Development of water hyacinth briquetting machine

Briquetting technology is one of the renewable sources of energy that was developed to address problems concerning global warming, energy catastrophe, as well as solid waste management. Nigeria has abundant supplies of biomass resources and unrestricted solid waste, whose potentials are yet to be fully tapped for energy generation. It is, therefore, necessary to convert these waste into a product that will provide alternative energy to the people rather than constituting environmental problems. The study was undertaken to develop of hyacinth briquette machine and examine the properties of fuel briquettes produced from a mixture of waste paper (WP) and water hyacinth plant (WHP) using corn and cassava starch as a binder. WP from the academic environment and WHP harvested from the surface of fresh waters were used. Briquette machine was designed using a screw type extruder to convert the processed WHP and WP into solid briquette for domestic consumption. Samples of WHP was harvested, ground, dried and mixed with WP. The mixture was poured into a hopper. The physical and combustion properties of the briquette were determined at varying WHP and WP-binder ratios of 100:10, 100:15, 100:25, 100:30 and 100:45, 100:55 using corn starch as the binding agent. It was discovered that the binder ratio 100:25 demonstrated the most affirmative value of biomass energy than others. It was also observed that the cooking time for the briquette produced using WHP and WP was 40min/kg with SFC of 0.4kg/kg. The designed machine has production efficiency of 84% and also produced smoke-free WH briquettes with high resistance to mechanical action, better handling and efficient fuel characteristics for household use

Numerical energy and exergy evaluation of a filament bulb controlled convective heat dryer

The mathematical model for temperature regime thermal analysis evaluation of convective heat dryer has been done. Control volume analysis was adopted in this work while taking note of all the feasible heat transfer mechanisms around the system. Mathematical expressions for the energy, exergy, entropy generation as well as destroyed exergy were derived using the control volume. The consumed energy, exergy, entropy generation and exergy destruction of the dryer were computed. The system temperature gradually increased from its initial room temperature of 270˚C to 720˚C at approximately 2700 secs. The temperature thereafter dropped and stabilized to about 670˚C at 4600 secs while the element dried gradually. The moisture removal curve followed the same trend as that of the temperature with gradual variation from 0.5 to 13.2g/mol. The peak energy from the system is approximately 958J against the useful exergy of 443J which shows that 46.24% of the expended energy was actually useful for the drying purpose and about 10.23% was lost. The energy and exergy efficiencies were also computed and results showed that the efficiencies are functions of temperature just like other influencing parameters which has to be technically controlled. Peak energy efficiency of approximately 54.6% was recorded in the dryer with the peak exergy efficiency of 23.4%. The dryer also yielded a better dried product as compared with the traditional means of drying

Effect of corrosion rates of preheated Schinzochytrium sp. microalgae biodiesel on metallic components of a diesel engine

Hitherto, the myriad of researches conducted on biofuels coupled with their poor oxidative stabilities, show that none of these studies has considered monitoring the corrosive effects of Schinzochytrium sp. microalgae biodiesel on diesel engines. In this study, corrosion behaviors of mild steel (MS), aluminum (Al) and copper (Cu) were compared via immersion tests in preheated schinzochytrium sp. microalgae biodiesel and its blends at room temperature and 60 °C for 1200 h. Property-variation of the individual/blended fuels, corrosion rates/products of the metals, and their morphologies were examined. For the metals, the corrosion rates are in the order of Al < MS < Cu at room temperature and 60 °C. The degraded properties and corrosion rates of the metals in the diesel fuel (B-100) and biodiesel fuel-blends, were seen to be minimal relative to those of neat biodiesel (D-100). The morphologies of the metals in contact with the fuels, showed substantial variation in surface properties for the Al, MS and Cu specimens. Furthermore, of all the three metals, copper was most prone to biodiesel corrosion. Hence, the results suggest the need to anticipate a future where the use of corrosion inhibitors for preventing engine-part degradation induced by biofuels becomes a reality

Design and analysis of energy and exergy performance of an LPG-powered fish drying machine

A detailed design and analysis of the energy and exergy performance of a Liquefied Petroleum Gas (LPG)-powered fish drying machine are presented in this paper. The system designed is a modification to the conventional fish dryer which uses charcoal, electric or solar energy as sources of heat. The major problems of the conventional machines are; dangers of global warming from the burning of charcoals. The emission of smoke during operation causes environmental pollution which could have adverse effects on our respiratory systems. Moreover, it is difficult to attain uniform heat distribution using charcoal as a source of heat; erratic power supply in developing countries using electricity and inadequate sunshine using solar energy are all major problems of the conventional dryer. The gas-powered fish dryer is a fish processing device, which uses natural gas as the source of heat energy to reduce the moisture content of the fish. In this work, thermal analysis was carried out on the system after the design. The conduction and convection energy equations were applied to the system main component as well as the fish sample within the system. Numerical computational software (Scilab 6.0.0) was used in solving and analyzing the discretized form of the derived transient differential equations. Appropriate initial and boundary conditions were as well applied during the implementation of fully explicit forward and central difference numerical solutions for solving the differential equations. After solving and arriving at the temporal temperature profile of the dryer and the fish samples, other dependable parameters (energy consumed, exergy consumed, expended gas energy and exergy, energy and exergy efficiencies, etc.) were computed and plotted against time. After the result evaluation and testing, the designed machine proved successful and was found to have peak drying energy and exergy efficiencies of 90 % and 10% respectively

Modeling and analysis of energy and exergy performance of a PCM-augmented concrete-based Trombe wall systems

The aim of this research was to model the performances of energy and exergy on a Trombe wall system to enable an adequate thermal comfort. The main equations for the heat transfer mechanisms were developed from energy balances on subcomponents of the Trombe wall with the specification of the applicable initial and boundary conditions. During the incorporation of the PCM on the Trombe wall, the micro- encapsulation approach was adopted for better energy conservation and elimination of leakage for several cycling of the PCM. The charging and discharging of the PCM were equally accommodated and incorporated in the simulation program. The results of the study show that an enhanced energy storage could be achieved from solar radiation using PCM-augmented system to achieve thermal comfort in building envelope. In addition, the results correspond with those obtained from comparative studies of concrete-based and fired-brick augmented PCM Trombe wall systems, even though a higher insolation was used in the previous study

Design and Numerical Energetic Analysis of a Novel Semi-Automated Biomass-Powered Multipurpose Dryer

This work presents a new all-inclusive mathematical model that combines both processes and an energy analysis of a semi-automated biomass-powered multipurpose dryer. A mathematical model was developed and a wood sample was used to simulate the model. Energy interaction between the system and sample was established. Most importantly, the incorporation of a sensor control system ensures that, once there is an increase in thermal energy from the combustion of the biomass, a signal is passed to the temperature sensor module that controls the system’s temperature and hence shuts down the heat supply at a predetermined temperature; in this case, at 67 °C. The results of the system’s modification show that the peak temperature of the drying space and the sample was 67 °C and 56 °C, respectively, and that the maximum temperature lag witnessed by the two regimes was 10 °C. The peak temperature removal rate of the sample was 0.0066 kg/h, while the sample attained 0.4 (40%) moisture concentration of its initial value; 90% mass content removal (10% remaining mass content) of the initial mass of the sample was achieved at the end, with a simulation time of 240 s