Biochemical methane potential of three-phase olive mill solid waste:Influence of temperature and supplemental enzymes

Methane potential of three-phase olive mill solid waste(3POMSW)was evaluated by biochemical methane potential(BMP)tests at temperatures of 37.5◦C and 55◦C.The results have shown,that thermophilic processing has a higher methane and biogas yield by 10%and 17.2%,respectively,compared to mesophilic conditions.Concluding thermophilic conditions of 3POMSW results in higher conversion of the feedstock into biogas.The result of addition of enzymes(MethaPlus,Hemicellulase,PectinaseL,Amylase S and Lipase)and their mixtures to 3POMSW at 55◦C has shown that the optimum mixture of enzymes was Metha Plus and Hemicellulase,which resulted in an increase of methane yield by 1.3%compared to the base case without addition of enzymes.Simple model equations were developed based on first-order kinetic in order to calculate the biogas yield versus the time as a function of reaction rate constant(k)and the maximum biogas yield(ymax).In this study,results have shown two different reaction rates obtained for the mixtures of enzymes with 3POMSW of 0.130 d^(-1) from t=0…14 days and 0.034 d^(-1) from t=28…63 days.The developed simple model equations can be applied for calculating the biogas yield at the time and by optimizing the process improving biological nutrient removal.

Mineral analysis of sandstone formation using chelating agents during sandstone matrix acidizing

For many years,the most common acid practice for sandstone acidizing is based on mud acid and dolomite formations using hydrochloric acid.During various stages of sandstone acidizing,different acids react with different minerals,and interactions of minerals with acids are an origin for precipitation reactions,which can be possibly deleterious as they may reduce reservoir permeability.During this research,the effects of chelates on pore size distribution,mineralogy,and grain size distribution have been investigated.Various chelates(GLDA,HEDTA,EDTA)were examined to react with different Berea Sandstone samples at a temperature of 180F and under 1000 psi confining pressure.Experimental techniques and analysis like Tescan Integrated Mineral Analysis(TIMA),were implemented in this research to understand the effect of chelates on Berea Sandstone.These results are related to elemental mass,element deportment,mineral mass,mineral locking,grain size distribution,and particle size distribution of the core samples reacted with different chelating agents.It has been found that all the chelating agents are effective in increasing the porosity and dissolving the cations from the Berea sandstone core sample.HEDTA proved to be more effective in dissolving quartz as compared to other chelates.GLDA proved to be more effective in the dissolution of rutile and zircon minerals.The significance of this research is the application of environment-friendly chelating agents to sandstone formation.Moreover,the detailed mineral analysis revealed that the most number of particles were dissolved by HEDTA.