Ni-Ru/CeO₂ Catalytic Hydrothermal Upgrading of Water-Insoluble Biocrude from Algae Hydrothermal Liquefaction

Table 1

Elemental compositions, HHVs, and energy recoveries of B₁ (derived from algae HTL at 350°C, 20 min) and B₂ and (obtained from B₁ upgrading at 450°C, 60 min with different additives).

Additive	Biocrude	Element (wt%)					N/C	O/C	HHV; (MJ/kg)	Energy recovery (%)
		C	H	N	S	O
–	B1	77.05	9.76	4.82	0.53	6.84	0.063	0.089	38.81	62.46
None	B2	79.74	9.44	4.24	0.37	5.21	0.053	0.065	39.54	38.03
H2	B2	79.19	9.59	4.37	0.41	5.44	0.055	0.069	39.53	40.61
Ni-Ru/CeO2	B2	79.63	9.55	4.03	0.19	5.6	0.051	0.070	39.57	36.89
Ni-Ru/CeO2+H2	B2	80.23	9.57	4.12	0.22	4.86	0.051	0.061	39.94	46.24
Ni/CeO2+H2	B2	79.27	8.87	4.55	0.45	5.86	0.057	0.074	38.46	37.80
None		80.26	9.49	4.04	0.25	4.96	0.050	0.062	39.82	32.11
H2		80.63	9.77	3.59	0.35	4.66	0.045	0.058	40.41	30.10
Ni-Ru/CeO2		81.26	9.57	3.54	0.18	4.45	0.044	0.055	40.35	23.24
Ni-Ru/CeO2+H2		81.9	9.73	3.62	0.19	3.56	0.044	0.043	40.96	29.25
Ni/CeO2+H2		81.4	9.6	3.89	0.16	3.95	0.048	0.049	40.53	24.75