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The catalytic steam gasification of bio-oil/biochar slurry (bioslurry) for hydrogen-rich syngas production was investigated in a fixed-bed reactor using LaXFeO3 (X=Ce, Mg, K) perovskite-type catalysts. The effects of elemental substitution in LaFeO3, temperature, water to carbon molar ratio (WCMR) and bioslurry weight hourly space velocity (WbHSV) were examined. The results showed that La0.8Ce0.2FeO3 gave the best performance among the prepared catalysts and had better catalytic activity and stability than the commercial 14 wt.% Ni/Al2O3. The deactivation caused by carbon deposition and sintering was significantly depressed in the case of La0.8Ce0.2FeO3 catalyst. Both higher temperature and lower WbHSV contributed to more H2 yield. The optimal WCMR was found to be 2, and excessive introducing of steam reduced hydrogen yield. The La0.8Ce0.2FeO3 catalyst gave a maximum H2 yield of 82.01% with carbon conversion of 65.57% under the optimum operating conditions (temperature=800°C, WCMR=2 and WbHSV=15.36h(-1))., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Hydrogen is crucial in achieving global energy transition and carbon neutrality goals. Existing market estimates typically presume linear or exponential growth but fail to consider how market demand responds to the declining cost of underlying technologies. To address this, this study utilizes a learning curve model to project the cost of electrolyzers and its subsequent impact on hydrogen market, aligning with a premise that the market demand is proportional to the cost of hydrogen. In a case study of China's hydrogen market, projecting from 2020 to 2060, we observed substantial differences in market evolution compared to exponential growth scenarios. Contrary to exponential growth scenarios, China's hydrogen market experiences faster growth during the 2020–2040 period rather than later. Such differences underscore the necessity for proactive strategic planning in emerging technology markets, particularly for those experiencing rapid cost decline, such as hydrogen. The framework can also be extended to other markets by using local data, providing valuable insights to investors, policymakers, and developers engaged in the hydrogen market. [ABSTRACT FROM AUTHOR]

The increasing penetration of renewable and distributed resources signals a global boom in energy transition, but traditional grid utilities have yet to share in much of the triumph at the current stage. Higher grid management costs, lower electricity prices, fewer customers, and other challenges have emerged along the path toward renewable energy, but many more opportunities await to be seized. Most importantly, there are insufficient studies on how grid utilities can thrive within the hydrogen economy. Through a case study on the State Grid Corporation of China, we identify the strengths, weaknesses, opportunities, and threats (SWOT) of grid utilities within the hydrogen economy. Based on these factors, we recommend that grids integrate hydrogen into the energy-as-a-service model and deliver it to industrial customers who are under decarbonization pressure. We also recommend that grid utilities fund a joint venture with pipeline companies to optimize electricity and hydrogen transmissions simultaneously. [ABSTRACT FROM AUTHOR]

Waste rice husk char supported Fe and Ni were synthesized to prepare the monometallic and bimetallic catalysts for removing the tar model compound benzene in a laboratory dual-stage reactor. The prepared catalysts were examined by microstructure and textural characterization to analyse catalytic performance and stability. The molar proportions of CO, H 2 , CO 2 and CH 4 in the generated gas and the influence of residence time (τ) and the steam-to-carbon ratio (S/C) on the catalytic reaction were investigated. The results show that the rice husk char-based catalysts showed excellent catalytic activity for syngas production and benzene conversion. Under optimized conditions, the benzene conversion can reach 95.2%, and the mol% of syngas in the generated gas is greater than 93.0%, of which 91.0% is H 2. The experimental results show that the influence of residence time on catalytic performance is greater than that of the steam-to-carbon ratio, and that excessive τ or S/C values will have no more positive effect on the performance of the catalyst. The stable active sites on the catalyst surface can guarantee the catalytic activity in the reaction. Ultimately, rice husk char-based catalysts can be used to remove tar and produce syngas. • The as-synthesized catalysts show excellent selectivity for syngas (93.0%–93.8%). • The benzene conversion can reach 95.2% under the optimized conditions. • The mol% of H 2 in the generated gas can reach 91.0%. • Bimetallic (Fe/Ni) catalysts can combine the advantages of two metal elements. • The Fe–Ni/rice husk char catalyst still has good catalytic capacity after 10 h. [ABSTRACT FROM AUTHOR]

Pyrolytic catalysis technology has been considering a promising strategy to convert waste plastics into high-value products from economic and environmental perspectives. The design of efficient catalysts plays a key role in product distribution. In this study, Ni-supported hierarchical ZSM-5 (designated as Ni/ZSM-5-M) was developed for the pyrolytic catalysis of polyethylene (PE) to produce carbon nanotubes (CNTs) and hydrogen by using two-stage fixed bed reactor. Results showed that the Ni/ZSM-5-M catalyst generated the highest carbon material yield of 43.8 wt% and the maximum hydrogen production of 5.2 wt% about 26.27 mmol/gPE. In order to understand the correlation between catalysts structure and products, the essential structural characteristics of as-prepared catalyst were characterized by the comprehensive approach such as SEM, TEM, XRD, TPR and so on. The results indicated that alkali treatment introduced a hierarchical structure and significantly improved the dispersion of Ni particles, producing a catalyst surface area of 356 m2/g and average Ni particle size of ∼14.8 nm, which further enhancing catalytic activity for the production of hydrogen and CNTs. The Ni/ZSM-5-M catalyst produced a higher yield of carbon deposits (43.8 wt%), including over 66% high-value CNTs (289 mg/gPE) and hydrogen yield (5.2 mg/gPE). This study suggests alkali modification method to prepare Ni/ZSM-5-M catalyst is a promising way to promote the production of valuable CNTs and hydrogen from waste plastics. • Ni-supported hierarchical ZSM-5 catalyst was prepared for polyethylene pyrolysis. • Ni active metal disperses well and has small particles. • The Ni/ZSM-5 show excellent selectivity for carbon nanomaterials (40.8%). • The yield of hydrogen reached 26.27 mmol/gPE. • The carbon nanotubes have high purity and graphitization degree. [ABSTRACT FROM AUTHOR]

• The catalytic ability of HZSM-5 and activated carbon as carrier was compared. • Activated carbon with disordered structure has better H 2 production performance. • The hydrogen yield can reach 0.27 g/g PP under the optimized conditions. • A stable Ni-Fe co-crystal is present in the bimetallic catalyst. • The presence of Ni enhances the dispersion uniformity of Fe in bimetallic catalyst. Hydrogen production by catalytic pyrolysis of waste plastics has attracted extensive attention in recent years. This paper takes hydrogen production as the starting point. A variety of supported nickel catalysts were developed for the catalytic pyrolysis of polypropylene using a two-stage fixed bed reactor. Based on the better characteristics of bimetallic catalysts, calcium, magnesium, iron doped nickel bimetallic catalysts were prepared to explore the improvement effect of catalytic hydrogen production performance. The micromorphology, structure composition and active substance distribution of different supported catalysts and bimetallic catalysts were measured. The experimental results show that the catalyst with powdered activated carbon as the support has the best catalytic performance of hydrogen production. In a series of molecular sieve catalysts, the smaller the Si/Al ratio of the support, the higher the catalytic performance. Among the bimetallic catalysts, Fe-Ni bimetallic catalysts have better catalytic advantages than Ca-Ni and Mg-Ni bimetallic catalysts, which is closely related to the stable Fe-Ni alloy structure formed on the catalyst surface. In conclusion, the differences in catalytic performance between catalyst support and active metal discussed in this paper will provide theoretical support for the catalytic pyrolysis technology of plastics to produce hydrogen. [ABSTRACT FROM AUTHOR]

The removal of biomass tar is the key technology in the pyrolysis and gasification technology, and the advantages of solid waste pyrolysis char in tar removal gradually become prominent. In this paper, the tar model compound (benzene) was catalytic reformed by a novel hybrid carrier catalysts using a laboratory dual-stage reactor. The hybrid carrier catalyst was prepared by wet impregnation method with nickel active substance, and the carrier was a two-material mixture of peat char and sludge char. In the reaction of steam reforming benzene, the effects of temperature (600–800 °C) and nickel load (5%–20%) on benzene conversion were investigated, showing that the catalyst have good benzene removal ability (91.8%) and the gas product with high syngas content (93.6%) was obtained. The surface properties of the catalyst was detected by SEM, EDS, BET and XRD detection, in order to prove that the catalytic performance was related to surface nanoparticles and abundant active sites. The novel hybrid carrier catalyst can effectively remove the aromatic tar and produce syngas with high performance. • A novel PC-SC based Ni catalyst was prepared for benzene removal. • The benzene conversion can reach 91.8% under the optimized conditions. • The as-synthesized catalysts show excellent selectivity for syngas (93.6%). • The active substance is present in the form of Ni and NiSi. • The selectivity for CO 2 increased gradually with the increase of time. [ABSTRACT FROM AUTHOR]

LaCo 1− x Cu x O 3 ( x = 0, 0.1, 0.2, 0.3) perovskite-type catalysts were prepared, characterized and tested for hydrogen-rich syngas production from steam gasification of bio-oil/biochar slurry (bioslurry). The effects of the Cu-substitution, temperature, water to carbon molar ratio (WCMR) and bioslurry weight based hourly space velocity (W b HSV) on the hydrogen (H 2 ) yield were investigated. The results showed that the activity of LaCoO 3 was improved by Cu-substitution. LaCo 0.9 Cu 0.1 O 3 exhibited the best performance and gave higher H 2 yield and higher carbon conversion than that of non-catalytic process and also that of commercial 14 wt% Ni/ZrO 2 . Coke deposition could be depressed by higher temperature, higher WCMR or lower W b HSV, while higher temperature and lower W b HSV made for higher H 2 yield. 2 was deemed to be the optimum WCMR. A maximum H 2 yield of 75.33% and a maximum carbon conversion of 80.42% were obtained at 800 °C with a combination of WCMR = 2 and W b HSV = 15.36 h −1 . [ABSTRACT FROM AUTHOR]

Hydrogen-rich syngas production from the catalytic steam reforming of bio-oil from fast pyrolysis of pinewood sawdust was investigated by using La 1−x K x MnO 3 perovskite-type catalysts. The effects of the K substitution, temperature, water to carbon molar ratio (WCMR) and bio-oil weight hourly space velocity (W b HSV) on H 2 yield, carbon conversion and the product distribution were studied in a fixed-bed reactor. The results showed that La 1−x K x MnO 3 perovskite-type catalysts with a K substitution of 0.2 gave the best performance and had a higher catalytic activity than the commercial Ni/ZrO 2 . Both high temperature and low W b HSV led to higher H 2 yield. However, excessive steam reduced hydrogen yield. For the La 0.8 K 0.2 MnO 3 catalyst, a hydrogen yield of 72.5% was obtained under the optimum operating condition (T = 800 °C, WCMR = 3 and W b HSV = 12 h −1 ). The deactivation of the catalysts mainly was caused by coke deposition. [ABSTRACT FROM AUTHOR]