scholarly journals Optimized Organosolv Pretreatment of Biomass Residues Using 2-Methyltetrahydrofuran and n-Butanol

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 2051
Author(s):  
Egidio Viola ◽  
Francesco Zimbardi ◽  
Massimo Morgana ◽  
Nadia Cerone ◽  
Vito Valerio ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Wheat Straw ◽  
Glucose Production ◽  
Operating Conditions ◽  
Free Sugar ◽  
Process Conditions ◽  
Eucalyptus Wood ◽  
Cellulose Digestibility ◽  
Free Glucose ◽  
Acid Load

Wheat straw and eucalyptus residues were pretreated in a biphasic system, constituted of butanol (n-butanol) or 2-methyltetrahydrofuran (2M-THF) and aqueous oxalic acid solutions. The pretreatments were carried out in a 300 mL Parr reactor (Autoclave Buchi Limbo-li®) with a solid load of 5 wt.%, the temperature in the range 140–180 °C, oxalic acid load from 0 to 10 wt.% and a duration of 30–90 min. The obtained slurry was then fractionated in three streams: the aqueous phase which contained solubilized hemicellulose, the organic phase which contained the solvated lignin, and the solid residue which contained cellulose. The solid was hydrolyzed using a commercial mix of enzymes to assess cellulose digestibility and glucose production. The pretreatment was optimized to maximize the purity of the cellulose and hemicellulose fractions and the glucose recovery as free sugar. The optimization was done by using an experimental design and response surface methodology. The mass flow details of the four optimized processes were obtained. In terms of biomass fractionation, butanol demonstrated significant advantages over 2M-THF in the same range of process conditions as shown by the recovery yield of free glucose which reached 98% of the theoretical value with butanol but was 67% with 2M-THF. Tests at low temperature and low enzyme loading highlighted the importance of the solvent choice over the operating conditions. 2M-THF showed interesting performances only in the delignification step, with 90% efficiency for the straw. Regarding the use of different feedstock, fractionation and recovery were generally higher for wheat straw than for eucalyptus wood residues.

scholarly journals Reuse of Spent Hydrotreating Catalyst of the Middle Petroleum Fractions

2019 ◽  
Vol 20 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Safa Nabeel Abdulqahar ◽  
Majid I. Abdulwahab ◽  
Khalid K. Hummadi
Keyword(s):  
Oxalic Acid ◽  
Catalyst Activity ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Process Conditions ◽  
Operating Pressure ◽  
Active Components ◽  
Petroleum Fractions ◽  
Contaminant Metals ◽  
Coke Removal

Reuse of spent hydrodesulphurization (HDS) of middle petroleum fractions catalyst CoMo/γAl2O3 was accomplished via removal of coke and contaminants such as vanadium, Iron, Nickel, and sulfur. Three processes were adopted; extraction, leaching, decoking. Soluble and insoluble coke was removed. Leaching step used three different solvents (oxalic acid, ammonium peroxydisulfate and oxalic acid + H2O2) in separate in order to remove contaminant metals (V, S, Ni and Fe).    The effect of soluble coke removal on leaching step was studied. It was found that the removal of soluble coke significantly enhances the leaching of contaminants and barely affected the removal of active metals (Co and Mo). It was found that the best route (sequence) was soluble coke extraction followed by contaminants leaching then decoking process and the best leaching solvent was oxalic acid. According to this determination, the removed contaminants were 79.9 % for sulfur, 13.69% for vanadium, 82.27 % for iron, and 76.34 % for nickel. The active components loss accompanied with this process were 5.08 % for cobalt and 6.88% for molybdenum. Leaching process conditions (leaching solvent concentration, temperature and leaching time) were studied to determine the best-operating conditions. The rejuvenated catalyst activity was examined by a pilot scale HDS unit of naphtha. Sulfur content removal of naphtha was found to be 85.56 % for single pass operation under typical operating conditions of refinery HDS unit of naphtha which are 1 ml/min feed flow rate, 200 H2/HC ratio, 32 bar operating pressure and 320 °C operating temperature.

scholarly journals Alkali treatment of fungal pretreated wheat straw for bioethanol production

Bioethanol ◽  
2016 ◽  
Vol 2 (1) ◽  
Author(s):  
María García-Torreiro ◽  
Miguel Álvarez Pallín ◽  
María López-Abelairas ◽  
Thelmo A. Lu-Chau ◽  
Juan M. Lema
Keyword(s):  
Wheat Straw ◽  
Alkali Treatment ◽  
Alkaline Treatment ◽  
White Rot ◽  
White Rot Fungus ◽  
Process Conditions ◽  
Alkali Pretreatment ◽  
Irpex Lacteus ◽  
C 30 ◽  
Pretreated Wheat Straw

AbstractBioconversion of lignocellulosic materials into ethanol requires an intermediate pretreatment step for conditioning biomass. Sugar yields from wheat straw were previously improved by the addition of a mild alkali pretreatment step before bioconversion by the white-rot fungus Irpex lacteus. In this work, an alternative alkaline treatment, which significantly reduces water consumption, was implemented and optimized. Sugar recovery increased 117% with respect to the previously developed alkaline wash process at optimal process conditions (30°C, 30 minutes and 35.7% (w/w) of NaOH). In order to further reduce operational costs, a system for alkali recycling was implemented. This resulted in the treatment of 150% more wheat straw using the same amount of NaOH. Finally, enzymatic hydrolysis was optimized and resulted in a reduction of enzyme dose of 33%.

Linking Microbial Community Dynamics in BIOX® Leaching Tanks to Process Conditions: Integrating Lab and Commercial Experience

2017 ◽  
Vol 262 ◽  
pp. 38-42 ◽  
Author(s):  
Mariette Smart ◽  
Robert J. Huddy ◽  
Catherine J. Edward ◽  
Charl Fourie ◽  
Trust Shumba ◽  
...  
Keyword(s):  
South Africa ◽  
Community Structure ◽  
Microbial Community ◽  
Research University ◽  
Community Dynamics ◽  
Operating Conditions ◽  
Process Conditions ◽  
Significant Shift ◽  
Engineering Research ◽  
Microbial Community Dynamics

In the commercial BIOX® process, an acidophilic mixed bacterial and archaeal community dominated by iron and sulphur oxidising microorganisms is used to facilitate the recovery of precious metals from refractory gold-bearing sulphidic mineral concentrates. Characterisation of the microbial communities associated with commercial BIOX® reactors from four continents revealed a significant shift in the microbial community structure compared to that of the seed culture, maintained at SGS (South Africa). This has motivated more detailed study of the microbial community dynamics in the process. Microbial speciation of a subset of the BIOX® reactors at Fairview mines (Barberton, South Africa) and two laboratory maintained reactors housed at Centre for Bioprocess Engineering Research, University of Cape Town, has been performed tri-annually for three years by quantitative real-time polymerase chain reaction. The laboratory BIOX® culture maintained on Fairview concentrate was dominated by the desired iron oxidiser, Leptospirillum ferriphilum, and sulphur oxidiser, Acidithiobacillus caldus, when operated under standard BIOX® conditions. Shifts in the microbial community as a result of altered operating conditions were transient and did not result in a loss of the microbial diversity of the BIOX® culture. The community structure of the Fairview mines BIOX® reactor tanks showed archaeal dominance of these communities by organisms such as the iron oxidiser Ferroplasma acidiphilum and a Thermoplasma sp. for the period monitored. Shifts in the microbial community were observed across the monitoring period and mapped to changes in performance of the commercial process plant. Understanding the effect of changes in the plant operating conditions on the BIOX® community structure may assist in providing conditions that support the desired microbial consortium for optimal biooxidation to maximize gold recovery.

Taguchi Approach and ANOVA in Optimization of the Dissolution of Colemanite in CO2 and SO2- Water Systems

2020 ◽  
Vol 10 (2) ◽  
pp. 88-97
Author(s):  
Zafer Ekinci ◽  
Esref Kurdal ◽  
Meltem Kizilca Coruh
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Gas Flow ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Process Conditions ◽  
Liquid Ratio ◽  
Positive Effects ◽  
Controllable Factors

Background: Turkey is approximately 72% of the world’s boron sources. Colemanite, tincal, ulexite and pandermite are among the most significant in Turkey. Boron compounds and minerals are widely used in many industrial fields. Objective: The main purpose of this study was to investigate the control of impurities in the boric acid production process using colemanite by carrying out the reaction with a mixture of CO2 and SO2 - water, and determining the appropriate process conditions to develop a new process as an alternative to the use of sulfuric acid. Due to worrying environmental problems, intensive studies are being carried out globally to reduce the amount of CO2 and SO2 gases released to the atmosphere. Methods: The Taguchi method is an experimental design method that minimizes the product and process variability by selecting the most appropriate combination of the levels of controllable factors compared to uncontrollable factors. Results: It was evaluated the effects of parameters such as reaction temperature, solid-to liquid ratio, SO2/CO2 gas flow rate, particle size, stirring speed and reaction time. The optimum conditions determined to be reaction temperature of 45°C; a solid–liquid ratio of 0.083 g.mL−1; an SO2/CO2 ratio of 2/2 mL.s−1; a particle size of -0.354+0 .210 mm; a mixing speed of 750 rpm and a reaction time of 20 min. Conclusion: Under optimum operating conditions, 96.8% of colemanite was dissolved. It is thought that the industrial application of this study will have positive effects on the greenhouse effect by contributing to the reduction of CO2 and SO2 emissions that cause global warming.

Evaluation of GT Outboard Bleed Air on Overall Engine Efficiency and CO2e Emission in Natural Gas Compressor Stations

2013 ◽  
Author(s):  
K. K. Botros ◽  
H. Golshan ◽  
D. Rogers ◽  
B. Sloof
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Heat Rate ◽  
Operating Conditions ◽  
Process Conditions ◽  
Inlet Temperature ◽  
Predictive Tool ◽  
Valve Opening ◽  
Overall Efficiency ◽  
Engine Emission

Gas turbine (GT) engines employed in natural gas compressor stations operate in different modes depending on the power, turbine inlet temperature and shaft speeds. These modes apply different sequencing of bleed valve opening on the air compressor side of the engine. Improper selection of the GT and the driven centrifugal gas compressor operating conditions can lead to larger bleed losses due to wider bleed valve openings. The bleed loss inevitably manifests itself in the form of higher overall heat rate of the GT and greater engine emission. It is therefore imperative to determine and understand the engine and process conditions that drive the GT to operate in these different modes. The ultimate objective is to operate the engine away from the inefficient modes by adjusting the driven gas compressor parameters as well as the overall station operating conditions (i.e. load sharing, control set points, etc.). This paper describes a methodology to couple the operating conditions of the gas compressor to the modes of GT bleed valve opening (and the subsequent air bleed rates) leading to identification of the operating parameters for optimal performance (i.e., best overall efficiency and minimum CO2e emission). A predictive tool is developed to quantify the overall efficiency loss as a result of the different bleed opening modes, and map out the condition on the gas compressor characteristics. One year’s worth of operating data taken from two different compressor stations on TransCanada Pipelines’ Alberta system were used to demonstrate the methodology. The first station employs GE-LM1600 gas turbine driving a Cooper Rolls-RFBB-30 centrifugal compressor. The second station employs GE-LM-2500+ gas turbine driving NP PCL-800/N compressor. The analysis conclusively indicates that there are operating regions on the gas compressor maps where losses due to bleed valves are reduced and hence CO2 emissions are lowered, which presents an opportunity for operation optimization.

A Novel Methodology for Optimal Design of Compressor Plants Using Probabilistic Plant Design

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Rainer Kurz ◽  
J. Michael Thorp ◽  
Erik G. Zentmyer ◽  
Klaus Brun
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Operating Conditions ◽  
Process Conditions ◽  
Plant Design ◽  
Well Performance ◽  
Worst Case ◽  
Gas Industry ◽  
Machine Performance ◽  
Equipment Sizing

Equipment sizing decisions in the oil and gas industry often have to be made based on incomplete data. Often, the exact process conditions are based on numerous assumptions about well performance, market conditions, environmental conditions, and others. Since the ultimate goal is to meet production commitments, the traditional method of addressing this is to use worst case conditions and often adding margins onto these. This will invariably lead to plants that are oversized, in some instances, by large margins. In reality, the operating conditions are very rarely the assumed worst case conditions, however, they are usually more benign most of the time. Plants designed based on worst case conditions, once in operation, will, therefore, usually not operate under optimum conditions, have reduced flexibility, and therefore cause both higher capital and operating expenses. The authors outline a new probabilistic methodology that provides a framework for more intelligent process-machine designs. A standardized framework using a Monte Carlo simulation and risk analysis is presented that more accurately defines process uncertainty and its impact on machine performance. Case studies are presented that highlight the methodology as applied to critical turbomachinery.

scholarly journals Pretreatment of Wheat Straw with Phosphoric Acid and Hydrogen Peroxide to Simultaneously Facilitate Cellulose Digestibility and Modify Lignin as Adsorbents

Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 844 ◽  
Author(s):  
Xue Wan ◽  
Fengpei Yao ◽  
Dong Tian ◽  
Fei Shen ◽  
Jinguang Hu ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Regression Analysis ◽  
Phosphoric Acid ◽  
Wheat Straw ◽  
Oxidative Modification ◽  
Integrated Process ◽  
Lignin Valorization ◽  
Lignin Modification ◽  
Adsorption Capacities ◽  
Cellulose Digestibility

Effective valorization of lignin is crucial to achieve a sustainable, economic and competitive biorefinery of lignocellulosic biomass. In this work, an integrated process was proposed based on a concentrated phosphoric acid plus hydrogen peroxide (PHP) pretreatment to simultaneously facilitate cellulose digestibility and modify lignin as adsorbent. As a dominant constitutor of PHP pretreatment, H2O2 input and its influence on the overall fractionation/lignin modification performance was thoroughly investigated. Results indicated that wheat straw was fractionated more efficiently by increasing the H2O2 input. H2O2 input had a significant influence on the digestibility of the obtained cellulose-rich fraction whereby almost 100.0% cellulose-glucose conversion can be achieved even with only 0.88% H2O2 input. Besides, the adsorption capacity of lignin on MB was improved (74.3 to 210.1 mg g−1) due to the oxidative-modification in PHP pretreatment with H2O2 inputs. Regression analysis indicated that –COOH groups mainly governed the lignin adsorption (R2 = 0.946), which displayed the considerable adsorption capacities for typical cationic substances. This work shows a promising way to integrate the lignin modification concept into the emerging PHP pretreatment process with the dual goal of both cellulose utilization and lignin valorization.

Elastocaloric Cooling With Ni-Ti Based Alloys: Material Characterization and Process Variation

2015 ◽  
Author(s):  
Marvin Schmidt ◽  
Johannes Ullrich ◽  
André Wieczorek ◽  
Jan Frenzel ◽  
Andreas Schütze ◽  
...  
Keyword(s):  
Solid State ◽  
Heat Source ◽  
Boundary Conditions ◽  
Shape Memory ◽  
Heat Sink ◽  
Operating Conditions ◽  
Process Conditions ◽  
Cooling Process ◽  
Elastocaloric Cooling ◽  
Latent Heats

Solid state refrigeration processes, such as magnetocaloric and electrocaloric refrigeration, have recently shown to be a promising alternative to conventional compression refrigeration. A new solid state elastocaloric refrigeration process using the latent heats within Shape Memory Alloys (SMA) could also hold potential in this field. This work investigates the elastocaloric effects in Ni-Ti-based superelastic Shape Memory Alloy (SMA) systems for use in an elastocaloric cooling processes. Ni-Ti alloys exhibits large latent heats and a small mechanical hysteresis, which may potentially lead to the development of an efficient environmentally friendly solid-state cooling system, without the need for ozone-depleting refrigerants. A systematic investigation of the SMA is conducted using a novel custom-built scientific testing platform specifically designed to measure cooling process related phenomena. This testing system is capable of performing tensile tests at high rates as well as measuring and controlling the solid-state heat transfer between SMA and heat source/heat sink. Tests are conducted following a cooling process related training cycle where the material has achieved stabilized behavior. First, a characterization of the elastocaloric material properties is performed followed by an investigation of the material under cooling process conditions. A comprehensive monitoring of the mechanical and thermal parameters enables the observation of temperature changes during mechanical cycling of the SMA at high strain rates. These observations can be used to study the rate dependent efficiency of the elastocaloric material. The measurement of the temperature of both the heat source/heat sink and the SMA itself, as well as the required mechanical work during a running cooling process, reveals the influence of the operating conditions on the elastocaloric effect of the material. Furthermore investigations of the process efficiency at different thermal boundary conditions (temperature of heat source/heat sink), indicates that the process is dependent on the boundary conditions which have to be controlled in order to optimize the efficiency.

scholarly journals Optimization of Biohydrogen Production with Biomechatronics

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Shao-Yi Hsia ◽  
Yu-Tuan Chou
Keyword(s):  
Hydrogen Production ◽  
Taguchi Method ◽  
Alternative Energy ◽  
Production Efficiency ◽  
Biological Effects ◽  
Dark Fermentation ◽  
Operating Conditions ◽  
Biohydrogen Production ◽  
Process Conditions ◽  
Ultrasonic Frequency

Massive utilization of petroleum and natural gas caused fossil fuel shortages. Consequently, a large amount of carbon dioxide and other pollutants are produced and induced environmental impact. Hydrogen is considered a clean and alternative energy source. It contains relatively high amount of energy compared with other fuels and by-product is water. In this study, the combination of ultrasonic mechanical and biological effects is utilized to increase biohydrogen production from dark fermentation bacteria. The hydrogen production is affected by many process conditions. For obtaining the optimal result, experimental design is planned using the Taguchi Method. Four controlling factors, the ultrasonic frequency, energy, exposure time, and starch concentration, are considered to calculate the highest hydrogen production by the Taguchi Method. Under the best operating conditions, the biohydrogen production efficiency of dark fermentation increases by 19.11%. Results have shown that the combination of ultrasound and biological reactors for dark fermentation hydrogen production outperforms the traditional biohydrogen production method. The ultrasonic mechanical effects in this research always own different significances on biohydrogen production.

scholarly journals Analysis of particle dynamics in a pin mill by Discrete Element Method

2021 ◽  
Vol 249 ◽  
pp. 07010
Author(s):  
Wei Pin Goh ◽  
Mojtaba Ghadiri
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Discrete Element Method ◽  
Discrete Element ◽  
Particle Dynamics ◽  
Operating Conditions ◽  
Impact Testing ◽  
Process Conditions ◽  
Pharmaceutical Industries ◽  
Element Method

Milling is an important process for tailoring the particle size distribution for enhanced attributes, such as dissolution, content uniformity, tableting, etc., especially for active pharmaceutical ingredients and excipients in pharmaceutical industries. Milling performance of particulate solids depends on the equipment operating conditions (geometry, process conditions and input energy etc.) as well as material properties (particle size, shape, and mechanical properties, such as Young’s modulus, hardness and fracture toughness). In this paper the particle dynamics in a pin mill is analysed using Discrete Element Method (DEM), combined with a novel approach for assessing particle breakability by single particle impact testing. A sensitivity analysis is carried out addressing the effect of the milling conditions (rotational speed and feed particle flow rate), accounting for feed mechanical properties on the breakage behaviour of the particles. Particle collision energy spectra are calculated and shown to have a distribution with the upper tail end being close to the maximum energy associated with the collision with the rings. Breakage is primarily due to collisions with the rings, except for large particles that are comparable in size with the gap between the rings, nipping is also a contributory breakage mechanism.

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