Comparative study of energetic potential from anaerobic digestion and direct combustion of date palm wastes

This work aims to evaluate the technical and environmental feasibility of converting date palm waste from a Moroccan oasis into energy.In this study,two different scenarios were analysed.The first proposed scenario is the valorization of the date palm substrates using direct combustion(thermochemical conversion)to produce energy.The second proposed scenario is the valorization of the substrates using combined anaerobic digestion of the substrate and direct combustion of the digestate.In this study,two different date palm wastes are:empty fruit bunch(EFB)and palm leaflet(PL).The experimental lower heating values of the digestates studied are 12.93 and 12.71 MJ/kg,respectively.The results show that using Scenario 1,the estimated output energies for the EFB and PL waste were 1.13 and 1.17 MWh,respectively.Using Scenario 2,the EFB and PL output energies were 1.27 and 1.39 MWh,respectively.The study revealed that the combined process is possible as an alternative way to produce energy.Furthermore,combining anaerobic digestion and direct combustion of lignocellulosic waste can contribute to reducing greenhouse gas emissions.

Outdoor cultivation of microalgae in a coal-fired power plant for conversion of flue gas CO_(2)into microalgal direct combustion fuels

Microalgae have piqued renewed interest as a sustainable biofuel feedstock owing to their high CO_(2)conversion efficiency.However,the major limitation of microalga-based biofuel production is low productivity.In this study,CO_(2)in flue gas emitted from the coal-fired power plants was fixed through mass microalgal cultivation using only sunlight as an energy source.To minimize the cost and energy required to supply the flue gas and efficiently utilize the microalgal biomass,a polycarbonate(PC)greenhouse and polymeric photobioreactors were installed near the power plant stack.Four different microalgal strains(Chlamydomonas reinhardtii,Chlorella sorokiniana,Neochloris oleoabundans,and Neochloris oleoabundans#13)were subjected to semi-continuous culturing for 1 month.The maximum biomass productivity was achieved by the N.oleoabun-dans#13 strain(0.703 g L^(−1)day^(−1)).Additionally,polymerase chain reaction analysis revealed that the individual microalgal culture was not cross-contaminated with other microalgal cultures in this cultivation system,owing to the structural proper-ties of photobioreactor comprising individual modules.The lipid content and calorific productivity of N.oleoabundans#13 biomass were 45.70%and 3.553 kJ L^(−1)day^(−1),respectively,which indicate satisfactory performance of biomass as a direct combustion fuel.The CO_(2)fixation rate,which was calculated based on the carbon content in the biomass,was 0.309 g CO_(2)L^(−1)day^(−1).Therefore,large amounts of CO_(2)can be reduced using the large-scale microalgal cultivation system,which enables efficient biological CO_(2)conversion and maximizes microalgal biomass utilization.

Replacement of Diesel Generator Sets in Isolated Communities with More Efficient Biomass Combustion Process

Electrical power supply to communities isolated from urban areas is typically complex and expensive. Their geographical situation and the lack of infrastructure and qualified workforce impede the provision of electricity. Many are the sources of energy available, but few are appropriate or sustainable. Combustion of diesel fuel is a good technical solution; however, it is neither economic nor environmentally tenable. This paper presents the advantages of using biomass as an energy source, along with its potential increase in efficiency when steam is generated in specific circumstances of temperature and pressure.

A review of engine application and fundamental study on turbulent premixed combustion of hydrogen enriched natural gas

The application and fundamental study on turbulent premixed combustion of hydrogen enriched natural gas is reviewed in this paper.Discussions include the combustion characteristics of direct injection engine fueled with hydrogen enriched natural gas,visualization study of direct injection combustion of hydrogen enriched natural gas using a constant volume vessel,and the fundamental study of turbulent premixed combustion of hydrogen enriched natural gas.The effect of additional hydrogen on the combustion process of natural gas engine is investigated from the fundamental view of the interaction between combustion reaction and turbulent flow.