Journal Of Environmental Management, cilt.306, ss.1-15, 2022 (SCI-Expanded)
The present analysis was conducted as the
first research to assess the techno-economic viability of the value-added by-products (struvite, blood meal,
bone meal, and raw sheepskin) from a medium-scale sheep slaughterhouse facility
with a slaughtering capacity of 300 sheep per day. For this aim, a comparative
technical and economic feasibility analysis was performed to assess the
synergistic use of slaughterhouse-oriented rendering wastes and struvite
recovery from real sheep abattoir effluent within the framework of detailed
cost breakdown, break-even point, and payback period analyses. The
experimental findings clearly showed that under the optimal
conditions (chemical combination of MgCl2.6H2O +
NaH2PO4.2H2O, a molar
ratio of Mg2+:NH4+-N:PO43--P
= 1.2:1:1, a
reaction pH of 9.0, an initial ammonium
concentration of 240 mg NH4+-N/L, and a reaction time of 15 min), struvite precipitation could
effectively remove about 73%, 64%, 59%, and 82% of NH4+-N,
TCOD, SCOD, and color, respectively, from the real sheep slaughterhouse
waste stream. Based on various up-to-date techno-economic items considered within the break-even point analysis, the sheep slaughterhouse facility was
estimated to achieve the targeted net income (€100/day) for any selling prices
of €1041.30/ton, €640.05/ton,
€263.72/ton, and €1.012/hide, respectively, for struvite, blood meal,
bone meal, and raw sheepskin. Steel construction and chemicals were determined
as the most costly components for CAPEX (capital expenditures) and OPEX (operating
expenditures), respectively, and selling prices of bone meal and
raw sheepskin were found to be the most critical income items on the
profitability of the slaughterhouse facility. Co-monetary assessment of the struvite process and valorized compounds
corroborated the economic viability of the proposed project with the payback
periods of about 6.3 and 5.5 years, respectively, for the current market and the profit-oriented
conditions without
subsidy.
The findings of this feasibility
analysis, as the first of its own, could be used as guideline for simplifying
the decision-making with regards to the feasibility of similar facilities and
commercialization of profitable by-products.