Publications by authors named "Peiyong Qin"

32 Publications

Hydrophobic-modified metal-hydroxide nanoflocculants enable one-step removal of multi-contaminants for drinking water production.

iScience 2021 May 30;24(5):102491. Epub 2021 Apr 30.

Department of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UK.

Flocculation is a mainstream technology for the provision of safe drinking water but is limited due to the ineffectiveness of conventional flocculants in removing trace low-molecular-weight emerging contaminants. We described a synthesis strategy for the development of high-performance nanoflocculants (hydrophobic-organic-chain-modified metal hydroxides [HOC-M]), imitating surfactant-assembling nano-micelles, by integration of long hydrophobic chains with traditional inorganic metal (Fe/Al/Ti)-based flocculants. The core-shell nanostructure was highly stable in acidic stock solution and transformed to meso-scale coagulation nuclei in real surface water. In both jar and continuous-flow tests, HOC-M was superior over conventional flocculants in removing many contaminants (turbidity, UV, and DOC: >95%; TP and NO-N: >90%; trace pharmaceuticals [initial concentration: 100 ng/L]: >80%), producing flocs with better structural and dewatering properties, and lowering the environmental risk of metal leaching. The rationally designed nanoflocculants have large application potential, as a solution to increasing public concern about micro-pollutants and increasing water quality requirements.
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http://dx.doi.org/10.1016/j.isci.2021.102491DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8169996PMC
May 2021

A Particle-Driven, Ultrafast-Cured Strategy for Tuning the Network Cavity Size of Membranes with Outstanding Pervaporation Performance.

ACS Appl Mater Interfaces 2020 Jul 30;12(28):31887-31895. Epub 2020 Jun 30.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, China.

Poly(dimethylsiloxane) (PDMS) membranes are widely used for bioethanol separation. However, the network cavity size of PDMS membranes is generally smaller than the ethanol kinetic radius (0.225 nm), which limits the transport of ethanol molecules and weakens the pervaporation performance. Herein, we proposed a particle-driven, ultrafast-cured strategy to overcome the above key issue: (1) Incorporating particles into PDMS for preventing polymer chains from packing tightly, (2) freezing particles within a PDMS layer by the ultrafast UV-cross-linking for improving its distribution and increasing the chain extension of the polymer, and (3) covalently bonding particles with PDMS to enhance their compatibility. Consequently, was increased to 0.262 nm, and an extremely high loading membrane (50 wt %) with an ultrashort curing time (20 s) was prepared, which is difficult to be realized by the conventional thermally driven approach. As a result, a separation factor of 13.4 with a total flux of 2207 g m h for separating ethanol from a 5 wt % aqueous solution at 60 °C was obtained. This strategy shows the feasibility of recovery of different bioalcohols and the large-scale continuous membrane preparation.
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http://dx.doi.org/10.1021/acsami.0c05859DOI Listing
July 2020

The Ultrafast and Continuous Fabrication of a Polydimethylsiloxane Membrane by Ultraviolet-Induced Polymerization.

Angew Chem Int Ed Engl 2019 11 17;58(48):17175-17179. Epub 2019 Oct 17.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, No. 15 North 3rd Ring East Road, Beijing, 100029, P. R. China.

The polydimethylsiloxane (PDMS) membrane commonly used for separation of biobutanol from fermentation broth fails to meet demand owing to its discontinuous and polluting thermal fabrication. Now, an UV-induced polymerization strategy is proposed to realize the ultrafast and continuous fabrication of the PDMS membrane. UV-crosslinking of synthesized methacrylate-functionalized PDMS (MA-PDMS) is complete within 30 s. The crosslinking rate is three orders of magnitude larger than the conventional thermal crosslinking. The MA-PDMS membrane shows a versatile potential for liquid and gas separations, especially featuring an excellent pervaporation performance for n-butanol. Filler aggregation, the major bottleneck for the development of high-performance mixed matrix membranes (MMMs), is overcome, because the UV polymerization strategy demonstrates a freezing effect towards fillers in polymer, resulting in an extremely high-loading silicalite-1/MA-PDMS MMM with uniform particle distribution.
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http://dx.doi.org/10.1002/anie.201908386DOI Listing
November 2019

Selective binding of heparin oligosaccharides in a magnetic thermoresponsive molecularly imprinted polymer.

Talanta 2019 Aug 20;201:441-449. Epub 2019 Apr 20.

Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China. Electronic address:

Heparin is a highly sulfated polysaccharide, applied in clinic for treatment of thrombotic diseases. The biological activity is closely related to its molecular structure e.g. compositions of disaccharides and oligosaccharides units. The classical method to isolate the oligosaccharides after depolymerization by heparinases or nitrous acid I s by size exclusion chromatography which is a time-consuming process. In this study, we explored the possibility for rapid separation of oligosaccharides using a novel polymer material. The magnetic thermoresponsive molecularly imprinted polymers (MIPs) were synthesized using heparin disaccharide as a template, AEM, NIPAAm, and AAm as functional monomer, and MBAA as crosslinker by surface radical polymerization in an aqueous media. Incubation of the MIP with hepairn oligosaccharides demonstrated specific binding to the template molecule. This binding to the targeted molecule was affected by reaction temperature with regard to binding capacity and specificity. The recognition specificity and selectivity can be modulated by varying the compositions of multi-functional monomers. The pseudo-second-order kinetic model and Langmuir isotherm model provide the best fit to the equilibrium adsorption of heparin disaccharides by MIPs. The results suggest that the new material can be used for rapid separation of di- and tetra-saccharides of heparin, which can also be adapted to the applications for isolation of oligosaccharides from other polysaccharides, e.g. heparan sulfate and chondoriting sulfate.
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http://dx.doi.org/10.1016/j.talanta.2019.04.050DOI Listing
August 2019

Novel distillation process for effective and stable separation of high-concentration acetone-butanol-ethanol mixture from fermentation-pervaporation integration process.

Biotechnol Biofuels 2018 20;11:286. Epub 2018 Oct 20.

3National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing, 100029 People's Republic of China.

Background: One of the major obstacles of acetone-butanol-ethanol (ABE) fermentation from renewable biomass resources is the energy-intensive separation process. To decrease the energy demand of the ABE downstream separation processes, hybrid in situ separation system with conventional distillation is recognized as an effective method. However, in the distillation processes, the high reflux ratio of the ethanol column and the accumulation of ethanol on top of the water and butanol columns led to poor controllability and high operation cost of the distillations. In this study, vacuum distillation process which is based on a decanter-assisted ethanol-butanol-water recycle loop named E-TCD sequence was developed to improve the conventional separation sequence for ABE separation. The permeate of in situ pervaporation system was used as the feed.

Results: The distillation processes were simulated and optimized by iterative strategies. ABE mixture with acetone, butanol and ethanol concentrations of 115.8 g/L, 191.4 g/L and 17.8 g/L (the other composition was water) that obtained from fermentation-pervaporation integration process was used as the feed. A plant scaled to 1025 kg/h of ABE mixture was performed, and the product purities were 100 wt% of butanol, 99.7 wt% of acetone and 95 wt% of ethanol, respectively. Results showed that only 5.3 MJ/kg (of butanol) was required for ABE separation, which was only 37.54% of the energy cost in conventional distillation processes.

Conclusions: Compared with the drawbacks of ethanol accumulation in butanol-water recycle loop and the extremely high recovery rate of ethanol in conventional distillation processes, simulation results obtained in the current work avoided the accumulation of ethanol based on the novel E-TCD sequence.
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http://dx.doi.org/10.1186/s13068-018-1284-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6195753PMC
October 2018

Simultaneous acetone-butanol-ethanol fermentation, gas stripping, and full-cell-catalyzed esterification for effective production of butyl oleate.

Bioprocess Biosyst Eng 2018 Sep 30;41(9):1329-1336. Epub 2018 May 30.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, No.15, East Road of the North 3rd Ring, Chaoyang District, Beijing, 100029, People's Republic of China.

In this study, aiming to improve the economic feasibility of acetone-butanol-ethanol (ABE) fermentation process, generate valuable products and extend the product chain, esterification catalyzed by Candida sp. 99-125 cells was hybrid with the ABE fermentation-gas-stripping integration system. The gas-stripping condensate that contained concentrated ABE products was directly used for esterification without the participation of toxic organic solvents. Full-cell catalysis temperature and the cell dosage rate on oleate production were evaluated and optimized in the esterification process. Under the optimized conditions (35 °C, 8% of cells), ~ 68% of butyl oleate and ~ 12% of ethyl oleate were obtained after 4 h of esterification. The Candida sp. 99-125 cells were able to be reused for at least four cycles. The novel cascade process showed environmental benefits, which also showed promising in improving the economic feasibility of the conventional ABE fermentation process.
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http://dx.doi.org/10.1007/s00449-018-1960-xDOI Listing
September 2018

Integrated in situ gas stripping-salting-out process for high-titer acetone-butanol-ethanol production from sweet sorghum bagasse.

Biotechnol Biofuels 2018 10;11:134. Epub 2018 May 10.

1National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing, 100029 People's Republic of China.

Background: The production of biobutanol from renewable biomass resources is attractive. The energy-intensive separation process and low-titer solvents production are the key constraints on the economy-feasible acetone-butanol-ethanol (ABE) production by fermentation. To decrease energy consumption and increase the solvents concentration, a novel two-stage gas stripping-salting-out system was established for effective ABE separation from the fermentation broth using sweet sorghum bagasse as feedstock.

Results: The ABE condensate (143.6 g/L) after gas stripping, the first-stage separation, was recovered and introduced to salting-out process as the second-stage. KPO and KHPO were used, respectively. The effect of saturated salt solution temperature on final ABE concentration was also investigated. The results showed high ABE recovery (99.32%) and ABE concentration (747.58 g/L) when adding saturated KPO solution at 323.15 K and 3.0 of salting-out factor. On this condition, the energy requirement of the downstream distillation process was 3.72 MJ/kg of ABE.

Conclusions: High-titer cellulosic ABE production was separated from the fermentation broth by the novel two-stage gas stripping-salting-out process. The process was effective, which reduced the downstream process energy requirement significantly.
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http://dx.doi.org/10.1186/s13068-018-1137-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5944105PMC
May 2018

Towards an energy-friendly and cleaner solvent-extraction of vegetable oil.

J Environ Manage 2018 Jul 5;217:196-206. Epub 2018 Apr 5.

Beijing University of Chemical Technology, School of Life Science and Technology, Beijing, China.

The extraction of vegetable oils is an energy-intensive process. It has moreover a significant environmental impact through hexane emissions and through the production of organic-loaded wastewater. A rice bran oil process was selected as the basis, since full data were available. By using Aspen Plus v8.2 simulation, with additional scripts, several improvements were examined, such as using heat exchanger networks, integrating a Vapor Recompression Heat Pump after the evaporation and stripping, and examining a nitrogen stripping of hexane in the rice bran meal desolventizing unit followed by a gas membrane to recover hexane. Energy savings by the different individual and combined improvements are calculated, and result in a 94.2% gain in steam consumption and a 73.8% overall energy saving. The power consumption of the membrane unit reduces the overall energy savings by about 5%. Hexane separation and enrichment by gas membranes facilitates its condensation and re-use, while achieving a reduction of hexane emissions by over 50%. Through the considerable reduction of required steam flow rates, 61% of waste water is eliminated, mostly as organic-loaded steam condensate. Through overall energy savings, 52% of related CO emissions are eliminated.
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http://dx.doi.org/10.1016/j.jenvman.2018.03.061DOI Listing
July 2018

Bio-plasticizer production by hybrid acetone-butanol-ethanol fermentation with full cell catalysis of Candida sp. 99-125.

Bioresour Technol 2018 Jun 17;257:217-222. Epub 2018 Feb 17.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

Hybrid process that integrated fermentation, pervaporation and esterification was established aiming to improve the economic feasibility of the conventional acetone-butanol-ethanol (ABE) fermentation process. Candida sp 99-125 cells were used as full-cell catalyst. The feasibility of batch and fed-batch esterification using the ABE permeate of pervaporation (ranging from 286.9 g/L to 402.9 g/L) as substrate were compared. Valuable butyl oleate was produced along with ethyl oleate. For the batch esterification, due to severe inhibition of substrate to lipase, the yield of butyl oleate and ethyl oleate were only 24.9% and 3.3%, respectively. In contrast, 75% and 11.8% of butyl oleate and ethyl oleate were obtained, respectively, at the end of the fed-batch esterification. The novel integration process provides a promising strategy for in situ upgrading ABE products.
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http://dx.doi.org/10.1016/j.biortech.2018.02.066DOI Listing
June 2018

Two-stage pervaporation process for effective in situ removal acetone-butanol-ethanol from fermentation broth.

Bioresour Technol 2017 Jan 5;224:380-388. Epub 2016 Nov 5.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

Two-stage pervaporation for ABE recovery from fermentation broth was studied to reduce the energy cost. The permeate after the first stage in situ pervaporation system was further used as the feedstock in the second stage of pervaporation unit using the same PDMS/PVDF membrane. A total 782.5g/L of ABE (304.56g/L of acetone, 451.98g/L of butanol and 25.97g/L of ethanol) was achieved in the second stage permeate, while the overall acetone, butanol and ethanol separation factors were: 70.7-89.73, 70.48-84.74 and 9.05-13.58, respectively. Furthermore, the theoretical evaporation energy requirement for ABE separation in the consolidate fermentation, which containing two-stage pervaporation and the following distillation process, was estimated less than ∼13.2MJ/kg-butanol. The required evaporation energy was only 36.7% of the energy content of butanol. The novel two-stage pervaporation process was effective in increasing ABE production and reducing energy consumption of the solvents separation system.
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http://dx.doi.org/10.1016/j.biortech.2016.11.010DOI Listing
January 2017

Comparison of two-stage acid-alkali and alkali-acid pretreatments on enzymatic saccharification ability of the sweet sorghum fiber and their physicochemical characterizations.

Bioresour Technol 2016 Dec 21;221:636-644. Epub 2016 Sep 21.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

Two-stage acid/alkali pretreatment was used to enhance the saccharification efficiency of sweet sorghum fiber. The physicochemical characterizations of the pretreated fibers were evaluated by SEM, FTIR and XRD. The acid and alkali sequence in the two-stage pretreatment process was compared, and their dosage was optimized. The results indicated that the two-stage pretreatment showed better saccharification performance when compared with conventional single stage pretreatment. And compared with the acid-alkali sequence, the alkali-acid sequence achieved higher glucose yield (0.23g·g) under the optimized conditions, which was 1.64 and 1.21 times higher than that of the single stage and the acid-alkali pretreatments, respectively. Overall, the two-stage pretreatment process is a promising approach to achieve high fermentable glucose conversion rate of cellulosic material.
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http://dx.doi.org/10.1016/j.biortech.2016.09.075DOI Listing
December 2016

Immobilized ethanol fermentation coupled to pervaporation with silicalite-1/polydimethylsiloxane/polyvinylidene fluoride composite membrane.

Bioresour Technol 2016 Nov 12;220:124-131. Epub 2016 Aug 12.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

A novel silicalite-1/polydimethylsiloxane/polyvinylidene fluoride hybrid membrane was used in ethanol fermentation-pervaporation integration process. The sweet sorghum bagasse was used as the immobilized carrier. Compared with the conventional suspend cells system, the immobilized fermentation system could provide higher ethanol productivity when coupled with pervaporation. In the long-term of operations, the ethanol productivity, separation factor, total flux and permeate ethanol concentration in the fed-batch fermentation-pervaporation integration scenario were 1.6g/Lh, 8.2-9.9, 319-416g/m(2)h and 426.9-597.2g/L, respectively. Correspondingly, 1.6g/Lh, 7.8-9.8, 227.8-395g/m(2)h and 410.9-608.1g/L were achieved in the continuous fermentation-pervaporation integration scenario, respectively. The results indicated that the integration process could greatly improve the ethanol production and separation performances.
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http://dx.doi.org/10.1016/j.biortech.2016.08.036DOI Listing
November 2016

Effect of chemical pretreatments on corn stalk bagasse as immobilizing carrier of Clostridium acetobutylicum in the performance of a fermentation-pervaporation coupled system.

Bioresour Technol 2016 Nov 21;220:68-75. Epub 2016 Aug 21.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

In this study, different pretreatment methods were evaluated for modified the corn stalk bagasse and further used the pretreated bagasse as immobilized carrier in acetone-butanol-ethanol fermentation process. Structural changes of the bagasses pretreated by different methods were analyzed by Fourier transform infrared, crystallinity index and scanning pictures by electron microscope. And the performances of batch fermentation using the corn stalk based carriers were evaluated. Results indicated that the highest ABE concentration of 23.86g/L was achieved using NaOH pretreated carrier in batch fermentation. Immobilized fermentation-pervaporation integration process was further carried out. The integration process showed long-term stability with 225-394g/L of ABE solvents on the permeate side of pervaporation membrane. This novel integration process was found to be an efficient method for biobutanol production.
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http://dx.doi.org/10.1016/j.biortech.2016.08.049DOI Listing
November 2016

The optimization of l-lactic acid production from sweet sorghum juice by mixed fermentation of Bacillus coagulans and Lactobacillus rhamnosus under unsterile conditions.

Bioresour Technol 2016 Oct 20;218:1098-105. Epub 2016 Jul 20.

National energy R&D center for biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

The cost reduction of raw material and sterilization could increase the economic feasibility of l-lactic acid fermentation, and the development of an cost-effective and efficient process is highly desired. To improve the efficiency of open fermentation by Lactobacillus rhamnosus based on sweet sorghum juice (SSJ) and to overcome sucrose utilization deficiency of Bacillus coagulans, a mixed fermentation was developed. Besides, the optimization of pH, sugar concentration and fermentation medium were also studied. Under the condition of mixed fermentation and controlled pH, a higher yield of 96.3% was achieved, compared to that (68.8%) in sole Lactobacillus rhamnosus fermentation. With an optimized sugar concentration and a stepwise-controlled pH, the l-lactic acid titer, yield and productivity reached 121gL(-1), 94.6% and 2.18gL(-1)h(-1), respectively. Furthermore, corn steep powder (CSP) as a cheap source of nitrogen and salts was proved to be an efficient supplement to SSJ in this process.
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http://dx.doi.org/10.1016/j.biortech.2016.07.069DOI Listing
October 2016

Co-generation of microbial lipid and bio-butanol from corn cob bagasse in an environmentally friendly biorefinery process.

Bioresour Technol 2016 Sep 21;216:345-51. Epub 2016 May 21.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

Biorefinery process of corn cob bagasse was investigated by integrating microbial lipid and ABE fermentation. The effects of NaOH concentration on the fermentations performance were evaluated. The black liquor after pretreatment was used as substrate for microbial lipid fermentation, while the enzymatic hydrolysates of the bagasse were used for ABE fermentation. The results demonstrated that under the optimized condition, the cellulose and hemicellulose in raw material could be effectively utilized. Approximate 87.7% of the polysaccharides were converted into valuable biobased products (∼175.7g/kg of ABE along with ∼36.6g/kg of lipid). At the same time, almost half of the initial COD (∼48.9%) in the black liquor could be degraded. The environmentally friendly biorefinery process showed promising in maximizing the utilization of biomass for future biofuels production.
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http://dx.doi.org/10.1016/j.biortech.2016.05.073DOI Listing
September 2016

Acetone-butanol-ethanol from sweet sorghum juice by an immobilized fermentation-gas stripping integration process.

Bioresour Technol 2016 Jul 1;211:704-10. Epub 2016 Apr 1.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

In this study, sweet sorghum juice (SSJ) was used as the substrate in a simplified ABE fermentation-gas stripping integration process without nutrients supplementation. The sweet sorghum bagasse (SSB) after squeezing the fermentable juice was used as the immobilized carrier. The results indicated that the productivity of ABE fermentation process was improved by gas stripping integration. A total 24g/L of ABE solvents was obtained from 59.6g/L of initial sugar after 80h of fermentation with gas stripping. Then, long-term of fed-batch fermentation with continuous gas stripping was further performed. 112.9g/L of butanol, 44.1g/L of acetone, 9.5g/L of ethanol (total 166.5g/L of ABE) was produced in overall 312h of fermentation. At the same time, concentrated ABE product was obtained in the condensate of gas stripping.
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http://dx.doi.org/10.1016/j.biortech.2016.03.155DOI Listing
July 2016

Biorefinery of corn cob for microbial lipid and bio-ethanol production: An environmental friendly process.

Bioresour Technol 2016 Jul 1;211:677-84. Epub 2016 Apr 1.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

Microbial lipid and bio-ethanol were co-generated by an integrated process using corn cob bagasse as raw material. After pretreatment, the acid hydrolysate was used as substrate for microbial lipid fermentation, while the solid residue was further enzymatic hydrolysis for bio-ethanol production. The effect of acid loading and pretreatment time on microbial lipid and ethanol production were evaluated. Under the optimized condition for ethanol production, ∼131.3g of ethanol and ∼11.5g of microbial lipid were co-generated from 1kg raw material. On this condition, ∼71.6% of the overall fermentable sugars in corn cob bagasse could be converted into valuable products. At the same time, at least 33% of the initial COD in the acid hydrolysate was depredated.
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http://dx.doi.org/10.1016/j.biortech.2016.03.159DOI Listing
July 2016

Improvement of l-lactic acid productivity from sweet sorghum juice by repeated batch fermentation coupled with membrane separation.

Bioresour Technol 2016 Jul 22;211:291-7. Epub 2016 Mar 22.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

In order to efficiently produce l-lactic acid from non-food feedstocks, sweet sorghum juice (SSJ), which is rich of fermentable sugars, was directly used for l-lactic acid fermentation by Lactobacillus rhamnosus LA-04-1. A membrane integrated repeated batch fermentation (MIRB) was developed for productivity improvement. High-cell-density fermentation was achieved with a final cell density (OD620) of 42.3, and the CCR effect was overcomed. When SSJ (6.77gL(-1) glucose, 4.51gL(-1) fructose and 50.46gL(-1) sucrose) was used as carbon source in MIRB process, l-lactic acid productivity was increased significantly from 1.45gL(-1)h(-1) (batch 1) to 17.55gL(-1)h(-1) (batch 6). This process introduces an effective way to produce l-lactic acid from SSJ.
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http://dx.doi.org/10.1016/j.biortech.2016.03.095DOI Listing
July 2016

Effect of dilute alkaline pretreatment on the conversion of different parts of corn stalk to fermentable sugars and its application in acetone-butanol-ethanol fermentation.

Bioresour Technol 2016 Jul 15;211:117-24. Epub 2016 Mar 15.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

To investigate the effect of dilute alkaline pretreatment on different parts of biomass, corn stalk was separated into flower, leaf, cob, husk and stem, which were treated by NaOH in range of temperature and chemical loading. The NaOH-pretreated solid was then enzymatic hydrolysis and used as the substrate for batch acetone-butanol-ethanol (ABE) fermentation. The results demonstrated the five parts of corn stalk could be used as potential feedstock separately, with vivid performances in solvents production. Under the optimized conditions towards high product titer, 7.5g/L, 7.6g/L, 9.4g/L, 7g/L and 7.6g/L of butanol was obtained in the fermentation broth of flower, leaf, cob, husk and stem hydrolysate, respectively. Under the optimized conditions towards high product yield, 143.7g/kg, 126.3g/kg, 169.1g/kg, 107.7g/kg and 116.4g/kg of ABE solvent were generated, respectively.
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http://dx.doi.org/10.1016/j.biortech.2016.03.076DOI Listing
July 2016

Effect of acid pretreatment on different parts of corn stalk for second generation ethanol production.

Bioresour Technol 2016 Apr 28;206:86-92. Epub 2016 Jan 28.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

In this study, the effects of different parts of corn stalk, including stem, leaf, flower, cob and husk on second generation ethanol production were evaluated. FTIR, XRD and SEM were performed to investigate the effect of dilute acid pretreatment. The bagasse obtained after pretreatment were further hydrolyzed by cellulase and used as the substrate for ethanol fermentation. As results, hemicelluloses fractions in different parts of corn stalk were dramatically removed and the solid fractions showed vivid compositions and crystallinities. Compared with other parts of corn stalk, the cob had higher sugar content and better enzymatic digestibility. The highest glucose yield of 94.2% and ethanol production of 24.0 g L(-1) were achieved when the cob was used as feedstock, while the glucose yield and the ethanol production were only 86.0% and 17.1 g L(-1) in the case of flower.
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http://dx.doi.org/10.1016/j.biortech.2016.01.077DOI Listing
April 2016

Effective multiple stages continuous acetone-butanol-ethanol fermentation by immobilized bioreactors: Making full use of fresh corn stalk.

Bioresour Technol 2016 Apr 21;205:82-9. Epub 2016 Jan 21.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

In order to make full use of the fresh corn stalk, the sugar containing juice was used as the sole substrate for acetone-butanol-ethanol production without any nutrients supplement, and the bagasse after squeezing the juice was used as the immobilized carrier. A total 21.34g/L of ABE was produced in batch cells immobilization system with ABE yield of 0.35g/g. A continuous fermentation containing three stages with immobilized cells was conducted and the effect of dilution rate on fermentation was investigated. As a result, the productivity and ABE solvents concentration reached 0.80g/Lh and 19.93g/L, respectively, when the dilution rate in each stage was 0.12/h (corresponding to a dilution rate of 0.04/h in the whole system). And the long-term operation indicated the continuous multiple stages ABE fermentation process had good stability and showed the great potential in future industrial applications.
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http://dx.doi.org/10.1016/j.biortech.2016.01.034DOI Listing
April 2016

Ethanol fermentation integrated with PDMS composite membrane: An effective process.

Bioresour Technol 2016 Jan 2;200:648-57. Epub 2015 Nov 2.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China.

The polydimethylsiloxane (PDMS) membrane, prepared in water phase, was investigated in separation ethanol from model ethanol/water mixture and fermentation-pervaporation integrated process. Results showed that the PDMS membrane could effectively separate ethanol from model solution. When integrated with batch ethanol fermentation, the ethanol productivity was enhanced compared with conventional process. Fed-batch and continuous ethanol fermentation with pervaporation were also performed and studied. 396.2-663.7g/m(2)h and 332.4-548.1g/m(2)h of total flux with separation factor of 8.6-11.7 and 8-11.6, were generated in the fed-batch and continuous fermentation with pervaporation scenario, respectively. At the same time, high titre ethanol production of ∼417.2g/L and ∼446.3g/L were also achieved on the permeate side of membrane in the two scenarios, respectively. The integrated process was environmental friendly and energy saving, and has a promising perspective in long-terms operation.
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http://dx.doi.org/10.1016/j.biortech.2015.09.117DOI Listing
January 2016

Open fermentative production of L-lactic acid using white rice bran by simultaneous saccharification and fermentation.

Bioresour Technol 2015 Dec 25;198:664-72. Epub 2015 Sep 25.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China. Electronic address:

To reduce raw material cost for lactic acid production, white rice bran as an important byproduct in rice milling, was used in l-lactic acid production by open simultaneous saccharification and fermentation (SSF). Although one thermotolerant strain was used at a temperature as high as 50°C, the open fermentation was still inefficient due to the indigenous thermophilic bacteria from corn steep liquor powder. A stepwise controlled pH was proposed in open SSF process, and no complicated pretreatment or sterilization was needed before fermentation. In batch fermentation, 117 gL(-1) lactic acid was obtained, and the productivity and yield reached 2.79 gL(-1) h(-1) and 98.75%, respectively. These results showed an efficient way to develop high value-added products from white rice bran.
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http://dx.doi.org/10.1016/j.biortech.2015.09.010DOI Listing
December 2015

Efficient magnesium lactate production with in situ product removal by crystallization.

Bioresour Technol 2015 Dec 26;198:658-63. Epub 2015 Sep 26.

National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, PR China. Electronic address:

In this paper, attempts were made to develop an in situ product removal process for magnesium lactate production based on crystallization. The crystallization was conducted at 42°C without seed crystal addition. The product concentration, productivity and yield of fermentation coupled with in situ product removal (ISPR) reached 143 g L(-1), 2.41 g L(-1)h(-1) and 94.3%. In four cycles of crystallization, the average reuse rate of fermentation medium and removal rate of product reached 64.0% and 77.7%. At the same time, ISPR fermentation saved 40% water, 41% inorganic salts and 43% yeast extract (YE) as compared to fed-batch fermentation. The process introduces an effective way to reduce the amount of waste water and the raw material cost in magnesium lactate fermentation.
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http://dx.doi.org/10.1016/j.biortech.2015.09.058DOI Listing
December 2015

A novel method for furfural recovery via gas stripping assisted vapor permeation by a polydimethylsiloxane membrane.

Sci Rep 2015 Mar 30;5:9428. Epub 2015 Mar 30.

National energy R&D center for biorefinery, Beijing University of Chemical Technology, Beijing, China.

Furfural is an important platform chemical with a wide range of applications. However, due to the low concentration of furfural in the hydrolysate, the conventional methods for furfural recovery are energy-intensive and environmentally unfriendly. Considering the disadvantages of pervaporation (PV) and distillation in furfural separation, a novel energy-efficient 'green technique', gas stripping assisted vapor permeation (GSVP), was introduced in this work. In this process, the polydimethylsiloxane (PDMS) membrane was prepared by employing water as solvent. Coking in pipe and membrane fouling was virtually non-existent in this new process. In addition, GSVP was found to achieve the highest pervaporation separation index of 216200 (permeate concentration of 71.1 wt% and furfural flux of 4.09 kg m(-2) h(-1)) so far, which was approximately 2.5 times higher than that found in pervaporation at 95°C for recovering 6.0 wt% furfural from water. Moreover, the evaporation energy required for GSVP decreased by 35% to 44% relative to that of PV process. Finally, GSVP also displayed more promising potential in industrial application than PV, especially when coupled with the hydrolysis process or fermentation in biorefinery industry.
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http://dx.doi.org/10.1038/srep09428DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4377579PMC
March 2015

Biogas by semi-continuous anaerobic digestion of food waste.

Appl Biochem Biotechnol 2015 Apr 14;175(8):3901-14. Epub 2015 Mar 14.

School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, People's Republic of China,

The semi-continuous anaerobic digestion of food waste was investigated in 1-L and 20-L continuously stirred tank reactors (CSTRs), to identify the optimum operation condition and the methane production of the semi-continuous anaerobic process. Results from a 1-L digester indicated that the optimum organic loading rate (OLR) for semi-continuous digestion is 8 g VS/L/day. The corresponding methane yield and chemical oxygen demand (COD) reduction were 385 mL/g VS and 80.2 %, respectively. Anaerobic digestion was inhibited at high OLRs (12 and 16 g VS/L/day), due to volatile fatty acid (VFA) accumulation. Results from a 20-L digester indicated that a higher methane yield of 423 mL/g VS was obtained at this larger scale. The analysis showed that the methane production at the optimum OLR fitted well with the determined kinetics equation. An obvious decrease on the methane content was observed at the initial of digestion. The increased metabolization of microbes and the activity decrease of methanogen caused by VFA accumulation explained the lower methane content at the initial of digestion.
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http://dx.doi.org/10.1007/s12010-015-1559-5DOI Listing
April 2015

Impact of sweet sorghum cuticular waxes (SSCW) on acetone-butanol-ethanol fermentation using Clostridium acetobutylicum ABE1201.

Bioresour Technol 2013 Dec 2;149:470-3. Epub 2013 Oct 2.

Beijing Key Lab of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, PR China.

The effect of cuticular waxes of sweet sorghum stem on acetone-butanol-ethanol (ABE) fermentation process was investigated. About 22.9% of butanol and 25.4% of ABE were decreased with fermentation period extended when SSCW was added. The inhibition of SSCW militate against both acidogenesis and solventogenesis phase, which were inconsistent with the inhibition of lignocellulose hydrolysate. Further studies on the composition of SSCW were performed. Regulations of inhibition with different carbon chain length of main compositions of SSCW on ABE fermentation were also investigated.
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http://dx.doi.org/10.1016/j.biortech.2013.09.122DOI Listing
December 2013

Preparation of poly(phthalazinone-ether-sulfone) sponge-like ultrafiltration membrane.

Langmuir 2013 Mar 12;29(12):4167-75. Epub 2013 Mar 12.

Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Technology, Beijing, P R China.

Poly(phthalazinone-ether-sulfone) (PPES) polymer is a relatively newly developed material with a bis(4-fluorodiphenyl) sulfone group. The formation of the PPES membrane by wet-phase inversion can proceed according to a slow or fast gelation method. These formation mechanisms were studied experimentally. The resulting membrane morphology was investigated using both optical and scanning electron micrography. The effects of PPES concentration and two additives, polyvinylpyrrolidone (PVP) and oxalic acid (OA), on the apparent viscosity and gelation rate of PPESK/NMP solutions and membrane performance have also been investigated. It was found that the gelation rate is important to obtain a sponge-like membrane structure, however favored by a fast gelation rate. The membrane obtained by a fast gelation rate showed a high pure water flux and rejection of bovine serum albumin (BSA), contrary to previous findings. On the basis of the experimental results, the actual membrane structure and pure water flux were related, and in agreement with the optical micrograph and gelation rate, respectively. The current results provide a fundamental insight in this novel copolymer, useful in future applications, especially in the membrane formation process.
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http://dx.doi.org/10.1021/la400324bDOI Listing
March 2013

Real time monitoring of on-chip coenzyme regeneration with SPR and DPI.

Anal Chem 2013 Feb 1;85(4):2370-6. Epub 2013 Feb 1.

National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.

We report in this work real time characterization of enzyme-coenzyme binding by using surface plasmon resonance (SPR) and dual polarization interferometry (DPI) analyses. Results showed that diaphorase (DP) and lactate dehydrogenases (LDH) had distinct binding selectivity and preference over reduced and oxidized states of coenzyme NAD(H). On the basis of that, DP and LDH were chosen as indicator enzymes to distinguish the specific state of surface-bound NAD(H). The transformation between NADH and NAD(+) during enzyme-catalyzed redox reactions was therefore transduced into variation in interaction signals as indicated via the binding status of the indicator enzymes as detected with both SPR and DPI. This real time molecule-specific detection strategy revealed quick and direct reflection of the state and reactivity of the coenzyme, promising a unique way of precise molecular interaction analysis.
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http://dx.doi.org/10.1021/ac303392aDOI Listing
February 2013

[Contamination mechanism and regeneration strategies of chromatographic resin in separation process for expression product from mammary gland bioreactor].

Sheng Wu Gong Cheng Xue Bao 2011 Nov;27(11):1645-54

College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.

This study focused on the contamination mechanism and regeneration strategies of sulfopropyl ion exchange resin (SP Sepharose FF) during the separation of recombinant human lactoferrin from transgenic bovine milk. We analyzed primary constituents' contents in chromatorgraphic material and fractions. The results showed that the lipid in milk can clog the column or adhere to the resin through hydrophobic interaction, leading to an increase in column pressure. Some casein molecules were found to adsorb onto the resin through electrostatic interaction, therefore the adsorption capacity was decreased. There was no direct interaction between lactose and the resin in the chromatorgraphic process. Increased continuous chromatographic cycles and prolonged time interval between protein purification and column regeneration could enhance the undesirable interaction between the contaminants and resin, thus lowering the regeneration efficiency. NaOH was found to be effective in the removal of lipid and casein molecules from the column. Furthermore, normal microstructure and chromatographic performance of the ion exchanger was recovered after this cleaning procedure.
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November 2011
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