Preliminary Economic Analysis Research Articles

Experimental results of a waste-heat powered thermoacoustic refrigeration system for ships

Greenhouse gas emissions are a major concern for maritime transport. TheInternational Maritime Organization (IMO)presents Waste Heat Recovery Systems (WHRS) from engine exhaust gas as a viable solution to improve energy utilization and reduce greenhouse gas emissions for marine power plants. In this paper, we present an original thermoacoustic WHRS and its associated experimental setup for validation. This WHRS aims to transport heat from a lower to a higher temperature reservoir (heat pump) and maintain a fridge at 0 °C. For the experimental setup, exhaust gases from a 4-stroke marine diesel engine are used to generate pressure waves (work) in thermoacoustic engines. The main result is the Coefficient of Performance (COP) of the system, around 0.3, assessed for various cold loads. The first results estimate that the system could substitute part of the chiller cold production onboard. Also, a preliminary economic analysis suggests that this system could perform 2% fuel savings that allow for a payback time below one year.

Utilization of Carbon Monoxide as a Fuel: Economic Analysis and Reactor Design for Carbon Monoxide Oxidation Coupled with Heat Recuperation

Carbon Monoxide is one of the unrequired and environmentally harmful by-products of various industries. A detailed design of process equipment for utilizing Carbon Monoxide as a fuel in industrial premises via Novel Zero Carbon Emission Process (NERS) is provided. A preliminary economic analysis of the designed system is also provided to enhance its practical viability. Based on economic evaluation, it is calculated that one can quickly achieve a temperature of around 523.15 K (250 °C) for water flowing at about 6 kg/s through the heat recuperation system installed in the process equipment. Hence a significant amount of energy that is otherwise wasted in the form of carbon emissions can be economically recovered (having an approximate payback period of around 1.5 years, based on economic analysis and reactor design as per bench-scale data available in the literature).

Electrochemical Oxidation of Anastrozole over a BDD Electrode: Role of Operating Parameters and Water Matrix

The electrochemical oxidation (EO) of the breast-cancer drug anastrozole (ANZ) is studied in this work. The role of various operating parameters, such as current density (6.25 and 12.5 mA cm−2), pH (3–10), ANZ concentration (0.5–2 mg L−1), nature of supporting electrolytes, water composition, and water matrix, have been evaluated. ANZ removal of 82.4% was achieved at 1 mg L−1 initial concentration after 90 min of reaction at 6.25 mA cm−2 and 0.1 M Na2SO4. The degradation follows pseudo-first-order kinetics with the apparent rate constant, kapp, equal to 0.022 min−1. The kapp increases with increasing current density and decreasing solution pH. The addition of chloride in the range 0–250 mg L−1 positively affects the removal of ANZ. However, chloride concentrations above 250 mg L−1 have a detrimental effect. The presence of bicarbonate or organic matter has a slightly negative but not significant effect on the process. The EO of ANZ is compared to its degradation by solar photo-Fenton, and a preliminary economic analysis is also performed.

Strawberry Leaves Extract for Cosmetic Industry

In 2020, Portugal had an average strawberry production of 10 thousand tons, and 15 % was considered strawberry plant residues. This work proposed a new product that uses the compounds extracted from the strawberry residues - stem and leaves, excluding the fruit - as an active ingredient for cosmetic application. Strawberry leaves were extracted with 50 % ethanol. This extract mainly consists of lactic acid, ascorbic acid, ascorbic acid, and agrimoniin; these compounds are used in the chemical industry due to their antioxidant properties. A gel-cream formulation with 17.5 % strawberry leaves extracts was proposed. It proposed an industrial-scale production and a preliminary economic analysis to evaluate the project's profitability. The Net Present Value (NPV) was estimated as 3.40 M€ (4th year), and the pay-back time is on eight quarters.

Preparation of valuable pyrolysis products from poplar waste under different temperatures by pyrolysis: Evaluation of pyrolysis products

Poplar waste is used as feedstock to prepare valuable pyrolysis products by pyrolysis under different temperature. The bio-oil is rich in aldehyde with the maximum relative content of 47.15%, which has potential application in chemical industries. Pyrolysis temperature has significantly influenced the composition and heating value of bio-gas. The maximum heating value of bio-gas is 14.56 MJ/Nm3. Biochar is used as an adsorbent to adsorb Ag+ from aqueous solution with the adsorption capacity of 76.09 mg/g. Biochar forms the value-added Ag-Biochar composite by reduction after adsorption Ag+. While, Ag-Biochar composite can be used as catalyst for methyl orange removal with the maximum removal of 94.08%. Ag-Biochar composite is also used as lithium ion battery cathode material for energy storage with the specific capacity of 345 mAh/g. Besides, preliminary economic analysis is used to evaluate the economics of pyrolysis process with the total annual revenue of $115, 725/year.

Biochar from sugarcane bagasse for reactive dye adsorption considering a circular economy approach

Ethanol from sugarcane has advantages over fossil fuel in reducing greenhouse gas emissions and improving the air quality in cities. However, ~280kg of sugarcane bagasse, an agro-industrial waste, are still generated during the processing of 1 ton of sugarcane. In this paper, the sugarcane bagasse, was converted into activated biochar (AB) and the physicochemical properties and morphology of the AB were determined. The potential absorbent for reactive blue 19 dye (RB19) onto AB under different conditions was studied, considering the pH influence, adsorption isotherms, kinetic studies and thermodynamic parameters. Finally, a preliminary circular economic analysis was also performed. The characterization of AB showed microtubes of up to 1µm diameter and cavities lower than 0.5µm, with a specific surface area of 687m2/g and an iodine number of 656mg I2/g. The Freundlich adsorption isotherm resulted in the best fit for the experimental data, with maximum adsorption of 58.1 mg/g at pH 2 and 31.4mg/g at pH 5. The adsorption took place in the first 2h, following a pseudo-second-order kinetic model. The thermodynamic experiments showed that higher temperatures improved the removal efficiency by ~10% and that the process is endothermic. The preliminary circular economic analysis for AB preparation revealed a cost of 2.18USD/Kg of adsorbent. This study indicates that AB is an economical material for large-scale wastewater treatment in textile industries, offering an alternative pathway for the agro-industrial waste generated during the ethanol production.

An integrated process of CO2 mineralization and selective nickel and cobalt recovery from olivine and laterites

Laterites are important nickel and cobalt natural resources. However, the current production technologies are challenged by limited application to different laterites ore types and large carbon footprints. The clean energy transition requires enhanced production of nickel and cobalt for battery manufacture with significant progress toward carbon neutrality. This work presents an integrated process of CO2 mineralization and simultaneously selective nickel and cobalt recovery from various feed materials including saprolite and limonite laterites and olivine. Carbon dioxide gas is reacted with magnesium and iron in the laterite of feed materials to form stable mineral carbonates for permanent CO2 storage. Simultaneously, nickel and cobalt are selectively leached into aqueous solution by using a complex ligand nitrilotriacetic sodium (NTA) and then recovered by sulfide precipitation as nickel sulfide concentrates. In the integrated process, the chemical consumption is limited to CO2 for carbon storage and hydrogen sulfide for precipitation of nickel and cobalt. Preliminary economic analysis and carbon neutrality calculations have been performed and confirm the feasibility for laterite processing. Each one tonne of laterite studied in this work can contribute to production of 10.1 ∼ 19.6 kg nickel and 0.33 ∼ 0.54 kg cobalt with nearly 90 % recovery and earn net benefits at $254 ∼ 547 with net carbon neutrality at 15 ∼ 63 kg CO2 sequestered as stable mineral carbonates. The novel process is favourable in technical feasibility, economics, and carbon neutrality and thus can make a significant contribution to the clean energy transition, CO2 storage and utilization, enhanced supply of critical metals, and comprehensive utilization of mineral resources.

Bonding performance evaluation on WTR-APAO composite modified asphalt as waterproof adhesive layer for concrete bridge

• The preferred concrete surface depth was 0.88 mm, and the gravel covering rate at 70 %. • The optimal dosages of WRAMA, WRMA, and SMA were 1.7 kg/m 2 ,1.2 kg/m 2 and 1.2 kg/m 2 . • WRAMA has higher bonding performance than WRMA and SMA at mid and high temperatures. • WRAMA shows good resistance to water immersion, freeze–thaw cycling, and aging. • The material cost of WRAMA is 30% lower than SMA based on economic comparison. Insufficient bonding at the waterproof adhesive layer (WAL) between the concrete bridge deck and asphalt pavement surface often leads to distress on the bridge or its surfacing pavement. This study proposes a relatively novel material, WTR (Waste Tire Rubber)/APAO (Amorphous Poly Alpha Olefin) composite modified asphalt (WRAMA), as WAL and evaluates its bonding performance compared to the commonly used interlayer SBS modified asphalt (SMA) and waste tire rubber modified asphalt (WRMA). The bonding performance was evaluated using straight shear tests and pulling out tests. Firstly, the optimal concrete surface chiseling depth was explored and determined at 0.88 mm, corresponding to 2 rounds of chiseling on the concrete surface. Then the preferred gravel coverage rate was set at 70 %, and optimum asphalt dosages were determined at 1.7 kg/m 2 , 1.2 kg/m 2 , and 1.2 kg/m 2 for SMA, WRMA, and WRAMA, respectively. While all three asphalts show good impermeability at their preferred dosage, WRAMA has the highest shear and pulling strength. Secondly, the bonding performances of investigated asphalts were evaluated and compared under controlled environments, including water immersion, temperature, free-thaw cycle, and aging. The results showed that WRAMA has the slightest temperature sensitivity but the least moisture resistance than SMA and WRMA. However, the shearing and pulling strength of WRAMA after freeze–thaw and water immersion was around 0.45 MPa, still higher than SMA (around 0.40 MPa) and WRMA (around 0.39 MPa). All three asphalts have decent resistance to aging. Thirdly, a preliminary economic analysis was conducted, and the results show that the material cost of WRAMA is around 66 % of SMA. Considering the WRAMA makes use of wasted tire rubber, this research reveals that the proposed WTR/APAO composite modified asphalt is potentially a cost-effective and environmental-friendly waterproof adhesive layer.

Efficient peroxymonosulfate activation of immobilized Fe–N–C catalyst on ceramsite for the continuous flow removal of phenol

Nowadays, developing environmentally friendly catalysts with both low cost and high efficiency was still a challenge in actual organic wastewater purification. Herein, the Fe–N–C catalyst was successfully immobilized on solid waste derived ceramsite for efficient degradation of phenol under continuous flow conditions by activating peroxymonosulfate (PMS). After the introduction of ceramsite, the microstructure of Fe–N–C catalyst was changed from granular structure to worm-like structure, promoting the dispersion of the nanoscale catalyst and providing more reactive sites. Therefore, the phenol removal rate and mineralization rate of the obtained 0.5FNNC within 30 min were up to 96.79% and 71.79%, respectively. In addition, the degradation rate of the optimal composite (0.5FNNC)/PMS system was about 4.06 times higher than that of bare Fe–N–C/PMS system. Intriguingly, the Fe ion leaching from 0.5FNNC during the degradation reaction was significantly lower than bare Fe–N–C owing to the strong catalyst-support chemical bonding. Based on electron paramagnetic resonance, quenching experiments, X-ray photoelectron spectroscopy analysis and electrochemical analysis, it was indicated that the non-radical processes (1O2 and high valent iron-oxo species) should be responsible for the phenol degradation. Meanwhile, the possible phenol degradation pathways were proposed, and the intermediates were evaluated for ecotoxicity by ECOSAR. Finally, a preliminary economic analysis of this process was carried out. Overall, this work would provide a new strategy for the construction of ceramsite based multi-pore composite catalysts and the large-scale application of persulfate oxidation technology in organic wastewater treatment.

Technical and economic aspects of a sequential MF + NF + zeolite system treating landfill leachate

This work explores the techno-economic aspects of landfill leachate treatment by an integrated scheme composed of microfiltration (MF), nanofiltration (NF), and zeolite application for carbon and nitrogen removal. In bench-scale experiments, MF and NF were investigated, and zeolite batch tests were carried out to determine optimum conditions. A preliminary economic analysis is presented for a 200 m3 d−1 full-scale treatment facility based on the data obtained from experimental tests and literature surveys. The maximum removals of 92%, 94%, and 79% for chemical oxygen demand (COD), absorbance at 254 nm, and ammonium nitrogen (NH4 +-N) were achieved in bench experiments, respectively. It was possible to reach the local discharge standard for COD (200 mg L−1), but it was not possible to reach the Brazilian disposal requirement for NH4 +-N (20 mg L−1). The total cost of the integrated MF + NF + zeolite system was estimated at 19.89 US$m−3. In this study, the costs of the zeolite application account for around 70% of the total costs of the integrated scheme. Membrane process integration was an adequate strategy for removing organic compounds at low operating costs; However, further NH4 +-N depuration is needed to meet discharge requirements.

Changes of phosphorus species during (hydro) thermal treatments of iron-rich sludge and their solubilization mediated by a phosphate solubilizing microorganism

This study systematically evaluated phosphorus (P) solubilization from pyrochar and hydrochar derived from both raw sludge and iron-rich sludge. The data indicated, that an increase in thermal treatment temperature and the presence of iron promoted the accumulation of P in both pyrochar (derived at 300, 500, and 800 °C) and hydrochar (derived at 100, 200, and 280 °C). After incubating pyrochar and hydrochar with a phosphate solubilizing microorganism (PSM) (Pseudomonas aeruginosa) for 30 days, PSM significantly promoted the solubilization of P in pyrochar and hydrochar synthesized at low temperatures rather than those at high temperatures, with a 59 % increase for the pyrolysis of raw sludge at 300 °C than that pyrolyzed at 800 °C and a 62 % increase for the hydrothermal treatment of raw sludge at 100 °C than that treated at 280 °C. And the phenomena were more obvious on the char samples derived from iron-rich sludge. The mass balance of different P species in the solid and liquid phases indicated that after incubating with PSM for 30 days, NaOH-P was the main P solubilized from the solid phase of pyrochar and HCl-P was the main P solubilized from the solid phase of hydrochar. Considering P availability to plants, the preliminary economic analysis indicated that the hydrothermal treatment of iron-rich sludge at 100 °C showed the highest economic benefits for P recovery, with the net cost of 28.79 USD/ton wet sludge. This study was useful in giving novel insights into the reuse of char samples as P fertilizer, and also suggested the importance of Pseudomonas aeruginosa and other bacteria in sludge application, particularly in terms of P solubilization.

Preliminary Economic Analysis of Red Mud Valorization via Colloidal Aqueous Electrolytic Reduction in a Modern Electricity Infrastructure

Preliminary Economic Analysis of Red Mud Valorization via Colloidal Aqueous Electrolytic Reduction in a Modern Electricity Infrastructure

A two-stage heating process with low energy consumption for treatment of preliminary desalinated impregnation effluent to produce xylose

Production of xylose from preliminary desalinated impregnation effluent (PDSIE) containing hemicellulose is an economical way of the effluent treatment. However, due to the high alkali and salt contents in PDSIE, its resource utilization is limited in the developed treatment process for pulp-impregnated effluent that has been deeply desalted. In this study, based on analysis of reaction rate and kinetic characteristics of pre-hydrolysis, a two-stage pre-hydrolysis heating process including heating at a high temperature for a short time followed by slow cooling to enzymatic hydrolysis temperature (HCP) with low energy consumption was developed for PDSIE. The heating time was shortened from 2 h to 0.5 h, the inhibition of conversion from hemicellulose to xylose by the high alkali and salt contents in PDSIE was alleviated, and the loss of xylose was reduced by HCP, compared to those under the constant temperature heating conditions. The heating cost based on coal consumption was reduced by 75.54% in HCP according to the preliminary economic analysis. Based on xylose yield and energy-saving results, the temperature in the first stage of HCP was determined to be 120 °C, and the cooling time in the second stage was determined to be 6 h.

Produce individual medium chain carboxylic acids (MCCA) from swine manure: Performance evaluation and economic analysis

Environmental issues caused by untreated animal manure require the development of resource recovery from waste through a circular economy approach. Producing medium chain carboxylic acids (MCCA) with higher value than biogas from manure has become promising. The objective of this study was to develop an effective individual MCCA produce process utilizing manure. In this study, animal manure was firstly anaerobic fermentation into short chain fatty acids (SCFA), then acidified manure and ethanol were fed into the chain elongation reactor with gradually increasing the organic loading rate (OLR) from 7.0 to 18.5 gCOD/L/d, and the mixed MCCA was separated individually via a fractional distillation process. The SCFA fermentation occurred mainly at the first 10 days, and the optimum concentrations of SCFA for treatments at 2 %VS, 4 %VS and 6 %VS were 6.58, 10.40 and 14.10 g/L, respectively. For the chain elongation reactor, the maximum concentrations of n-caproate and n-caprylate were 10.25 and 0.63 g/L, respectively, which were comparable with that obtained from other complex wastes. Over 90% MCCA can be recovered from the fermentation broth via the optimized extractant of methyl tert-butyl ether (MTBE) and the fractional distillation system. Preliminary economic analysis shows that this MCCA production process presented a higher economic benefit (9.25 $/m3 manure) than traditional biogas production (2.65 $/m3 manure), making MCCA production from swine manure economically competitive. This work provides a new route for manure resource recovery besides the biogas process.

Field solution to produce irrigation-drinking water by condensation irrigation system from seawater

Abstract Condensation irrigation (CI) combines desalination with subsurface irrigation. Here, solar stills are used to heat and humidity air, which is condensed in underground drainage pipes to irrigate the soil, directly in the root zone. This article describes and evaluates a CI field test at Shahid Chamran University of Ahvaz in Iran. The objective was to gain a deeper understanding of the CI system in the production of drinking and irrigation water and to do a detailed assessment of heat and moisture transfer in the soil. Perforated and unperforated PVC pipes were used in two separate experiments while airflow properties, soil temperature and humidity, and ambient air temperature were monitored. The system produced 6 kg of irrigation water during 8 hours in the 25 m long pipe. When using an unperforated pipe, 4 kg of freshwater was collected at the pipe ending after 8 hours of operation. The preliminary economic analysis of irrigation system indicates a payback time of less than six years.

Effects of LED lighting on Nannochloropsis oceanica grown in outdoor raceway ponds

Growth in most microalgal mass cultivation systems is light-limited, particularly in raceway ponds (RWP) where the light path is higher. Artificial lighting can be a promising solution to diminishing dark zones and enhance microalgal productivity. Therefore, our goal was to prevent the cell shift from photosynthesis to a respiration-only stage by resorting to LED illumination. Nannochloropsis oceanica cultures were accordingly grown outdoors in a preliminary small-scaleexperiment, followed by pilot-scale trials. In the former, three 3.0-m2 RWP were set up under three distinct conditions: 1) without LEDs (control); 2) LEDs turned on during the night; and 3) LEDs turned on for 24 h. In the pilot-scale trial, one of two 28.9-m2 pilot-scale RWPs was coupled to the best LED setup – determined in the small-scale preliminary experiment – using the same light intensity (normal mode) and half of the intensity (economy mode), with the second RWP serving as a control. In the preliminary experiment, the use of LEDs for 24 h was deemed as not helpful during daytime, before the culture reached ≈0.5 g DW L−1 – when dark zones appeared during the day due to sunlight attenuation in the 0.1 m-deep cultures. Overall, use of LEDs increased biomass growth chiefly by increasing nighttime productivities – materialized in higher chlorophyll, protein, and carbohydrate productivities in LED-lit cultures. A higher impact of LED lighting was observed under lower sunlight irradiances. A preliminary economic analysis indicates that use of LEDs in RWPs outdoors should be considered for high-value metabolites only.

CO2 mineralization of carbide slag for the production of light calcium carbonates

The production of polyvinyl chloride by calcium carbide method is a typical chemical process with high coal consumption, leading to massive flue gas and carbide slag emissions. Currently, the carbide slag with high CaO content is usually stacked in residue field, easily draining away with the rain and corroding the soil. In this work, we coupled the treatment of flue gas and carbide slag to propose a facile CO2 mineralization route to prepare light calcium carbonate. And the route feasibility was comprehensively evaluated via experiments and simulation. Through experimental investigation, the Ca2+ leaching and mineralization reaction parameters were determined. Based on the experiment, a process was built and optimized through Aspen Plus, and the energy was integrated to obtain the overall process energy and material consumption. Finally, the net CO2 emission reduction rate of the entire process through the life-cycle assessment method was analyzed. Moreover, the relationship between the parameters and the CO2 emission life-cycle assessment was established. The final optimization results showed that the mineralization process required 1154.69 kW·h·(t CO2)−1 of energy (including heat energy of 979.32 kW·h·(t CO2)−1 and electrical energy of 175.37 kW·h·(t CO2)−1), and the net CO2 emission reduction rate was 35.8%. The light CaCO3 product can be sold as a high value-added product. According to preliminary economic analysis, the profit of mineralizing can reach more than 2,100 CNY·(t CO2)−1.

The feasibility and acceptability of a pilot comprehensive resilience‐building psychosocial intervention (CREST) for people with memory problems/dementia in the community

AbstractBackgroundA dementia diagnosis can lead to a decline in cognitive, social, and physical health, but people with dementia can live meaningful lives and participate actively in society with psychosocial support [1‐3]. This pilot study explored the feasibility and acceptability of a comprehensive resilience‐building psychosocial intervention (CREST) for people with memory problems/dementia (PWMPD), their caregivers, GPs, and the public.MethodNine PWMPD and their primary caregivers living in the community (N=9 pairs) completed the CREST intervention. The three components (cognitive stimulation therapy [CST], physical exercise, and dementia education) were delivered in five programmes. The PWMPD attended a 7‐week CST programme and an 8‐week exercise programme. The caregivers attended a 6‐week educational programme. Dementia education programmes were held for the community and local GPs. Quantitative secondary outcomes for participants were assessed at baseline and following the 15‐week intervention; qualitative interviews were conducted during and post‐intervention. All study components were assessed to determine the feasibility of conducting a future definitive trial.ResultHigh attendance and adherence to content were maintained for each component. The PWMPD and caregivers enjoyed each component of the CREST intervention, with only minor changes being recommended. The PWMPD enjoyed the CST and Exercise components; they felt their concentration and fitness had improved over the 15‐week intervention and particularly enjoyed the social aspects (e.g., group classes, exercising with partners from the community). Secondary elements of the Exercise component (home diaries and Fitbit use) were not feasible. Caregivers felt that they had better knowledge and understanding following their education component and reported that the social aspects (interacting and sharing experiences with each other) were important elements. The quantitative measures were confirmed feasible by participant feedback and data analysis, and health economic tools were confirmed feasible by preliminary health economic analysis. Recruitment posed significant delays to the onset and conduct of the CREST intervention.ConclusionThe CREST intervention was acceptable to the participants and each component was considered feasible. However, significant difficulties with recruitment impacted the viability of delivering the intervention in the community and further work is needed identify barriers to the recruitment of PWMPD before a full‐scale or RCT can be conducted.

Freeze-thaw combined with activated carbon improves electrochemical dewaterability of sludge: analysis of sludge floc structure and dewatering mechanism.

Freeze-thaw (F/T) and electrochemistry both are environment-friendly and efficient sludge treatment technologies. In this study, the sludge samples were frozen at - 15°C, and 20% g/gTss activated carbon (AC) was added to the dissolved sludge. Finally, the uniformly mixed sludge was treated at a voltage of 15V for 25min. During the experiment, the effect of F/T on the floc structure was analyzed by a laser particle analyzer and scanning electron microscope. F/T treatment improved the dewatering performance of the sludge and promoted the aggregation of sludge flocs into larger particles either. At the same time, the median diameter (D50) increased from 45.27 to 128.94μm. AC was added to the thawed sludge solution before electrochemical treatment (EP). The conductivity of AC enhanced the effect of EP, thereby cracking the sludge flocs. Therefore, the three-dimensional excitation-emission matrix (3D-EEM) intensity of tightly bound extracellular polymeric substances (TB-EPS) decreased significantly. The protein in TB-EPS decreased from 54 to 33%, and the D50 was also reduced to 105.3μm. The final specific resistance of filtration and water content were reduced by 96.39% and 32.17%, respectively. The dehydrated cake elemental analysis showed that increased AC improved the sludge cake's combustion efficiency significantly. Moreover, the preliminary economic analysis indicated that the cost of this research was low, which implied the potential application value of combined treatment.

Conceptual considerations of the modernization of the main fan stations of mine Y and their economic aspect

In connection with the liquidation of the hard coal mine Y and the change its functionality, it is necessary to modernize the main fan station installed at the “Northern” shaft of mine Y. The article presents concepts of changing the efficiency of WPK 5.0 fans installed in the “Northern” shaft and the methods of air flow regulation for target model of a mine with a reduced network of mining excavations. It discusses four alternative variants of technical solutions. The most effective of them are illustrated with a preliminary economic analysis, the results of which enable the right investment decision to be made.