Thermo-acidic pretreatment of marine brown algae Fucus vesiculosus to increase methane production—a disposal principle for macroalgae waste from beaches

Thermo-Acidic Pretreatment of Beach Macroalgae from Rügen to Optimize Biomethane Production—Double Benefit with Simultaneous Bioenergy Production and Improvement of Local Beach and Waste Management

“…Different mechanical, thermal, enzymatic, and thermo-chemical pretreatment methods have been shown to have a great effect on the improvement of the methane yield [ 16 , 17 , 18 ]. In particular, mechanical maceration and chopping [ 18 , 19 ] and thermo-chemical pretreatment at medium temperature (~80 °C) and moderate acidity range (0.15 M–0.2 M HCl) [ 20 ] are two seemingly effective techniques for biomass disintegration. Thermo-acidic pretreatment has been tested on macroalgal species, such as L. japonica , to increase the biomass saccharification and to improve the output of microbial hydrogen production, showing promising results [ 21 , 22 , 23 ].…”

“…Different techniques to guarantee constant biomass supply and to monitor or predict the accumulation of seaweeds have been proposed, such as hydrodynamic models [ 38 ] and beach monitoring systems [ 30 ]. Barbot et al (2014) [ 20 ] suggest a waste management concept in which beach macroalgal biomass is pretreated using other process waste products, such as flue gas condensate and waste heat from combustion processes, to increase the biomethane output. The accumulation of heavy metals in marine biomass has been detected in marine areas suffering from strong discharges of industrial wastes which lack proper distribution via tidal activity, such as the Baltic Sea shore [ 39 ].…”

“…To increase the biomethane conversion efficiency, thermo-chemical acid hydrolysis pretreatment using industry-grade acid (HCl) and FGC is performed to enhance substrate degradation and to facilitate microbial conversion. As hydrolysis is known to represent a key step in the rate of the anaerobic digestion process, and macroalgae composition is susceptible to mild pretreatment conditions, this approach is expected to be sufficient for adequate presolubilization of RM biomass [ 20 ]. With the intention to supply current running biogas plants, frequently operating with maize silage, with macroalgal biomass, a co-digestion approach of RM together with maize silage is analyzed with respect to BMP and CH 4 formation dynamics.…”

A Review of Seaweed Pre-Treatment Methods for Enhanced Biofuel Production by Anaerobic Digestion or Fermentation

“…The benefits of increased solubility of seaweed on biogas yields appeared quite limited after pre-treatment with NaOH or HCl (Table 6). Pre-treatment of F. vesiculosus with 0.2 M HCl (80 • C, 12 h) enhanced methane yield by almost 2.5 times compared to untreated seaweed and was 1.6 times higher than hydrothermal treatment (80 • C, 24 h) [146]. Comparatively, a similar treatment of Ulva spp.…”

Two-Stage Dry Anaerobic Digestion of Beach Cast Seaweed and Its Codigestion with Cow Manure

“…The use of macroalgae as a fertiliser on agricultural land for nonfood crops has been recommended [28]. In a recent study of the brown algae Fucus vesiculosus, the concentrations of heavy metals (Cd, 0.7; Pb, <1; Cr, 1; Cu, 4; Ni, 7; Hg < 0.04; and Zn, 87 mg/kg TS) were comparable to that of maize and the digestate was recommended for land application as a fertiliser [29]. Evaluation of the heavy metal content of seaweed is therefore recommended before application of seaweed or a mixture of seaweed and manure digestate as a fertiliser.…”