Ahmad Addo

Kwame Nkrumah University Of Science and Technology | KNUST · Department of Agricultural and Biosystems Engineering

Due to the world's rising population, coupled with the increasing energy demands and concerns about global warming, new alternative energy options with a low carbon footprint are being sought. Furthermore, the grave threat of global warming caused by greenhouse gases and the depletion of commercially available conventional fossil fuels restricts th...

Transfer of laboratory-scale experiments to production-scale ethanol fermentation is time-consuming and involves expensive prototype systems from complex experimental designs that determine optimal operating conditions for minimal substrate and product inhibitions. The study developed and validated a Simulink-based model for optimal pH and temperat...

The study presents the economic feasibility assessment of converting the produced biogas from water hyacinth biomass into electricity. Approximately, 0.3793 m ³ CH 4 /kgVS was generated from the water hyacinth biomass. The research indicated that the available water hyacinth population on the Lower Volta River in the year 2020 could potentially gen...

The study focused on the impact of particle size on methane and biogas production by digesting water hyacinth biomass as substrate and fruit waste sludge inoculum for 110 days under mesophilic conditions. A modern BlueSens laboratory-scale anaerobic digestion equipment was employed for the experimental work which focused on four distinct particle s...

Abstract In order to gain understanding on the utilization of biogas fuel derived from water hyacinth (WH) biomass and render it appealing as a sustainable gaseous fuel, the study reports on its various thermophysical, combustion and thermodynamic parameters. The parameters include, specific enthalpy, internal energy, low heating value, Wobbe numbe...

Lack of techno-economic framework for optimal gasification and the identification of critical parameters for optimal operations is one of the major challenges restricting the gasification of crop residues. This study aims to develop an optimal techno-economic framework for the gasification of crop residues from clustered small/medium-scale farms. T...

The seeds of baobab were found to have both industrial and domestic uses due to their essential oil qualities for topical medication. However, the seeds found in this study area in Ghana are underutilised and sometimes thrown away after being taken off the pulp. The present study is aimed at examining the impact of the two predominant techniques us...

The seeds of baobab have found both industrial and domestic use due to their essential oil qualities for topical medication. However, the seeds found in this study area in Ghana are underutilised and sometimes thrown away after being taken off the pulp. The present study aimed to examine the impact of the two predominant techniques used for oil ext...

Lack of sustainable feedstock quantity and quality has been reported to be one of the major challenges confronting operations of gasifier plants in Ghana. In this paper, TOPSIS (Technique for order of Preference by Similarity to Ideal Solution) COPRAS (Complex Proportional Assessment) and VIKOR (Multi-criteria Optimisation and Compromise Solution)...

A comprehensive methodological approach taken into account concerns of end users, optimal technical engineering parameters is proposed in this study to select optimal gasifier reactor type for the gasification of crop residues in Ghana. Eleven technical/economic user requirements based on the existing challenges of the gasification system in Ghana...

The study evaluated the influence of variety and temperature on the retention of nutrient antioxidants, vitamins A and E of Abotem, Aborohema, Omankwa, Abeleehi and Dorke SR varieties of maize. The exact retentions (mg/100mg) were computed using the yield expressed as a ratio of the absorbances dilution factor to the weight of the sample. The loss...

Scientific study on non-timber forest products with potential for use by humans has recently experienced a resurgence. Baobab is one of these non-timber forest products, and every part of the baobab has been shown by studies to be useful. Because the fruit products of the baobab tree contain enormous amounts of phytochemicals, these products have f...

Gasification technology has a critical role to play in the quest to provide off and on-grid renewable energy solutions for rural agricultural communities. Optimal gasifier design is essential for sustainable energy generation and operation of gasifier systems. The aim of this study is therefore to design an optimal gasifier reactor for the gasifica...

In this study, the effect of moisture content on the physical attributes of baobab seeds was examined, along with the implications for the design of machinery for postharvest handling and processing of the seeds. The seed's volume, sphericity, aspect ratio, axial dimensions, arithmetic, and geometric mean diameters were all determined. Gravimetric...

Cassava has rapidly gained recognition as a very useful crop in Africa and other parts of the world, not just for its consumption domestically, but most importantly for its industrial use. Due to the rapid rate of deterioration, cassava needs to be processed almost immediately after harvest, and peeling is one of the first operations in cassava pro...

Several post-harvest technologies have been introduced over the past years to help smallholder farmers in sub-Saharan Africa reduce crop losses. However, not all these technologies fit the same application purpose to meet the needs of farmers in different locations. This study, therefore, applied a multi-criteria decision method, the analytical hie...

Four mango fruit varieties of average slice thickness 0.6 cm and slice area 10 cm2 were dried using a mechanical dryer at varied temperatures, 55°C, 65°C, and 75°C. In general, the moisture content (MC) for all samples analyzed decreased with increasing drying time. Palmer and Haden varieties recorded the lowest MCs of 8.7% (w.b.) and 9.3% (w.b.),...

This study was carried out to investigate the effects of soaking temperature and variety on the rehydration parameters and solute loss (essential minerals and vitamin C) of two maize varieties. Sun-dried kernels of the maize varieties (Omakwa and Abrohemaa) were soaked at four different water temperatures of 30oC, 40oC, 50oC and 60oC in a thermosta...

Uniformity in plant spacing, evenness of dropping, planter capacity and among others has been identified as constraints facing planter performance. The main objective of the study was to evaluate the technical performance of the developed double row yam minisett (DRYM) planter. Category (I) tractor 50 hp was used to carry out field trials to determ...

Drudgery in manual yam minisett planting was identified as a major constraint facing yam cultivation in Ghana. The main objective of the study was to develop a double row yam minisett (DRYM) planter using Finite Element Analysis (FEA). A potato planter was adopted and modified to suit the design of DRYM planter. The main task was to perform 3D mode...

The utilization of bio-based technology for energy has piqued researchers' curiosity around the world. As a result, bioethanol fermentation has been a hot topic of research for many scientists since it uses less energy and chemicals, produces fewer harmful by-products and emissions, and has environmentally favorable applications. The modeling and s...

In Ghana, smallholder maize farmers continue to serve as the primary contributor to maize production. These farmers, however, still face challenges of access to appropriate, effective, and efficient drying systems. They continue to depend on open sun drying, which leads to high post-harvest losses. In this study, a 500 kg portable column dryer with...

Lignocellulosic biomass represents an important chemical resource. In the quest for the heightened interest for waste management and the successful utilization of solid waste materials into useful products, cocoa pod husk, an agricultural waste material generated in several metric per year (~ 800, 000 MT/per) is a potential source of lignocellulosi...

Uncertainty in operating parameters such as temperature undermines the reliability of using kinetic models in performance projections for plants operated under ambient non-isothermal conditions. This study develops a theoretical framework, which uses process kinetics, uncertainty quantification to define robust operating limits known as self-optimi...

The blend of mathematical modelling with process data affords both meaningful qualitative and quantitative interpretation of outcomes which may advance our knowledge of microbial physiology and even suggest newer developments in fermentation technology. The study focused on the formulation of a generalized framework to modelling two-dimensional inh...

Tomato fruit (Lycopersicon esculentum Mill) is an important vegetable commodity in Ghana, as it is consumed daily in many households either heat-treated or without any form of heat treatments. Tomato production is a major source of income for many smallholder producers in Northern Ghana especially through dry season farming when the major supply of...

This paper presents a theoretical framework to model anaerobic digester structures and define performance targets using regions of attainability constructed using kinetic models and fundamental processes: mixing and biodegradation. Two digestion cases, diary manure (case 1) and diary manure + lagoon inoculum (case 2) were considered and the followi...

Technical and economic performance of mechanized reaping and sickle harvesting methods were assessed under farmer’s field conditions in the Ashanti Region of Ghana for Amankwatia and AGRA rice varieties. Harvesting trials and field measurements were statistically analyzed as a split-plot layout in a randomized complete block design with three repli...

Performance analysis of a 1.0 tonne desiccant evaporative cooling storage structure for mango fruits was studied. The study examined the effects of inlet air conditions and water flow rates through an absorber on the cooling performance of the system. The airflow rate was approximately 0.24 m3·s-1 and water flow rates through the absorber varied fr...

The design of biogas reactors for blackwater treatment provides special challenges due to significant variability in blackwater characteristics, the complexity of biological systems, and the need, in many cases, to operate in an extremely hygienic environment. In this study, mathematical models were formulated based on microbial growth kinetics to...

This study sets out to develop an approach that couples attainable regions and fuzzy multicriteria decision methods for modeling optimal configurations of multistage digesters without using a kinetic model of the process. The approach is based on geometric analysis of methane curves as their shapes contain valuable insight into substrate biodegrada...

Anaerobic digesters are seldom designed based on process kinetics, but rather on a combination of hydraulic and organic loading, which may limit operational performance. This study focuses on the incorporation of process kinetics in the design of anaerobic digesters, within the attainable region conceptual framework. Candidate attainable regions fo...

Current practice to design methane bioreactors does not consider all degrees of freedom simultaneously, which raises question of global optimality. This study presents a model-based design framework, which simultaneously integrates process kinetics and business parameters into the design process, a key motivation for investors. Within the study, a...

The °catalytic depolymerization of lignocellulosic biomass to specialty chemicals is often hampered by challenges, which mainly includes cost of catalyst as well as degradation of the chemicals as they are produced. In order to enhance catalytic conversion of cocoa pod husk as an industrial alternative for the production of carboxylic acids, this s...

Analysis of networks of grain storage facilities in Ghana

Particles size of poultry feed as quality control method

Unlike high-rate anaerobic digesters that employ some mechanism to retain microbial sludge mass, low-rate systems use sufficiently long hydraulic retention times to ensure process stability, which becomes economically unattractive for treating large quantities of waste. This study presents the use of attainable region to develop a new strategy to e...

Anaerobic digestion involves multiple reactions, and when operated as a single stage, the process conditions are only suitable for all the reactions with no particular reaction being optimized, hence limiting overall performance. Multistage anaerobic digestion, in which multiple digesters are operated in a network are designed to optimize each proc...

Based on the UN Human Development Index, the West African sub-region holds one of lowest indices in development around the world. There is a glaring need for the sub-region to increase its electricity capacity; however, stringent global CO 2 policies have ‘choking’ effects on the growth of the electricity sector in energy deprived countries, like t...

The use of fermenters at large scale is usually hampered by sub-optimal conditions in terms of yield and productivity, along with the low tolerance of strains to process stresses, such as substrate and product toxicity, and other fermentation inhibitors. Attempts to improve the industrial efficacy of fermenters have been in the areas of genetic eng...

The water absorption kinetics of three cowpea varieties (Asontem, Hewale and Asomdwee) was studied following the phenomenological models derived from Fick’s law of diffusion. Soaking of seeds from each cowpea variety was carried out for 10 h at four temperatures (30˚C, 40˚C, 50˚C and 60˚C). The saturation moisture content was higher for Asontem (10...

This paper presents the optimal mapping of hybrid energy systems, which are based on wind and PV, with the consideration of energy storage and backup diesel generator, for households in six locations in the South-South geopolitical (SS) zone of Nigeria: Benin-city, Warri, Yenagoa, Port Harcourt, Uyo and Calabar. The optima hybrid energy systems are...

Efficient cook stove design is a very vital aspect of effective processing operations. However the chimney configuration of a cook stove affects its overall performance. As such the current study seeks to evaluate the effect of two chimney configurations on the performance of a cook stove that was designed. The Autodesk CFD software was used to eva...

There is a general agreement between researchers that particle size of poultry feed should be between the size ranges of 600-900 µm. This study investigated the particle size of poultry feed produced in the Dormaa Municipality of Ghana. A survey was conducted on various feed mills which were made up of nine on-farm mills and five community-based co...

Farmers’ knowledge and perception of harvest and postharvest losses in rice production across three agro-ecological zones of Ghana were examined using farm-level data collected from 108 randomly selected rice farmers. To examine the perception and knowledge of farmers on harvest and postharvest losses, means of a 5-point Likert scale were estimated...

Governments in developing countries often face the daunting task of designing a network of grain storage facilities to simultaneously benefit the various stakeholders (farmers, market traders, exporters, etc.) in the grain supply chain irrespective of the conflicting objectives of these stakeholders. Existing decision support systems either require...

Threshing performance evaluation was carried out using thresh efficiency, grain clean rate and grain breakage at the Ghana Irrigation Development Rice Field (GIDA) Tema - Ghana. It was aimed at the comparative evaluation of Japanese rice thresher ‘Kubota MD300’ and locally built rice thresher in Ghana. The performance indices included threshing int...

The method of heat provision for artisanal palm oil production in Ghana is riddled with inefficient systems which create unfavourable working conditions (use of spent tyres, smoke filled work tents etc.) for the women who engage in this process. This creates health hazards for the women and sometimes the children they carry along to work. This stud...

The method of heat provision for artisanal palm oil production is riddled with inefficient systems which create unfavourable working conditions (use of spent tyres, smoke filled work tents etc.) for the women who engage in this process. This creates health hazards for the women and sometimes the children they carry along to work. This study therefo...

Performance of a Yanmar DB 1000 mechanised paddy thresher was comparatively assessed against manual threshing by impact method using a locally-made wooden box for Amankwatia and AGRA rice varieties under farmer's field conditions at Nobewam in the Ashanti Region of Ghana. The mechanised thresher was evaluated at various threshing drum speeds (550 r...

In Ghana, Biogas Technology has been limited mostly to donor-funded projects in communal areas, educational and health institutions. This has made development of biogas technology relatively minimal. In most cases, some of these projects have been abandoned due to lack of sustained funding, poor maintenance and proper management of the facilities....

Background Policy makers seek to understand the trade-offs needed between economic growth and climate change. This provides the context to explore low-carbon development (LCD) pathways for the West African electricity system. Methods The study relied on both primary and secondary sources to elicit required information. These data were elicited from...

Performance of a Sifang mini rice combine, originally developed in China, was evaluated under local farmer field conditions in Benin. Results from field evaluation show that the combine worked satisfactorily on less dense rice fields with minimal weeds at grain moisture contents between 19.1% and 20.1% w.b. on soils with moisture content from 23% t...

The objective of this study was to evaluate the performance of a mechanical yam harvester. The harvester was operated at average soil depth of 0.30-0.33 m and tuber spread values of 0.18-0.22 cm. The tuber length varied from 0.33 to 0.38 cm and tuber depth of penetration also varied from 0.29 to 0.37 cm irrespective of yam variety. The tractor harv...

The coastline rural communities in the Niger Delta region of Nigeria have long suffered from the consequences of poor rural electrification, environmental degradation, and health challenges. There is an urgent need to provide an optimal sustainable and environment-friendly energy system for the coastline rural communities in Nigeria, which has the...

Yam is a tuber crop and its harvesting is a major challenge as a result of drudgery and high manpower requirement. Therefore, the objective of this study was to develop a tractor operated implement for the mechanization of yam harvesting. The most important component of a root and tuber harvester is the blade since it interacts directly with the so...

In farming communities in Ghana and the West African region, crop residues are often unused and remain available for valorisation. This study has analysed the prospects of electricity generation using crop residues from smallholder farms within defined clusters. Data was collected from 14 administrative districts in Ghana, where surveys were conduc...

Recently ethanol production involved the processing and fermentation of sorghum and maize extracts. Sorghum and maize are cheaper, locally available and a substitute to imported barley malt. Large scale ethanol fermentation systems are usually hampered by instability, in the form of oscillations resulting from ethanol inhibition and the lag respons...

The fermentation of cassava extracts in brewing is often hampered by microbial inhibitors and oscillations from product and substrate inhibitions, which often decrease ethanol yields. Previous evaluation of the modeling of ethanol inhibition during fermentation of cassava extracts showed low model accuracy. This low model accuracy is due to substra...

Background Nigeria’s rural coastline communities have long suffered from the consequences of both poor rural electrification and environmental degradation. Therefore, there is an urgent need to provide an optimal sustainable and environment-friendly energy system for the coastline communities in Nigeria, which has the potential of ameliorating the...

2)4: 831-839] © 2016 IJSRSET | Volume 2 | Issue 4 | Print ABSTRACT Moisture-dependent engineering properties of seeds are important in the design of postharvest equipment for their handling and processing. In this study, the physical properties of shea kernels were determined as a function of moisture content in the range of 6.24 to 25% (d.b.) usin...