Gabriel Laryea - Academia.edu (original) (raw)

Papers by Gabriel Laryea

Biomass is a predominant feedstock for household cooking and heating in developing countries. Cha... more Biomass is a predominant feedstock for household cooking and heating in developing countries. Charcoal fired cookstoves can be considered an important intermediary for sustainable energy consumption as well as promoting healthy kitchen environments due to the significant reduction in the emission of indoor pollutants associated with smoke in wood fires. The performance indicators (Boiling time, Burning rate, Thermal efficiency and specific fuel consumption) of three popular charcoal fired cookstoves in Ghana (Gyapa, Ahinbenso and the Traditional coalpot) were assessed using the water boiling test (WBT) version 4.1.2 method with Kopie von WBT data calculation sheet 4.1.2 software to generate the performance indicators for five (5) replicate measurements. Charcoal from neem was used as fuel. The specific fuel consumption (MJmin -1 L -1 ) at low power was determined to be 0.018±0.004 MJmin -1 L -1 for Ahinbenso, 0.022±0.004 MJmin -1 L -1 for Gyapa and 0.023±0.010 MJmin -

Journal of Applied Science and Technology, 2014

The primary factors considered in the design and construction of a modified De-Montfort type inte... more The primary factors considered in the design and construction of a modified De-Montfort type intermittent incinerator for combusting medical wastes were the waste types, fuel, chimney size, and flue gas residence time. The design analysis was based on flue gas flow rate of 0.13 m 3 /s, maximum primary chamber temperature of 870 °C and minimum ambient temperature of 27 °C. The total flue gas residence time of 6.9 s was achieved for the three chamber system of 0.9 m3 total volume. The medical wastes generated from the four medical facilities in Ga East District (Ghana) consisted of infectious sharp objects, syringes, wound dressings and gloves; which were incinerated at a throughput of 80 kg/day with destruction efficiency of 98.47 %, using fuelwood as primary fuel. The natural convection thermo-fluid flow was controlled by ambient wind speed of ~ 3.8 ms-1, at temperature of 31.5 °C. The primary combustion chamber temperature attained was ~ 516 °C, while the third chamber temperature ...

International Journal of Applied Science and Technology, 2019

This paper presents basic statistical model to predict emissions factors of CO, CO 2 and PM 2.5 f... more This paper presents basic statistical model to predict emissions factors of CO, CO 2 and PM 2.5 from the thermal performance (firepower) using results from an experimental Water Boiling Test with Laboratory Emissions Monitoring System of twelve (12) different traditional and improved charcoal fired cookstoves. The development of improved biomass cookstoves with superior thermal performance and emission characteristics thus has huge environmental and social benefits because of the risks associated with inefficient stoves. A statistical Pearson correlation coefficient (r) was used to determine the degree of linear association of the combustion characteristics with the emissions factors. The models for the evaluation of cookstove emissions from the firepower of a charcoal fired cookstove proved reasonably accurate for the prediction of CO 2 , CO and PM 2.5 without direct measurement using laboratory emissions monitoring systems.

Case Studies in Thermal Engineering, 2020

International Journal of Technology and Management Research, 2020

The cost of extending electrical power systems to remote areas is expensive and the option is to ... more The cost of extending electrical power systems to remote areas is expensive and the option is to decentralise small scale energy power systems that could meet the demand in those areas. Wind potential at selected locations in Ghana has been studied for wind energy purpose since there is an increase in socio-economic development in the country. Four (4) of the three-cup anemometers and data-loggers were installed on a 20-m and 30m masts at Amedzofe, Anloga, Areeba-Nkwanta and Kue-Nkwanta (all in the Volta region). The recorded data were analyzed using STATISTICAL software and calculations were made to obtain the Weibull distribution two-parameters and prediction for hourly, monthly mean wind speeds and mean wind power densities were predicted at 50 m above ground level. Among the selected sites, the mean wind power density of Amedzofe and Anloga fell into Classes 3 and 6 of the commercially international system of wind classification respectively, while Areeba-Nkwanta and Kue-Nkwanta...

AMB Express, 2015

Solid state fermentation of cassava residue with Trichoderma pseudokoningii was conducted for 12 ... more Solid state fermentation of cassava residue with Trichoderma pseudokoningii was conducted for 12 days. The fermentation was carried out at temperature of 24 °C and a pH of 5.0. Urea and ammonium sulphate were used as nutrient sources and moisture content varied at 60 and 70 %. Protein content of the unfermented cassava residue was increased from 8.4 to 12.5 % when urea was used with initial moisture content of 70 % w/v. This study showed that a maximum of 48.1 % protein enrichment was achieved using urea as a source of nutrient for the growth of the fungi, whiles ammonium sulphate achieved 36.9 % protein enrichment under the same condition.

The modern global society faces great challenges in supply of energy and management of wastes in ... more The modern global society faces great challenges in supply of energy and management of wastes in sustainable ways. One way of resolving the local challenges is to develop environmentally appropriate and socio-economically viable biotechnological processes for converting biomass to energy. The general principles of anaerobic bio-digestion, digester design and features of bio-digestion are presented in the feature article, focusing on the prospects of utilizing cassava peels as a readily available lignocellulosic feedstock for co-digestion with manure for the production of biogas and bio-fertilizer. Aside of the high cyanogenic properties, cassava peels would require pre-treatment before use as a substrate, hence, a multi-stage and high rate digestion system might be adopted in efficient digestion of cassava peels. To optimize carbon-nitrogen ratio for efficient digestion, cassava should be co-digested with manure. The socioeconomic benefits of the anaerobic co-digestion technology an...

Atomization and Sprays, 2005

Journal of Electrostatics, 2004

Journal of Electrostatics, 2003

An electrostatic pressure-swirl nozzle have been developed and tested. The result proves to be re... more An electrostatic pressure-swirl nozzle have been developed and tested. The result proves to be relevant due to the minimum pesticide input, increase deposition and reduction in drift. In this paper two systems have been described such as (1) the developed nozzle and its ...

This paper presents the combustion characteristics of hydrocarbon fuel from a conventional pressu... more This paper presents the combustion characteristics of hydrocarbon fuel from a conventional pressure-swirl nozzle of a small-scale burner. The nozzle has orifice diameters of 0.256 mm and liquid flow rates ranging from 50 to 64 mL/min were selected for the experiments. The furnace temperature distribution along the axial distance, the gas emission such as CO, , NOx, , flue gas temperature, and combustion efficiency were studied. The local furnace and flue gas temperatures decreased with an increase in air velocity. At injection pressures of 1.1 and 1.3 MPa the maximum furnace temperatures occurred closer to the burner exit, at an axial distance of 242 mm from the diffuser tip. The CO and concentrations decreased with an increase in air velocity, but they increased with an increase in injection pressure. The effect of air velocity on NOx was not clearly seen at low injection pressures, but at injection pressure of 1.3 MPa it decreased with an increase in air velocity. The effect of ai...

This paper presents an investigation for spray characteristics of charge injected electrostatic p... more This paper presents an investigation for spray characteristics of charge injected electrostatic pressure-swirl nozzle. The work forms part of the design and development of electrospray nozzle for practical oil burner application. The designed nozzle used in the experiment consists of a sharp pointed tungsten wire as a charge injector and the nozzle body grounded. The spray characteristics of the nozzle have been investigated by using a kerosine without active surface agent. The liquid breakup length decreased while the spray angle increased with an increase in applied voltage and injection pressure. An empirical equation to predict the breakup length for electrostatic pressure-swirl nozzle has been suggested. The experimental result was within the range of the predicted equation. Introduction The conventional atomization techniques in oil burner for combustion rely mostly on air or any other form of mechanical disturbance in order to disintegrate bulk liquid fuel into required dropl...