Energy and economic evaluation of three generations of anaerobic reactors for starch wastewater treatment

Figures & data

Table 1. Parameters of the AD, UASB, and IC reactors [24, 25].

	Reactor dimensions		COD removal efficiency (%)
Reactor	Height (m)	Diameter (m)	5,000 mg/L	10,000 mg/L	15,000 mg/L	20,000 mg/L
AD	5	18	50	55	60	60
UASB reactor	17	6	75	80	85	85
IC reactor	15	3	85	90	95	95

Figure 1. Energy flow diagram.

Figure 2. Average monthly water temperature and air temperature in Fuyang City, Anhui Province, in 2014.

Figure 3. Monthly heat loss for the AD, UASB, and IC reactors.

Table 2. Biogas produced and heat supplied by the biogas for the three anaerobic reactors at different COD concentrations.

		Influent COD concentration (mg/L)
		5,000	10,000	15,000	20,000
Biogas production (m^3/d)	AD	569	1,225	1,838	2,625
	UASB	1,125	2,400	3,825	5,100
	IC	1,275	2,700	4,275	5,700
Heat supplied by the biogas (kW)	AD	125.34	269.95	404.93	578.47
	UASB	247.92	528.89	842.92	1,123.89
	IC	280.97	595.00	942.08	1,256.11

Note: Explanations for the variables seen in the figure appear below Equation (1).

Figure 4. Net energy production of the AD.

Figure 5. Net energy production of the UASB reactor.

Figure 6. Net energy production of the IC reactor.

Figure 7. COD concentration versus annual net energy production for the three reactors.

Figure 8. COD concentration versus annual net economic value for the three anaerobic reactors.

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