Optimized Liquid-Liquid Extractive Rerefining of Spent Lubricants

Table 3

Coefficients and their significance in the multivariate process models for the sludge yields during liquid-liquid extraction.

Model for ln(𝑌𝐴) (7)				Model for ln(𝑌𝐾) (8)
𝑖	𝛽𝑖	𝑡 value	𝑃 value	𝑖	𝛽𝑖	𝑡 value	𝑃 value
0	3.4647152913𝐸−1	14.0289	0	0	7.0973841576𝐸−2	5.9947	0
1	−1.6031743008𝐸−2	11.2060	0	1	−1.0642033303𝐸−3	4.5225	0.0005
2	1.7569070873𝐸−4	10.8303	0	2	1.2171694089𝐸−1	5.7975	0
3	−1.1948361975𝐸−2	3.2110	0.0068	3	−1.3824578194𝐸−2	4.3070	0.0007
4	−1.7129433714𝐸−1	5.0145	0.0002	4	−1.3118016465𝐸−2	3.3267	0.0050
5	1.9652042724𝐸−2	3.8254	0.0021	5	−8.1160210718𝐸−3	4.6210	0.0004
6	1.9649280989𝐸−4	1.5759	0.0230	6	1.9244882179𝐸−4	1.8834	0.0120
7	1.3402240277𝐸−2	3.3195	0.0055	7	1.1153219527𝐸−3	1.9886	0.0098
8	−1.9433649876𝐸−3	1.2426	0.0430

Significance level = 0.05.