Process Economic Analysis Research Articles

The coMforT study of a trauma-informed mindfulness intervention for women who have experienced domestic violence and abuse: a protocol for an intervention refinement and individually randomized parallel feasibility trial

BackgroundDomestic violence and abuse (DVA) is common and destructive to health. Post-traumatic stress disorder (PTSD) is a major mental health consequence of DVA. People who have experienced DVA have specific needs, arising from the repeated and complex nature of the trauma. The National Institute for Health and Care Excellence recommends more research on the effectiveness of psychological interventions for people who have experienced DVA. There is growing evidence that mindfulness-based interventions may help trauma symptoms.MethodsIntervention refinement and randomized controlled feasibility trial. A prototype trauma-informed mindfulness-based cognitive therapy (TI-MBCT) intervention will be co-produced following qualitative interviews and consensus exercise with stakeholders. Participants in the feasibility trial will be recruited from DVA agencies in two geographical regions and randomized to receive either TI-MBCT or usual care (self-referral to the Improving Access to Psychological Therapies (IAPT) service). TI-MBCT will be delivered as a group-based eight-week program. It will not be possible to blind the participants or the assessors to the study allocation. The following factors will inform the feasibility of progressing to a fully powered trial: recruitment, retention, intervention fidelity, and the acceptability of the intervention and trial design to participants. We will also test the feasibility of measuring the following participant outcomes before and 6 months post-randomization: PTSD, dissociative symptoms, depression, anxiety, DVA re-victimization, self-compassion, and mother-reported child health. Process evaluation and economic analysis will be embedded within the feasibility trial.DiscussionThis study will lead to the development of a TI-MBCT intervention for DVA survivors with PTSD and inform the feasibility and design of a fully powered randomized controlled trial (RCT). The full trial will aim to determine the effectiveness and cost-effectiveness of a TI-MBCT intervention in improving the clinically important symptoms of PTSD in DVA survivors.Trial registrationISRCTN, ISRCTN64458065, Registered 11 January 2019.

Biodiesel production from waste cooking oil using copper doped zinc oxide nanocatalyst – process optimisation and economic analysis

Biodiesel production from waste cooking oil using copper doped zinc oxide nanocatalyst – process optimisation and economic analysis

Biodiesel production from waste cooking oil using copper doped zinc oxide nanocatalyst – process optimisation and economic analysis

India is the world's third largest consumer of energy. India's energy consumption consists of 44% coal, biomass and waste 24%, petroleum and other liquids 23% and other renewable sources such as wind, solar, nuclear and biofuels. Due to the shortage of diesel and increasing prices, biodiesel gained its importance as an alternate to the petroleum based fuels. This paper deals with the transesterification of waste cooking oil to biodiesel with copper doped zinc oxide nanocatalyst under varying parameters such as oil to methanol ratio (1:2-1:5 mol), catalyst loading (2-8% w/w), reaction time (30-60 minutes) and temperature (40-70°C). Results show that the maximum yield of about 97.7% was obtained at optimum reaction conditions. This result is further validated. The economic analysis of biodiesel production is carried out and the cost of biodiesel per litre works out to be 68 rupees INR ($0.99). [Received: August 3, 2018; Accepted: June 1, 2019]

A group intervention to improve quality of life for people with advanced dementia living in care homes: the Namaste feasibility cluster RCT

People with advanced dementia who live and die in nursing homes experience variable quality of life, care and dying. There is a need to identify appropriate, cost-effective interventions that facilitate high-quality end-of-life care provision. To establish the feasibility and acceptability to staff and family of conducting a cluster randomised controlled trial of the Namaste Care intervention for people with advanced dementia in nursing homes. The study had three phases: (1) realist review and (2) intervention refinement to inform the design of (3) a feasibility cluster randomised controlled trial with a process evaluation and economic analysis. Clusters (nursing homes) were randomised in a 3 : 1 ratio to intervention or control (usual care). The nature of the intervention meant that blinding was not possible. Nursing homes in England providing care for people with dementia. Residents with advanced dementia (assessed as having a Functional Assessment Staging Test score of 6 or 7), their informal carers and nursing home staff. Namaste Care is a complex group intervention that provides structured personalised care in a dedicated space, focusing on enhancements to the physical environment, comfort management and sensory engagement. The two contender primary outcome measures were Comfort Assessment in Dying - End of Life Care in Dementia for quality of dying (dementia) and Quality of Life in Late Stage Dementia for quality of life. The secondary outcomes were as follows: person with dementia, sleep/activity (actigraphy), neuropsychiatric symptoms, agitation and pain; informal carers, satisfaction with care at the end of life; staff members, person-centred care assessment, satisfaction with care at the end of life and readiness for change; and other data - health economic outcomes, medication/service use and intervention activity. Phase 1 (realist review; 86 papers) identified that a key intervention component was the activities enabling the development of moments of connection. In phase 2, refinement of the intervention enabled the production of a user-friendly 16-page A4 booklet. In phase 3, eight nursing homes were recruited. Two homes withdrew before the intervention commenced; four intervention and two control homes completed the study. Residents with advanced dementia (n = 32) were recruited in intervention (n = 18) and control (n = 14) homes. Informal carers (total, n = 12: intervention, n = 5; control, n = 7) and 97 staff from eight sites (intervention, n = 75; control, n = 22) were recruited over a 6-month period. Recruitment is feasible. Completion rates of the primary outcome questionnaires were high at baseline (100%) and at 4 weeks (96.8%). The Quality of Life in Late Stage Dementia was more responsive to change over 24 weeks. Even where economic data were missing, these could be collected in a full trial. The intervention was acceptable; the dose varied depending on the staffing and physical environment of each care home. Staff and informal carers reported changes for the person with dementia in two ways: increased social engagement and greater calm. No adverse events related to the intervention were reported. A subsequent definitive trial is feasible if there are amendments to the recruitment process, outcome measure choice and intervention specification. In a full trial, consideration is needed of the appropriate outcome measure that is sensitive to different participant responses, and of clear implementation principles for this person-centred intervention in a nursing home context. Current Controlled Trials ISRCTN14948133. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 6. See the NIHR Journals Library website for further project information.

The Impact of Digitalization of the Economy on the Competitiveness of Business Structures

The current stage in the development of civilization is characterized by the development and practical implementation of advanced technology, particularly innovative information technology, which affects all areas of society. Digitalization of the economy forms new competitiveness factors for business structures and calls for a comprehensive consideration of all competitiveness factors in managerial decision-making.Aim. The study aims to determine the effects of digitalization of the economy on the competitiveness of business structures and to identify additional factors that need to be taken into account during its assessment.Tasks. The authors determine the specific features of digitalization of the economy, reveal the integral factors of the competitiveness of business structures, and identify the specifics of consideration of competitiveness factors in the context of digitalization of the economy.Methods. The study is based on the dialectical systems approach as well as logical and factorial analysis using the theoretical framework of analysis of economic processes. The analysis is based on the international scientometric database Scopus and the bibliographic database of the Russian Science Citation Index (RSCI).Results. The authors substantiate the need to make allowance for additional specific factors of competitiveness of business structures under modern conditions, particularly in the assessment of the competitiveness of business structures, financial factors, and the level of human capital development in addition to the factors of operating efficiency, strategic positioning, and innovation potential.Conclusions. During the assessment of competitiveness of business structures, particularly in the context of digitalization, it is advisable to make allowance for return on assets, indicators of innovation potential, integrated human capital development index, and integrated indices of financial sustainability, variability and at the same time stability of the financial state of a business structure.

Techno-economic analysis of the effects of heat integration and different carbon capture technologies on the performance of coal-based IGCC power plants

Coal-based Integrated Gasification Combined Cycle (IGCC) power plants show obvious gains over conventional pulverized coal power plants by achieving higher efficiency, lower carbon emissions and lower energy penalty for incorporating different carbon capture and storage (CCS) technologies. However, due to the lack of standardised designs, current IGCC-CCS projects are hindered by higher capital expenditures limiting their commercial implementation. Therefore, the key challenge is carrying out a techno-economic optimisation of IGCC-CCS power plants to ensure compatible power generation efficiency and accessibility. This study aims to optimise the performance of a coal-based IGCC plant with two different CCS technologies (double-stage Selexol absorption cycle and Ni-based chemical looping combustion (CLC) process) through intensive process simulation, heat integration and economic analysis. Heat integration has increased the net plant efficiency by more than 12% and decreased the levelised cost of electricity (LCOE) no less than 5 cents kWh−1. The CLC technology offered near-zero carbon emissions with higher plant efficiency and lower value of LCOE. Decreasing the CO2 capture rate by Selexol caused a decrease in LCOE and an increase in the corresponding CO2 specific emissions. Therefore, an appropriate decarbonisation scenario depends on a trade-off between the degree of carbon capture and the allowed CO2 specific emissions.

“Mordovian Silk”: Development of Hemp Growing in Mordovia in the 1930–1950s

Introduction. The development of hemp growing in Mordovia in the 1930s – 1950s attracted attention of researchers due to the recent revival of interest of agricultural producers in the world, Russia and the Republic of Mordovia to the cultivation of hemp and its production. Being unheralded during the second half of the 1980s – 1990s, hemp becomes popular again in the agriculture of the Mordovia Republic, Russia and other countries. Materials and Methods. An integrative approach is used as a theoretical and methodological base of the study, microeconomic processes of a particular region against the background of macroeconomic phenomena are analyzed. Socio-economic approach allows observing the elements of material incentives within the socialist economy. Along with the analysis of economic processes, non-economic factors are taken into account. Results. Despite many climatic, socio-economic and technical problems, the cultivation of hemp in Mordovia in the 1930s – 1950s was highly profitable. Discussion and Conclusions. The success of the hemp growers contributed to: targeted state support for hemp farms, active financial incentives of collective farms and collective farmers, the development of agriculture, as well as non-economic motivation of Soviet peasants. Much success in the production of “Mordovian silk” was made by Atyashevskiy, Dubensky, Zubovo-Polyanskiy, Ichalkovsky, Kochkurovskiy, Krasnoslobodsky and Kadoshkiny districts.

A multi-perspectives analysis of methane oxidative coupling process based on miniplant-scale experimental data

A multi-perspectives analysis of the potentials, challenges and characteristics of possible future industrial-scale ethylene production via Oxidative Coupling of Methane (OCM) process was performed in this research. In doing so, miniplant-scale experimental data were utilized to scale-up, predict and represent the performance of the unit operations in the industrial-scale operation of a reference stand-alone and two different integrated OCM process configuration, each with an assumed capacity of one million tons per year ethylene production. Technical, environmental and economic performance of these alternative OCM processes were analyzed and compared using Aspen Plus simulations and Aspen Process Economic Analyzer. The assumptions and the conceptual conclusions made in the analysis are also discussed in this paper. The technologies and the costs associated with conditioning the methane feed stream originated from natural gas or biogas were compared and their impacts, through reducing the resulted price of methane-feed, on the economy of the OCM process are discussed. Moreover, the integration potentials of the OCM process with the ethane dehydrogenation process and the clear impacts of the resulted increase in the ethylene production on the whole process economy are also considered in this paper. The feasibility and the specifications of the selected integrated OCM process configuration, providing the fastest return of investments around 9.5year, are discussed in this paper. The economic and environmental performance indicators of this integrated process along with the potentials and some suggestions for further improving its performance are also highlighted in this paper.

Process synthesis and economic analysis of cyanobacteria biorefineries: A superstructure-based approach

In this study, we develop, synthesize, and evaluate a cyanobacteria biorefinery incorporating all relevant subsystems including: (1) supply of CO2, water, and nutrients, (2) production at cultivation ponds, and (3) products separation and purification. A superstructure-based approach is proposed to evaluate technical and economic feasibility of cyanobacteria biorefineries to produce biochemicals. Supply subsystems include a wastewater treatment (WWT) facility and a power plant to provide water, nutrients, and CO2. In the production subsystem, an approach to model cultivation ponds is developed based on production requirements and cyanobacteria characteristics i.e. residence time and productivity. In the purification subsystem, optimal separation technologies are selected based on product attributes and concentration to recover products and recycle water and nutrients, while minimizing costs. Later, all subsystems are integrated and system-wide optimization is performed. Impacts of key parameters such as cyanobacteria productivity and performance for a cellular level analysis; and CO2 transportation phase, distances, and product titers for a systems level analysis are investigated. Results indicate that depending on product attributes, the production cost could vary between $2.74−$34/kg ($0.7−$2.65/kg) at product concentrations of 0.5 g/L (10 g/L), highlighting the importance of achieving higher product titers. Analyses for the base-case show that for a titer of 0.5 g/L, reducing productivity from 30 to 5 g m−2 day−1 while increasing residence time from 5 to 30 days increases the production cost by about 22% in the system with water and nutrients supply form WWT, respectively. Results show that providing water and nutrients from a WWT facility improves the economics. The present study provides critical insights for future research and development and successful commercialization of cyanobacteria biorefineries.

Energy indicators for microwave-assisted biodiesel production from waste fish oil

ABSTRACT Biodiesel is produced from renewable sources such as vegetable oils and animal fats as a fuel for replacing fossil fuels in diesel engines. Energy efficiency and energy intensity in production processes are a significant issue. In this research work, the process energy indices and economic analysis have been investigated due to determine the potential advantages of using microwave energy for waste fish oil biodiesel production. A flow process including a magnetic stirrer and a microwave reactor has been used for transesterfication reaction. The equivalent of input and output energy of the biodiesel production process and the energy indices were obtained. According to the results, the total amount of input and output energy was 48.839 and 50.866 MJ.L−1, respectively. The values of energy ratio, energy efficiency and energy intensity for producing one liter of biodiesel were calculated 1.0415, 0.0178 kg.MJ−1 and 56.0724 MJ.kg−1. Renewable and non-renewable energy values were obtained at 41.962 and 6.877 MJ.L−1, respectively. Economic efficiency was also achieved at 1.6637 kg.$−1. In other words, in this work, the price of produced biodiesel per gasoline-gallon equivalents (GGEs) will be 3.72 USD.

Techno‐economic and life‐cycle assessments of small‐scale biorefineries for isobutene and xylo‐oligosaccharides production: a comparative study in Portugal and Chile

AbstractThis work presents a comparative simulation study involving the techno‐economic and environmental assessment of lignocellulosic‐based small‐scale biorefineries, integrated with a piggery waste‐based anaerobic digestion platform (ADB), located in Portugal and Chile. Two main products are obtained: isobutene and xylo‐oligosaccharides (XOS). The bioproduction of isobutene using a genetically engineered organism (Escherichia coli), coupled with the removal and purification of high added‐value XOS, obtained after a feedstock hydrothermal pre‐treatment, was evaluated. Two lignocellulosic agricultural wastes were used: corn stover in the Portuguese case study and wheat straw in Chilean case study. Both processes were simulated using the Aspen Plus modeling software tool, while the Aspen Process Economic Analyzer was used to carry out the economic evaluation. The simulation results were validated with experimental data from the laboratory and the literature. An economic assessment was performed considering the different locations of both biorefineries. A life‐cycle analysis (LCA) was also applied to evaluate the differences in environmental impacts on both locations. The results showed that the isobutene / XOS biorefinery concept was economically viable in both Portugal and Chile, mainly due to the high market value of XOS. The biorefinery has lower production costs for isobutene and XOS (1 US$/kg of isobutene and 1.18 US$/kg of XOS) when located in Portugal, as compared with Chile (1.14 US$/kg of isobutene and 1.56 US$/kg of XOS). Conversely, it leads to less environmental impact when located in Chile: 48.8 kgCO2eq./GJisobutene, in comparison to 60.7 kgCO2eq./GJisobutene in Portugal. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd

A techno-economic-environmental study evaluating the potential of oxygen-steam biomass gasification for the generation of value-added products

The production of renewable chemicals and fuels is driving modern society towards a type of sustainable development which involves a decreasing dependency on fossil fuels and the minimisation of waste. Biomass, a waste by-product from the urban environment, is a carbon dioxide neutral organic fuel that can potentially serve as a feedstock for the production of sustainable power and heat. Gasification is preferred over the other thermal conversion options for biomass processing whereby the product synthesis gas can be utilised to power generators/turbines and generate clean energy, ammonia and methanol. Incidentally, efficient and economically sound biomass driven supply chains can be integrated into an existing petrochemical infrastructure. Moreover, the potential production volumes of fuels and green chemicals can also be increased by the addition of multiple biomass sources, thereby creating potential positive scale effects. This study proposes a new poly-generation process that utilises multiple sources of biomass feedstock to produce high quality urea, methanol, Fisher-Tropsch liquids and power. Four flowsheet configurations are simulated using Aspen Plus software and the built-in capabilities of the activated analysis using Aspen Process Economic Analyzer and Aspen Energy Analyzer to perform the economic, energy and environmental impact calculations. The results demonstrate that the methanol production technique is the most economic process pathway with a net profit of approximately $0.035 per kg of biomass input, whilst the urea process pathway presents the lowest environmental impact solution with approximately 0.71 kg of CO2-e per kg of biomass input. These results are relative and can be analysed from different perspectives based on the market demand of the products and their applications and local need. For instance, considering at the economic and environmental indicators relative to the production capacity, production of liquid fuels achieve net profits of approximately $0.27 per kg of product, whilst urea production demonstrates the lowest environmental emissions of approximately 3.93 kg of CO2-e per kg of product.

CO2 Freezing Area Concept for Improved Cryogenic Distillation of Natural Gas

Sweetening process for natural gas with high content of sour gas (≥ 40% mol of CO2 & H2S) is difficult to be profitable. A lot of gas fields in Indonesia has high content of sour gas. New improved cryogenic distillation process of natural gas applying the concept of CO2 freezing in the middle of the column is promising. To study the feasibility of this technology, comparison with other two methods (Absorption and Membrane process) in technical and economic aspects were elaborated. Process simulation of improved cryogenic distillation steady-state model was developed using Aspen HYSYS. CAPEX of all methods were estimated using Aspen Process Economic Analyzer. Compared to the other methods, this improved cryogenic distillation process showed tendency to have lower CAPEX and OPEX, but have some uncovered operational problems.

Techno-economic modeling and optimization of catalytic reactive distillation for the esterification reactions in bio-oil upgradation

Equilibrium reactive distillation (RD) process simulation and economic evaluation were carried out for the esterification of complex mixtures of several fatty acids and water (representative of crude bio-oils) with n-butanol using Aspen PLUS process simulator and economic analyzer. Complete design and optimization were carried out using evolutionary techniques from simplest system to the most rigorous one with introduction of intermittent progressive complexity. Prior to distillation design, esterification reaction kinetics and binary/ternary interactions were analyzed using Aspen RGibbs reactor module and Property PLUS, respectively. Simple distillation column was designed and optimized to obtain the initial trial parameters to be used in RD simulation. UNIQUAC is used as base property method and reaction equilibria estimated by minimization of Gibbs free energy. Near atmospheric column pressure, reflux ratio of 0.95, distillate to feed ratio of 0.505 and total 18 stages were found to be optimum based on attainable reaction conversion, ester separation, heat duties, and capital and operating costs. The effects of n-butanol:acid feeding ratio and water percent in bio-oil and their relationship were also analyzed to predict n-butanol requirement. The results of this study, including the optimized parameters, could serve as design platforms for pyrolysis bio-oil upgradation to transportation fuels.

Process modeling and economic analysis for bio-heavy-oil production from sewage sludge using supercritical ethanol and methanol

The solvothermal liquefaction of sewage sludge (SS) has received much attention as an ecofriendly method of liquid fuel production. In this study, we evaluated the economic feasibility of bio-heavy-oil (BHO) production from 100 t/d SS using supercritical ethanol (scEtOH) and methanol (scMeOH). The process included a dryer, supercritical reactor, BHO separator, steam boiler, wastewater treatment unit and storages. Two cases for the techno-economic analysis (TEA) were considered: BHO production with scEtOH (Case 1) and with scMeOH (Case 2). The four-level economic potential approach (4-level EP) was used for the TEA. The total capital investments of Cases 1 and 2 were 19.6 and 19.5 million dollars, respectively. Case 2 showed higher economic potential than Case 1 because of the low price of methanol. The BHO plant using scMeOH was economically feasible with a return on investment of 21%/a.

Analysis of the features of economic relations of the European Union with the ASEAN (Association of Southeast Asian Nations) countries

The object of research is the features of economic relations of the European Union and countries-members of the ASEAN (Association of Southeast Asian Nations) union. One of the most problematic places is that European Union as a supranational institution is currently experiencing a crisis, on various levels. From economic problems beginning, especially with the so-called PIGS countries (Portugal, Italy, Greece, and Spain), through difficulties in concluding internal political consensus and «speaking» with one voice on the international forum, ensuring security of Europe on the eastern border.In the process of research, general scientific and special methods of cognition were used: analysis of economic processes, generalization of analyzed features of economic cooperation of the European Union and countries-members of ASEAN. The structurally-functional method has allowed to highlight the main risks and areas of the program implementation strategy for cooperation with ASEAN members. The statistical method was used in assessing and analyzing the state of trade balance between the EU and ASEAN members.In the course of the research it was identified that in the resolution of political or security difficulties, the European Community mainly depends solely on its own strength. In terms of economic matters there are a number of regions with which this closer cooperation seems to be a logical solution that may bring benefits in the near future. One of them is Southeast Asia. As a result of the research it is shown that ASEAN has been a rapidly growing organization in the region for many years and its trade potential for EU is increasing rapidly. Strengthening international cooperation on the European Union – ASEAN line may prove to be a very important alternative for European economies. In addition, such an alliance may be the basis for a broad exchange of technological and educational experience, creating the nucleus of future strategic relations.The results of research shows not fully used potential with ASEAN members’ cooperation. Abilities and areas of future cooperation of EU companies particularly and EU countries in general could be the ground for future investigations with ASEAN members.

Integrated biomass thermochemical conversion for clean energy production: Process design and economic analysis

In this study, conversion of Napier grass bagasse into biofuel was carried out through steady state process modelling and simulation using Aspen Plus software. An integrated thermochemical system consisting pyrolysis, gasification and combustion section for pyrolytic oil production and upgrading, non-condensable gas/syngas and bio-char valorisation was developed in a single flowsheet with capacity of 49 kg/h feedstock. Aspen process economic analyser was used to generate both capital and operating costs estimates, and other investment analysis following first quarter 2016 pricing basis. The simulation result showed that about 68 wt% of the feedstock could be processed into pyrolytic oil at 480 °C with corresponding liquid biofuel yield of 5.35 kg/h, which is equivalent to about 11 wt% of the initial feedstock through in-situ hydrodeoxygenation process. The result of economic evaluation of the entire process plant indicated that a total capital cost of $2.13 M and operating cost/year of $0.3 M is required for 25-year economic life of the project with net present value of $15.18 M at 8% internal rate of return. The standalone biomass refining plant is expected to produce fuel at minimum fuel selling price of $5.81/gallon ($1.45/L) gasoline equivalent, mainly driven by the capital cost. This work presents a systematic combination of process units that will be needed to produce advanced cellulosic biofuels in the near future.

A Structural Analysis of Economic Processes by the Use of “Energy Content Value”

Since currency is a means of exchange, it forms a standard of value. Modern economics uses the function of currency as a “general standard of value” and describes the economic processes in the terms of value by the quantity of money. The most notable indicator to symbolize this situation is “Gross Domestic Product” (GDP). However, GDP, in general, does not indicate the economic process as a whole. It is necessary to add intermediate inputs to the GDP in order to calculate the total amount of industrial output of a country, and this total industrial output can never realize without energy supply. In other words, the total industrial output of a country and the total amount of energy supplied (= consumed) constitute an inseparable relationship like the front and back of the coin. This research tries to propose an alternative evaluation indicator based on “energy”, which is the most important economic substance and the indispensable requirement for all human activities. Regarding this issue, this study deals with the following problems. First, we refer to a dualistic composition which Soddy had adopted, from the beginning, to classify wealth, which is a product of economic processes, into two categories: one on a physical dimension (Wealth I · II) and the other on a psychological dimension (Virtual Wealth). Then, based on the dualistic framework proposed by Soddy, we present that we can evaluate the economic process, through a compound-eye view, on two dimensions: the physical dimension (energy flow) and the institutional dimension (money flow). Next, we focus on ‘the economic process presented by monetary value’ (A) and ‘the energy quantity which effectually supports this process’ (B). We have introduced how to project (B) onto the constituent elements of (A). Thus, we take a case study on Japan by use of dualistic aspects approach.

Dynamic process model and economic analysis of microalgae cultivation in flat panel photobioreactors

Microalgae are often considered an important renewable feedstock for production of bio-energy and value-added products and have the potential to help meet the rising demands of energy, food and feed in the world. To determine microalgae productivity in outdoor commercial scale flat panel photobioreactors for a given algal species and any given location, a first-principles based quantitative growth model was developed taking into account geospatial variabilities. Based on local climatic factors, which included solar irradiance, air temperature, relative humidity and wind velocity, a combined heat and mass transfer model was developed to predict temperature of the culture medium where microalgae was cultivated. The temperature data was further incorporated into a biological growth kinetics model for a given algal species to predict microalgae productivity potential for that location. Yearly microalgae productivity ranged between 3800 and 13,000 t km−2 year−1 for the different locations examined. A detailed economic analysis was conducted to assess microalgae cost for the locations. Based on the economic analysis, microalgae production cost for in flat panel photobioreactor systems ranged between 2895 $ t−1 to 9564 $ t−1. The robust techno-economic analysis demonstrates that microalgae production costs depend significantly on geospatial location, microalgae productivity potential as well as engineering and process parameters of algae cultivation.

Process design and economic analysis of methacrylic acid extraction for three organic solvents

Abstract In this work, a techno-economic study for the solvent based extraction of methacrylic acid from an aqueous solution is presented. The involved phase equilibrium calculations in process design are verified by measured experimental data. First, experiments are conducted with different solvent candidates to measure LLE (liquid–liquid equilibrium) data and to establish the effects of extraction temperature and dosage of solvent. Next, the binary interaction parameters for the UNIQUAC model to be used for equilibrium calculations are fine-tuned with measured data. Then, a process for the solvent based extraction of methacrylic acid recovery is designed and verified through simulation with the regressed UNIQUAC model parameters. The optimal configuration of the process flowsheet is determined by minimizing the total annualized cost. Among the three solvent candidates considered-cyclohexane, hexane and toluene-the highest efficiency and the lowest total annualized cost is found with toluene as the solvent.