Potential of Jackfruit Waste as Anaerobic Digestion and Slow Pyrolysis Feedstock

Nsubuga Denis,Banadda Noble,Kabenge Isa,Wydra Kerstin D. 한국농업기계학회 2021 바이오시스템공학 Vol.46 No.2

Purpose The estimated annual worldwide production of jackfruit peelings (JP) and jackfruit seeds is 2.96 million tonnes. This study assesses the suitability of this jackfruit waste from soft and firm jackfruit varieties as potential feedstocks for anaerobic digestion and slow pyrolysis. Methods Proximate, ultimate, calorific values, thermogravimetric, compositional and lignocellulosic analyses were conducted. Results The volatile matter, fixed carbon, hydrogen and carbon content of soft and firm jackfruit waste (peelings and seeds) ranged between 76.81 and 78.83%, 18.28 and 19.42%, 5.43 and 7.13% and 43.89 and 48.08%, respectively. The higher heating values (HHV) of soft and firm jackfruit waste ranged between 17.42 and 19.81 MJ/kg. The ash content of jackfruit waste from both varieties varied within the recommended range of less than 8%. The starch content of jackfruit peelings and seeds from both soft and firm varieties ranged between 29.05 and 59.54% while the sugar content of jackfruit peelings and seeds from soft and firm varieties ranged from 2.04 to 68.8%. The maximum weight degradation rate for the jackfruit waste for both jackfruit varieties occurred in the temperature range of 450–550 °C which is within the slow pyrolysis regime. Generally, cellulose formed the biggest proportions of the lignocellulosic composition followed by hemicellulose and lignin. Conclusion Jackfruit waste from both soft and firm varieties is a potential feed stock for slow pyrolysis while soft variety jackfruit waste is more suitable for biogas production compared to the firm jackfruit wastes.

Can cities become self-reliant in energy? A technological scenario analysis for Kampala, Uganda

Nicholas Munu,Noble Banadda 대한환경공학회 2016 Environmental Engineering Research Vol.21 No.3

Energy self-reliance is important for economic growth and development for any nation. An energy self-reliance technological analysis for Kampala the capital city of Uganda is presented. Three renewable energy sources: Municipal Solid Waste (MSW), solar and wind are assessed for the period of 2014 to 2030. Annual MSW generation will increase from 6.2 × 10<SUP>5</SUP> tons in 2014 to 8.5 × 10<SUP>5</SUP> and 1.14 × 10<SUP>6</SUP> tons by 2030 at 2% and 3.9% population growth respectively. MSW energy recovery yield varies from 136.7 GWh (2014, 65% collection) to 387.9 GWh (2030, 100% collection). MSW can at best contribute 2.1% and 1.6% to total Kampala energy demands for 2014 and 2030 respectively. Wind contribution is 5.6% and 2.3% in those respective years. To meet Kampala energy demands through solar, 26.6% of Kampala area and 2.4 times her size is required for panel installation in 2014 and 2030 respectively. This study concludes that improving renewable energy production may not necessarily translate into energy self-reliant Kampala City based on current and predicted conditions on a business as usual energy utilization situation. More studies should be done to integrate improvement in renewable energy production with improvement in efficiency in energy utilization.

Optimizing slow pyrolysis of banana peels wastes using response surface methodology

Godfrey Omulo,Noble Banadda,Isa Kabenge,Jeffrey Seay 대한환경공학회 2019 Environmental Engineering Research Vol.24 No.2

Renewable energy from biomass and biodegradable wastes can significantly supplement the global energy demand if properly harnessed. Pyrolysis is the most profound modern technique that has proved effective and efficient in the energy conversion of biomass to yield various products like bio-oil, biochar, and syngas. This study focuses on optimization of slow pyrolysis of banana peels waste to yield banana peels vinegar, tar and biochar as bio-infrastructure products. Response surface methodology using central composite design was used to determine the optimum conditions for the banana wastes using a batch reactor pyrolysis system. Three factors namely heating temperature (350-550℃), sample mass (200-800 g) and residence time (45-90 min) were varied with a total of 20 individual experiments. The optimal conditions for wood vinegar yield (48.01%) were 362.6℃, 989.9 g and 104.2 min for peels and biochar yield (30.10%) were 585.9℃, 989.9 g and 104.2 min. The slow pyrolysis showed significant energy conversion efficiencies of about 90% at p-value ≤ 0.05. These research findings are of primary importance to Uganda considering the abundant banana wastes amounting to 17.5 million tonnes generated annually, thus using them as pyrolysis feedstock can boost the country’s energy status.

Membrane fouling control in low pressure membranes

Samuel Gyebi Arhin,Noble Banadda,Allan John Komakech,Isa Kabenge,Joshua Wanyama 대한환경공학회 2016 Environmental Engineering Research Vol.21 No.2

Conventional treatment techniques cannot meet the stringent modern water quality regulations emanating from the need to provide high quality drinking water. Therefore, a number of studies have suggested low pressure membrane filtration as a worthwhile alternative. However, a major constraint to the extensive use of this technology in low and middle income countries is the high operating and maintenance costs caused by the inherent predisposition to membrane fouling. Notwithstanding, pretreatment of feed water using techniques such as coagulation, adsorption, oxidation and bio-filtration is believed to control fouling. In this review paper, the existing scientific knowledge on membrane fouling and pretreatment techniques for controlling fouling in low pressure membranes is analyzed with the aim of providing new and valuable insights into such techniques, as well as unveiling crucial issues noteworthy for further studies. Among the techniques reviewed, coagulation was observed to be the most cost-effective and will remain the most dominant in the coming years. Although oxidants and magnetic ion exchange resins can also control fouling, the propensity of oxidants to form health treating precursors and the high economic implications of magnetic ion exchange resins will hinder their adoption in developing countries.

Substrate Mixture Optimization of Nutrients Needed for Methane Yield

Peter Tumutegyereize,Clever Ketlogetswe,Jerekias Gandure,Noble Banadda 한국농업기계학회 2019 바이오시스템공학 Vol.44 No.2

Purpose The twofold aim of this study was to optimize nutrients important for methane yield in substrate mixtures and to assess the effect of the optimized nutrients on methane production. Method Augmented simplex lattice design was used on three substrates, i.e., matooke peels (MPs), cassava peels (CPs), and sweet potato peels (SPs) wherein 16 ratio combinations were assessed for their macro- and micronutrient compositions and methane production potential. Experimental data was simulated using canonical polynomial models to determine mixture combinations with optimal nutrients stimulatory to methane yield. Results Six optimization solutions with the global optimal having a desirability of 0.93 and a ratio of 0.611:0.375:0.015 were observed to be localized over the design space. Biomethane experiments were in agreement with the optimized mixture ratios as ratios that gave the highest methane yield of 0.3 Nm3CH4/kg VS and above lay in the optimized design region. Conclusion Therefore, charts showing optimized regions of different substrate mixtures in terms of their nutrients can be a tool in biogas digester operations.

Grain Hermetic Storage and Post-Harvest Loss Reduction in Sub-Saharan Africa: Effects on Grain Damage, Weight Loss, Germination, Insect Infestation, and Mold and Mycotoxin Contamination

Okori Francis,Cherotich Sam,Baidhe Emmanuel,Komakech Allan John,Banadda Noble 한국농업기계학회 2022 바이오시스템공학 Vol.47 No.1

Purpose The purpose of this study was to review the different hermetic storage (HS) systems used in Sub-Saharan Africa (SSA) and their effectiveness against the agents of storage quality deterioration. Method Relevant studies on grain HS in SSA conducted in the past two decades for effectiveness against the agents of storage losses are reviewed. Specifically, the study comprehensively reviewed the effectiveness of HS technologies against insectinduced damage and weight loss, seed germination, insect infestation, and mold and mycotoxin contamination. Traditional grain storage methods and HS technologies used in SSA are reviewed, including those suitable for smallholder farmers and traders. Future developments and modifications to HS are also discussed. Results Most grain HS studies are carried out in SSA where post-harvest storage losses are considered one of the world’s largest. Scholarly studies compared the performance of HS against traditional technologies for storage periods of up to 7 months and a few extending to 1 year or more. Commonly studied HS technologies include hermetic layered bags and grain silos. In general, HS offers superior protection against the agents of grain deterioration for long-term storage compared to conventional storage technologies. Conclusion HS technologies are highly effective in protecting stored grains from quantitative and qualitative storage losses and thus guarantee that stored grains can attract better prices and are safe and nutritious to the consumer.