Sustainability of Renewable Energy Systems with Special Reference to Ocean Thermal Energy Conversion Schemes

It was required to determine relative merits of commonly used renewable energy (RE) systems for which estimation of their individual sustainability percent achievable was chosen as the single criterion assessment tool. The methodology developed for estimating sustainability included identification of individual sustainability indices (SI) and examining the scope of sustainability percent input /kWh power generation for each of SI indices and summing them up estimating total sustainability accrued from respective RE systems. The RE systems studied included photo-voltaic (PV) cells, bio-fuels, on-shore & off-shore wind energy and OTEC schemes. Coal power plant being commercially viable was studied as the referral energy scheme. Nine SI indices identified for study included resource potential, greenhouse gas saving, influence on flora & fauna, effects on human health, land loss aspects, food and potable water security, economy evaluation, and improvement in quality of life from economic growth. Total sustainability achievable showed the highest in OTEC, followed by wind, bio-fuels and PV, respectively. SI index on quality of life showed RE schemes like OTEC & bio-fuels competing equally with coal power plant having poor sustainability with the least power generation cost; whence Hybrid OTEC showed the highest sustainability with high power production cost. Four fold approaches have been suggested for reducing power generation cost of OTEC. (i) Adopting economically viable scheme of not less than 40 MW. (ii) Heating up the working fluid with solar irradiation, terming SOTEC scheme. (iii) Saving cable laying cost, from hydrogen production utilizing the power generated. (iv) Hybridization of OTEC scheme

Utilization of oil palm biomass as a renewable and sustainable energy source in Aceh province

Oil palm production can convert and produce biomass waste, which has high energy value. Oil palm biomass (OPB) that can be discarded includes empty fruit bunches, palm oil leaves, stems, palm kernel shells and mesocarp fibres. Palm oil mills can produce a variety of products, one of which is renewable and sustainable energy, especially for power plant generators. This research concentrated on biomass-based cogeneration plant modelling and simulation. The objective of this article was to develop unit processes and configurations, simulate and optimize the cogeneration process in Aspen Plus simulator using biomass such as EFB, PKS and OPF as fuel. Moreover, this simulation is carried out to find the constant value of the biomass flow rate and the airflow rate and to do some variations with different variables and scenarios. Simulation results have shown results that are appropriate for the biomass flow rate of 5 kg/s with an airflow rate of 58.5 kg/s. Recycle LP-Stream without utilizing stream exhaust which is simulated that the recycle value that can be charged is 20%. While recycle using the exhaust value that can be installed is 80%. The more recycles that are made with various variations show better results. Overall simulation results in this paper have reached a constant value

Intelligent control of a ph neutralization process plant - comparison of pid controller and fuzzy logic controller

Advanced control techniques for process industries have become more damaging due to the increasing complexity of the processes and stricter requirements for the product quality and environmental factors. Intelligent based control approach has become a trend for advanced control techniques mainly neural network and fuzzy logic. Control of pH neutralization process is a challenging process because its inherent strong nonlinearity. Failure to control the process will have significant impact to the environment. In this project, a mathematical model of pH neutralization with specific plant parameters is developed. The model of the process and its simulation are implemented in MATLAB application. The model obtained will be used for application of classic PID and intelligent based fuzzy logic controller for evaluation. Each controller performances are analyzed for comparison based on preset control performance criteria