Simultaneous Coproduction of Hydrogen and Ethanol in Anaerobic Packed-Bed Reactors

Table 2

Distribution of generated metabolites as a function of HRT for R030 and R060.

APBR	HRT (h)	EtOH/SMP; (%)	HAc/SMP; (%)	HPr/SMP; (%)	HBu/SMP; (%)	MetOH/SMP; (%)	TVFA; (mmol L^−1)	SMP; (mmol L^−1)	HAc/HBu*	HAc/EtOH*
R030	8	32.7	31.8	0.3	28.8	6.5	18.8	30.9	1.1	0.9
	6	31.7	29.1	15.0	15.6	8.6	19.3	32.3	1.9	0.9
	4	57.5	21.1	9.7	4.6	7.1	17.3	48.7	4.7	0.4
	2	59.7	18.5	9.7	3.0	9.1	14.6	46.9	6.2	0.3
	1	39.2	36.5	11.5	3.9	8.8	19.8	38.1	9.3	0.9
R060	8	33.0	29.6	2.9	27.5	6.9	14.9	24.9	1.2	0.9
	6	29.1	25.2	23.5	14.3	7.9	18.9	29.9	1.8	0.9
	4	50.5	25.8	12.3	5.2	6.3	20.4	47.1	4.9	0.5
	2	40.1	27.0	21.7	5.0	6.2	11.0	20.5	5.4	0.7
	1	36.5	39.4	13.1	5.2	5.9	20.2	35.1	7.6	1.2

TVFA: total volatile fatty acids, TVFA = HAc + HBu + HPr, and SMP = TVFA + EtOH.
*Molar ratio.