id	keyword
cet-2970	lignin
cet-2970	reforming
cet-2970	iron
cet-2970	samples
cet-2970	microwave
cet-2970	mwr
cet-2970	particles
cet-2970	carbon
cet-2970	heating
cet-2970	surface
cet-2970	nanoparticles
cet-2970	wt.%