Composting and Methane Emissions of Coffee By-Products

Abstract

In the last 20 years, the demand for coffee production has increased detrimentally, heightening the need for production, which is currently driving the increase in land cultivation for coffee. However, this increase in production ultimately leads to the amplification of waste produced. This study aims to develop an experimental methodology for sustainable coffee by-products (Pulp (CP)) in Costa Rica for nutrient-rich compost. The performance of the experiments is to explore and optimize composting processes following its key parameters. This will allow quantifying the emissions rate to obtain an emission factor for CP during the open composting process and optimizing the conditions to minimize CH4 emissions using P and green waste (GW) materials. Five CP and GW mixtures were analyzed for the composting process for ten weeks, acting P as primary input material as a by-product. Quantification of the methane emissions was performed in two areas: composting area and open field deposition. Peak temperatures of compost appeared at twenty-five days for control and five days for GW added treatments. CP emission factors provide a similar result with the standard values recommended by the literature, accomplishing the emission reductions. Thus, this study designed and validated a sustainable protocol for transforming coffee by-products into compost.

Spent Coffee Grounds Valorization in Biorefinery Context to Obtain Valuable Products Using Different Extraction Approaches and Solvents

“…Under the Paris agreement in 2015, the EU committed to cut greenhouse gas emissions in the EU by at least 40% below the 1990 levels by 2030. In 2021, the target was changed to at least 55% reduction by 2030, climate neutrality by 2050, 27% renewable energy capacity installed for the entire EU energy supply and a 27% improvement in energy efficiency [ 6 , 7 , 8 ]. It is clear that terms such as reuse, recycling and environmental sustainability are outlined as priorities of the European Union.…”

Nitrous Oxide Emission Fluxes in Coffee Plantations during Fertilization: A Case Study in Costa Rica

“…After placing the hood, an air exchange begins, which reaches equilibrium when the amount of N 2 O flowing out of the hood equals the flux of N 2 O emitted from the ground. From this point on, the N 2 O concentration difference between the hood and the environment and the flow rate divided by the soil area covered by the chamber equals the soil emission rate.The N 2 O concentrations were taken using methods in [30][31][32][33][34][35]. The chamber was made of a polyvinylchloride (PVC) material with a cylindrical shape, enhancing a better mixing of the enclosed air, fitted with a vent to avoid pressure changes during the measurements.…”

“…by the soil area covered by the chamber equals the soil emission rate.The N2O concentrations were taken using methods in [30][31][32][33][34][35]. The chamber was made of a polyvinylchloride (PVC) material with a cylindrical shape, enhancing a better mixing of the enclosed air, fitted with a vent to avoid pressure changes during the measurements.…”

“…Finally, the fertilizer was applied manually to the base of the coffee plant (band fertilization), following the process at the coffee farms (Table 2). In this case, two types of fertilizer were added in two different coffee plants, 2 kg of compost in one plant coming from the coffee byproducts and green waste from the harvest 2019-2020, and all the measurements were made in duplicate [32]. Finally, all of these measurements were compared with a control where no fertilizer nor compost was added, with the same conditions as the rest of the coffee plantation except with the fertilizer being added during the fertilization period of the plantation, mentioned in Table 2.…”

A bitter future for coffee production? Physiological traits associated with yield reveal high vulnerability to hydraulic failure in Coffea canephora

“…Thus, considering the continuous rise in global demand for coffee, there is an urgent need to improve the C. canephora production. However, this increase in coffee production must be coordinated with strategies that minimize the environmental impacts associated with the expansion in land cultivation (San Martin Ruiz et al, 2021), especially in areas already threatened by anthropogenic disturbances, such as the Amazon (Silva Junior et al, 2021), a traditional region for coffee production (Junior et al, 2021; Moraes et al, 2021). Although challenging, an alternative to improve the sustainability of coffee cultivation would involve the increase in production per land area, which may be achieved through a better characterization of the physiological traits associated with coffee yield to allow the selection/generation of improved cultivars.…”