Economic, energetic and environmental analysis of the utilization of swine manure in Brazil: Opportunities and challenges

Abstract

Faced with the worsening of climate issues, nations are directing efforts to build renewable energy matrices. Specifically with regard to biomass, it can contribute to the creation and strengthening of green competitive advantages in terms of cost for agricultural units. Strictly, swine biomass, considered to have a high polluting load, can contribute to achieving the aforementioned benefits. Therefore, the objective of this article is to analyze the potential economic, environmental and energy contribution of this waste, whether in breeding units, as well as in the Brazilian energy matrix, both aiming to guide investments in the sector and also to guide the elaboration of public policies for the valorization of externalities ecosystemic of this waste, with emphasis on the bioelectricity, biofertilizers and biomethane market. The methodology used was the analysis of the financial viability of breeding units from 100 to 500 swines from 25 kg to 100 kg, with 252 days of operation, 10 h a day, with the use of canvas biodigestor and motor generator with efficiency between 25% up to 38% for electricity price ranges from USD 35.35/MWh to USD 155.35/MWh, sale of carbon credit, simple superphosphate and potassium chloride. Taxes on the sale of electricity and fertilizers at 34%, with a minimum attractive rate of 12% per annum. The results indicate viability for the entire range of numbers of swine, with the sale of fertilizers and electricity and electricity at a price of USD 35.35/MWh. For the exclusive sale of electricity, for efficiency of the thermoelectric motor between 25% and 38%, there is economic and financial viability beginning at 31% for production units of 100 swine with a price of USD 125.35/MWh. This business is viable with at least 200 swine through the replacement of diesel with 10% generated biogas. It can be concluded that there is a need to reformulate the incentive policy in Brazil, through the implementation of feed in tariffs; price the MWh, in the regulated market, based on its environmental externalities; extension of the free market hiring period; the development of teaching policies with farmers about the importance of reusing waste, aiming at replacing synthetic fertilizer with biofertilizer; convergence between the Union and Federative Units on incentive policies, with emphasis on the standardization of biomethane and the creation of captive markets, which provide predictability to agricultural investors, the industries that manufacture biomethane engines and expansion of the gas pipeline network in the country.