Related by context. Frequent words. (Click for all words.) 66 biomass 59 fossil fuels 57 biofuels 56 fossil fuel 55 Biomass 55 bio fuels 54 feedstocks 54 cleaner fuels 53 alternative fuels 53 biofuel 53 feedstock 53 renewable 53 wood pellets 52 renewable fuels 52 fuels 52 renewable energy 52 switchgrass 51 bioenergy 51 cellulosic 50 biogas 50 cleaner burning 50 liquid fuels 50 coal gasification 50 alternative energies 49 wood burning stoves 49 wood chips 49 renewable energies 49 renewables 48 biofuel crops 48 corn ethanol 47 wood stoves 47 stoves 47 IGCC 47 syngas 46 cellulosic ethanol 46 gasification 46 biodiesel 46 bio diesel 45 petroleum coke 45 bio ethanol 44 coal fired 44 Renewable 44 Biogas 44 boilers 44 coal 44 internal combustion engines 44 ethanol 43 cogeneration 43 combustion 43 Renewable energy 43 briquettes 43 Biofuel 43 synthetic fuels 43 anaerobic digestion 43 furnaces 43 Lithium ion batteries 42 wood pellet 42 bioethanol 42 carbon sequestration 42 poultry litter 42 Renewables 42 vegetable oils 42 carbon capture 42 coal combustion 41 Biofuels 41 compact fluorescent bulbs 41 incandescent bulbs 41 incinerators 41 distillers grains 41 incandescents 41 diesel engines 40 cellulose 40 woodchips 40 hydroelectricity 40 animal fats 40 biochar 40 CFLs 40 greenhouse gases 40 energy 40 electricity 40 biorefineries 40 greenhouse gasses 40 BTUs 40 charcoal 40 reducing carbon emissions 40 hydropower 39 Bioenergy 39 jatropha 39 compressed natural 39 lignite 39 photovoltaics 39 carbon dioxide emissions 39 incineration 39 sulfur coal 39 reduce carbon emissions 39 burning fossil fuels 39 organic fertilizers 39 baseload 39 natural gas 39 legumes 39 bioplastics