The current energy crisis could be alleviated by enhancing energy generation using the abundant biomass waste resources. Agricultural and forest wastes are the leading organic waste streams that can be transformed int...The current energy crisis could be alleviated by enhancing energy generation using the abundant biomass waste resources. Agricultural and forest wastes are the leading organic waste streams that can be transformed into useful alternative energy resources. Pyrolysis is one of the technologies for converting biomass into more valuable products, such as bio-oil, bio-char, and syngas. This work investigated the production of bio-oil through batch pyrolysis technology. A fixed bed pyrolyzer was designed and fabricated for bio-oil production. The major components of the system include a fixed bed reactor, a condenser, and a bio-oil collector. The reactor was heated using a cylindrical biomass external heater. The pyrolysis process was carried out in a reactor at a pressure of 1atm and a varying operating temperature of 150˚C, 250˚C, 350˚C to 450˚C for 120 minutes. The mass of 1kg of coconut fiber was used with particle sizes between 2.36 mm - 4.75 mm. The results show that the higher the temperature, the more volume of bio-oil produced, with the highest yield being 39.2%, at 450˚C with a heating rate of 10˚C/min. The Fourier transformation Infrared (FTIR) Spectroscopy analysis was used to analyze the bio-oil components. The obtained bio-oil has a pH of 2.4, a density of 1019.385 kg/m<sup>3</sup>, and a calorific value of 17.5 MJ/kg. The analysis also showed the presence of high-oxygenated compounds;carboxylic acids, phenols, alcohols, and branched oxygenated hydrocarbons as the main compounds present in the bio-oil. The results inferred that the liquid product could be bestowed as an alternative resource for polycarbonate material production.展开更多
Use of biomass in domestic cookstoves leads to the release of oxides of nitrogen (NO<sub>x</sub>), nitric oxide (NO), nitrogen dioxide (NO<sub>2</sub>), carbon monoxide (CO) and hydrocarbons C&...Use of biomass in domestic cookstoves leads to the release of oxides of nitrogen (NO<sub>x</sub>), nitric oxide (NO), nitrogen dioxide (NO<sub>2</sub>), carbon monoxide (CO) and hydrocarbons C<sub>x</sub>H<sub>x</sub> that can be detrimental to health of the public and the environment. Attainment of complete combustion is the best strategy for mitigating the release of these emissions. This study sought to experimentally determine the effects of secondary air injection on the emission profiles of NO<sub>x</sub> (NO & NO<sub>2</sub>), CO and C<sub>x</sub>H<sub>x</sub> in a charcoal operated cookstove. Charcoal from Eucalyptus glandis was bought from Kakuzi PLC. Composites from three batches were analyzed for chemical composition and the stoichiometric air equivalent. Proximate analysis data show that the charcoal composed 58.72% ± 3.3% C, 15.95% ± 1.2% Volatile Matter, 4.69% ± 0.55% Moisture, 20.7% ± 0.8% Ash, High heat value (HHV) of 30.5 ± 1.1 and 29.3 ± 1.3 Low heat value (LHV) (MJ/kg) with a chemical formula of C<sub>18</sub>H<sub>2</sub>O and a stoichiometric air requirement of 5.28 ± 0.6 with a fuel flow rate of 1 kg fuel/hr. Emission profiles for CO and C<sub>x</sub>H<sub>x</sub> reduced significantly by 70% and 80% respectively with secondary air injection whereas those of NO<sub>x</sub> increased by between 15% and 20% for NO<sub>2</sub> and NO. The study reveals that secondary air injection has potential to mitigate on emission release, however other measures are required to mitigate NO<sub>x</sub> emissions.展开更多
Biogas is a renewable source of energy that when upgraded can be adopted as a reliable and sustainable alternative.This study evaluates the performance of thermal swing adsorption technology applying resistive heating...Biogas is a renewable source of energy that when upgraded can be adopted as a reliable and sustainable alternative.This study evaluates the performance of thermal swing adsorption technology applying resistive heating,in upgrading biogas obtained from anaerobic digestion to biomethane.Commercial coconut shell-based activated carbon was used as an adsorbent in the four-step cycle process to capture carbon dioxide,using a fabricated adsorption model.The influence of minor gas constituents of biogas in carbon dioxide breakthrough curves was analyzed.Dynamic adsorption tests were carried out to evaluate the system performance in carbon dioxide capture.The maximum regeneration temperature of 60℃was found to have peak carbon dioxide concentration of 39%in the waste gas,maximum energy requirements of 0.1538 kWh per cycle,and an energy efficiency of 87%.This is a good trade-off between adsorbent recovery and system energy efficiency.The adoption of thermal swing adsorption technology in biogas upgrading systems is a viable alternative for water-deficient regions.展开更多
文摘The current energy crisis could be alleviated by enhancing energy generation using the abundant biomass waste resources. Agricultural and forest wastes are the leading organic waste streams that can be transformed into useful alternative energy resources. Pyrolysis is one of the technologies for converting biomass into more valuable products, such as bio-oil, bio-char, and syngas. This work investigated the production of bio-oil through batch pyrolysis technology. A fixed bed pyrolyzer was designed and fabricated for bio-oil production. The major components of the system include a fixed bed reactor, a condenser, and a bio-oil collector. The reactor was heated using a cylindrical biomass external heater. The pyrolysis process was carried out in a reactor at a pressure of 1atm and a varying operating temperature of 150˚C, 250˚C, 350˚C to 450˚C for 120 minutes. The mass of 1kg of coconut fiber was used with particle sizes between 2.36 mm - 4.75 mm. The results show that the higher the temperature, the more volume of bio-oil produced, with the highest yield being 39.2%, at 450˚C with a heating rate of 10˚C/min. The Fourier transformation Infrared (FTIR) Spectroscopy analysis was used to analyze the bio-oil components. The obtained bio-oil has a pH of 2.4, a density of 1019.385 kg/m<sup>3</sup>, and a calorific value of 17.5 MJ/kg. The analysis also showed the presence of high-oxygenated compounds;carboxylic acids, phenols, alcohols, and branched oxygenated hydrocarbons as the main compounds present in the bio-oil. The results inferred that the liquid product could be bestowed as an alternative resource for polycarbonate material production.
文摘Use of biomass in domestic cookstoves leads to the release of oxides of nitrogen (NO<sub>x</sub>), nitric oxide (NO), nitrogen dioxide (NO<sub>2</sub>), carbon monoxide (CO) and hydrocarbons C<sub>x</sub>H<sub>x</sub> that can be detrimental to health of the public and the environment. Attainment of complete combustion is the best strategy for mitigating the release of these emissions. This study sought to experimentally determine the effects of secondary air injection on the emission profiles of NO<sub>x</sub> (NO & NO<sub>2</sub>), CO and C<sub>x</sub>H<sub>x</sub> in a charcoal operated cookstove. Charcoal from Eucalyptus glandis was bought from Kakuzi PLC. Composites from three batches were analyzed for chemical composition and the stoichiometric air equivalent. Proximate analysis data show that the charcoal composed 58.72% ± 3.3% C, 15.95% ± 1.2% Volatile Matter, 4.69% ± 0.55% Moisture, 20.7% ± 0.8% Ash, High heat value (HHV) of 30.5 ± 1.1 and 29.3 ± 1.3 Low heat value (LHV) (MJ/kg) with a chemical formula of C<sub>18</sub>H<sub>2</sub>O and a stoichiometric air requirement of 5.28 ± 0.6 with a fuel flow rate of 1 kg fuel/hr. Emission profiles for CO and C<sub>x</sub>H<sub>x</sub> reduced significantly by 70% and 80% respectively with secondary air injection whereas those of NO<sub>x</sub> increased by between 15% and 20% for NO<sub>2</sub> and NO. The study reveals that secondary air injection has potential to mitigate on emission release, however other measures are required to mitigate NO<sub>x</sub> emissions.
基金supported in part by the German Academic Exchange Service(DAAD)and Japan International Cooperation Agency(JICA)through the AFRICA-ai-JAPAN project(Grant No.:iPIC/C2/07/22).
文摘Biogas is a renewable source of energy that when upgraded can be adopted as a reliable and sustainable alternative.This study evaluates the performance of thermal swing adsorption technology applying resistive heating,in upgrading biogas obtained from anaerobic digestion to biomethane.Commercial coconut shell-based activated carbon was used as an adsorbent in the four-step cycle process to capture carbon dioxide,using a fabricated adsorption model.The influence of minor gas constituents of biogas in carbon dioxide breakthrough curves was analyzed.Dynamic adsorption tests were carried out to evaluate the system performance in carbon dioxide capture.The maximum regeneration temperature of 60℃was found to have peak carbon dioxide concentration of 39%in the waste gas,maximum energy requirements of 0.1538 kWh per cycle,and an energy efficiency of 87%.This is a good trade-off between adsorbent recovery and system energy efficiency.The adoption of thermal swing adsorption technology in biogas upgrading systems is a viable alternative for water-deficient regions.
