Effect of species, particle size and compacting pressure on relaxed density and compressive strength of fuel briquettes

Abstract

Reversible solid oxide cells can provide efficient and cost-effective scheme for electrical-energy storage applications. However, this technology faces many challenges from material development to system-level operational parameters , which should be tackle for practical purposes. Accordingly, this study focuses on developing novel robust artificial intelligence-based blackbox models to optimize operational variables of the system. A genetic-programming algorithm is used for Pareto modeling of reversible solid oxide cells in a multi-objective fashion based on experimental input-output data. The robustness of the obtained optimal model evaluated using Monte Carlo simulations technique. An optimization study adopted to optimize the operating parameters, such as temperature and fuel composition using a differential evolution algorithm. The objective functions that have been considered for Pareto multi-objective modeling process are training error and model complexity. In addition, the discrepancy between maximum and minimum output voltage in the whole operation of the system is chosen as the optimization process objective function. The robustness of the optimal trade-off model is shown in terms of statistical indices for varied uncertainty levels from 1 to 10%. The optimized operational condition based on the suggested model reveals optimal intermediate temperature of 762 °C and fuel mixture of about 29% H 2 , 25% H 2 O, and 14% CO.

Characterization and Production of Fuel Briquettes Made from Biomass and Plastic Wastes

“…The average particle size determined was 0.1466 mm for date palm trunk and of 2 mm for sawdust. These results confirmed that small particle sizes favor the densification of the material as this type of particles have greater surface area during the compaction, as already said in different studies [48,49]. Other reason, as mentioned, is the different lignin content of these two biomass feedstocks.…”

Characterization and Production of Fuel Briquettes Made from Biomass and Plastic Wastes

“…For that purpose, a Coulter LS−230 laser light−scattering apparatus (BeckmanCoulter, Miami, FL) was used, being the average particle size determined of 0.1466 mm for date palm trunk and of 2 mm for sawdust. These results confirmed that small particle size could favor the densification of the material as this type of particles have greater surface area during the compaction, as already said in different studies [48,49]. Other reason, as mentioned, is the different lignin content of these two biomass feedstocks.…”

Effects of operating variables on durability of fuel briquettes from rice husks and corn cobs

“…The variability of biomass materials have resulted in inconsistency in the characteristics of fuel briquettes produced from different types of residues [8,57], this may even apply to the same type of residues grown at different season or different locations. It becomes necessary to understand the influence of the variability on biomass densification and fuel briquette's quality.…”

“…Briquettes manufactured at lower pressures of 30 to 60 MPa crumble easily, while those produced at higher pressures of 150 to 250 MPa remain compacted and durable [57], for example, increasing the compaction pressure from 1 to 10 MPa increased the shear strength of briquettes from 2.8 x 10 -2 kPa to 9.6 x 10 -2 kPa [43]. Currently, efforts are directed towards improving the quality of fuel briquettes produced at lower pressures.…”