_Applied_  
_sciences_  
_Article_  
**Parabolic Dish Collector as a New Approach for Biochar Production: An Evaluation Study**  
**[PERSON] 1,*\({}^{\text{\textregistered}}\), [PERSON] 1\({}^{\text{\textregistered}}\), [PERSON] 2\({}^{\text{\textregistered}}\), [PERSON] 1\({}^{\text{\textregistered}}\) and [PERSON] 2,*\({}^{\text{\textregistered}}\)**  
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surface area (SSA), and valuable amounts of nutrients [1; 9]. However, the physiochemical properties of biochar vary and are largely influenced by the type and structure of feedstock, pyrolysis environment (maximum temperature, heating rate, and pyrolysis duration), and modification process [10; 11; 12]. The organic compounds present in the biomass decompose at a specific temperature in an oxygen-limited environment, yielding several gases (carbon dioxide, carbon monoxide, hydrogen, methane, and ethane), liquid (tar), and a black solid material as a byproduct (char) [2; 13]. There are numerous techniques for biochar formation from organic residues by thermochemical degradation, which are mainly classified into traditional and modern approaches. According to [PERSON] et al. (2020), traditional reactors are manufactured from different materials such as clay burners, firebrick pits, brick kilns, iron retorts, and steel oven reactors [2]. Depending on the temperature range and the heating rate, pyrolysis may be slow or fast. Slow pyrolysis takes place at a temperature range of 300-600 \({}^{\circ}\)C and a heating rate of 5 to 7 \({}^{\circ}\)C per minute, whereas fast pyrolysis reactors use temperatures above 500 \({}^{\circ}\)C and a heating rate of 300 \({}^{\circ}\)C per minute. Modern technologies include flash pyrolysis (temperature above 1000 \({}^{\circ}\)C for one minute and a heating rate of 1000 \({}^{\circ}\)C per second), vacuum pyrolysis (residues are subjected to pressures between 0.5 and 2 bar and a temperature of 450-600 \({}^{\circ}\)C), gasification (temperature more than 700 \({}^{\circ}\)C), and microwave pyrolysis [2]. Regardless of the type of pyrolysis, the energy source used greatly influences the environment and economic sectors. Lately, solar radiation as a renewable source of energy for the pyrolysis process has received more attention due to its potential to reduce pollutants and gas emissions. Through the use of solar energy directly, it is possible to reduce the negative impact caused by the combustion of fuels and/or the generation and transportation of electricity [13]. In that sense, all available amounts of agricultural residues can be transformed into biochar, hence providing a higher proportion compared with conventional systems. Many solar collectors have been proposed to concentrate the radiation beam directly to the reactor for agricultural residue pyrolysis and management, for instance, elliptical reflectors, mirrors, deep-dish parabolic mirrors, and lamp reflector windows. Depending on the solar concentrator, the temperature ranged from 300 \({}^{\circ}\)C to 900 \({}^{\circ}\)C [14]. The average temperature obtained by the parabolic dish reactor that utilizes a low-temperature reactor was 360-600 \({}^{\circ}\)C [15]. [PERSON] et al. (2017) produced bio-oil (20%) from Jatropha biomass by a parabolic dish reflector to concentrate the solar radiation onto a pyrolysis reactor, which ranged from 250 to 320 \({}^{\circ}\)C [16]. However, the biochar properties produced by parabolic dish reactors have not been thoroughly studied in the literature. The present study proposes a cavity chamber sealed from air and fixed on a solar parabolic dish collector to directly heat the agricultural residues.