Partial and Total Solvent-Free Limonene’s Hydrogenation: Metals, Supports, Pressure, and Water Effects

Table 5

Recyclability of Rh/Al₂O₃ (5% wt).

Cycles	Conversion (%)	Menthene/menthane (%)	Cis/transmenthane (%)
Rh/Al 2 O 3  + 100 µl H 2 O (2.75 MPa)
1	100	90/10	49/51
2	100	90/10	50/50
3	100	90/10	48/52
4	100	90/10	49/51
5	100	89/11	48/52
6	100	94/6	46/54
7	100	93/7	44/56
Rh/Al 2 O 3 (2.75 MPa)
1	100	0/100	44/56
2	100	85/15	45/55
3	100	94/6	47/53
4	91	95/5	43/57
5	77	97/3	33/67

Experimental conditions: pure limonene, the catalyst, and room temperature.