines 43 renewable energies 43 water soluble 43 organic compounds 43 Biomass 43 bioplastic 43 biofuels 43 solar cells 43 cleaner fuels 43 contaminate groundwater 42 woody biomass 42 efficacious 42 landfilling 42 byproducts 42 catalysis 42 solvents 42 biopolymers 42 electrochemical 42 anaerobic digestion 42 pyrolysis 42 hydrocarbon fuels 42 cleaner burning 42 antimicrobials 42 alternatives 42 integrated gasification 42 inexpensive 42 combustion