Publications by authors named "Ronghou Liu"

Although two-stage anaerobic digestion (TSAD) technology has been investigated, the mechanisms regarding the impact of acidogenic off-gas (AOG) on successive methane production have not been well addressed. In this study, a novel TSAD system was designed. Food waste, as the main substrate, was co-digested with chicken manure and corn straw.

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In this work, the corn straw (CS) with concentrations of 3%, 6%, and 9% (w/v) were pretreated by rumen fluid (RF) and then used for batched mesophilic biogas production. The results showed that after a 6-day pretreatment, volatile fatty acid (VFAs) production of 3.78, 8.

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The objective of this review is to encourage the technical development of biochar-assisted microbial fermentation. To this end, recent advances in biochar applications for microbial fermentation processes (i.e.

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Slurry reflux is a low-cost slurry reduction technology, which can solve the problem that a large amount of slurry cannot be completely consumed in a biogas plant. Anaerobic digestion (AD) of corn stalks with slurry reflux and non-reflux was compared and evaluated in continuous anaerobic digestion to clarify the effects of slurry reflux on AD with organic loading rate (OLR) variation. It was found that slurry reflux increased cumulative methane production and improved system stability.

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High impurity concentration of biogas limits its wide commercial utilization. Therefore, the integration of two-stage anaerobic digestion process with in situ biogas upgrading technologies is reviewed, with emphasis on their principles, main influencing factors, research success, and technical challenges. The crucial factors that influence these technologies are pH, alkalinity, and hydrogenotrophic methanogenesis.

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Article Synopsis
  • Py-GC/MS and thermogravimetric analysis were used to study the catalytic pyrolysis of poplar sawdust using a bi-metallic Fe-Ni/ZSM-5 catalyst, which enhanced the production of monocyclic aromatic hydrocarbons.
  • The Fe-Ni/ZSM-5 catalyst significantly increased toluene yield by 41.4% compared to Fe/ZSM-5 and 80.9% compared to Ni/ZSM-5.
  • Kinetic analysis indicated that the average activation energy for catalyzed pyrolysis was lower than that of non-catalytic pyrolysis, suggesting the process follows diffusion and nucleation models, with thermodynamic parameters showing non-spontaneous reactions.
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Co-digestion is known to effectively alleviate trace elements (TEs) deficiency in mono-substrates; however, the bioavailability of TEs is crucial for the stability of anaerobic digestion. Therefore, this study investigated the effects of co-digestion of food waste (FW), corn straw (CS) and chicken manure (CM) in two-stage anaerobic digestion on TEs bioavailability and microbial community composition. Various VS:(VSVS) ratios of 8:2, 7:3, 4:6, and 2:8 were evaluated in two-stage (group A, B, C, D) anaerobic digestion in which the VS:VS ratio was fixed at 3:1.

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Char-based catalyst has a promising application for biomass thermal conversion technology. In this work, Fe-Ni/Activated Char (AC) catalyst was prepared by impregnation method and used for the catalytic gasification of pine wood to obtain syngas. Further, the catalytic performance of Fe-Ni/AC was established by doing a comparative study of catalytic gasification of different biomass feedstocks.

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The synergistic effect of the cotton stalk (CS) and the high-ash coal (HAC) on the gas production in the co-pyrolysis/gasification processes was studied using the newly designed quartz boat in this work. The gas yield and the concentrations of main gas components were quantitatively compared between the co-pyrolysis/gasification and the individual pyrolysis/gasification. The results showed that the gas yield during the co-pyrolysis was promoted at 950℃.

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The performance of biochar mediated anaerobic co-digestion (co-AD) of corn stover (CS) and chicken manure (CM) using continuous stirred tank reactor (CSTR) was studied. Results showed that urea pretreated CS (UPCS) and biochar addition in anaerobic digestion (AD) system can improve co-AD. The effect of urea pretreatment is similar to that of biochar addition, and their synergistic effect was apparent under medium and high OLR conditions.

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The pretreatment effects and synergistic effects of anaerobic co-digestion of pretreated corn stover (CS) with chicken manure (CM) were studied. Results showed that the NaOH-HO pretreatment effect on CS was better than urea pretreatment in terms of anaerobic digestion promotion. The highest cumulative methane yield of 332.

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In this work, a 30-days batched mesophilic assay on pretreated food waste (PFW) under different inoculum/substrate (I/S) ratios (1:5, 1:2, 1:1, 2:1, 4:1 and 1:0) was carried out, to target the most important parameters in AD matrix on regulating iron (Fe) chemical speciation. Correlation coefficients were calculated within four Fe chemical forms and AD parameters of pH, volatile fatty acids (VFAs), inorganic acid radicals (IARs), and alkalinity. Results showed that IARs were not key factors on regulating Fe speciation.

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The different physicochemical properties of various agro-waste biomasses require a diversity of bioenergy utilization patterns. This study investigated the characteristics of a total of 74 manures and 78 crop straw samples from East China to identify the primary characteristic indicators that are essential to distinguish specific agro-wastes from others. Principal component analysis was applied, to discover critical features of biomass for the decision-making regarding the bioenergy production mode.

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The synergetic effects during co-pyrolysis of biomass and waste tire (WT) were investigated concerning the product distribution and reaction kinetics. Two biomass feedstocks were separately mixed with WT at different effective hydrogen/carbon ratio (H/C), and analytical co-pyrolysis of mixtures was conducted using pyrolysis gas chromatography/mass spectroscopy at 500 °C. Product distributions were similar between different biomass feedstocks but varied significantly at different H/C values.

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The physicochemical properties and adsorption capacities of yak manure biochar (SP350-YMB) and modified yak manure biochar by HO (AC-YMB) were investigated. Results showed the oxygen content and the carboxyl group content of manure biochar increased by 63.4% and 101%, and the ash content decreased 42% after modification, respectively.

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The feasibility of co-digestion of chicken manure (CM) and maize silage (MS) without water dilution was investigated in 5-L digesters. Specific methane production (SMP) of 0.309LCH4g(-1) volatile solids (VS) was achieved but only at lower %CM.

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Anaerobic digestions of pig manure (PM), dairy manure (DM), chicken manure (CM) and rabbit manure (RM) at initial volatile solid loading (VSL) of 8 g VS/L, 16 g VS/L, 32 g VS/L, 64 g VS/L were investigated under mesophilic conditions. The maximum methane yields of 410, 270, 377 and 323 mL CH4/g VSadded for PM, DM, CM and RM were all obtained at initial VSL of 8 g VS/L, respectively. The improvement of substrate concentration to 64 g VS/L not only decreased the methane yield and biodegradability both by 22.

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The degradation kinetics of swine and buffalo manure for methane production was investigated. Six kinetic models were employed to describe the corresponding experimental data. These models were evaluated by two statistical measurements, which were root mean square prediction error (RMSPE) and Akaike's information criterion (AIC).

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The three-parallel-DAEM-reaction model was used to study the slow pyrolysis kinetics of rice straw based on thermogravimetric analysis (TGA) data. The kinetic parameters of the model were calculated using the pattern search method. A comparison between the predicted DTG data and experimental values showed good agreement.

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The effect of particle size on the gasification performance of a pilot-scale (25 kg/h) downdraft fixed bed gasification system was investigated using prunings from peach trees at five different size fractions (below 1, 1-2, 2-4, 4-6 and 6-8 cm). The gas and hydrocarbon compositions were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS), respectively. With increasing particle size, gas yield increased while tar and dust content decreased.

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To improve the enzymatic digestibility of sweet sorghum bagasse and bioethanol production, five pretreatment methods have been investigated and compared, including (1) dilute NaOH solution autoclaving pretreatment, (2) high concentration NaOH solution immersing pretreatment, (3) dilute NaOH solution autoclaving and H(2)O(2) immersing pretreatment, (4) alkaline peroxide pretreatment and (5) autoclaving pretreatment. Among them, the best result was obtained when sweet sorghum bagasse was dilute NaOH solution autoclaving and H(2)O(2) immersing pretreatment. The highest cellulose hydrolysis yield, total sugar yield and ethanol concentration were 74.

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Steam reforming of two kinds of bio-oil from rice husks fast pyrolysis was conducted for hydrogen production at three temperatures (650, 750 and 850 °C) with Ni-based catalyst in a fixed-bed reactor. The gas composition and organic compounds in liquid condensate were detected by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), respectively. In addition, the carbon deposition was also investigated.

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Sweet sorghum bagasse (SSB) was steam pretreated in the conditions of 190 °C for 5 min to assess its amenability to the pretreatment and enzymatic hydrolysis. Results showed that pretreatment conditions were robust enough to pretreat SSB with maximum of 87% glucan and 72% xylan recovery. Subsequent enzymatic hydrolysis showed that the pretreated SSB at 2% substrate consistency resulted in maximum of 70% glucan-glucose conversion.

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To produce high quality bio-oil from biomass using fast pyrolysis, rice husks were pyrolyzed in a 1-5 kg/h bench-scale fluidized-bed reactor. The effect of hot vapor filtration (HVF) was investigated to filter the solid particles and bio-char. The results showed that the total bio-oil yield decreased from 41.

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Using some theoretically simulated data constructed from known sets of the activation energy distribution f(E) (assumed to follow the Gaussian distribution [Formula in text] where E is the activation energy, E(0) is the mean value of the activation energy distribution, and σ is the standard deviation of the activation energy distribution) and the frequency factor k(0), a critical study of the use of the Miura-Maki integral method for the estimation of the kinetic parameters of the distributed activation energy model has been performed from three cases. For all cases, the use of the Miura-Maki integral method leads to important errors in the estimation of k(0). There are some differences between the assumed and calculated activation energy distributions and the differences decrease with increasing the assumed k(0) values (for Case 1), with increasing the assumed σ values (for Case 2), and with decreasing the b values (for Case 3).

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