. Analytical methods
The ash content of the feedstocks and the products were
measured with a thermogravimetric analyzer (TGA, Q 500, TA
Instruments, USA) according to a National Renewable Energy Laboratory
Technical Report (NREL/TP-510-42622). Around 10 mg of
sample was loaded onto the pan, and the temperature of the furnace
was increased as described below in an air atmosphere. The
temperature was held at 105 ◦C for 12 min and was ramped up to
250 ◦C at 10 ◦C/min. After it was held at 250 ◦C for 30 min, it was
increased to 575 ◦C at 20 ◦C/min and held there for 1 hour