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Integrating the acetone-butanol-ethanol fermentation with pervaporation or gas stripping for in situ product recovery is considered as an effective way for biobutanol production, and the following downstream distillation sequences have been extensively investigated. Whereas, there are still no comprehensive comparison of the reported distillation processes in sight of the techno-economic feasibility. In this study, three alternative distillation sequences that contains a decanter and recycle loops are selected and compared by steady-state simulation. ABE condensates collected by ISPR, with different solvent concentrations and constituents, are considered as the feed stream of distillation. The impact of ABE ratio on energy consumption and techno-economics of the selected distillation sequences are analyzed. Results indicate the separation performances, including the energy requirement and economics, are highly influenced by the distillation sequence. Compared with other Scenarios, when feeding the extreme ABE constituents within the confidence interval, the sequence that consisted of three columns and a decanter with two recycle loops exhibits the lower energy requirement (7.99 MJ/kg) and TAC (4.15 × 106 US $/yr). The current work guides to the designation of suitable ISPR-distillation process in future works.

The enhanced enzymatic activity and thermal stability of cutinase 1 from Thermobifida cellulosilytica by enzyme engineering were utilized to achieve efficient degradation of post-consumer polyethylene terephthalate (PET) bottle particles.

The use of traditional chemical catalysis to produce chemicals has a series of drawbacks, such as high dependence on fossil resources, high energy consumption, and environmental pollution. With the development of synthetic biology and metabolic engineering, the use of renewable biomass raw materials for chemicals synthesis by constructing efficient microbial cell factories is a green way to replace traditional chemical catalysis and traditional microbial fermentation. This review mainly summarizes several types of bulk chemicals and high value-added chemicals using metabolic engineering and synthetic biology strategies to achieve efficient microbial production. In addition, this review also summarizes several strategies for effectively regulating microbial cell metabolism. These strategies can achieve the coupling balance of material and energy by regulating intracellular material metabolism or energy metabolism, and promote the efficient production of target chemicals by microorganisms.

Distillation processes for separation of biphasic ABE solution from in situ gas stripping were developed. The distillation sequences were investigated and optimized. Results proved the energy requirement of distillation was effectively reduced when feeding the biphasic ABE mixture. After techno-economic analysis, a superior scenario that started with a decanter followed with side-by-side sequences for separation acetone and ethanol was selected. Compared with the conventional processes that detractively concentrate the biphasic ABE mixture, energy requirement and total annual cost (TAC) of the novel distillation process were decreased by 25.8% and 17.4%, respectively. $ 4102.98 K per year of TAC was estimated in a case with a capacity of 30 K tons of butanol per year.

The acid pretreated sweet sorghum bagasse was mixed with the fermentable juice for ethanol production by simultaneous saccharification and juice co-fermentation (SSJcF). The effect of sulfuric acid concentration on ethanol production was evaluated. Two-phase of fermentation was occurred distinctly during the process. Under the optimized conditions (2% of sulfuric acid and 20 FPU/g of cellulase added at 0 h), 120.41 ± 0.4 g/L of ethanol was achieved after 216 h of inoculation, with ethanol yield of 67.75 g/kg of the fresh sweet sorghum stalk (FSSS) that contained water and was rich in monosaccharide and cellulosic biomass. This study provided a potential way for high titer ethanol production by SSJcF using FFFS, which is benefited to the downstream ethanol separation processes.

RNA-sequencing enables accurate and low-cost transcriptome-wide detection. However, expression estimates vary as reference genomes and gene annotations are updated, confounding existing expression-based prognostic signatures. Herein, prognostic 9-gene pair signature (GPS) was applied to 197 patients with stage I lung adenocarcinoma derived from previous and latest data from The Cancer Genome Atlas (TCGA) processed with different reference genomes and annotations. For 9-GPS, 6.6% of patients exhibited discordant risk classifications between the two TCGA versions. Similar results were observed for other prognostic signatures, including IRGPI, 15-gene and ORACLE. We found that conflicting annotations for gene length and overlap were the major cause of their discordant risk classification. Therefore, we constructed a prognostic 40-GPS based on stable genes across GENCODE v20-v30 and validated it using public data of 471 stage I samples (log-rank P

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. Electronic supplementary material The online version of this article (10.1186/s13068-018-1284-8) contains supplementary material, which is available to authorized users.

Aiming to improve the economic feasibility of the corncob biorefinery process, fibers, including the corncob bagasse, xylose-extracted corncob residue and the ethanol-processing residue, were used as the reinforcing phase for the preparation of wood plastic composites (WPCs). The mechanical properties and the weathering performance of the composites were compared. The results indicated that the WPCs reinforced by the ethanol-processing residue showed balanced advantages in mechanical properties and weathering performance. The effects of the compatibilizer and the cellulose/lignin mixture on the WPC properties were further evaluated, indicating that use of 4 wt % of Polyethylene-graft-maleic anhydride (PE-g-MA) as the compatibilizer and a mixture of the EPR with lignin at a ratio of (9:1) were the optimized conditions for WPCs. The current work showed potential in making full use of the solid residue of biorefinery processes and making the waste profitable.

In this work, the acetone-butanol-ethanol (ABE) fermentation was upgraded in order to improve its economy. Fed-batch fermentation was integrated with two-stage gas stripping-pervaporation unit. The permeated ABE condensate was used as substrate for oleates production. Candida sp. 99–125 cells, being rich in lipase activity, were used as full-cell catalyst. Different ABE feeding strategies in the esterification process were compared. As results, 10.1%, 68.6% and 72.5% of butyl oleate were obtained in the one-step added scenario, the stepwise-added scenario, and the simultaneous fed-batch scenario, respectively. The novel hybrid process was energy-saving, environmentally friendly and profitable, showing promise in future industrialization.

Using the lignocellulosic biomass materials to produce wood (wood fibers/natural fibers) plastic composites (WPCs) is one of the most environmentally friendly and economical ways to solve the residuals of biorefineries. In this study, tropical maize bagasse (TMB), sweet sorghum bagasse (SSB) and sugarcane bagasse (SCB), the solid residuals from bio-ethanol plants, were used as the reinforcement phase in the production of WPCs. The mechanical, thermal and accelerated weathering behaviors of WPCs were evaluated. The experimental results indicated that the TMB reinforced composites showed better mechanical properties, with tensile strength and flexural strength of 26.8 ± 3.4 and 46.1 ± 3.1 MPa, respectively. Moreover, the retention ratios of the rupture modulus and the elasticity modulus of the SSB reinforced composites were the highest among the three groups after multigelation and 2000 h of xenon lamp weathering, which were reached 84.9 ± 6.7 and 76.0 ± 4.4%, and 76.1 ± 4.7 and 69.4 ± 2.9%, respectively. The production of WPCs reinforced by solid residuals showed potential in connecting with the biorefinery plants.

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.

Fermentation–pervaporation–catalysis (FPC) integration process was employed to produce bio-butadiene using sweet sorghum juice as feedstock. After in situ ethanol removal from fermentation broth, permeate of pervaporation membrane (478.6 g/L bio-ethanol) was directly converted into butadiene by an Ag/Mg–Si catalyst. A butadiene yield of 64.1% with a butadiene selectivity of 75.8% was achieved within 6 h of operation. The integration process showed a great potential on high final product yield in a long-term operation. Following this protocol, about 16 g of bio-butadiene was produced from 1 kg sweet sorghum stalk. The integration process showed a potential in further application for bio-butadiene and materials production.

Corn stover bagasse hydrolysate was used as the substrate for fed-batch acetone-butanol-ethanol (ABE) fermentation and in situ product removal by intermittent gas stripping. The mutant strain Clostridium acetobutylicum ABE-P 1201 was inoculated for ABE production. As results, a final cumulative butanol concentration of 18.6 g/L (total ABE: 28.3 g/L) was produced from 97.6 g/L of total fermentable sugars (75.3 g/L of glucose and 22.3 g/L of xylose), with an ABE yield of 83.2 g/kg of CSB. The gas stripping condensate obtained in the integrated process contained 77–136 g/L of butanol and 115–220 g/L of total ABE.

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-1) 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.

Large amounts of effluent discharge and a costly wastewater treatment hinder the scale-up of the lignocellulosic acetone-butanol-ethanol (ABE) fermentation process. By recycling the broth after solvents removal and using it in the subsequent cycles of biomass hydrolysis and fermentation, the overall amount of effluent can be reduced. However, the ABE production is severely inhibited by the accumulated acids and other toxic by-products when reusing the cycled streams. In this study, a pervaporation assisted sequential fermentation was performed. The ABE liquor recovered after batch fermentation and ex situ pervaporation was used as the buffer for corn stover pulp hydrolysis and the following microbial lipids fermentation. In microbial lipids fermentation stage, toxic acid by-products remained in the liquor can be co-utilized as a substrate. The acids eliminated post-harvested broth was further cycled as the buffer for pulp hydrolysis and ABE fermentation. As a result, ABE yield of 0.349 g/g and concentration of 14.40 g/L were achieved after 3 cycles of operation, which show only 3.86% and 14.98% reduction compared to those of the initial cycle. Remarkably, the effluent discharge was reduced by 92.20% after applying the hybrid two-stage sequential fermentation. Meanwhile, 8.20 g/L of microbial lipids can be co-generated. The novel process offers an environmentally friendly strategy for the co-production of ABE and microbial lipids from lignocelluloses under the concept of biorefinery.

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.

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.

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.

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.

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.

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.

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.

In this study, an integrated gas stripping–pervaporation (GS–PV) process was established to enhance the butanol concentration and to reduce the cost of the product separation processes. Batch pervaporation was integrated with in situ gas stripping system of fed-batch acetone–butanol–ethanol (ABE) fermentation. A total 706.68 g/L ABE (54.2 g/L of ethanol, 169.93 g/L of acetone, and 482.55 g/L of butanol) was collected after 11 h of pervaporation separation. The recovery rates of butanol, acetone and ethanol were 98.8%, 99.5% and 82.8% (w/v), respectively. Attractively, the liquor on the permeate side of pervaporation membrane exceeded its azeotropic point which have not been achieved in previous processes basing on individual gas stripping or pervaporation. Furthermore, aiming to construct consolidate commercial guide of biobutanol producing process, GS–PV–distillation process was established and compared with traditional GS–distillation scheme. As a result, 24.83 MJ/kg of butanol was consumed in the novel GS–PV–distillation process. In this scheme, the beer column was deleted from the rectifying column series. Moreover, based on the consolidate GS–PV–distillation integration process, heat recovery network was simulated and designed by Pinch Analysis, and 1.72 MJ/kg of heat could be further saved after heat exchange in the distillation system. And the overall energy demand for butanol production was further decreased to 23.07 MJ/kg, which was only 29.2% of the conventional distillation procedure.

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.

In order to effectively evaluate the distillers dried fibers with solubles (DDFS) obtained from biorefinery processes, sorghum distiller (SD), cassava distiller (CD) and corn cob distiller (CCD) residuals from different generation bioethanol plants were used as the reinforcing phase for polyethylene composites. The mechanical performances and the physical properties of the polyethylene/DDFS composites were evaluated. The results showed that the CCD reinforced specimen offered the best mechanical performances, with a flexural strength of 21.8 ± 2.2 MPa and a tensile strength of 39.7 ± 3.2 MPa. After multigelation, the retention ratios of the rupture modulus and the elasticity modulus of the CCD reinforced specimen reached 88.7 ± 6.7% and 84.1 ± 2.7%, while after 2000 h of xenon lamp weathering they reached 96.2 ± 4.7% and 82 ± 1.8%, respectively. Hybridizing the biorefinery process with the process of composites production was feasible.

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.

Additional file 1: Fig. S1. Fed-batch ABE fermentation integrated with pervaporation using sweet sorghum juice; Fig. S2. Influence of the reflux ratio of ethanol column on ethanol concentration in distillate. Fig. S3. Grid diagram, hot and cold composite, and grand composite curve of heat-exchange system for the atmospheric distillation processes. Fig. S4. Effect of condenser pressure of acetone and ethanol columns on the distillate temperatures. Fig. S5. Effect of reflux ratio of columns on the output purities of solvents production. Fig. S6. Grid diagram, hot and cold composite, and grand composite curve of heat-exchange system for the VPD. Table S1. Comparison of streams and flow rates of the TCD (scenario 1) and E-TCD (scenario 2) sequences based on atmospheric distillations. Table S2. Comparison of streams and flow rates of the TCD (scenario 3) and E-TCD (scenario 4) sequences based on VDP.

In this study, the influence of sweet sorghum bagasse (SSB) as immobilized carrier on acetone–butanol–ethanol (ABE) fermentation integrated with gas stripping was investigated. During the integrated process, the immobilized bioreactor was also treated as the spinner flask for gas stripping. It appeared that the homogenization of the fermentation broth and the efficiency of solvents separation were enhanced. With the immobilized bioreactor treated as the spinner flask, fed-batch fermentation that integrated with intermittent and that integrated with continuous gas stripping were investigated, respectively. As a result, 155.7–255.6 g/L of ABE solvent was achieved in the condensate with 0.38 ± 0.06 g/L/h of productivity in the intermittent gas stripping scenario, while 180 ± 25 g/L of ABE in the condensate with productivity of ∼1.15 g/L/h were achieved in the continuous gas stripping integrated scenario. The simplified integrated process showed advantage both in ABE productivity and concentration compared with other reports.

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.

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.

Evaporation and chemical preservation were combined for long‐term storage of sweet sorghum juice (SSJ). The preserved SSJ was further used as substrate for ethanol fermentation. Different chemicals including hydrogen peroxide, sodium hypochlorite, sodium benzoate, and methyl paraben were used as co‐preservatives and were added into concentrated SSJ that contains ~40% (w/v) of sugars. The effects of chemical preservatives on sugar storage and ethanol fermentation were compared. The results showed that methyl paraben has better sugar preservation ability and an acceptable yeast toxicity when compared with other chemicals. The addition of methyl paraben in concentrated SSJ was further evaluated and optimized. By adding 0.4 g/L of methyl paraben, 95.1% of fermentable sugars in SSJ were preserved after a 90‐day preservation at room temperature. Ethanol concentration of 121.1 ± 4.6 g/L with a yield of 0.45 ± 0.02 g/g was obtained using the preserved SSJ in batch fermentation. PRACTICAL APPLICATIONS: Ethanol production by sugar‐containing juices is of interest because it is more effective, cheaper, and easier than the lignocellulosic routes. However, the commercialization of the bioethanol plants that uses the sweet sorghum juice as a substrate has long suffered from the deterioration of sugars. As a consequence, the ethanol fermentation process is limited by the short intermittent substrate supplementation in order to satisfy the harvest of the fresh stalks. This work comes up with a novel “evaporation+chemical” preservation method. The synergistic effect of high concentration of sugars and methyl paraben preservative showed inspiring sugar preservation results. Most of the sugars in the sweet sorghum juice were preserved for at least 90 days at room temperature and can be used for ethanol fermentation effectively. The continuity of fermentation can be significantly improved, which showed promising results in year‐round operations.

In this work, the preparation of chitosan-poly(acrylic acid)-calcium phosphate hybrid nanoparticles (CS-PAA-CaP NP) based on the mineralization of calcium phosphate (CaP) on the surface of chitosan-poly (acrylic acid) nanoparticles (CS-PAA NPs) was reported. CS-PAA-CaP NPs were achieved by directly adding ammonia to the aqueous solution of CS-PAA nanoparticles or by thermal decomposition of urea in the aqueous solution of CS-PAA nanoparticles, resulting in the mineralization of CaP on the surface of CS-PAA NPs. Through these two routes, especially using urea as a pH-regulator, the precipitation of CS-PAA NPs, a common occurrence in basic environment, was avoided. The size, morphology and ingredient of CS-PAA-CaP hybrid nanoparticles were characterized by dynamic light scattering (DLS), transmission electron microscope (TEM), scanning electron microscope (SEM), thermogravimetry analysis (TGA) and X-ray diffractometer (XRD). When urea was used as the pH regulator to facilitate the mineralization during the thermal urea decomposition procedure, regular CS-PAA-CaP hybrid nanoparticles with a porosity-structural CaP shells and 400–600 nm size were obtained. TGA result revealed that the hybrid NPs contained approximately 23% inorganic component, which was consistent with the ratio of starting materials. The XRD spectra of hybrid nanoparticles indicated that dicalcium phosphate (DCP: CaHPO4) crystal was a dominant component of mineralization. The porous structure of the CS-PAA-CaP hybrid NPs might be greatly useful in pharmaceutical and other medical applications.

β-Cyclodextrin modified chitosan–poly(acrylic acid) nanoparticles (CS–PAACD NPs) were obtained by polymerizing acrylic acid (AA) and β-cyclodextrin (β-CD) substituted acrylic acid (AACD) in chitosan (CS) solution. These CS–PAACD NPs, characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) as well as atomic force microscopy (AFM), were quite small in size about 40–50 nm. The size and the microstructure of these CS–PAACD NPs could be accurately controlled by changing the ration of AACD to AA. As the ratio of AACD to AA increased, the size of these NPs decreased. These as-prepared CS–PAACD NPs showed enhanced solubility for paclitaxel (PTX) in aqueous solution and exhibited a typical pH-sensitive release property for the encapsulated drug in vitro. The presence of the β-cyclodextrin inside the CS–PACD NPs greatly enhanced the ability to load hydrophobic drugs, which significantly broadened the application of CS–PAACD NPs in biomedical fields.

For the problem of high harmonics amplification existences in the reactive power compensation with capacitor at presently, a research on simulation of reactive power compensation is carried out with MATLAB simulation software, the diversification of harmonics and reactive current are detected, and a detailed FFT analysis of the simulation result is presented.