For example, it was reported in a literature [11] that even 9.3 ppmv of
naphthalene could reduce the solid oxide fuel cell (SOFC) performance,
although other works reported that SOFCs with Ni/
gadolinium-doped ceria anodes were unlikely to suffer from carbon
deposition with increasing steam content of syngas [12,13]. Tar
removal can be accomplished by the treatment of tar inside a
gasifier (primary method) and/or by applying tar removal equipment
after a gasifier (secondary method) [14]. The secondary
method has been demonstrated to have a positive effect on tar
removal, but it is generally considered uneconomical due to the
high initial installation and operating costs of equipment. In order
to economically remove tar, the primary method has priority