## 3 Results and Discussion
### Policies and Standards Linked with the Energetic Use of Agricultural Waste in Ecuador
This estimation considers that the thermal power that can be recovered from a pyrolysis facility with a load capacity of 1200 t/year is 150 kWth [51]. From the policies and regulations that were analyzed (Table 2), although the conversion of agricultural waste into value-added products is considered in the main Ecuadorian environmental regulation (the TULSMA and the Organic Code of the Environment), there are no specific laws or standards to control or supervise thermochemical conversion processes, such as pyrolysis, or other types of recycling technologies. The existing environmental regulations regard the energetic conversion of agricultural waste in cogeneration plants with a thermal power superior to what could be implemented in farmers' cooperatives. In addition to the pyrolysis processes significantly differing from that combustion processes, the thermal energy required by these farmers' cooperatives is also below this threshold. Therefore, the implementation of the pyrolysis technology as an alternative to promote the bioconomy in the farmers' cooperatives and the rural sector will require the development of specific regulations for the medium- and small-scale sectors (under 3 MWth) to define and normalize the thermochemical conversion processes that take place in a pyrolysis facility, along with regulations regarding the pyrolysis products (e.g., biochar). Nonetheless, whether the innovative technology should arise before the legislation is still a topic of discussion. \begin{table}
\begin{tabular}{c c c} \hline \hline  & **Policies and Standards** & **Reference** \\ \hline
1 & The Unified Text of Secondary Environmental Legislation (TULSMA, Texto & \\  & Unificado de Legislation Secundaria de Medio Ambiente) & [32] \\
2 & Standard for Gaseous Emissions to the Atmosphere from Stationary Sources & [33] \\  & of Combustion & [34] \\
3 & Presidential Decrees 1054 and 1158 & [34] \\
4 & The National Program for the Integral Management of Solid Waste (PNGIDS, & [47] \\  & Programa Nacional de Gestion Integral de Desechos Solidos & \\  & Environmental technical standards for the prevention and control of & \\
5 & environmental pollution for the infrastructure sectors: electric, & [50] \\  & telecommunications, and transportation (ports and airports) & \\
6 & The Organic Code of the Environment & [31] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Policies and standards linked with the energetic use of agricultural waste in Ecuador. Technological Alternatives for the Conversion of Agricultural Waste into Biochar in the Studied Farmers' Cooperatives  
In tropical regions, the production of charcoal is often performed in masonry kilns, mud kilns, retorts, and converters [52]. The use of masonry and mud kilns constitutes a major environmental and health concern because harmful compounds within the pyrolytic gases are released with no treatment into the environment [53]. Although the carbonization temperature can be recorded and the physicochemical properties of the charcoal may be homogeneous when using masonry and mud kilns, avoidance of the release of pyrolysis gases into the atmosphere is one of the selection criteria (Table 1). Unlike mud kilns, the retorts and converters can be adapted to recover energy and other products from the pyrolysis gases (e.g., liquid condensates, tars, and syngas) while avoiding the direct release of pyrolysis gases into the atmosphere [54]. Nonetheless, retorts and converters are tailored for the use of forest biomass as feedstock (e.g., logs, large pieces of wood). The use of agricultural waste (Figure 2c) to produce charcoal in retorts and converters is less well known and may require studies and major adaptations. In particular, models of retorts and converters are not adapted to the use of agricultural waste with particle size several times smaller than forest biomass, in addition to the significant differences in physicochemical properties.