id	keyword
american_scientific_journal-7884	biogas
american_scientific_journal-7884	technology
american_scientific_journal-7884	research
american_scientific_journal-7884	energy
american_scientific_journal-7884	university
american_scientific_journal-7884	vol
american_scientific_journal-7884	doi
american_scientific_journal-7884	engineering
american_scientific_journal-7884	digester
american_scientific_journal-7884	study
american_scientific_journal-7884	biogas technology
american_scientific_journal-7884	data
american_scientific_journal-7884	journal
american_scientific_journal-7884	sciences
american_scientific_journal-7884	analysis
american_scientific_journal-7884	academic
american_scientific_journal-7884	volume
american_scientific_journal-7884	asrjets
american_scientific_journal-7884	no1
american_scientific_journal-7884	process
american_scientific_journal-7884	american
american_scientific_journal-7884	monitoring
american_scientific_journal-7884	countries
american_scientific_journal-7884	methane
american_scientific_journal-7884	anaerobic
american_scientific_journal-7884	total
american_scientific_journal-7884	operation
american_scientific_journal-7884	research journal
american_scientific_journal-7884	studies