scholarly journals Environmental and Economic Assessment of Portable Systems: Production of Wood-Briquettes and Torrefied-Briquettes to Generate Heat and Electricity

Fuels ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 345-366
Author(s):  
Kamalakanta Sahoo ◽  
Sevda Alanya-Rosenbaum ◽  
Richard Bergman ◽  
Dalia Abbas ◽  
E. M. (Ted) Bilek

This study assessed the environmental impacts and economic feasibility of generating heat using wood-briquettes (WBs), and heat and electricity using torrefied-wood-briquettes (TWBs). WBs and TWBs were manufactured from forest residues using portable systems and delivered to either residential consumers or power plants in the United States. An integrated cradle-to-grave life-cycle assessment (LCA) and techno-economic analysis (TEA) approach was used to quantify environmental impacts and minimum-selling prices (MSPs) of heat and electricity, respectively. Results illustrated that 82% and 59% of the cradle-to-grave global warming (GW) impact of producing heat resulted from the feedstock preparation in WBs and torrefaction in TWBs, respectively. About 46–54% of total cost in the production of heat were from labor and capital costs only. The GW impact of electricity production with TWBs was dominated by the torrefaction process (48% contribution). Capital cost (50%) was a major contributor to the total cost of electricity production using TWBs. The GW impacts of producing heat were 7–37 gCO₂eq/MJ for WBs, and 14–51 gCO₂eq/MJ for TWBs, whereas producing electricity using TWBs was 146–443 gCO₂eq/kWhe. MSPs of generating heat from WBs and TWBs were €1.09–€1.73 and €1.60–€2.26/MJ, respectively, whereas the MSP of electricity from TWBs was €20–€25/kWhe. Considering carbon and pile-burn credits, MSPs of heat and electricity were reduced by 60–90% compared to the base-case.

Author(s):  
Bruce A. Young ◽  
Sang-Min Lee ◽  
Paul M. Scott

As a means of demonstrating compliance with the United States Code of Federal Regulations 10CFR50 Appendix A, General Design Criterion 4 (GDC-4) requirement that primary piping systems for nuclear power plants exhibit an extremely low probability of rupture, probabilistic fracture mechanics (PFM) software has become increasingly popular. One of these PFM codes for nuclear piping is Pro-LOCA which has been under development over the last decade. Currently, Pro-LOCA is being enhanced under an international cooperative program entitled PARTRIDGE-II (Probabilistic Analysis as a Regulatory Tool for Risk-Informed Decision GuidancE - Phase II). This paper focuses on the use of a pre-defined set of base-case inputs along with prescribed variation in some of those inputs to determine a comparative set of sensitivity analyses results. The benchmarking case was a circumferential Primary Water Stress Corrosion Crack (PWSCC) in a typical PWR primary piping system. The effects of normal operating loads, temperature, leak detection, inspection frequency and quality, and mitigation strategies on the rupture probability were studied. The results of this study will be compared to the results of other PFM codes using the same base-case and variations in inputs. This study was conducted using Pro-LOCA version 4.1.9.


2006 ◽  
Vol 17 (4) ◽  
pp. 19-24
Author(s):  
M T E Kahn ◽  
W Fritz

The World Summit on Sustainable Development (WSSD) was attended by approximately 21 000 international delegates in Johannesburg, South Africa in 2002. The aim was to institute ecologically sound environmental management. Research has shown that fossil fuel or coal fired power plants are the major cause of air pollution in electricity generation. This paper seeks to show technologies that can contribute to reducing the environmental impacts of electricity production, via emission control systems, industry energy policy, renewable energy technologies etc. and the promotion of active research and development in alternative energy applications in Africa. Innovative energy technology research and development and applications such as smaller scale distributed generation and solid state lighting (SSL) are seen as capable of adding a positive contribution in this area.


Mechanika ◽  
2020 ◽  
Vol 26 (3) ◽  
pp. 242-251
Author(s):  
M. AMANI ◽  
A. SMAILI ◽  
A. GHENAIET

The aim of this study is the thermo-economic assessments of an integrated solar combined cycle (ISCC) system, in terms of thermal efficiency, electricity production and levelized electricity cost (LCOE). During the day light the power plant operates as an ISCC and operates as a conventional combined cycle (CC) during the night or cloudy days. In one hand the obtained results show that at the design point the solar electricity ratio may reach about 17 % and the global thermal efficiency 63 %, leading to lower fuel consumption and carbon emission. On the other hand, the economic assessment depicts that LCOE may reach 0.0222 $/kWh, which is about 28 % higher than that of (CC) power plants. Furthermore, by introducing the environmental effect LCOE becomes equal to 0.0272 $/kWh which is higher. Therefore, the annual solar contribution relatively to this ISCC installation site will allow about 18.45 million $ of fuel saving, avoiding emission of 0.89 million ton of CO2 over 30 years operation.


2021 ◽  
Vol 2021 ◽  
pp. 1-25
Author(s):  
Shadwan M. M. Esmail ◽  
Jae Hak Cheong

In the planning and management of the interim storage of spent nuclear fuel, the technical and economic parameters that are involved have a significant role in increasing the efficiency of the storage system. Optimal parameters will reduce the total economic costs for countries embarking on nuclear energy, such as the UAE. This study evaluated the design performance and economic feasibility of various structures and schedules, to determine an optimal combination of parameters for the management of spent nuclear fuel. With the introduction of various storage technology arrangements and expected costs per unit for the storage system design, we evaluated eight major scenarios, each with a cost analysis based on technological and economic issues. We executed a number of calculations based on the use of these storage technologies, and considered their investment costs. These calculations, which were aligned with the net present value approach and conducted using MS Project and MATLAB software programs, considered the capacities of the spent fuel pools and the amount of spent nuclear fuel (SNF) that will be transferred to dry storage facilities. As soon as they sufficiently cool, the spent nuclear fuel is to be stored in a pool storage facility. The results show that applying a centralized dry storage (CDS) system strategy is not an economically feasible solution, compared with using a permanent disposal facility (PDF) (unless the variable investment cost is reduced or changed). The optimal strategy involves operating a spent fuel pool island (SFPI) storage after the first 20 years of the start of the permanent shutdown of the reactor. After 20 years, the spent fuel is then transferred to a PDF. This strategy also results in a 20.9% to 26.1% reduction in the total cost compared with those of the other strategies. The total cost of the proposed strategy is approximately 4,307 million USD. The duration of the fuel storage and the investment cost, particularly the variable investment cost, directly affect the choice of facility storage.


Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 351
Author(s):  
Yuxi Wang ◽  
Jingxin Wang ◽  
Xufeng Zhang ◽  
Debangsu Bhattacharyya ◽  
Edward M. Sabolsky

Activated carbons (AC) from lignocellulosic biomass feedstocks are used in a broad range of applications, especially for electrochemical devices such as supercapacitor electrodes. Limited studies of environmental and economic impacts for AC supercapacitor production have been conducted. Thus, this paper evaluated the environmental and economic impacts of AC produced from lignocellulosic biomass for energy-storage purposes. The life cycle assessment (LCA) was employed to quantify the potential environmental impacts associated with AC production via the proposed processes including feedstock establishment, harvest, transport, storage, and in-plant production. A techno-economic model was constructed to analyze the economic feasibility of AC production, which included the processes in the proposed technology, as well as the required facility installation and management. A base case, together with two alternative scenarios of KOH-reuse and steam processes for carbon activation, were evaluated for both environmental and economic impacts, while the uncertainty of the net present value (NPV) of the AC production was examined with seven economic indicators. Our results indicated that overall “in-plant production” process presented the highest environmental impacts. Normalized results of the life-cycle impact assessment showed that the AC production had environmental impacts mainly on the carcinogenics, ecotoxicity, and non-carcinogenics categories. We then further focused on life cycle analysis from raw biomass delivery to plant gate, the results showed that “feedstock establishment” had the most significant environmental impact, ranging from 50.3% to 85.2%. For an activated carbon plant producing 3000 kg AC per day in the base case, the capital cost would be USD 6.66 million, and annual operation cost was found to be USD 15.46 million. The required selling price (RSP) of AC was USD 16.79 per kg, with the discounted payback period (DPB) of 9.98 years. Alternative cases of KOH-reuse and steam processes had GHG emissions of 15.4 kg CO2 eq and 10.2 kg CO2 eq for every 1 kg of activated carbon, respectively. Monte Carlo simulation showed 49.96% of the probability for an investment to be profitable in activated carbon production from lignocellulosic biomass for supercapacitor electrodes.


Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3637
Author(s):  
Eduardo Leiva ◽  
Carolina Rodríguez ◽  
Rafael Sánchez ◽  
Jennyfer Serrano

Water scarcity is causing a great impact on the population. Rural areas are most affected by often lacking a stable water supply, being more susceptible to the impact of drought events, and with greater risk of contamination due to the lack of appropriate water treatment systems. Decentralized greywater treatment systems for water reuse in rural areas can be a powerful alternative to alleviate these impacts. However, the economic feasibility of these systems must be thoroughly evaluated. This study reports an economic analysis carried out on the viability of greywater reuse considering scenarios with light greywater or dark greywater to be treated. For this, data obtained from the assembly and monitoring of greywater treatment systems located in the north-central zone of Chile, supplemented with data obtained from the literature were used. The results showed that both scenarios are not economically viable, since the investment and operating costs are not amortized by the savings in water. In both evaluated cases (public schools), the economic indicators were less negative when treating light greywater compared with the sum of light greywater and dark greywater as the inlet water to be treated. The investment and operating costs restrict the implementation of these water reuse systems, since in the evaluation period (20 years) a return on the initial investment is not achieved. Even so, our results suggest that the best alternative to reuse greywater in small-scale decentralized systems is to treat light greywater, but it is necessary to consider a state subsidy that not only supports capital costs but also reduces operating and maintenance costs. These findings support the idea that the type of water to be treated is a factor to consider in the implementation of decentralized greywater treatment systems for the reuse of water in rural areas and can help decision-making on the design and configuration of these systems.


Author(s):  
Patricia Seevam ◽  
Julia Race ◽  
Martin Downie ◽  
Julian Barnett ◽  
Russell Cooper

Climate change has been attributed to green house gases, with carbon dioxide (CO2) being the main contributor. Sixty to seventy percent of carbon dioxide emissions originate from fossil fuel power plants. Power companies in the UK, along with oil and gas field operators, are proposing to capture this anthropogenic CO2 and either store it in depleted reservoirs or saline aquifers (carbon capture and storage, CCS), or use it for ‘Enhanced Oil Recovery’ (EOR) in depleting oil and gas fields. This would involve extensive onshore and offshore pipeline systems. The decline of oil and gas production of reservoirs beyond economic feasibility will require the decommissioning onshore and offshore facilities post-production. This creates a possible opportunity for using existing pipeline infrastructure. Conversions of pipelines from natural gas service to CO2 service for EOR have been done in the United States. However, the differing sources of CO2 and the differing requirements for EOR and CCS play a significant part in allowing the re-use of existing infrastructure. The effect of compositions, the phase of transportation, the original pipeline specifications, and also the pipeline route require major studies prior to allowing re-use. This paper will first review the requirements for specifying the purity of the CO2 for CCS and to highlight the implications that the presence of impurities and the current water specifications for pipelines has on the phase diagram and the associated physical properties of the CO2 stream. A ‘best’ and ‘worst’ case impurity specification will be identified. Then an analysis on the impact and subsequent validation, of equations of state based on available experimental data on the phase modelling of anthropogenic CO2 is presented. A case study involving an existing 300km gas pipeline in the National Transmission System (NTS) in the UK is then modelled, to demonstrate the feasibility of using this pipeline to transport anthropogenic CO2. The various issues involved for the selected ‘best’ and ‘worst’ case specification are also covered. This is then followed by an investigation of the options for transport in the ‘gas’ phase and ‘supercritical’ phases, and also identifying the limitations on re-using pipeline infrastructure for CCS.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2576
Author(s):  
Cristina Moliner ◽  
Elisabetta Arato ◽  
Filippo Marchelli

This work analyses and discusses data on thermochemical plants in Southern Italy that are fed with solid biomass. The analysis takes into account the biomass availability and potential together with the cost-benefit analysis using technology development and economic indicators (LCOE). A total of 63,762 units have been categorised according to the employed technology and produced energy: power plants for electricity production or cogeneration plants for combined heat and electricity production (53 plants) and thermal units for heat production (63,709 units). The eight regions of the area have noteworthy differences. In terms of electricity generated from solid biomass Calabria is by far the largest producer, followed by Apulia. Sicily, Sardinia and Molise provide lower amounts while Abruzzo, Basilicata and Campania generate almost negligible amounts. Regarding thermal production, Campania and Calabria are the largest producers, but Basilicata, Molise and Abruzzo generate the highest amount per capita. The area is far from fully exploiting its biomass potential, and there are also no district heating grids. Bioenergy can be remarkably competitive, provided that capital costs are relatively low and low-cost biomass is available, as it is the case of Italy. New applications and markets for sub-products (i.e., char, ash) would help in lowering the still not competitive economic indicators (LCOE).


2020 ◽  
Author(s):  
Esmaeili Shayan Mostafa ◽  
Ghasemzadeh Farzaneh

Both solar energy and nuclear energy face significant economic challenges. Sustainable energy costs have traditionally been greater than any of those associated with the growth of fossil fuel power generation, although the costs of renewable energy technologies (especially photovoltaic) have dropped. Furthermore, capital costs remain a big challenge in the nuclear generation. In many nations, the cost of building small nuclear power plants is quite large due to time, technology, and environmental and safety challenges for consumers. Such problems might not be as big for state-owned corporations or controlled industries for which utilities have quick access to cheap resources, and this partially explains why the interest for nuclear reactors in Asia is far greater than in the United States or Europe. Learning could help decrease costs for both types of technologies, but the track record for learning-by-doing in the nuclear sector is not good.


2020 ◽  
pp. 2150001
Author(s):  
JENNIFER MORRIS ◽  
HAROON KHESHGI ◽  
SERGEY PALTSEV ◽  
HOWARD HERZOG

Using the MIT Economic Projection and Policy Analysis (EPPA) model, we explore factors influencing carbon capture and storage (CCS) deployment in power generation and its role in mitigating carbon emissions. We find that in the 2∘C scenario with EPPA’s base-case technology cost and performance assumptions, CCS plays an important role in the second half of the century: by 2100 CCS is applied to almost 40% of world electricity production, with a third coming from coal with CCS and the other two-thirds from gas with CCS. Results on CCS deployment depend on the assumed fraction of carbon captured in CCS power plants, as emissions constraints get tighter and the carbon price rises. Adding options for higher capture fractions or offsetting uncaptured emissions leads to greater deployment of CCS than in the 2∘C base case. We provide a sensitivity analysis by making favorable assumptions for CCS, nuclear and renewables. We also explore regional differences in the deployment of CCS. We find that US and Europe mostly rely on gas CCS, whereas China relies on coal CCS and India pursues both options. We also assess how these projections align with assessment of CO2 storage potential, and find that storage potential is larger than storage demand at both global and regional scales. Ultimately, we find that under stringent mitigation scenarios, the power sector relies on a mix of technological options, and the conditions that favor a particular mix of technologies differ by region.


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