Insights into correlation between hydrogen yield improvement and glycerol addition in photo-fermentation of Arundo donax L.

This study aimed to explore the correlation between hydrogen yield improvement of photo-fermentation of Arundo donax L. and glycerol addition. Different glycerol concentrations (g/L) (0, 10, 15, 20, and 30) were replenished to establish co-substrate system.

Effect of alkaline pretreatment on photo-fermentative hydrogen production from giant reed: Comparison of NaOH and Ca(OH).

Giant reed was the first time used for photo-fermentative hydrogen production with HAU-M1 bacteria. Effects of NaOH and Ca(OH) pretreatments of giant reed on structural changes, enzymatic digestibility, hydrogen production, and energy conversion efficiency were evaluated. Compared to Ca(OH) pretreatment, NaOH pretreatment removed more dry matter and lignin at the same loading.

Macromolecular crowding effects on transcription and translation are regulated by free magnesium ion.

Cell-free metabolic engineering is an emerging and promising alternative platform for the production of fuels and chemicals. In recent years, macromolecular crowding effect, which is an important function in living cells but ignored in cell-free systems, has been transferred to cell-free protein synthesis (CFPS). However, inhibitory effects of crowding agents on CFPS were frequently observed, and the mechanism is unclear.

Sequential dark and photo fermentation hydrogen production from hydrolyzed corn stover: A pilot test using 11 m reactor.

Pilot tests of sequential dark and photo fermentation H production were for the first time conducted in a 11 m reactor (3 m for dark and 8 m for photo compartments). A combined solar and light-emitting diode illumination system and a thermal controlling system was installed and tested. With dark fermentation unit maintained at pH 4.

Anaerobic digestion of food waste - Challenges and opportunities.

The disposal of large amounts of food waste has caused significant environmental pollution and financial costs globally. Compared with traditional disposal methods (i.e.

Effect of substrate concentration on hydrogen production by photo-fermentation in the pilot-scale baffled bioreactor.

Effect of substrate concentration on photo-fermentative hydrogen production was studied with a self-designed 4m pilot-scale baffled photo-fermentative hydrogen production reactor (BPHR). The relationships between parameters, such as hydrogen production rate (HPR, mol H/m/d), hydrogen concentration, pH value, oxidation-reduction potential, biomass concentration (volatile suspended solids, VSS) and reducing sugar concentration, during the photo-fermentative hydrogen production process were investigated. The highest HPR of 202.

Comparison of sodium hydroxide and calcium hydroxide pretreatments of giant reed for enhanced enzymatic digestibility and methane production.

NaOH pretreatment with leachate reuse and Ca(OH) pretreatment were compared for improved enzymatic digestibility and biogas production from giant reed, a promising energy crop. The NaOH pretreatment with leachate reuse increased glucose yields during enzymatic hydrolysis by 2.6-fold, and methane yields during anaerobic digestion by 1.

Photo-fermentative hydrogen production from crop residue: A mini review.

Photofermentative hydrogen production from crop residues, if feasible, can lead to complete conversion of organic substances to hydrogen (and carbon dioxide). This mini review lists the studies on photofermentative hydrogen production using crop residues as feedstock. Pretreatment methods, substrate structure, mechanism of photosynthetic bacteria growth and metabolism were discussed.

Comparison of liquid hot water and alkaline pretreatments of giant reed for improved enzymatic digestibility and biogas energy production.

Liquid hot water (LHW) and alkaline pretreatments of giant reed biomass were compared in terms of digestibility, methane production, and cost-benefit efficiency for electricity generation via anaerobic digestion with a combined heat and power system. Compared to LHW pretreatment, alkaline pretreatment retained more of the dry matter in giant reed biomass solids due to less severe conditions. Under their optimal conditions, LHW pretreatment (190°C, 15min) and alkaline pretreatment (20g/L of NaOH, 24h) improved glucose yield from giant reed by more than 2-fold, while only the alkaline pretreatment significantly (p<0.

Recovery of failed solid-state anaerobic digesters.

This study examined the performance of three methods for recovering failed solid-state anaerobic digesters. The 9-L digesters, which were fed with corn stover, failed at a feedstock/inoculum (F/I) ratio of 10 with negligible methane yields. To recover the systems, inoculum was added to bring the F/I ratio to 4.

Value-added processing of crude glycerol into chemicals and polymers.

Crude glycerol is a low-value byproduct which is primarily obtained from the biodiesel production process. Its composition is significantly different from that of pure glycerol. Crude glycerol usually contains various impurities, such as water, methanol, soap, fatty acids, and fatty acid methyl esters.

Comparison between ensilage and fungal pretreatment for storage of giant reed and subsequent methane production.

Ensilage and fungal pretreatment of giant reed harvested from August through December were compared based on their effects on feedstock preservation, glucose yield, and subsequent methane production via anaerobic digestion (AD). Compared to fungal pretreatment, ensilage obtained lower total solids (<1.2%) and cellulose (<3.

Solid-state anaerobic digestion of lignocellulosic biomass: Recent progress and perspectives.

Solid-state anaerobic digestion (SS-AD), which has gained popularity in the past decade as an environmentally friendly and cost-effective technology for extracting energy from various types of lignocellulosic biomass, is reviewed in this paper. According to data of biomass and methane yields of lignocellulosic feedstocks, crop residues have the highest methane production potential in the U.S.

Effect of harvest date on Arundo donax L. (giant reed) composition, ensilage performance, and enzymatic digestibility.

Composition and ensilage performance of giant reed harvested in August, October, November, and December, were evaluated and compared. Generally, late-harvested giant reed had higher dry matter content, lower nitrogen content, and higher water soluble carbohydrates (WSC) content than early-harvested giant reed. During 90days of ensilage, giant reed harvested in October, November, and December showed dry matter losses of about 1%, while giant reed harvested in August showed a higher dry matter loss of about 8%.

Fungal pretreatment of non-sterile miscanthus for enhanced enzymatic hydrolysis.

Miscanthus was pretreated with the fungus Ceriporiopsis subvermispora under non-sterile conditions, using sterile miscanthus that had been previously colonized with the fungus as the inoculum. Inoculum ratios equal to or greater than 30% yielded a successful pretreatment, enhancing the enzymatic digestibility of miscanthus by 3- to 4-fold over that of raw miscanthus, which was comparable with the fungal pretreatment under sterile conditions. This enhanced digestibility was linearly correlated with lignin degradation.

Biological conversion of biogas to methanol using methanotrophs isolated from solid-state anaerobic digestate.

The aim of this work was to isolate methanotrophs (methane oxidizing bacteria) that can directly convert biogas produced at a commercial anaerobic digestion (AD) facility to methanol. A methanotrophic bacterium was isolated from solid-state anaerobic digestate. The isolate had characteristics comparable to obligate methanotrophs from the genus Methylocaldum.

Beyond land application: Emerging technologies for the treatment and reuse of anaerobically digested agricultural and food waste.

Effective treatment and reuse of the massive quantities of agricultural and food wastes generated daily has the potential to improve the sustainability of food production systems. Anaerobic digestion (AD) is used throughout the world as a waste treatment process to convert organic waste into two main products: biogas and nutrient-rich digestate, called AD effluent. Biogas can be used as a source of renewable energy or transportation fuels, while AD effluent is traditionally applied to land as a soil amendment.

Effect of urea addition on giant reed ensilage and subsequent methane production by anaerobic digestion.

The effect of urea addition on giant reed ensilage and sequential anaerobic digestion (AD) of the ensiled giant reed was evaluated. The dry matter loss during ensilage (up to 90 days) with or without urea addition was about 1%. Addition of 2% urea enhanced production of lactic acid by about 4 times, and reduced production of propionic acid by 2-8 times.

Cultivation of marine microalgae using shale gas flowback water and anaerobic digestion effluent as the cultivation medium.

The potential of shale gas flowback water and anaerobic digestion (AD) effluent to reduce the water and nutrient requirements for marine microalgae cultivation was evaluated with the following strains: Nannochloropsis salina, Dunaliella tertiolecta, and Dunaliella salina. N. salina and D.

Integration of Shiitake cultivation and solid-state anaerobic digestion for utilization of woody biomass.

Pretreatment technologies that can not only reduce the recalcitrance of woody biomass but also achieve a high benefit-cost ratio are desirable for bioenergy production from woody biomass. In this study, an integrated process was proposed and conducted by pretreating woodchips via Shiitake cultivation for improved methane yield during solid-state anaerobic digestion (SS-AD), and simultaneously producing mushrooms as a high-value co-product. Shiitake cultivation using woodchips as the main substrate ingredient obtained mushroom yields comparable to those using a commercial substrate.

Effect of limited air exposure and comparative performance between thermophilic and mesophilic solid-state anaerobic digestion of switchgrass.

Switchgrass is an attractive feedstock for biogas production via anaerobic digestion (AD). Many studies have used switchgrass for liquid anaerobic digestion (L-AD), but few have used switchgrass for solid-state anaerobic digestion (SS-AD). Limited air exposure to the reactor headspace has been adopted in commercial scale anaerobic digesters for different applications.

Biological conversion of methane to liquid fuels: status and opportunities.

Methane is the main component of natural gas and biogas. As an abundant energy source, methane is crucial not only to meet current energy needs but also to achieve a sustainable energy future. Conversion of methane to liquid fuels provides energy-dense products and therefore reduces costs for storage, transportation, and distribution.

Solid-state anaerobic co-digestion of spent mushroom substrate with yard trimmings and wheat straw for biogas production.

Spent mushroom substrate (SMS) is a biomass waste generated from mushroom production. About 5 kg of SMS is generated for every kg of mushroom produced. In this study, solid state anaerobic digestion (SS-AD) of SMS, wheat straw, yard trimmings, and their mixtures was investigated at different feedstock to effluent ratios.

Biogas energy production from tropical biomass wastes by anaerobic digestion.

Anaerobic digestion (AD) is an attractive technology in tropical regions for converting locally abundant biomass wastes into biogas which can be used to produce heat, electricity, and transportation fuels. However, investigations on AD of tropical forestry wastes, such as albizia biomass and food wastes, such as taro, papaya, and sweet potato, are limited. In this study, these tropical biomass wastes were evaluated for biogas production by liquid AD (L-AD) and/or solid-state AD (SS-AD), depending on feedstock characteristics.

Fungal pretreatment of unsterilized yard trimmings for enhanced methane production by solid-state anaerobic digestion.

Fungal pretreatment is an environmentally friendly process that has been widely studied to improve the digestibility of lignocellulosic biomass. However, sterilization of feedstocks, a costly process, is generally required prior to the fungal pretreatment. In this study, fungal pretreatment of unsterilized yard trimmings using yard trimmings pre-colonized with Ceriporiopsis subvermispora as an inoculum was investigated.