Electricity Production Performance Of Algae Biomass In Fuel Cells

With the development of society,the inherent problems of traditional energy like depletion of raw materials,inefficient,environmental pollution become more and more serious,human need urgently to develop clean reproducible energy.Algae are considered to be one of the most promising renewable energy.Enteromorpha prolifera is a typical macroalgae and has the characteristic of high yield,high regeneration ability,easily growing,and rapid propagating.Its strong reproductive capacity in eutrophic water bodies will cause the green tide.Hence,it's of great significant to utilize Enteromorpha prolifera.In this paper,methods of national standard were used to analyze the composition of the dried Enteromopha prolifera biomass.It turned out that the content of polysaccharide is 50.72%,higer than general microalgae and macroalgae.Polysaccharide can be easily hydrolyzed to liquid mixture by acids or enzymes,the hydrolysates mainly contains lower molecular weight sugars and it's a source of bioenergy.Enteromopha prolifera was pretreated by diluted hydrochloric acid and controlling variables experiments were designed to detect the effect of dilute hydrochloric acid concentration,reaction temperature,reaction time on hydrolysis reaction.The best results were obtained with acid concentration of 2%,at170°C for 45min.The content of reducing sugar in hydrolysate was 18.15 g/L,and the yield was 27.23%under optimum condition.In the electricity production stage,we chose a methyl viologen modified nickel foam electrode(MV-Ni)as anode and a rolling air-diffusion electrode as cathode,developed a type of alkaline fuel cell contained no precious metal catalysts.Then we producted electricity by the alkaline fuel cell with Enteromorpha prolifera hydrolysates as fuel and KOH solution as electrolyte,and studied the influence factors on the performance such as the concentration of Enteromorpha prolifera hydrolysates and KOH.The results showed that the maximum power density can reach 3.81 W/m~2at room temperature under the condition of 3 M KOH and 18.15 g/L reducing sugar in hydrolysate,coulombic efficiency is 10.85%,higher than any other reported algae-fed fuel cells.In the meantime,it's varied that the Enteromorpha prolifera hydrolysates oxidized easier in alkaline fuel cell by comparing the electricity production performance of Enteromorpha prolifera hydrolysates and glucose solution at the same concentration.In addition,we contrasted a microbial fuel cell and studied the influence factors on electricity production like the concentration of hydrolysate and PBS.It turned out that the maximum power density can reach 0.64 W/m~2 when the Enteromorpha prolifera hydrolysates diluted 5.6 times,coulombic efficiency is 30.82%and within appropriate range,the cell's power density can be improved with the increasing of PBS concentration.