Preparation of Bio-hydrogen and Bio-fuels from Lignocellulosic Biomass Pyrolysis-Oil

In recent years, production of engine fuels and energy from biomass has drawn much interest. In this work, we conducted a novel integrated process for the preparation of bio-hydrogen and bio-fuels using lignocellulosic biomass pyrolysis-oil （bio-oil）. The process includes （i） the production of bio-hydrogen or bio-syngas by the catalytic cracking of bio-oil, （ii） the adjustment of bio-syngas, and （iii） the production of bio-fuels by ole nic polymerization （OP） together with Fischer-Tropsch synthesis （FTS）. Under the optimal conditions, the yield of bio-hydrogen was 120.9 g H2/（kg bio-oil）. The yield of hydrocarbon bio-fuels reached 526.1 g/（kg bio-syngas） by the coupling of OP and FTS. The main reaction pathways （or chemical processes） were discussed based on the products observed and the catalyst property.

Valorization of Agricultural Residues for Hydrogen-Based Electricity Generation towards Circular Bioeconomy

Global crises, notably climate shocks, degraded ecosystems, and growing energy demand, enforce sustainable production and consumption pathways. A circular bioeconomy offers the opportunities to actualize resource and eco-efficiency enhancement, valorization of waste streams, reduction of fossil energy and greenhouse gas (GHG) emissions. Albeit biomass resources are a potential feedstock for bio-hydrogen (bio-H2) production, Ghana’s agricultural residues are not fully utilized. This paper examines the economic and environmental impact of bio-H2 electricity generation using agricultural residues in Ghana. The bio-H2 potential was determined based on biogas steam reforming (BSR). The research highlights that BSR could generate 2617 kt of bio-H2, corresponding to 2.78% of the global hydrogen demand. Yam and maize residues contribute 50.47% of the bio-H2 produced, while millet residues have the most negligible share. A tonne of residues could produce 16.59 kg of bio-H2 and 29.83 kWh of electricity. A total of 4,705.89 GWh of electricity produced could replace the consumption of 21.92% of Ghana’s electricity. The economic viability reveals that electricity cost is $0.174/kWh and has a positive net present value of $2135550609.45 with a benefit-to-cost ratio of 1.26. The fossil diesel displaced is 1421.09 ML, and 3862.55 kt CO2eq of carbon emissions decreased corresponding to an annual reduction potential of 386.26 kt CO2eq. This accounts for reducing 10.26% of Ghana’s GHG emissions. The study demonstrates that hydrogen-based electricity production as an energy transition is a strategic innovation pillar to advance the circular bioeconomy and achieve sustainable development goals.

Effect of hydraulic retention time on the hydrogen yield and population of Clostridium in hydrogen fermentation of glucose

The conversion of glucose to hydrogen was evaluated using continuous stirred tank reactor at pH 5.5 with various hydraulic retention times （HRT） at 30℃. Furthermore, the population dynamics of hydrogen-producing bacteria was surveyed by fluorescence in-situ hybridization using probe Clost IV targeting the genus Clostridium based on 16S rRNA. It was clear that positive correlation was observed between the cells quantified with probe Clost IV and hydrogen yield of the respective sludge. The numbers of hydrogen- producing bacteria were decreased gradually with increasing HRT, were 9.2 × 10^8, 8.2 × 10^8, 2.8 × 10^8, and 6.2 × 10^7 cell/mL at HRT 6, 8, 12, and 14 h, respectively. The hydrogen yield was 1.4-1.5 mol H2/mol glucose at the optimum HRT range 6-8 h. It is considered that the percentage of the hydrogen-producing bacteria to total bacteria is useful parameter for evaluation of hydrogen production process.

Rheological Characterization of a Mixed Fruit/Vegetable Puree Feedstock for Hydrogen Production by Dark Fermentation

Bio-hydrogen (Bio-H2) production from the organic fraction of solid waste, as fruit and vegetable wastes, constitutes an interesting and feasible technology to obtain clean energy. In spite of the feasibility to produce Bio-H2 from fruit/vegetable wastes (FVW), data about its rheological characterization are scarce. This information is useful to establish the hydrodynamic behavior, which controls the overall mixing process when the feedstock for Bio-H2 production process is a mixture of FVW. In this work, the rheological behavior of a vegetable/fruit waste mixture was characterized. The effect of the solids content (%, w/w), temperature, time (tyxotropy effects) and shear rate over the apparent viscosity of the mixture was evaluated. Most of the mixtures showed non-Newtonian behavior. The curves are typical rheofluidizing fluids. The rheological curves were different at increasing solids contents (80%, 60%, 40% and 30%), independent from the temperature. Rheological data were fitted to the power law model. Correlation factors R2 for the different mixtures were 0.991-0.995 for 80%, 0.961 -0.986 for 60%, 0.890 -0.925 for 40%. In the case of 30% of solids, the R2 value was not acceptable, and it was also found that this mixture was very near to the Newtonian behavior. Calculated activation energies (Ea) values were 15.98, 14.89 and 20.96 kJ/mol for the 80%, 60%, 40% mixtures, respectively. FVW purees rheological behavior was well characterized by Carbopol solutions at given concentrations and pH values. This fluid can be used as a model for other studies, e.g. LDA (Laser Doppler Anemometry) and PIV (Particle Image Velocimetry).

Fermentative bio-hydrogen production using lignocellulosic waste biomass:a revie

Solid waste management needs,increasing pollution level by burning or dumping of waste,and the use of fossil fuels and depleting energy resources are a few of the problems of the decade that need to find answers.Disposal of lots of compound polymers-rich biomass waste is done worldwide by dumping on land or into water bodies or else by incineration or long-term storage in an available facility commonly.This kind of disposal instead becomes a reason to add the soil,water,and air pollution.A lot of multidisciplinary collaboration in different streams of science and technology has added to the efficiency of using such waste for use as an alternative energy form,like biogas and biohydrogen.The use of biogas plants for converting biological waste into methane using municipal solid waste(MSW)is known since a long time.Along with MSW,a lot of other agricultural waste and kitchen waste are also added every day to nature.But the complex components of such waste material like lignocellulosic wastes still don’t pass the test of qualifying as a resource for biogas and even more energy-efficient and cleaner biofuel,bio-hydrogen.It may be because of its complicated structure and a lot of parameters that affect its use for converting it into bio-hydrogen.This review is designed to analyze and compare these parameters for optimum lignocellulosic waste conversion,more specifically agriculture and food waste,into cleaner energy forms that would help to tackle the solid waste management and air pollution control more effectively.

CFD modeling and experiment of heat transfer in a tubular photo-bioreactor for photo-fermentation bio-hydrogen production

Temperature is one of the most important parameters that need to be controlled in photo-fermentation bio-hydrogen production(PFHP)system.Since the high temperature and big temperature fluctuation have adverse impacts on bio-hydrogen yield,the system numerical simulation based on the operating conditions and environmental factors is desirable.This research focused on the investigation of heat transfer properties of the PFHP system.Enzymatic hydrolysate from agricultural residues was taken as substrate,and up-flow tubular photo-bioreactor was adopted for PFHP.Temperatures inside the photo-bioreactor were monitored.The experimental design and computational modeling for the determination of the heat transfer behavior in tubular photo-bioreactor was presented.Energy balance analysis was conducted to determine the energy efficiency,and optimize the operation parameters in order to obtain higher energy efficiency.The commercial software FLUENT was also adopted in order to predict the transient temperature distribution in the photo-bioreactor.The results showed that mathematical and computational modeling method has a clear potential for improving the performance of photo-bioreactor in the process of PFHP.Up-flow tubular bioreactor has tiny temperature fluctuant,and is suitable for PFHP.