Dynamic simulation and optimization of anaerobic digestion processes using MATLAB

Time series-based modeling provides a fundamental understanding of process fluctuations in an anaerobic digestion process. However, such models are scarce in literature. In this work, a dynamic model was developed based on modified Hill’s model using MATLAB, which can predict the biomethane production with time series. This model can predict the biomethane production for both batch and continuous process, across substrates and at diverse conditions such as total solids, loading rate, and days of operation. The deviation between literature and the developed model was less than ±7.6%, which shows the accuracy and robustness of this model. Moreover, statistical analysis showed there was no significant difference between literature and simulation, verifying the null hypothesis. Finding a steady and optimized loading rate was necessary to an industrial perspective, which usually requires an extensive experimental data. With the developed model, a stable and optimal methane yield generating loading rate could be identified at minimal input.

Effect of interaction from the reaction of carboxyl/epoxy hyperbranched polyesters on properties of feedstocks for metal injection molding

The purpose of this study is to improve the properties of the feedstocks and shape retention of debinded parts by the reaction between 17-4PH stainless steel powders. Carboxyl-terminated hyperbranched polyester (CTHP) and epoxy-terminated hyperbranched polyester (ETHP) were used to treat the powders, and termed as CTHP-m and ETHP-m with carboxyl and epoxy group, respectively. Comparing with pristine, CTHP-m and ETHP-m, feedstock prepared from equal amount of CTHP-m and ETHP-m (CTHP-m/ETHP-m) possessed more excellent properties. The experimental results showed that the critical solids loading, flexural modulus, density and melt flow index of CTHP-m/ETHP-m feedstock were 63.8 vol.%, 2800 Mpa, 5.06 g/cm3 and 62 g/10min, respectively, which were obviously higher than that of others. Also, the shape retention of CTHP-m/ETHP-m debinded parts was the best of all the samples. The improved properties of CTHP-m/ETHP-m feedstock were attributed to the powder interaction between CTHP-m and ETHP-m formed by the chemical reaction between epoxy and carboxyl group.

Biorefinery Cascade Processing For Converting Corncob To Xylooligosaccharides And Glucose By Maleic Acid Pretreatment

Corncob as an abundance and low-cost waste resource has received increasing attention to produce value added chemicals, it is rich in xylan and regarded as the most preferable feedstock for preparing xylooligosaccharides, which possesses highly commercial value due to a range of health benefits. The strategy with xylooligosaccharides as core products can cut costs and improve economic efficiency of biorefinery. Therefore, a cascade processing for converting corncob to xylooligosaccharides and glucose by sequential maleic acid pretreatment and enzymatic hydrolysis was design. Based on overarching aim of this study that maximally yielding xylooligosaccharides, corncob was first subjected to response surface methodology experimental procedure for optimizing the conditions. Correspondingly, a maximum xylooligosaccharides yield of 52.9% was achieved with 0.5% maleic acid at 155 °C for 26 min. Maleic acid, a non-toxic and edible catalyst, was able to effectively hydrolyze xylan into xylooligosaccharides and simultaneously generate a positive pretreated effect for improve the enzymatic hydrolysis efficiency. Finally, an enzymatic hydrolysis yield of 87.5% was achieved from maleic acid-treated corncob at 10% solids loading. This cascade processing may provide a novel strategy for the other biomass wastes utilization.

EOR Returned Polymer Removal from Produced Water by Chemical Coagulation – A Successful Pilot Testing

Severe fouling of crude oil and produced water treatment equipment of Mangala Processing Terminal (MPT) with elastic deposits has been observed after EOR polymer breaking through to the producing wells. Fouling by polymer containing solids caused the system bottlenecking impacting on crude production rates and deterioration of water quality for injection due to increase of total solids loading. The objective of the study included developing the water treatment technology for removing the returned polymer, developing the pilot run for implementation of the technology and scaling up the process if the pilot shows success. Crude processed at MPT is produced from Mangala, Bhagyam and Aishwarya fields which are located at the north-west part of India. Full field polymer flooding has been implemented in the Mangala field from 2015. Fouling of downhole and topside equipment with elastic deposits has been reported soon after polymer breakthrough the same year. For reducing the fouling potential and solids loading, the concept of removing the returned polymer from produced water has been considered as beneficial. Removal of polymer through the chemical coagulation was considered for developing. Extensive laboratory and bench testing have been carried out. Based on the laboratory results, the pilot was developed and carried out on the flotation equipment available at MPT. In the laboratory and bench test for polymer coagulation, over 70% polymer removal was achieved with non-sticky flocks and minimal sludge. The tests also demonstrated reduced suspended solids, residual oil and filterability improvement of treated water. The pilot run confirmed effectiveness of the chemical coagulation process to remove polymer. Polymer removal > 70% was observed during the pilot. Oil removal from produced water at 60-80% was seen. Cloud point of polymer remaining in water increased from 60°C to > 110°C indicating on the significant potential reduction of remaining polymer to precipitate from treated water. The pilot results demonstrated on the applicability of the technology of chemical polymer removal at MPT and will be used for scaling up the treatment facilities.

High-Performance BaTiO3 Film Based on Aqueous Tape Casting for Ultrathin MLCC Applications

Environment-friendly aqueous tape-casting are proposed as an inevitable tendency for producing a high-quality BaTiO3-based film in the development of ultra-thin multilayer ceramic capacitors. In this study, aqueous BaTiO3 suspension with high solids loading produced by using polycarboxylate ammonium salt APC (dispersant), proprietary acrylic formulation binder solution WB4101 (binder), and acrylic resin PL002 (plasticizer), respectively. It is demonstrated that the green density, tensile strength, and strain at failure of the 9.5-μm-thin BaTiO3 tape achieves 3.65 g/cm3, 7.65 MPa, and 11%, respectively. In particular, the capacitance and dielectric loss of BaTiO3-based MLCC chips at room temperature are found to be approximately 28 nF and 0.02 compatible with Pt electrodes. Additionally, the TCC, ferroelectric hysteresis loops, change of dielectric constants versus DC-BIAS field, and evolution of electrical resistivity under accelerated DC stressing of BaTiO3-based MLCC are studied. The results provide an effective method for the future improvement in aqueous MLCC applications.

A high solids field-to-fuel research pipeline to identify interactions between feedstocks and biofuel production

Background Environmental factors, such as weather extremes, have the potential to cause adverse effects on plant biomass quality and quantity. Beyond adversely affecting feedstock yield and composition, which have been extensively studied, environmental factors can have detrimental effects on saccharification and fermentation processes in biofuel production. Only a few studies have evaluated the effect of these factors on biomass deconstruction into biofuel and resulting fuel yields. This field-to-fuel evaluation of various feedstocks requires rigorous coordination of pretreatment, enzymatic hydrolysis, and fermentation experiments. A large number of biomass samples, often in limited quantity, are needed to thoroughly understand the effect of environmental conditions on biofuel production. This requires greater processing and analytical throughput of industrially relevant, high solids loading hydrolysates for fermentation, and led to the need for a laboratory-scale high solids experimentation platform. Results A field-to-fuel platform was developed to provide sufficient volumes of high solids loading enzymatic hydrolysate for fermentation. AFEX pretreatment was conducted in custom pretreatment reactors, followed by high solids enzymatic hydrolysis. To accommodate enzymatic hydrolysis of multiple samples, roller bottles were used to overcome the bottlenecks of mixing and reduced sugar yields at high solids loading, while allowing greater sample throughput than possible in bioreactors. The roller bottle method provided 42–47% greater liquefaction compared to the batch shake flask method for the same solids loading. In fermentation experiments, hydrolysates from roller bottles were fermented more rapidly, with greater xylose consumption, but lower final ethanol yields and CO2 production than hydrolysates generated with shake flasks. The entire platform was tested and was able to replicate patterns of fermentation inhibition previously observed for experiments conducted in larger-scale reactors and bioreactors, showing divergent fermentation patterns for drought and normal year switchgrass hydrolysates. Conclusion A pipeline of small-scale AFEX pretreatment and roller bottle enzymatic hydrolysis was able to provide adequate quantities of hydrolysate for respirometer fermentation experiments and was able to overcome hydrolysis bottlenecks at high solids loading by obtaining greater liquefaction compared to batch shake flask hydrolysis. Thus, the roller bottle method can be effectively utilized to compare divergent feedstocks and diverse process conditions.

Development of a new low impact development planning tool

The purpose of this research is to develop a new planning tool to evaluate the efficiency of Low Impact Development (LID) for single-family homes in Ontario. A comprehensive literature review was conducted to compare major LID planning tool available for public to identify the key features of an ideal LID planning tool. A study across four regions in Ontario was conducted to obtain rainfall, soil, and housing-types data. U.S. EPA Stormwater Management Model (SWMM) was selected to perform all the simulation for establishing a common database for the new tool. With the new tool, users can estimate the runoff reduction, total suspended solids loading reduction, total phosphorus loading reduction and total cost by several clicks and few data inputs. The case study of Bayview Wellington Center in Town of Aurora illustrated that the new tool achieved required accuracy level.

Development of a new low impact development planning tool

The purpose of this research is to develop a new planning tool to evaluate the efficiency of Low Impact Development (LID) for single-family homes in Ontario. A comprehensive literature review was conducted to compare major LID planning tool available for public to identify the key features of an ideal LID planning tool. A study across four regions in Ontario was conducted to obtain rainfall, soil, and housing-types data. U.S. EPA Stormwater Management Model (SWMM) was selected to perform all the simulation for establishing a common database for the new tool. With the new tool, users can estimate the runoff reduction, total suspended solids loading reduction, total phosphorus loading reduction and total cost by several clicks and few data inputs. The case study of Bayview Wellington Center in Town of Aurora illustrated that the new tool achieved required accuracy level.