Comparative Techno-economic Assessment Research Articles

Comparative techno-economic assessment of sugarcane biorefineries producing glutamic acid, levulinic acid and xylitol from sugarcane

In this study, six alternative biorefinery scenarios for the production of levulinic acid (LA), glutamic acid (GA) and/or xylitol- or a combination of these chemicals- annexed to an existing sugar mill in 1G-only (molasses feedstock) or integrated 1G2G (molasses and sugar cane lignocellulose feedstock) configurations were simulated in AspenPlus®. Then, mass and energy balances obtained from the simulations were used for the subsequent equipment sizing and costing and to perform the economic performance assessments of the scenarios. All the investigated scenarios were identified as profitable scenarios with the internal rates of return (IRRs) ranging from 21.3%−59.8%. Generally, GA scenarios showed better economic outcomes compared to LA counterparts, attributed to the factors such as higher market prices, higher product throughput and less complicated processing technology which lowers the cost of production. Considering the market size and economic outcome, the 1G GA scenario producing 11.1 t/h GA showed the best economic performance with 59.8% IRR and a minimum product selling price (MSP) of $1687/t. However, a multiproduct facility (1G2G GA-xylitol) can result in more robust economic performance, as a result of implementing xylitol mature technology. Although all investigated scenarios showed profitability potential, life cycle analysis (LCA), social impact assessment and market analysis are required to find out the most sustainable biorefinery option.

Comparative techno-economic assessment of osmotically-assisted reverse osmosis and batch-operated vacuum-air-gap membrane distillation for high-salinity water desalination

New developments in pressure- and thermally driven membrane desalination technologies offer the potential to cost-effectively treat high-salinity waters, especially when powered by low-cost solar electricity and thermal energy. This paper presents a comparative techno-economic assessment of the state-of-the-art most promising pressure- and thermally driven membrane technologies for high recovery desalination, namely, osmotically-assisted reverse osmosis (OARO) and batch-operated vacuum-air-gap membrane distillation (batch V-AGMD), to produce potable water while concentrating brine within the range of 140–290 g/L TDS for minimum-liquid-discharge (MLD) and zero-liquid-discharge (ZLD) applications. It is shown that both OARO and batch V-AGMD can treat feedwater and brines with TDS in the range of 30–125 g/L with corresponding fresh water recovery rates of 85–25%. When low cost solar electricity and thermal energy are used, the resulting levelized cost of water (LCOW) from OARO is in the range of 0.70–6.28 $/m3, and that from batch-V-AGMD is in the range of 1.74–2.77 $/m3. OARO is more cost-effective than batch V-AGMD when feedwater salinity is below 70 g/L and recovery below 75%, whereas batch V-AGMD is more cost-effective at higher recovery rates and salinity levels. The sensitivity of this comparison on energy prices and module costs is discussed.

Comparative techno-economic assessment of bio-methanol and bio-DME production from oil palm residue

The techno-economic assessment was performed to investigate and compare the production of bio-methanol and bio-dimethyl ether (bio-DME) via the combined gasification and chemical synthesis processes (i.e., gasification-methanol (MeOH) and gasification-DME). The combined processes were simulated using oxygen as a gasifying agent and the oil palm trunk, the agricultural waste generated from the palm oil industry, as feedstock. The gasification-MeOH process offered a higher amount of valuable product (methanol) and released a larger amount of CO2. The energy analysis indicated the two biomass conversion processes were exothermic process. The gasification-DME process presented a higher biomass conversion efficiency of 59.5% compared to 47.6% of the gasification-MeOH. The pinch analysis of gasification-MeOH and the gasification-DME processes indicated threshold pinch that required only cold utility of 0.5542 kW and 0.7258 kW, respectively. Regarding the economic aspect, the two processes were still not economically feasible, and the methanol and DME prices and the project lifetime influenced their economic performance. However, due to the high product price, the gasification-DME process was approximately 7% more economically feasible than the gasification-MeOH process.

A Comparative Techno-Economic Assessment of Bidirectional Heavy Duty and Light Duty Plug-In Electric Vehicles Operation: A Case Study

A Comparative Techno-Economic Assessment of Bidirectional Heavy Duty and Light Duty Plug-In Electric Vehicles Operation: A Case Study

To shred or not to shred: A comparative techno-economic assessment of lithium ion battery hydrometallurgical recycling retaining value and improving circularity in LIB supply chains

Present techniques for recycling lithium-ion batteries (LIBs) tend to employ shredding as a preliminary step. This results in size reduction and passivation of reactive components. However, it also delivers lower purity products, decreasing process economics. We propose that disassembly followed by delamination retains product value and simplifies downstream chemistries. A retro-economic analysis shows the theoretical cost of reprocessing for a hypothetical $100 / kWh battery. Ten different hydrometallurgical approaches to LIB recycling are contrasted through techno-economic analysis of the wet part of the process. We show that shredded material can be recycled into new cathode material with a cost saving of up to 20%. Comparable processes using disassembled cells enable up to 80% cost saving (not accounting for the actual step of disassembling the cell). In the light of these results, we set out the barriers to disassembly of LIB cells, recommending the importance of design for disassembly as key to improving the circularity of LIB supply chains, ensuring that greater value is retained within the system.

Postcombustion CO2 Capture: A Comparative Techno-Economic Assessment of Three Technologies Using a Solvent, an Adsorbent, and a Membrane

This work compares three postcombustion CO2 capture processes based on mature technologies for CO2 separation, namely, (i) absorption using an aqueous piperazine solution, (ii) adsorption using Zeolite 13X in conventional fixed beds (either vacuum swing adsorption or temperature swing adsorption), and (iii) multistage membrane separation using a polymeric material (with CO2/N2 selectivity of 50 and permeability for CO2 of 1700 GPU). All three capture plants are assumed to be retrofitted to a generic industrial CO2-emitting source with 12% CO2 v/v (with 95% relative humidity at the inlet temperature and pressure of 30 °C and 1.3 bar, respectively) to deliver CO2 at 96% purity. In the cases of adsorption and membranes, the flue gas is dried before feeding it to the CO2 capture unit. In a first step, the capture processes (i.e., components and design parameters) are optimized based on their technical performance, defined through process exergy requirement and plant productivity; exergy–productivity Pareto fronts are computed for varying CO2 recovery rates. Second, the economic performance of the processes is assessed through a cost analysis. Estimates of CO2 capture costs are provided for each process as a function of the plant size and CO2 recovery rate. The comparative assessment shows that, although the adsorption- and membrane-based processes analyzed may become cost competitive at the small scale (i.e., below sizes of 100 tons of flue gas processed per day) and low recovery rates (i.e., below ca. 40%), the absorption-based process considered is the most cost-effective option at most plant sizes and recovery rates.

Comparative techno-economic assessment of a large-scale hydrogen transport via liquid transport media

A large-scale point to point hydrogen transport is one strategy for a prospective energy import scenario for certain countries. The case for a hydrogen transport from Australia to Japan has been addressed in several studies. However, most studies lack transparency and detailed insights into the made assumptions thus a fair evaluation of different transport pathways is challenging. To address this issue, we developed a model where a large-scale point to point hydrogen transport of liquid hydrogen is compared with the transport via liquid organic hydrogen carrier (LOHC), namely via methyl cyclohexane and hydrogenated dibenzyl toluene. We analyzed, where energy is required along the different pathways, where hydrogen losses do occur and how the costs are put together. Furthermore, the influence of hydrogen feed costs is also considered. For hydrogen production costs of 5 €2018/kgH2 the total delivery costs are in the range of 6.40– 8.10 €2018/kgH2.

Comparative techno-economic assessment of integrated PV-SOFC and PV-Battery hybrid system for natural gas processing plants

Natural gas will remain among the leading sources of energy, at least for the next few decades. Further, it is necessary to make natural gas processing operation a cost-competitive, clean, and efficient energy source, and less dependent on the grid. A comparative investigation based on two case studies is presented in this paper for a natural gas processing plant; an integration of Photovoltaic panels with Battery Energy Storage System (PV-BESS) and an integration of Photovoltaic panels with Solid Oxide Fuel cell (PV–SOFC) technologies. The aim is to be more independent from the grid for efficient operations and to reduce the emissions by introducing renewable energy in gas processing operation plant.A techno-economic analysis is performed for both cases considering a PV capacity of 33.5 MW. The outcome of this study indicates that for 25 years of operation, the Levelized cost of electricity (LCOE) for PV-BESS is found to be 0.16 US$/kWh, and for PV-SOFC is 0.11 US$/kWh, which makes the PV-SOFC option more economical and feasible than PV-BESS. Besides, in the projected scenario where investment cost is expected to reduce, PV-SOFC’s IRR is 3% and has a positive NPV of 5 Million USD$ for an internal rate of 4%. Furthermore, the LCOE for PV-SOFC in this scenario is around 0.04 USD$ per kWh, which is still less than the LCOE of PV-BESS and less than the tariff set by the Qatari electric authority for bulk industries.

A comparative techno-economic assessment of biochar production from different residue streams using conventional and microwave pyrolysis

A comparative techno-economic assessment and Monte Carlo risk analysis is performed on large scale (3 tonne/h) biochar production plants for conventional (CPS) and microwave (MWP) pyrolysis using six different residue streams. Both plants are viable with minimum selling prices between € 436/tonne and € 863/tonne for CPS, and between € 564/tonne and € 979/tonne for MWP. The CPS is therefore more viable than MWP as it is a simpler and more established technology. However, a 20% biochar price increase due to higher biochar quality makes the MWP technology more viable. Nevertheless, the discounted payback period remains higher than this of CPS due to the increased CAPEX. Biochar price is the most important determinant of a biochar production plant’s feasibility, motivating the need for economic and market research on biochar prices in function of biochar characteristics to reduce fluctuations in widely varying biochar prices.

Hybrid systems based on gas turbine combined cycle for trigeneration of power, cooling, and freshwater: A comparative techno-economic assessment

The objective of this study is to develop and thoroughly evaluate several feasible hybrid trigeneration configurations based on a gas turbine combined cycle (GTCC) for generating electricity, freshwater, and cooling. Six hybrid configurations are developed by integrating different desalination and chiller systems to the GTCC. Desalination systems include multi effect distillation (MED) and reverse osmosis (RO) with pressure exchanger (PEX) and chiller systems include double effect and half effect water-lithium bromide absorption chillers (DEABC and HEABC) and a vapor compression chiller (VCC) with different working fluids. The specific goal is to identify the optimal hybridization scheme and parameters among different configurations. The economic results show that implementation of RO is more economical than a hybrid MED-RO system in which the power cycle’s condenser is replaced by a MED. Also, the use of DEABC is more economical than a HEABC and a VCC. The results demonstrate that configuration 1 in which GTCC with the wet cooling tower is integrated with DEABC and RO is the most economical configuration. For this system, the levelized costs of electricity, water, and cooling (LCOE, LCOW, LCOC) are $0.0648/kWh, $0.7219/m3 and $0.0402/ton-hr, respectively, of which LCOE and LCOC are not the lowest values among different configurations.

Grid-independent PV system hybridization with fuel cell-battery/supercapacitor: Optimum sizing and comparative techno-economic analysis

In this paper, a comparative techno-economic assessment of two different hybrid energy storage system configurations viz. fuel cell-battery energy storage system (FC-BESS) and fuel cell-supercapacitor energy storage system (FC-SCESS), incorporated in a grid-independent photovoltaic (PV) based power system for a residential building is performed. Firstly, load for the residential building is calculated and accordingly optimum sizing of various constituents of the PV system is obtained using HOMER. Subsequently, the economic analysis for both configurations is performed in terms of cost of energy, net present cost, initial cost, and operating and maintenance cost. The simulation results of HOMER suggest that for grid-independent PV based power system, FC-SCESS configuration is better from the economic point of view. As HOMER’s inability to perform detailed technical analysis, MATLAB/Simulink models of both configurations are built and comparative analysis is performed in terms of different technical aspects such as active power balance, DC link voltage (VDC) regulation etc. From MATLAB results, it is observed that FC-SCESS configuration performs better by regulating the VDC more effectively and thereby helps maintain the active power balance between various constituents of the power system. Furthermore, feasibility of hardware implementation of each configuration is verified using hardware-in-loop real-time digital simulator.

CO2 utilization from power plant: A comparative techno-economic assessment of soda ash production and scrubbing by monoethanolamine

Abstract CO2 utilization for soda ash production via sodium hydroxide (NaOH) route was compared with the conventional CO2 scrubbing via monoethanolamine (MEA) route for the first time. The techno-economic and sustainability implications of these routes were assessed and compared; CO2 was considered to be captured from a natural gas combined cycle (NGCC) power plant. Process equipment were designed and sized from the estimation and simulation of process materials and energy requirements. Capital expenditure (CAPEX), cost of electricity (CoE), cost of CO2 avoided (CoA), and operational expenditure (OPEX) were estimated to compare the economic viability of the NaOH and MEA processes. Sensitivity analysis was carried out to investigate the effect of soda ash and NaOH prices on the process economics. Significant energy savings would be achieved from the NaOH process because this process eliminates the solvent regeneration and CO2 compression steps associated with the MEA process. The electricity requirement of the NaOH process was 35 kWh/t CO2, which was only 7% of the electricity requirement of the MEA process. NaOH process showed a total CAPEX of M$ 99.31 and an OPEX of M$ 18.68; this CAPEX was only 65% of that of the MEA scrubbing process. Sensitivity analysis showed that the cost of CO2 capture would be offset at a soda ash selling price of 18 $/t. NaOH process offers higher sustainability potential for CO2 utilization because it reduces the parasitic energy requirements and high initial capital cost associated with MEA scrubbing process.

Microalgae dewatering for biofuels: A comparative techno-economic assessment using single and two-stage technologies

Microalgae-based biofuels have the potential to replace fossil fuels and contribute towards carbon sequestration. However, the growth of this industry is challenged by the financial viability of scale-up at various production stages. Dewatering is a critical stage which accounts for 20–30% of biofuels‘ production costs, therefore a techno-economic assessment of two dewatering cases was conducted. The first case was a conventional clarifier-centrifuge dewatering system (Case 1), while the second case investigated a single stage dewatering approach, using the wet-end of a paper machine (Fourdrinier former; Case 2). Mass and energy balances were modelled at a process scale of 175 t/d to produce biomass with 25% dry substance content, from which the associated costs were calculated. The minimum selling price (MSP) to achieve a return of 12% at a corporate tax rate of 30% over a 20-year plant life, was AU$354.28/t and AU$59.68/t for Case 1 and Case 2 respectively. Electricity cost was 90% of operational expenditure for two-stage dewatering and 38% for single stage. Case 2 made a better investment case with an annual profit after tax of AU$131,020 and net present value (NPV) of AU$164 million, as against that of Case 1 with an annual profit after tax of AU$112,610 and NPV of AU$71 million. The single stage dewatering deserves further investigation to fully explore the cost reduction potentials. The adoption of low cost technologies with reduced energy use implies lower embedded GHG emissions and process costs when compared to conventional technologies. This is desired for the near-term actualization of sustainable and clean production pathways for microalgae based biofuels.

Comparative techno-economic assessment and environmental impacts of rice husk-to-fuel conversion technologies

This study compared techno-economic performances and environmental impacts of different technologies for rice husk-to-fuel biorefinery – hydrothermal carbonization with pelletization (HTC), pyrolysis (PYR) and anaerobic co-digestion (AD) process – and benchmarked against a conventional direct combustion (DC) for combined heat and power. Economic analysis through techno-economic (TE) model showed HTC with the greatest potentials compared to other processes due to its high-solid operating capacity and could be cost-competitive against the DC technology. Analysis results also highlighted a need for improvement of PYR and AD process in term of the increase of solid loading operation and the exploration of process wastes for better economic benefits and cost competitiveness. Based on life-cycle analysis (LCA) model, HTC yielded the lowest carbon and water footprints from amongst the analyzed options. Nevertheless, all three options had lower GHG emissions and water utilizations than DC process, indicating better environmentally advantageous of these processes. The LCA of three conversion technologies showed better environmental performances mainly lower global warming potential, lower photochemical oxidation potential and lower acidification potential than the DC reference system. The results obtained from this work could be exploited by decision makers for selecting appropriated biomass-to-fuel process based on environmental and economic performances.

Comparative techno-economic assessment of a converted DC refrigerator and a conventional AC refrigerator both powered by solar PV

A reliable and energy efficient approach of providing refrigeration needs is a major challenge in most developing countries, particularly sub-Saharan Africa. In this study, a comparative techno-economic assessment of a converted direct current refrigerator and a conventional alternating current refrigerator both powered by solar photovoltaic system has been conducted.Experimental results show that both refrigerators maintain almost the same cabinet and evaporator temperatures of about 2 °C and −10 °C respectively at compressor speed of 3000 rpm. However, it was observed that the AC refrigerator is associated with relatively high power consumption and power surges as compared to the DC refrigerator.An economic assessment conducted between the AC refrigerator (with an inverter) and the developed DC refrigerator (without an inverter) both powered by solar electric/photovoltaic system indicates that the DC refrigerator has the potential of reducing the overall system installation cost by 18% as compared to the AC refrigerator.

Comparative techno-economic assessment of biomass and coal with CCS technologies in a pulverized combustion power plant in the United Kingdom

The technical performance and cost effectiveness of white wood pellets (WWP) combustion in comparison to three types of coal namely U.S., Russian and Colombian coals are investigated in this study. Post-combustion capture and storage (CCS) namely with amine FG+, and oxy-fuel with carbon capture and storage (oxy-fuel) are applied to a 650MW pulverized combustion (PC) plant. The impacts of the Renewable Obligation Certificate (ROC) and carbon price (CP) policy in accelerating the CCS deployment in the framework of GHG emissions mitigation, are also evaluated. The operational factors affecting CCS costs and emissions in the power generation plants are taken into consideration, hence, the Integrated Environmental Control Model (IECM 8.0.2) is employed for a systematic estimation of plant performance, costs and emissions of different scenarios of fuel and CCS technologies.This study showed that the utilization of white wood pellets (WWP) in electricity generation can annually avoid about 3M tonnes CO2 emissions from a 650MW power plant. However, this mitigation process had impact on the plant efficiency and the cost of electricity. Further, the BECCS using white wood pellets has showed a better efficiency and lower cost of electricity with the oxy-fuel technology than the post-combustion CCS technology. However, in order to boost biomass energy CCS (BECCS) deployment with the WWP, an increase of the ROC for biomass power plants, or, an increase of the carbon price for the coal power plants is recommended. It was found that, the sensitivity of COE towards the ROC was higher than towards the carbon price variation. This result can be interpreted as the ROC has more positive impact than the carbon price, on the COE from the point of customers view without adding more burdens on the power generation companies.

Comparative techno-economic assessment and LCA of selected integrated sugarcane-based biorefineries

This work addresses the economic and environmental performance of integrated biorefineries based on sugarcane juice and residues. Four multiproduct scenarios were considered; two from sugar mills and the others from ethanol distilleries. They are integrated biorefineries producing first (1G) and second (2G) generation ethanol, sugar, molasses (for animal feed) and electricity in the context of Brazil. The scenarios were analysed and compared using techno-economic value-based approach and LCA methodology. The results show that the best economic configuration is provided by a scenario with largest ethanol production while the best environmental performance is presented by a scenario with full integration sugar – 1G2G ethanol production.

Feasibility study for thermal treatment of solid tire wastes in Bangladesh by using pyrolysis technology

In this study on the basis of lab data and available resources in Bangladesh, feasibility study has been carried out for pyrolysis process converting solid tire wastes into pyrolysis oils, solid char and gases. The process considered for detailed analysis was fixed-bed fire-tube heating pyrolysis reactor system. The comparative techno-economic assessment was carried out in US$ for three different sizes plants: medium commercial scale (144 tons/day), small commercial scale (36 tons/day), pilot scale (3.6 tons/day). The assessment showed that medium commercial scale plant was economically feasible, with the lowest unit production cost than small commercial and pilot scale plants for the production of crude pyrolysis oil that could be used as boiler fuel oil and for the production of upgraded liquid-products.