N2N regional circular agriculture model in China: A case study of Luofang biogas project

Figures & data

Figure 1. Flow chart of N2N circular agriculture model.

Table 1. Comprehensive technical and economic indicators of biogas engineering

index	numerical value	units
CSTR	27,000	m^3
Design organic waste treatment scale	200,000	t·a−1
Biogas	9.12	Million m^3·a−1
Biogas residue organic fertilizer	28,000	t·a−1
Biogas slurry organic fertilizer	150,000	t·a−1
Factory site area	127040	m^2
Factory building area	33048	m^2
The number of major equipment	130	sets
All staff	45	persons
Total investment	14.3	$ millions
Financial matching funds	5	$ millions
Local support	2.15	$ millions
Self-raised funds	7.15	$ millions

Table 2. Production cost and earnings of biogas project (millions US dollars)

Cost item		Cost	Revenue item	Revenue
Variable costs	Transportation	0.5	Centralized gas supply	0.16
	Electricity	0.51	Biogas power generation	1.764
	Organic fertilizer	1.96	Organic fertilizer	2.8
Fixed costs	Fixed assets depreciation	0.68	Biogas slurry	0.25
	Management expenses	0.45	dead pig treatment subsidy	0.23
	Finance charges	0.43	CDM	0
			wastes handling fees	0.334
	total	4.53	total	5.538
	profit	1.008

Table 3. The sensitivity analysis of the engineering efficiency of the power price fluctuation

power price/$	0.2	0.15	0.125	0.1	0.075	0.05
Total revenue/$ million	7.374	6.474	6.024	5.574	5.124	4.674
profits/$ million	2.844	1.944	1.494	1.044	0.594	0.144

Table 4. The sensitivity analysis of the engineering efficiency of biogas slurry price fluctuation

Biogas slurry price/$	5	3	1	0	−1	−3	−5
Total revenue/$ million	6.058	5.758	5.458	5.308	5.158	4.858	4.558
profits/$ million	1.528	1.228	0.928	0.778	0.628	0.328	0.028

Table 5. The sensitivity analysis of the engineering efficiency of raw material price fluctuation

Manure collection cost/$	−5	−3	−1	0	1	3	5
Total revenue/$ million	6.204	5.804	5.404	5.204	5.004	4.604	4.204
profits/$ million	1.674	1.274	0.874	0.674	0.474	0.074	−0.326