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• Two sub-period division strategies with MPCA are evaluated in SBR process. • Correlations between the different stages of SBR process are considered. • Four SBR parameters of field data from paper mill are utilized for fault diagnosis. • Sub-period division strategy based on similarity principle demonstrates best. Fault diagnosis of sequential batch reactor (SBR), a widely applied wastewater treatment technology in papermaking industry with huge discharge, has been a significant challenge due to the inherent multi-period characteristics of the process. In this paper, based on the conventional multi-way principal component analysis (MPCA) method (Scenario 0), two sub-period division strategies based on the processing phases of SBR process (Scenario 1) and the similarities of the loading matrices between the adjacent time slices (Scenario 2) are proposed for the detection of faults. Combined with Scenario 0, using the field data of blower current, level of SBR reactor, dissolved oxygen of wastewater and the blower valve opening in the SBR process of paper mill, two different fault diagnosis models with Scenarios 1 and 2 are developed and evaluated, respectively. The study results revealed that, both the calculated statistics of T2 and sum of prediction errors (SPE) of the fault diagnosis models with Scenarios 1 and 2 could detect the faults and identify the fault locations and sources. Compared to Scenario 0 which neglects the correlations between the different stages of SBR process, the fault diagnosis model by Scenario 2 demonstrated a superiority ability in fault identification in terms of the fault's time onset and fault's sources with adequate accuracy. The results enable the feasible and reliable implementation of the developed sub-MPCA diagnosis model with Scenario 2 in the actual SBR plants. [ABSTRACT FROM AUTHOR]

Pulp and paper industry has generated a higher contamination burden of the final mill wastewater which must be further treated to comply with the standards imposed by the legislation requirement. In this study, the removal efficiencies for chemical oxygen demand (COD) and color from pulp and paper wastewater using sequencing batch reactor (SBR) in combination with advanced oxidation processes (AOPs) at a bench scale were investigated. Response surface methodology (RSM) based on a three-variable-three-level central composite design (CCD) was employed to optimize the SBR process. At the optimal conditions of initial COD of 1000 mg/L, MLSS of 3000 mg/L and cycle time of 24 h, 74.8% COD, 58.3% of color removal and 80 mL/g of SVI were obtained in the pretreatment stage. The use of Fenton oxidation as post-treatment enhanced COD reduction and color removal. A percentage of 92.1% COD reduction and 90.3% of color removal was achieved in dosages of 3 mM Fe2+ and 9 mM H 2 O 2 at pH of 3.0 for a reaction time of 30 min, while a total of 98% reduction of COD and 94% removal of color for the combined treatment was achieved. [ABSTRACT FROM AUTHOR]

Using natural flocculants for water and wastewater treatment through coagulation-flocculation process has received growing attention due to its simplicity and safety process. In this research, the performance of pomegranate seed powder as a novel natural flocculant in treating pulp and paper wastewater (PPWW) was evaluated. Chemical oxygen demand (COD) reduction and turbidity removal from PPWW were monitored using different dosages of pomegranate seeds and alum salt. In addition, the synergistic effect of dual flocculation between pomegranate seeds and alum on PPWW treatment was investigated and optimized. Zeta potential (ZP), Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) analyses were conducted to elucidate the flocculation mechanism. The results revealed that pomegranate seeds composed of active substances such as protein, polysaccharides and fiber contents that contribute to its coagulating ability. The highest removal efficiencies of 60% and 87% were achieved for COD and turbidity, respectively when using pomegranate seeds at the optimal dosage of 600 mg/L after 30 min treatment. Dual flocculation of pomegranate seeds and alum showed a synergistic effect, resulting in a maximum removal of 81% of COD and 98% of turbidity under optimal condition: Alum = 400 mg/L and pomegranate seeds = 800 mg/L at much shorter treatment time (2 min). The ZP and FTIR test results and SEM images revealed that charge neutralization and sweeping mechanism induced by alum combined with bridging mechanism by pomegranate seeds led to the synergy. [Display omitted] [ABSTRACT FROM AUTHOR]

TiO 2 /PS composite is evaluated in photodegradation of lignin under UVA-LED irradiation. • TiO 2 /PS composite was synthesized by solvent-casting method. • The effects of operational parameters were evaluated and optimized by Box-Behnken design. • The toxicity effects after photodegradation process were not observed. • The reusability study confirmed the stability of TiO 2 /PS composite. In the present study, the photodegradation of lignin was studied using TiO 2 /Polystyrene composite under UV-LED irradiation in a batch-recirculated photoreactor as a supplementary treatment for pulp and paper industries. TiO 2 /PS composite was synthesized by the solvent-casting method and was characterized by scanning electron microscopy (SEM) and EDX analysis. The 3-level, 3-factor Box-Behnken design was applied to study the effects of main operating parameters and optimization of process circumstances. Besides, COD reduction efficiency, toxicity assays, and reusability were also investigated. The predicted model had R2 and R2 adj correlation coefficients of 0.97 and 0.99 respectively, which showed experimental results were very close to the predicted values. Furthermore, under the optimal conditions (reaction time = 72.5, volumetric flow rate = 230 mL/min and lignin = 51.8 mg/L) the lignin degradation efficiency was 93.98%. The maximum COD removal (89%) obtained by 250 mL/min volumetric flow rate and lignin concentration of 50 mg/L after 120 min reaction time. Bioassay using D. Magna exhibited that at the beginning of the process, the toxicity of solution increased but continuously decreasing after then to very low values achieved within 120 min of photodegradation. In addition, the reusability tests demonstrated that the TiO 2 /PS composite after 5 cycles has a good stability and photocatalytic activity. [ABSTRACT FROM AUTHOR]

Wastes from recycled paper industry (WRP) was hydrothermally carbonized to remove impurities to produce alternative biofuel. The chlorine behaviors during hydrothermal carbonization (HTC) and the fuel properties of the generated hydrochar were evaluated. The degradation of lignocellulosic components improved free -OH bond and small free cellulosic fragments facilitating dechlorination. Meanwhile, dechlorination process stimulated degradation of biomass. The carbon content and density of WRP were improved by HTC resulting in high heating value increasing from 5044.40 MJ/m³ to 17,004.88 MJ/m³. Pollutants emission from hydrochar combustion would be effectively controlled because of the removal of sulfur and chlorine. Hydrochar enjoyed higher ignition temperature and average combustion rate while lower burnout temperature, indicating that the combustion range has been narrowed, thus improving the combustion efficiency. The increase of HTC temperature facilitated hydrochars combustion and reduce energy consumption during hydrochar combustion. Mild HTC operating conditions (220 °C for 90 min and 240 °C for 60 min) were supposed to effectively improve the combustion intensity with stability meanwhile reached the highest dechlorination efficiency. These results evidence the feasibility of converting WRP to clean biofuel via HTC. [ABSTRACT FROM AUTHOR]

Wastes from recycled paper industry (WRP) was hydrothermally carbonized to remove impurities to produce alternative biofuel. The chlorine behaviors during hydrothermal carbonization (HTC) and the fuel properties of the generated hydrochar were evaluated. The degradation of lignocellulosic components improved free -OH bond and small free cellulosic fragments facilitating dechlorination. Meanwhile, dechlorination process stimulated degradation of biomass. The carbon content and density of WRP were improved by HTC resulting in high heating value increasing from 5044.40 MJ/m3 to 17,004.88 MJ/m3. Pollutants emission from hydrochar combustion would be effectively controlled because of the removal of sulfur and chlorine. Hydrochar enjoyed higher ignition temperature and average combustion rate while lower burnout temperature, indicating that the combustion range has been narrowed, thus improving the combustion efficiency. The increase of HTC temperature facilitated hydrochars combustion and reduce energy consumption during hydrochar combustion. Mild HTC operating conditions (220 ℃ for 90 min and 240 ℃ for 60 min) were supposed to effectively improve the combustion intensity with stability meanwhile reached the highest dechlorination efficiency. These results evidence the feasibility of converting WRP to clean biofuel via HTC. [Display omitted] [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the effect of electrical conductivity, pH and temperature which were kept constant during treatment via an advanced control strategy on chemical oxygen demand, color, turbidity and total suspended solids removal and energy consumption. Central Composite Design matrices were formed for aluminum and iron electrode systems separately with different combinations of 5 independent variables (electrical conductivity, pH, temperature, current intensity and electrolysis time). Obtained results revealed that aluminum electrode system was found to be more effective than iron electrode system under controlled conditions. Comparison of uncontrolled and controlled studies at optimum values of aluminum electrode system showed an increase by 31.67% in chemical oxygen demand removal and a decrease by 48.30% in energy consumption under controlled case. Results indicated that constant electrical conductivity, pH and temperature during electrocoagulation process of pulp and paper mill wastewater by means of a controller enhanced treatment efficiency. [ABSTRACT FROM AUTHOR]

Waste streams generated from pulp and paper mills show high potential to be used as alternatives raw materials for production of clinker. In this context, this work aims to evaluate the use of such materials to obtain hydraulic binders, which are referred to as Ecoclinfeers and Ecocements. Lime mud, wastewater treatment process sludge and biomass ashes were characterized, and five formulations (F1-F5) were developed by applying the Bogue equations. These compositions were processed at three different clinkering temperatures (1350,1440 and 1455 "C). The formulated Ecoclinfeers and a reference hydraulic binder were characterized by X-ray diffractometry to identify the crystalline phases, which were subsequently quantified by the Rietveld method. The results showed that crystalline phase characteristics of clinkers and cements, and compression strengths of ~20 MPa after 28 days curing time were obtained, confirming the potential use of the investigated waste as alternative materials for production of clinker. [ABSTRACT FROM AUTHOR]

Nowadays, dealing with the complex oil/water contamination that contains both oil/water mixtures and emulsions with desirable performance remains a huge challenge. Complicated fabrication procedures, low flux, and efficiency are shortcomings of the known materials. Herein, a facile and effective laser-assisted strategy is proposed to prepare super-hydrophobic graphene/PDMS paper (L-G-P), which perfectly takes advantage of both naturally strong capillary of paper tissue and high-quality graphene. Specifically, graphene is obtained by reducing graphene oxide via laser irradiation, which avoids introducing chemical reducing agents that are either hazardous or hard to separate. Meanwhile, the super-intensive instantaneous energy would create abundant defects on graphene sheets, thus the specific surface area increased by 25%. As for oil/water mixtures, the efficient sorption/separation can realize over 99.99% deep clean, meanwhile showing excellent durability after repeated cycles. As for water-in-oil emulsions, the high separation flux of surfactant-stabilized emulsions could reach 4421 L m-2 h-1 with an efficiency up to 99.85%. Moreover, the mechanical property of the composite was 80.50% stronger than uncoated paper tissue. The proposed L-G-P with durable and efficient oil/water separation performance is a promising material for practical applications for treating oil-contaminated wastewater in harsh environments. [ABSTRACT FROM AUTHOR]

[Display omitted] Nowadays, dealing with the complex oil/water contamination that contains both oil/water mixtures and emulsions with desirable performance remains a huge challenge. Complicated fabrication procedures, low flux, and efficiency are shortcomings of the known materials. Herein, a facile and effective laser-assisted strategy is proposed to prepare super-hydrophobic graphene/PDMS paper (L-G-P), which perfectly takes advantage of both naturally strong capillary of paper tissue and high-quality graphene. Specifically, graphene is obtained by reducing graphene oxide via laser irradiation, which avoids introducing chemical reducing agents that are either hazardous or hard to separate. Meanwhile, the super-intensive instantaneous energy would create abundant defects on graphene sheets, thus the specific surface area increased by 25%. As for oil/water mixtures, the efficient sorption/separation can realize over 99.99% deep clean, meanwhile showing excellent durability after repeated cycles. As for water-in-oil emulsions, the high separation flux of surfactant-stabilized emulsions could reach 4421 L m−2 h−1 with an efficiency up to 99.85%. Moreover, the mechanical property of the composite was 80.50% stronger than uncoated paper tissue. The proposed L-G-P with durable and efficient oil/water separation performance is a promising material for practical applications for treating oil-contaminated wastewater in harsh environments. [ABSTRACT FROM AUTHOR]

Integrated processes have been proposed for high strength wastewaters such as pulp and paper wastewater. In this work, electrocoagulation (EC) followed by UV/oxidant system was studied for the removal of organic compounds from pulp and paper wastewater. EC process was optimized by Box-Behnken design. Under optimum conditions (natural pH, time = 33.7 min and current density=5.55 mA/cm2), about 61% COD removal was achieved. The obtained effluent was remediated by UV/persulfate (PS) and UV/peroxymonosulfate (PMS). The results showed that UV/PS had the best performance in natural pH (pH of electrocoagulated effluent i.e. pH = 8.2) while UV/PMS required pH adjusting since pH = 4.0 provided the best efficiency. The scavenging effect was observed in overdosing oxidant in UV/PS while in UV/PMS, increase in PMS dosage increased the removal efficiency. The partial oxidation parameter showed that with increase of time, total oxidation was the predominant mechanism compared to partial oxidation. EC process was not effective in case of biodegradability improvement whereas EC along with UV/oxidant could significantly increase biodegradability (BOD5/COD ratio). In addition, the solar irradiation was tested as an alternative for UV source and the related results exhibited a negligible efficiency. Electrical energy consumption and current efficiency were also calculated. [ABSTRACT FROM AUTHOR]

[Display omitted] Extraction of cellulose nanocrystals (CNCs) from wastes is a valuable strategy from the environmental and economical points of view. Herein, a novel and cost-effective method for the preparation of superhydrophobic, environmentally friendly, and recyclable bio-aerogel by freeze-drying the aqueous suspension of CNCs extracted from waste tissue paper and polyvinyl alcohol (PVA) in the presence of hydrolyzed tetraethyl orthosilicate (TEOS) sol has been developed for the first time. The highly porous (98.42 %), ultralow density (0.017 g/cm3), and superhydrophobic (WCA of 154.93°±4.14) CNCs/PVA/TEOS aerogel can selectively remove oily contaminants from water (BET surface area of 76 m2/g). The aerogel showed a high sorption capacity in the range of 69−168 g/g for 6 oils and 8 organic solvents. The reusability experiments showed the aerogel could maintain more than 92 % of its sorption capacity even after 20 cycles of sorption-squeezing. The cyclic compressive stress-strain tests confirmed the good mechanical properties of the aerogel with 89 % of shape recovery after 50 cycles. The CNCs/PVA/TEOS aerogel can be used as a recyclable sorbent for removing oils/organic solvents from water. [ABSTRACT FROM AUTHOR]

Two types of waste paper materials, newspaper and office paper, were evaluated for their potential to be used as renewable feedstock for the production of fermentable sugars via the enzymatic hydrolysis of their cellulose fractions. The effects of four factors (hydrolysis time, enzyme loading, surfactant addition and phosphoric acid pretreatment) on the extent of sugar yield were assessed and quantified by using a methodical approach based on response surface methodology. The statistical experimental design used in this study requires fewer experimental runs compared to some commonly used experimental designs. In the newspaper hydrolysis case, response surface plots revealed that the degree of sugar release increased with an increase in hydrolysis time but it was hardly affected by the enzyme loading and acid pretreatment factors. The surfactant addition factor exhibited a positive effect when the enzyme loading level was relatively low. With office paper as the substrate, three of the four factors (hydrolysis time, enzyme loading and acid pretreatment) exhibited positive effects on the extent of sugar release. At local optimum conditions, the maximum sugar yield from office paper was found to be 0.82 g of reducing sugars per gram of paper, which was about 4.8 times higher than the maximum sugar release from the newspaper substrate. [ABSTRACT FROM AUTHOR]

Annual ryegrass (Lolium perenne L.) is an important cool-season forage grass in the southeastern US. Since large portions of soils in this region are too acidic for optimum ryegrass production, there exists an opportunity to use lime mud waste from numerous regional pulp and paper mills as an agricultural liming material. In this study, four lime mud application rates, 2.25 (L1). 4.51 (L2), 9.01 (L3), and 22.50 (l4) ton ha-1 dry weight basis, and a control (L0) were evaluated for response to ryegrass growth during the first 6 weeks to estimate an optimum application range over the testing soil for future field test. Results indicated that applied lime mud slowed ryegrass germination and seedling emergence, with differences of whole plant length among treatments L0-L4 significant only during the first three weeks. Differences of whole plant dry weight among treatments L0-L4 reduced thereafter. The initial soil pH increase due to the lime mud application dropped in treatments L1-L4 by the end of the 6-week experiment. The optimum lime mud application range was estimated between L2 and L3, which provided higher ryegrass yields (kg ha-1) of 84 and 80 over 77 of the control and complied with the Code of Federal Regulation, CFR 40 Part 503 for land application. [ABSTRACT FROM AUTHOR]

Pulp and paper industry has generated a higher contamination burden of the final mill wastewater which must be further treated to comply with the standards imposed by the legislation requirement. In this study, the removal efficiencies for chemical oxygen demand (COD) and color from pulp and paper wastewater using sequencing batch reactor (SBR) in combination with advanced oxidation processes (AOPs) at a bench scale were investigated. Response surface methodology (RSM) based on a three-variable-three-level central composite design (CCD) was employed to optimize the SBR process. At the optimal conditions of initial COD of 1000 mg/L, MLSS of 3000 mg/L and cycle time of 24 h, 74.8% COD, 58.3% of color removal and 80 mL/g of SVI were obtained in the pretreatment stage. The use of Fenton oxidation as post-treatment enhanced COD reduction and color removal. A percentage of 92.1% COD reduction and 90.3% of color removal was achieved in dosages of 3 mM Fe2+ and 9 mM H2O2 at pH of 3.0 for a reaction time of 30 min, while a total of 98% reduction of COD and 94% removal of color for the combined treatment was achieved. [ABSTRACT FROM AUTHOR]

• Solid fermentation of paper was successful in lysimeters at 35 and 55 °C. • Homoacetogenesis was prominent under mesophilic conditions. • Alcohol production, ethanol and methanol, was favored under thermophilic conditions. • Dysgonomonas and Ruminococcus were the most abundant populations at 35 °C. • Thermicanus was the main population at a thermophilic temperature of 55 °C. This study explored the hydrolysis and fermentation of paper with hydrogen (H 2) and volatile fatty acid (VFA) recovery using a natural microbial consortium added to lysimeters. Serial dilutions of rumen fluid in natura were performed to obtain a fermentative nonmethanogen consortium, which was used as inoculum in lysimeters under two different incubation temperatures, L1 at 35 °C and L2 at 55 °C. H 2 was detected in both lysimeters: 791.5 mL (L1) and 70.4 mL (L2). In L1, the production of 16,856 mg L−1 acetic acid was likely due to the occurrence of homoacetogenesis. Under thermophilic conditions, L2, a low volume of H 2 was detected, and the highlight was the production of ethanol and methanol at 2289 and 5614 mg L−1, respectively. According to the Shannon index, there was great diversity of microorganism populations in the rumen fluid in natura (6.34) compared with the purified rumen fluid (2.73), L1 (2.67) and L2 (3.21). The most abundant genus in the rumen fluid in natura was Prevotella (37.5 %); in the purified consortium (68.7 %) and L1 (63.8), Dysgonomonas ; and in L2 (88.7 %), Thermicanus. In conclusion, the temperature influenced the microbial community structure, the metabolic route and, consequently, the main byproducts produced by the fermentative activity at 35 °C and 55 °C. [ABSTRACT FROM AUTHOR]

The fixed-bed adsorption experiments are performed for the removal of copper [Cu(II)] and zinc [Zn(II)] by utilizing activated neem bark as an adsorbent. The present study demonstrated the effect of various parameters such as inlet concentration, adsorbent mass and inlet flowrate for the removal of Cu(II) and Zn(II) from aqueous solutions. Various kinetic parameters such as EBRT, stoichiometric capacity, breakthrough time, etc. are evaluated using the experimental data. Yoon-Nelson and Yan model available in the literature are also validated with the experimental data. The developed adsorbent is also tested for the simultaneous removal of multiple metal ions [Cr(VI), Cu(II), Zn(II), Pb(II), Ni(II) and Cd(II)] from the synthetically prepared pulp & paper industrial effluent. [ABSTRACT FROM AUTHOR]

This study focuses on the mineral carbonation to capture CO 2 using an alkaline industrial waste, the grits, formed during the kraft pulp production process. An indirect mineral carbonation route was adopted, composed by two steps: first the extraction of calcium from the grits and second the precipitation of calcium carbonate. Firstly, four solvents were analyzed (HNO 3 , CH 3 COOH, NaOH and NH 4 Cl). Only HNO 3 and CH 3 COOH have shown significant extraction efficiencies of 79.4 and 73.2 %, respectively, after 2 h at 30 °C. Kinetic tests demonstrated that equilibrium conditions are reached after 60 min. Since the nitric acid is a corrosive acid and with high associated costs, the acetic acid was selected for the dissolution of grits and extraction of calcium. The optimal conditions determined were an acetic acid concentration of 2 M, solid/liquid ratio of 30 g/L and temperature of 45 °C with an efficiency approximately of 77 %. In the second step, carbonation experiments were performed contacting the Ca-rich liquor, obtained from the extraction step, with a flux of pure CO 2 gaseous in a stainless inox reactor. The optimal conditions determined were 30 °C and 30 bar, reaching a carbonation efficiency of 74 %, corresponding a CO 2 sequestration capacity of 460 kg CO 2 /ton of grits. [ABSTRACT FROM AUTHOR]

In the present study, the photodegradation of lignin was studied using TiO2/Polystyrene composite under UV-LED irradiation in a batch-recirculated photoreactor as a supplementary treatment for pulp and paper industries. TiO2/PS composite was synthesized by the solvent-casting method and was characterized by scanning electron microscopy (SEM) and EDX analysis. The 3-level, 3-factor Box-Behnken design was applied to study the effects of main operating parameters and optimization of process circumstances. Besides, COD reduction efficiency, toxicity assays, and reusability were also investigated. The predicted model had R² and R²adj correlation coefficients of 0.97 and 0.99 respectively, which showed experimental results were very close to the predicted values. Furthermore, under the optimal conditions (reaction time = 72.5, volumetric flow rate = 230 mL/min and lignin = 51.8 mg/L) the lignin degradation efficiency was 93.98%. The maximum COD removal (89%) obtained by 250 mL/min volumetric flow rate and lignin concentration of 50 mg/L after 120 min reaction time. Bioassay using D. Magna exhibited that at the beginning of the process, the toxicity of solution increased but continuously decreasing after then to very low values achieved within 120 min of photodegradation. In addition, the reusability tests demonstrated that the TiCh/PS composite after 5 cycles has a good stability and photocatalytic activity. [ABSTRACT FROM AUTHOR]

A new carbonaceous adsorbent for heavy metals removal was prepared from paper sludge using sulfur impregnation. The sulfur-impregnated carbonaceous adsorbent with heavy metals removal ability can be obtained from sulfur-immersed sludge by pyrolysis. The product pyrolyzed at 400 °C has a maximum removal ability for nickel and lead ions, which has high specific surface area with sulfur-based functional to remove heavy metal ions. The product obtained at 400 °C indicates more effective removal for heavy metals ion than commercial charcoal, especially Ni2+ (66.7%) and Pb2+ (71.7%). With increasing pH of the solution, the adsorptions of Ni2+ and Pb2+ were increased and maximum removals of Ni2+ and Pb2+ were 99.6% above pH 7 and 100% above pH 6, respectively, The equilibrium data for nickel ion was found tofit the Langmuir isotherm better than Freundlich isotherm, with the calculated maximum adsorption capacity of 0.63 mmol/g, whereas the adsorption kinetics followed the pseudo-second-order kinetic model. The thermodynamic values, ΔG0, ΔH0 and ΔS0, indicated that adsorption was an endothermic and spontaneous process. The adsorbent can remove nickel ion from high saline water selectively. The desorption of nickel using H2SO4 solution is the most effective, but the cycle stability of the adsorbent is low. [ABSTRACT FROM AUTHOR]

The synthesis of carboxymethylcellulose was investigated using effluents containing short cellulose fibers. Carboxymethylcellulose was synthesized according to the slurry process using different amount of sodium hydroxide and different incubation times at 30°C after the etherification reaction as variables. Characterization of the product was conducted by Fourier transformed infrared spectroscopy, X-ray diffraction, degree of substitution, average degree of polymerization, water imbibing capacity, color, rheological properties, apparent viscosity and trace elements content. Incubation time slightly increased the yield of the reaction and the degree of substitution during the first 12 h. The reaction yield and degree of substitution both decreased when the initially concentration of NaOH was increased from 7.0 g/mL to 10.5 g/mL. The carboxymethylcellulose obtained was darker and had lower hydration properties than commercial samples. Trace elements content suggests that the product could be only used in paint factories or building materials industries. [ABSTRACT FROM AUTHOR]

The present paper deals with a study of the effect of ducting on explosions in vented enclosures. The presence of a duct was shown to increase the pressure reached in vented vessels. At the moment it is still not clear what are the main phenomena occurring in ducted-venting systems and no reliable correlations are available for the sizing of ducted vented systems. The only correlation available for gas explosions was developed by Bartknecht (1993) and assumed as a guideline in NFPA 68 (2002) while for dust explosions more correlations are available as reported in VDI 3673 (2002), in NFPA 68 (2002) and in Tamanini and Fisher (2003). This paper presents a critical review of available experimental and theoretical results on gas explosions in vessels vented through a duct that was carried out mainly to understand the role of the phenomena involved. Furthermore, the available correlations for ducted-venting of gaseous explosions of NFPA 68 (2002) and for dust explosions (Tamanini and Fisher, 2003; VDI 3673, 2002; NFPA 68, 2002) were applied to the experimental results available in the literature, to test their validity and applicability. [ABSTRACT FROM AUTHOR]

In the quest for a sustainable future, the bio-economy and biorefineries have emerged as pivotal agents of transformation. This review paper offers an accessible and comprehensive exploration of the multifaceted bio-economy landscape. Environmental concerns, resource scarcity, and the demand for renewable and bio-based products are the key drivers shaping this sustainable paradigm. Agriculture and agro-industry play an indispensable role, acting as the primary suppliers of the essential feedstock for biorefineries. They not only fuel the bio-economy but also foster sustainable farming practices and rural development, forming a mutually beneficial relationship. Biorefineries, the workhorses of the bio-economy, optimize resource usage, minimize waste, and produce a diverse range of bio-based products. Innovative biorefinery techniques are at the forefront, revolutionizing efficiency and expanding the array of feedstock's, thereby creating higher value-added derivatives. These value-added products, spanning biofuels, bio-plastics, and more, drive the market towards a greener and circular economy. The bio-economy's commitment to sustainability is evident through waste reduction and the promotion of circular economy principles. Policy, regulation, and market developments shape the bio-economy by promoting bio-based industries while favouring eco-friendly alternatives, creating a competitive and healthy ecosystem. While the bio-economy shows promise, it faces challenges. Optimizing conversion efficiency, discovering new feedstocks, and solving biorefinery environmental issues need technological breakthroughs and research. In summary, the bio-economy and biorefineries orchestrate a sustainable symphony, driven by environmental consciousness, rooted in agriculture, refined by innovative techniques, and harmonized by the production of bio-based products. The stage is set for a greener, more sustainable future. Bio-economy and biorefineries have become crucial drivers of transformation in the pursuit of a sustainable future. The review paper provides a thorough and easily understandable examination of the diverse bio-economy landscape. Environmental concerns, limited resources, and the need for biodegradable and renewable products are some of the main things that are shaping the sustainable paradigm. Agriculture and the agro-industry play a big role in this because they provide biorefineries with the feedstock they need. The bio-economy is not only fuelled by them, but they also contribute to sustainable farming practices and rural development, creating a mutually beneficial relationship. Biorefineries are the backbone of the bio-economy as they effectively utilize resources, minimize waste, and generate a wide array of bio-based products. At the forefront of innovation, biorefinery techniques are revolutionizing efficiency and expanding the range of feedstock's available. This, in turn, leads to the creation of higher-value derivatives and value-added products, such as biofuels and bioplastics, promoting a greener and more circular economy. The commitment of the bio-economy to sustainability is demonstrated through its efforts to reduce waste and promote the principles of a circular economy. Policy, regulation, and market developments impact the bio-economy by working together to support bio-based industries and encourage the use of eco-friendly alternatives. As a result, a competitive and healthy ecosystem is created. Although the bio-economy holds promise, it also encounters various challenges. Technological breakthroughs and research are necessary for optimizing conversion efficiency, discovering new feedstock's, and solving biorefinery environmental issues. In essence, a commitment to the environment guides how the bio-economy and biorefineries collaborate in a sustainable manner by utilizing innovative methods to refine and produce bio-based products. This harmonious process creates a symphony of sustainability, paving the way for the dream of a greener, more sustainable future. [ABSTRACT FROM AUTHOR]

Thermal power plants are pivotal in meeting global energy demands, yet enhancing their efficiency and sustainability remains an enduring challenge. While previous studies have scrutinized energy and exergy analyses of distinct plant components, there's a scarcity of comprehensive reviews integrating findings across diverse plant types. This paper bridges this gap by presenting a comprehensive synthesis of recent advancements in energy and exergy studies across coal, gas, biomass, oil, and combined cycle plants. The review focuses on critical aspects: optimizing operations through modeling and advanced controls, economic evaluations encompassing costs and revenue, and assessing environmental impacts such as emissions and water use. Achieving a balance between performance, cost-effectiveness, and environmental responsibility is crucial for sustainable thermal power generation worldwide. It requires an integrated approach that considers technical, economic, and environmental factors to ensure efficiency, profitability, and minimal adverse effects on health and climate. Key findings emphasize that, in most cases, the boiler emerges as the primary source of exergy destruction, accounting for over 50% of losses across varied plant configurations. Turbines and condensers also significantly contribute to energy losses. Supercritical and ultra-supercritical power plants exhibit higher efficiencies compared to subcritical counterparts. Integrating waste-to-energy technologies with coal plants holds promise, offering efficiency improvements and reduced environmental impact. Optimizing parameters such as pressure and temperature, along with component advancements, shows potential in curbing losses. These optimization endeavors have showcased a notable up to 6% enhancement in exergy efficiency. This review underscores the critical role of ongoing thermodynamic modeling and assessments in steering towards more sustainable thermal power generation. In summary, this paper delivers valuable insights into performance benchmarks and delineates effective strategies for augmenting thermal power plant efficiency through exhaustive energy and exergy analyses. [Display omitted] • Exergy analysis provides a broader perspective than energy analysis alone. • Boiler subsystem is a major source of exergy destruction (52-85% of total losses). • Supercritical and ultra-supercritical plants display higher efficiencies than subcritical ones. • Optimization of parameters like temperature and pressure can boost exergy efficiency by up to 6%. • Advanced combined cycles achieved over 50% efficiency, indicating potential for lower CO2/kWh. [ABSTRACT FROM AUTHOR]

With the development of the petrochemical industry, corrosion problems of special equipment occur frequently. How to achieve accurate prevention and control of equipment flow corrosion problems become a key factor in ensuring the safety of equipment processes. This paper combines industrial field operation data, through the isolated forest algorithm for the screening of abnormal values, focusing on the analysis of the type of corrosion in the heat exchanger. A Particle Swarm Optimization optimized Radial Basis Function (PSO-RBF) prediction model was constructed to achieve fast prediction of ammonium crystallization temperature, and the Particle Swarm Optimization (PSO) algorithm was optimized using an adaptive weight optimization scheme. It shows that the optimized model error is within 3%, while the prediction accuracy is improved by 9.54%, and the coefficient of determination has also been improved. This paper also compares and analyzes several mature algorithms commonly used today, and the results show that the model has significant advantages in terms of prediction performance. In addition, the model can be applied to the condition inspection of petrochemical equipment, providing a practical guarantee for equipment operation, and reducing the risk of enterprise operation and maintenance. [ABSTRACT FROM AUTHOR]

Gas processing industry is associated with high risks which have the potential to cause catastrophic accidents. Safety Instrumented Systems (SISs) are considered the most effective safety barriers in this sector aiming to prevent undesired events and mitigate their consequences. However, several factors can affect their performance including maintenance strategy in place. In this paper, a Stochastic Petri Net (SPN) model is proposed for evaluating maintenance strategies related to SIS. The model is applied to analyze the performance of an Emergency Shutdown System (ESD) in a Flared Gases Recovery Unit located at south Algerian field. Furthermore, the paper investigates the financial impact of proof tests, including direct costs (such as manpower, equipment, and transportation) and indirect costs (such as production losses and gas flaring tax). These costs can be effectively managed and reduced by optimizing proof test intervals and scheduling tests during planned plant shutdowns. The results demonstrate that the proposed Stochastic Petri Net (SPN) model successfully analyzes the impact of imperfect full and partial proof tests on PFD average values of Safety Instrumented Functions (SIFs). In addition, it has been shown through reliability analysis that the proposed model is able to minimize spare parts expenses leading to significant cost savings while maintaining the required safety integrity levels (SILs), about 60% benefit achieved within two years compared to the actual procurement process over same period. [ABSTRACT FROM AUTHOR]

Air pollution poses a grave threat to human health and everyday life. Accurate air-quality prediction plays a crucial role in effectively preventing and controlling air pollution. A multi-graph spatial-temporal attention network is proposed to predict the air quality in a given area by analyzing the interconnections between stations and the individual characteristics of each station. Firstly, this paper constructs multi-scale spatial-temporal graphs from spatial and temporal perspectives to effectively capture the interconnections between stations, thereby comprehensively understanding the spatial-temporal relationships among them. Secondly, incorporating the nonlinear temporal correlation of station data, this paper proposes a temporal multi-graph attention-fusion module to integrate information from both neighboring stations and the station itself. Finally, predictions are made using a spatial-temporal graph network. The experiments in this paper were based on air-quality data from Beijing and Tianjin, and the following experimental results were obtained. (1) The proposed model outperforms the baselines significantly in both single-step and multi-step prediction tasks. (2) The ablation study confirms that the graph constructed in this paper contributes to improving the performance of the model. (3) Comparing the performance of attention components, the proposed attention mechanism exhibits better performance than other attention mechanisms. [ABSTRACT FROM AUTHOR]

Aqueous two-phase systems (ATPS) are potent, biocompatible, and cost-effective techniques for partitioning, concentration, or purification of biomolecules. In this work, the direct recovery of Bacillus subtilis D3d xylanase from the fermentation broth by the polymer-salt ATPS was optimized using response surface methodology (RSM). The 96% of xylanase recovery in the polyethylene glycol phase with the maximum purification factor (2.17 ± 0.02) and partition coefficient (69.87 ± 2.10) were the optimum responses that obtained at 9.5% (w/w) of polyethylene glycol, 20% (w/w) of sodium citrate, and pH 10. A good agreement between experimental and predicted results verified the adequacy of the RSM models. Furthermore, the efficiency of the crude and ATPS-recovered enzyme were evaluated in the biobleaching of sugar beet pulp. The ATPS-recovered enzymatic treatment of sugar beet pulp resulted in a higher release of reducing sugars (10.29 and 21.83 mg g-1) and caused 4.5% and 10% reduction in kappa number over crude-enzyme and control, respectively. This study indicated that ATPS-recovered xylanase compared to the crude enzyme has a promising application in the pulp and paper industry. [ABSTRACT FROM AUTHOR]

Aqueous two-phase systems (ATPS) are potent, biocompatible, and cost-effective techniques for partitioning, concentration, or purification of biomolecules. In this work, the direct recovery of Bacillus subtilis D3d xylanase from the fermentation broth by the polymer-salt ATPS was optimized using response surface methodology (RSM). The 96% of xylanase recovery in the polyethylene glycol phase with the maximum purification factor (2.17 ± 0.02) and partition coefficient (69.87 ± 2.10) were the optimum responses that obtained at 9.5% (w/w) of polyethylene glycol, 20% (w/w) of sodium citrate, and pH 10. A good agreement between experimental and predicted results verified the adequacy of the RSM models. Furthermore, the efficiency of the crude and ATPS-recovered enzyme were evaluated in the biobleaching of sugar beet pulp. The ATPS-recovered enzymatic treatment of sugar beet pulp resulted in a higher release of reducing sugars (10.29 and 21.83 mg g−1) and caused 4.5% and 10% reduction in kappa number over crude-enzyme and control, respectively. This study indicated that ATPS-recovered xylanase compared to the crude enzyme has a promising application in the pulp and paper industry. [Display omitted] [ABSTRACT FROM AUTHOR]

In the field of radioactive waste management, particularly the geological disposal of higher activity radioactive waste, support for the longevity of engineering solutions in the repository is partly based on studies of natural systems, especially geological examples, often referred to as natural analogues (NA). Since the radioactive waste can be hazardous over hundreds of thousands of years, the long-term safety has to be assessed to very far future, e.g. up to 1 Ma from now. NA studies cover and exceed the time spans of interest. Despite of the long-acknowledged importance of NAs in the safety case for the geological disposal of radioactive waste, there is a lack of guidance and strategic planning to incorporate this information to the safety cases that assess the overall safety of the repositories – this leads to a certain lack of resilience. This paper presents the work undertaken to develop a strategy for utilising natural analogues (NAs) in Nuclear Waste Services (NWS), UK, geological disposal facility (GDF) programme. The work is largely based on the extensive review of the strategic use of NAs in the international context, lessons learnt from various past programmes and by considering how the strategy could look like in the current framework of the UK's GDF programme. The strategy presented aims to support this programme. The main message is that NA information and projects can and should be handled through the same procedures as any research utilising existing and upcoming NWS protocols. This means that NAs need to be a part of knowledge management, rather than, for example, a stagnant database. Including NAs as part of the data screening allows the knowledge base to be updated according to needs arising from the changes in the GDF programme when moving from generic stage towards more site and design specific phases. It is foreseen that key to the best utilisation of NA information is to include it in the NWS' digital safety case, making the information and the related methodology transparent. This paper refers to NWS' GDF siting programme as at September 2023. [ABSTRACT FROM AUTHOR]

Safety is paramount to any process plant facilities and its design process. To ensure that safety is considered in design stages, process safety analysis such as hazard and operability studies are often carried out to address safety concerns throughout the stages of plant design to operation. However, conventional HAZOP studies are labor-intensive and expensive. This paper aims to provide a semi-automated HAZOP study using a computer-aided tool called Stateflow. It describes the rule-based approach and algorithm used to develop the automated HAZOP process. The paper also highlights the limitations and challenges faced and finishes with the potential areas for further works on Stateflow to enhance the HAZOP automation capabilities. [ABSTRACT FROM AUTHOR]

The grinding process of the angle grinder generates a large amount of dust, which present hazards to the environment and workers' health. In order to capture the grinding dust more efficiently, this paper optimizes the performance of the dust collection hood of the angle grinder by building a grinding experimental platform and using the response surface method (RSM). Using the Box-Behnken design method, the collection quantity M total of all dust particles generated by grinding and the collection quantity M PM10 of PM10 are used as the main performance indicators of the dust collector. Four independent factors such as grinding wheel diameter, suction pipe diameter, mounting angle, and grinding wheel speed of the dust collection hood were optimized to arrive at the best combination of parameters. Through response surface analysis, a quadratic polynomial regression model between each influencing factor and performance indicator is established, and significance test and variance analysis are performed to verify the validity and applicability of the model. Finally, through three-dimensional response surface plots and contour plots, the interactions between each influencing factor are analyzed, and the predicted values of performance indicators under optimal experimental conditions are determined. The experimental results show that the mounting angle has the greatest impact on M total , and the grinding wheel speed has the greatest impact on M PM10. The field engineering application shows that the optimized dust collection hood can effectively prevent dust from escaping. The reduction efficiency of total dust concentration in the grinding place is over 83.6 %, and the reduction efficiency of respirable dust concentration is over 90.0 %. The research results of this paper provide some reference value for the research and application in the field of dust control. [Display omitted] [ABSTRACT FROM AUTHOR]

False alarms are detrimental to the safety of industrial processes and are often removed by alarm deadbands. However, most of the existing methods design alarm deadbands based on historic data samples under the assumption of stationarity, and may not achieve the desired performance in reducing false alarms for non-stationary process variables. This paper proposes an adaptive method to update alarm deadbands for non-stationary process variables to remove false alarms. Two technical challenges are addressed in this paper. First, time instants of statistically significant changes in process variables are detected based on mean values of maximum amplitude deviations between process variables and alarm trippoints. Second, when to update an alarm deadband width after detecting a mean change is determined based on a confidence interval of the designed width developed from Bayesian estimation rule. Numerical and industrial examples are provided to illustrate the proposed method and compare with alarm deadbands with fixed widths. [ABSTRACT FROM AUTHOR]

The urgent need to address greenhouse gas (GHG) emissions, particularly in relation to climate change, is driving the demand for new sustainable renewable fuels. This demand is promoting the expansion of de-carbonization efforts, which hold tremendous potential as a renewable energy source. One area of focus is the production of hydrogen (H 2), which has long been a popular subject of discussion. Currently, large quantities of H 2 are generated using conventional fossil fuels. However, the finite nature of these resources has compelled the global community to explore alternative, more environmentally friendly options like biomass. Generating H 2 on a large scale from various biomasses presents a complex challenge. Researchers have identified thermochemical (TC) and biological (BL) processes as the primary methods for converting biomass into H 2 , although other techniques exist as well. Commercializing H 2 as a fuel presents significant technological, financial, and environmental hurdles. Nevertheless, nanomaterials (NMs) have shown promise in overcoming some of the obstacles associated with H 2 production. This review focuses on the use of NMs in TC and BL processes for H 2 generation. Additionally, the paper provides a brief overview of the methods and financial considerations involved in enhancing biomass-based H 2 production. Studies indicate that the production of bio-H 2 is relatively expensive. Direct bio-photolysis costs range from $2.13 kg−1 to $7.24 kg-1, indirect bio-photolysis costs range from $1.42 kg−1 to $7.54 kg−1, fermentation costs range from $7.54 kg−1 to $7.61 kg−1, biomass pyrolysis costs range from $1.77 kg−1 to $2.05 kg−1, and gasification costs $1.42 kg−1. The paper also explores various challenges related to biomass conversion and utilization for H 2 production, aiming to better understand the feasibility of a biomass-based H 2 economy. [Display omitted] • The biological and thermochemical routes for renewable H 2 are elucidated and compared. • Biological routes basically have low H 2 production rate than thermochemical ones. • Ni and Fe are the most promising nanomaterials for H 2 production. • Economic analysis and challenges associated with both routes are explained. • Future research directions are presented based on identified literature gaps. [ABSTRACT FROM AUTHOR]

Multi-soil layering (MSL) is an efficient and eco-friendly soil-based system ingeniously engineered to circumvent common limitations imposed by soils when used as filtering materials for wastewater treatment. However, relatively few comprehensive and critical reviews emphasize the significant assets of successful application and durable operation and discuss the cutting-edge orientations to promote the acceptance and widespread use of this emerging Ecotechnology. To bridge the existing research gap, after giving the essential knowledge on the principle, typology, and treatment mechanisms of MSL reactors, the present paper reviews and criticizes current applications and discusses the most influencing factors to highlight their crucial role in maintaining sustainable design and effective operation. Furthermore, this paper provides guidance and discusses future scopes and novel perspectives to promote MSL systems' effectiveness, large-scale development, and sustainability by optimizing operational conditions and transitioning toward renewable energies and circular economy approaches. Further, the present paper gives an estimative evaluation of the capital cost of an MSL system based only on locally available materials. Lastly, this review summarizes the most relevant recommendations relative to sustainable design and operation in the form of holistic guidelines from emergence to recent state of art as a start-up and consultative base for stakeholders and researchers interested in MSL technology. • We provide essential knowledge on the history, fundament, and removal mechanisms of MSL eco-technology. • We review and criticized varied applications of MSL systems. • We discuss the operating parameters essential for the durable design and operation of MSL systems. • We review the potential role of MSL technology in the circular economy, and establish a capital-cost analysis for vertical flow MSL. • We gathered relevant practices in the form of holistic guidelines to implement and exploit MSL systems. [ABSTRACT FROM AUTHOR]

Nowadays, the increasing consumption of conventional fuels has led to rising pollutant emissions, among which soot has received much attention due to its harmful effects. In this paper, previous typical soot models are reviewed. Based on empirical, semi-empirical and detailed models, phenomenological models, the most popular models of recent years, are also summarized. This work also summarizes the application of existing soot models in combination with other models and methods in turbulent flame and diesel engine development based on existing models. Besides, as the development of clean alternative fuels continues, new fuels have received significant attention as a method to reduce soot formation. For different fuels, the reasons for reducing soot formation have also attracted the interest of researchers, and thus this paper reviews the current research about relevant carbon soot modeling for biodiesel, natural gas, and other new fuels. A detailed understanding of soot generation and soot modelling can help further research into methods to reduce soot emissions. [Display omitted] [ABSTRACT FROM AUTHOR]

The focus of this paper is to investigate the practicality of incorporating immersion cooling methods to mitigate the temperature elevation of motors utilized in hybrid aircraft. Air cooling, oil jacket cooling, slot-channel oil cooling and immersion cooling techniques are each applied to a permanent magnet synchronous motor. When a hybrid aircraft is operating, the amount of fuel it carries is limited and decreases over time. In this case, the normal operating time of the motor is investigated in this paper. The study shows that for the motors in this paper, immersion cooling is the most effective with a limited amount of coolant and takes the longest time to reach the upper temperature limit, which can be improved by 5.6 times compared to slot-channel cooling. This paper serves as a reference for the design of motors for hybrid aircraft utilizing immersion cooling technology. [ABSTRACT FROM AUTHOR]

Safety instrumented systems (SISs) are installed on process plants to protect against undesired events like e.g., gas leakage and overpressure. A SIS has reliability requirements that are determined during design, and conformance to these requirements should be verified during operation. It is therefore important that all SIS failures are recorded and classified according to their impact on the SIS reliability. Failures of SIS equipment classified as dangerous undetected are of particular interest because they are dormant (undetected) and will prevent the execution of the safety function (dangerous). Analysis of the failure mode and detection method is essential when deciding if a failure is dangerous and undetected. Such information is often provided as unstructured text in notifications registered into the maintenance management system. Therefore, the work of classifying failures requires considerable manual effort in reading and analyzing the texts. Approaches within natural language processing, like technical language processing, have the potential to be deployed more actively for this purpose. However, successful adoption relies on groundwork where classification rules are derived from international standards and commonly agreed industry practice. This paper presents a semi-automated process that incorporates classification rules and gives examples that indicate some of the capabilities of technical language processing for failure classification. The paper also elaborates on how the work relates to Industry 4.0 in creating digital representations to monitor the performance of safety instrumented systems. This work has been carried out as part of the APOS project (Automated process for follow-up of safety instrumented systems). The APOS project has developed knowledge and specifications that simplify and automate the design and operation of safety equipment and investigated how the failure classification process can be made more efficient. [ABSTRACT FROM AUTHOR]

This paper intends to give an impression of new technologies and processes that are in development for application to achieve decarbonization, and about which less or no experience on associated hazards exists in the process industry. More or less an exception is hydrogen technology because its hazards are relatively known and there is industry experience in handling it safely, but problems will arise when it is produced, stored, and distributed on a large scale. So, when its use spreads to communities and it becomes as common as natural gas now, measures to control the risks will be needed. And even with hydrogen, surprise findings have been shown lately, e.g., its BLEVE behavior when in a liquified form stored in a vessel heated externally. Substitutes for hydrogen are not without hazard concern either. The paper will further consider the hazards of energy storage in batteries and the problems to get those hazards under control. Relatively much attention will be paid to the electrification of the process industry. Many new processes are being researched, which given green energy, will be beneficial to reduce greenhouse gases and enhance sustainability, but of which hazards are rather unknown. Therefore, as last chapter the developments with respect to the concept of hazard identification and scenario definition will be considered in quite detail. Improvements in that respect are also being possible due to the digitization of the industry and the availability of data and considering the entire life cycle, all facilitated by the data model standard ISO 15926 with the scope of integration of life-cycle data for process plants including oil and gas production facilities. Conclusion is that the new technologies and processes entail new process and personal hazards, and that much effort is going into renewal but safety analyses are scarce. Right in a period of process renewal, attention should be focused on possibilities to implement inherently safer design. [ABSTRACT FROM AUTHOR]

This review paper focuses on investigating the effectiveness of washing pretreatment in reducing slagging and fouling index during the combustion process of empty fruit bunches (EFB) materials. Slagging and fouling are common problems encountered in combustion systems that burn these types of materials for energy generation, leading to operational and maintenance issues. Washing pretreatment has emerged as a promising solution to mitigate these problems by removing undesirable chemical species from the biomass before combustion. This paper examines the existing literature on the effectiveness of washing pretreatment in reducing slagging and fouling index during the combustion process. The review covers various aspects, including washing methods, and combustion conditions used in previous studies. The review highlights that washing pretreatment can effectively reduce slagging and fouling index during the combustion process of EFBs. The paper also discusses the mechanisms behind the effectiveness of washing pretreatments, such as the removal of alkali and heavy metal compounds, and the reduction in ash content. Finally, the review paper provides recommendations for future research directions in this area. Overall, this study provides valuable insight into the factors, such as temperature, soak time, and water use, that can reduce slagging and fouling during the combustion process and have the potential to increase the effectiveness and dependability of energy generation systems. [Display omitted] [ABSTRACT FROM AUTHOR]

A new method of recycling cooking with pulping wastewater was developed to save energy and reduce carbon dioxide emissions in a pulp mill, which used bio-fuel of eucalyptus instead of coal and oil, and reduced the steps of black liquor combustion and lime regeneration in the traditional pulp mill to reduce carbon dioxide emission. As results, the bio-fuel consumption and CO 2 emission are 2.04 × 104 MJ (1.2 tons of eucalyptus) and 2.2 tons for per ton of pulp. It reduces 28.23% of fuel energy consumption and 14.06% of CO 2 emission comparison with that by the traditional pulp mill. In addition, while using the generated lignin as part of bio-fuel, the product value-added is 765.88 RMB for per ton of pulp, being 23.72% lower than that of 1004.08 RMB by the traditional pulp mill. Therefore, this study demonstrates the advance and feasibility of using only bio-fuel for a new pulp mill with a new method of recycling cooking, and will promote the technological revolution of cleaner production in the pulp and paper industry. [ABSTRACT FROM AUTHOR]

This paper summarises the first results from the joint industry project (JIP) 'Risk-reduction for hydrogen installations by partial suppression of explosions' (HyRISE). The main objective of the project is to develop fundamental knowledge that can support the development of practical solutions for mitigating hydrogen explosions in congested and confined environments by means of active systems for chemical inhibition. The aim is not to extinguish the incipient flame, but rather to lower the reactivity of the fuel-air mixture prior to ignition, and thereby reduce the consequences of an accidental explosion to a tolerable level. The paper consists of three parts: a review of previous work on chemical inhibition of premixed hydrogen-air flames, simulations with the chemical kinetics software Cantera, and experiments conducted in a 20-litre explosion vessel. The results demonstrate that chemical inhibition can be effective for hydrogen-air mixtures. However, it remains to develop efficient inhibitors and practical systems that can be implemented in industrial facilities, with satisfactory performance over a wide range of hydrogen concentrations. [ABSTRACT FROM AUTHOR]

At present, China is facing a relatively serious water security problem, and virtual water trade is an important means to alleviate the shortage of water resources. It is of great practical significance for China to analysis of the multi-scale near-long-distance flow of virtual water between regions. In this paper, the multi-regional input-output model was used to measure the virtual water near-long-range transfer of 17 departments in eight regions in 2012 and 2017 in China. The measured results are further discussed in the context of K-means and structural decomposition analysis (SDA) methods. The results show that from 2012 to 2017, the overall trend of interregional virtual water flow and import and export volume of various regions and departments in China showed a downward trend, and there were significant differences in inflow, outflow, and distribution. In 17 sectors, the agricultural sector has a much higher virtual water flow than other sectors, particularly in the north-west and central regions. In addition, the food and tobacco industry and construction industries in most regions also have the characteristics of high outflows. This paper argues that China should Fully exploit the effect of industrial structure on the suppression of virtual water rise. At the same time, it is necessary to improve the virtual water trade pattern, especially the virtual water trade pattern of the agricultural sector, and then gradually optimize the distribution pattern of regional water resources in China. [ABSTRACT FROM AUTHOR]

This paper presents the development of a comprehensive self-assessment safety culture toolkit for the U.S. offshore oil and gas industry. Safety culture impacts organizational safety performance. Measuring safety culture will help an organization better understand the room for safety improvement. The major components of this toolkit are safety culture surveys, interviews, site safety walkthroughs, a review of previous incident investigations, a review of potential leading indicators (accident precursors), and a Safety and Environmental Management System (SEMS) review. This multi-component toolkit is expected to allow a comprehensive assessment of the offshore safety culture at single or multiple facilities. With careful wording of survey questions, safety culture surveys can provide insight into employee perceptions of safety. The paper discusses how safety culture surveys can be incorporated with all other key components to give a more complete picture of an organization's safety culture. A safety maturity model is proposed to incorporate the results from these safety culture measurements to describe an organization's safety maturity level. Like many safety maturity models, the model in this toolkit describes the safety culture maturity in a range from a reaction to events to continual improvement. The analysis of crucial safety culture-related assessment components supports the identification of a safety culture maturity level. [ABSTRACT FROM AUTHOR]

Recent years have seen the increasing complexity of engineered systems. Complexity and uncertainty also exist in engineered systems' interactions with human operators, managers, and the organization. Resilience, focusing on a system's ability to anticipate, absorb, adapt to, and recover from disruptive situations, can provide an umbrella concept that covers reliability and risk-based thinking to ensure these complex systems' safety. This paper discusses the quantitative aspects of the notion of resilience. Like the quantitative risk assessment framework, a generic framework should be developed for quantitative resilience assessment. This paper proposes a framework based on a triplet resilience definition consisting of disruption, functionality, and performance. Uncertainty treatment is also considered. The proposed framework aims to answer the question of "resilience of what to what" and how it can be quantitively assessed. [ABSTRACT FROM AUTHOR]

Risk assessment is one of the top requirements in maritime transportation due to the complexity of ship operations, particularly on tanker vessels. By carrying hazardous liquid cargo, tankers pose significant risks for life, property and the marine environment, which should be assessed in detail. This paper focuses on the manifold process during tanker cargo operation since it involves various risks that may lead to severe consequences such as human injury, gas poisoning, hull damage, cargo spill or explosion. The process is modelled via Bayesian network, and marine experts evaluate 12 failure modes with respect to Failure Mode, Effect and Criticality Analysis parameters. To fuse the expert judgment, Dempster–Shafer theory is applied with a rule-based approach in the Bayesian model. The highest crisp risk value is found 48.85 for Failure Mode (FM) 1.1 (Improper arrangement of valves and pipelines to be connected). It is followed by FM 1.2 (Improper connection between the line and the manifold) with a crisp risk value of 45.83, and FM 4.1 (Failure in earthing & bonding condition of equipment to be used) with 38.26 crisp risk value. According to results, control actions are presented to reduce the risks during the manifold process. Beside its technical background, the paper provides utmost contributions to maritime safety inspectors, tanker ship crew, tanker ship operators and safety researchers to improve safety process and minimize the operational risks of cargo manifold process. [ABSTRACT FROM AUTHOR]

The Shuiyindong gold mine in Guizhou is used as a case study in this paper to study patterns of dust pollution occurring with traditional electric-rake operation. In particular, the study uses the northern quarry of the twenty-third line in the first middle section of the second mining area and establishes a three-dimensional simulation model of equal size. It uses Computational Fluid Dynamics (CFD) to simulate and analyse the airflow traces and distribution of dust concentration in the relevant roadway during each stage of the electric-rake operation. The simulation results show that the airflow in the working roadway has a spiral movement and produces reverse dirty-wind circulation towards the end. Dust flows out of the working roadway from the 8th second of operation, and dust concentration reaches a peak in the working roadway at the 12th second of operation at an average dust concentration of 37.5 mg/m³. The dust concentration drops rapidly from the 120th second and reaches the maximum dust concentration permitted for operation at the 180th second of operation. The validity of the simulation is tested by comparing the actual measured data at the site with the simulation results. Finally, the simulation results are analysed using violent Python, and the solution is used to divide the roadway into areas according to the human breathing range. The paper analyses the distribution of dust concentration at an average human breathing height, providing an established theoretical basis for dust-control work in mines. [Display omitted] [ABSTRACT FROM AUTHOR]

Thermal fatigue cracking is a common problem for boiler waterwall tubes in power plants, resulting the risk of unscheduled plant shutdown. Developing an effective degradation model to predict the future condition of waterwall tubes is vital to assess boiler remaining life. Even though many numerical studies are available in the literature for understanding the physical mechanism (thermal fatigue cracking), the development of predictive models for future risks that can inform decision making are limited. One of the key impediments for developing predictive models is the lack of data. In the case of boiler critical subsystems, very few failures (if any) are recorded in its history. In addition, the number of inspections is limited due to access difficulties. Thus, in many practical cases, the condition data available for degradation modelling is sparse with both infrequent and (spatially) incomplete inspections. This paper presents the development of a stochastic degradation model prediction of thermal fatigue cracking severity in a boiler waterwall when the data is limited. The time evolution of the condition indicator for each waterwall tube is modelled using Markov Models and Bayesian identification algorithms are used to tractably address the large amount of missing data. The methodology presented in this paper employs a Markov Chain Monte Carlo (MCMC) scheme to account for the parameter uncertainty in the presence of missing data. Moreover, this paper also incorporates a novel grouping strategy in which the neighbouring components are grouped to tackle the problem of (spatial) data sparsity. The degradation modelling and prediction tools developed in this paper will support renewal decision making by using available onsite asset data and knowledge. A real-world case study of a boiler waterwall operating in an Australian power industry is also presented. It is found that the waterwall degradation appears to be slowing, but an additional inspection is recommended to confirm the trend. [ABSTRACT FROM AUTHOR]

A cyber-physical system (CPS) is an interconnected physical system that can be monitored, controlled, and operated remotely. A systems-based analysis of CPS is critical for enhancing operational safety and security. Such analysis is particularly important in light of the evolving Fourth Industrial Revolution (Industry 4.0) which is largely driven by CPS, Internet of Things (IoT), algorithmic systems, automation, and smart manufacturing. As a result of industries' and societies' growing dependence on CPSs, their safe and secure applications need to be scrutinized to avoid any threats or harm to processes and human lives. In order to achieve this target, the current work analyzes the literature to investigate challenges and opportunities present in the CPSs. The analysis attempts to answer the following Research Questions (RQs): (RQ1) What are the prominent trends in the field of safety and security of CPSs? (RQ2) What are the opportunities in Industry 4.0 technologies related to safety? (RQ3) What characteristics of CPSs are likely to cause safety and security issues? (RQ4) What are the emerging safety and security issues introduced by CPSs? (RQ5) How were these issues addressed in the literature? CPSs can address some traditional safety issues due to characteristics like high efficiency and control. However, a CPS is challenged by heterogeneity, dependencies, complexity, unattended nature, increased machine intelligence, autonomous reconfiguration, and uncertainties. Safety and security challenges include opaque system failure, complex socio-technical system, human-machine interface, cyber-physical attacks, unsecured remote configuration, lack of standards, and resilience. The paper is structured under the following key headings: bibliometric results, opportunities from Industry 4.0 technologies, issues introduced by Industry 4.0 technologies, literature proposed solutions, and research challenges. Based on the assessment of about 900 relevant publications extracted from two databases (Web of Science (WoS) Core Collection and Engineering village (EV)), the documents were categorized into eight major divisions: (i) Safety Opportunities, (ii) Hazardous Characteristics, (iii) Fault Occurrence, (iv) Cyber-physical attacks, (v) Human factors, (vi) occupational Health and safety, (vii) standards, and (viii) Reliability and resiliency. Proactive strategies were classified under four options: identification, evaluation, prevention, and management. The paper also raises some research needs and unanswered questions that require further analysis to address how security and safety mechanisms can introduce more complexity in the system that can lead to new risks. The paper concludes by emphasizing digital process safety as part of the engineering curriculum to address the process industry's need for digital solutions and to make process safety learning a conscious choice. [ABSTRACT FROM AUTHOR]

The paper evaluates all important aspects related to V present in coal and its behaviour during coal combustion with particular attention paid to its potential extraction from ash and slag wastes. Due to great environmental benefits of co-combustion of coal and wastes, these alternative fuels and corresponding ash and slag counterparts were also taken into evaluation. Specifically, the paper summarizes V levels in world coals, in other related materials (alternative fuels, additives etc.) and in ash and slag residues including V speciation and discussion of its valence states. Theoretically predicted (equilibrium-based) calculations and species are compared with experimental results; due to a significant effect on mitigating CO 2 emissions, attention is paid also to oxy-fuel combustion conditions. With the aim to extract V out of the ash and slag residues, physical, chemical, and biotechnological separation methods are discussed in detail along with dominant affecting factors. The paper includes also concluding remarks and highlights the most promising trends and limitations thereby providing suggestions for future research. [Display omitted] [ABSTRACT FROM AUTHOR]