scholarly journals On the Application of Small-Scale Turbines in Industrial Steam Networks

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3149
Author(s):  
Ansgar Weickgenannt ◽  
Ivan Kantor ◽  
François Maréchal ◽  
Jürg Schiffmann
Keyword(s):  
Energy Efficiency ◽  
Design Guidelines ◽  
Economic Feasibility ◽  
Small Scale ◽  
Economic Potential ◽  
Exergy Destruction ◽  
Thermodynamic Process ◽  
Industrial Data ◽  
Specific Investment ◽  
Wide Energy

This study investigates the technical and economic feasibility of replacing throttling valves with smale-scale, oil-free turbomachinery in industrial steam networks. This is done from the perspective of the turbomachine, which has to be integrated into a new or existing process. The considered machines have a power range of P=[0.5,…,250 kW] and have been designed using real industrial data from existing processes. Design guidelines are developed, which take into account the thermodynamic process as well as engineering aspects of such a turbomachine. The results suggest that steam conditioning prior to heat exchange could be completed by small expanders to produce mechanical work, reducing exergy destruction and improving site-wide energy efficiency compared to throttling valves. Cost estimates for such machines are presented, which serve as a basis for case-specific investment calculations. The resulting payback times of less than 18 months highlight the economic potential such solutions.

scholarly journals Performance Enhancement of Nitrogen Dual Expander and Single Mixed Refrigerant LNG Processes Using Jaya Optimization Approach

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3278
Author(s):  
Ali Rehman ◽  
Muhammad Abdul Qyyum ◽  
Ashfaq Ahmad ◽  
Saad Nawaz ◽  
Moonyong Lee ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Natural Gas ◽  
Design Optimization ◽  
Lower Energy ◽  
Operating Costs ◽  
Small Scale ◽  
Exergy Destruction ◽  
Capital Costs ◽  
Design Variables

The nitrogen (N2) expander and single mixed refrigerant (SMR) liquefaction processes are recognized as the most favorable options to produce liquefied natural gas (LNG) at small-scale and offshore sites. These processes have a simple and compact design that make them efficient with respect to their capital costs. Nevertheless, huge operating costs, mainly due to their lower energy efficiency, remains an ongoing issue. Utilization of design variables having non-optimal values is the primary cause for the lower energy efficiency; which, in turn, leads to exergy destruction (i.e., entropy generation), and ultimately the overall energy consumption is increased. The optimal execution of the design variables of LNG processes can be obtained through effective design optimization. However, the complex and highly non-linear interactions between design variables (refrigerant flowrates and operating pressures) and objective function (overall energy consumption) make the design optimization a difficult and challenging task. In this context, this study examines a new optimization algorithm, named “Jaya”, to reduce the operating costs of nitrogen dual expander and SMR LNG processes. The Jaya approach is an algorithm-specific parameter-less optimization methodology. It was found that by using the Jaya algorithm, the energy efficiency of the SMR process and nitrogen dual expander natural gas (NG) liquefaction process can be enhanced up to 14.3% and 11.6%, respectively, as compared to their respective base cases. Using the Jaya approach, significant improved results were observed even compared to other previously used optimization approaches for design optimization. Results of conventional exergy analysis revealed that the exergy destruction of SMR and N2 dual expander process can be reduced by 17.4% and 14%, respectively. Moreover, economic analysis identified the 13.3% and 11.6% relative operating costs savings for SMR and N2 dual expander LNG processes, respectively.

scholarly journals Feasibility Study of Plasma-Catalytic Ammonia Synthesis for Energy Storage Applications

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 999
Author(s):  
Kevin H. R. Rouwenhorst ◽  
Leon Lefferts
Keyword(s):  
Energy Efficiency ◽  
Ammonia Synthesis ◽  
Fast Response ◽  
Economic Feasibility ◽  
Small Scale ◽  
Plasma Catalysis ◽  
Case Scenario ◽  
Load Variations ◽  
Product Separation ◽  
Catalytic Ammonia Synthesis

Plasma catalysis has recently gained traction as an alternative to ammonia synthesis. The current research is mostly fundamental and little attention has been given to the technical and economic feasibility of plasma-catalytic ammonia synthesis. In this study, the feasibility of plasma-catalytic ammonia is assessed for small-scale ammonia synthesis. A brief summary of the state of the art of plasma catalysis is provided as well as a targets and potential avenues for improvement in the conversion to ammonia, ammonia separation and a higher energy efficiency. A best-case scenario is provided for plasma-catalytic ammonia synthesis and this is compared to the Haber-Bosch ammonia process operated with a synthesis loop. An ammonia outlet concentration of at least 1.0 mol. % is required to limit the recycle size and to allow for efficient product separation. From the analysis, it follows that plasma-catalytic ammonia synthesis cannot compete with the conventional process even in the best-case scenario. Plasma catalysis potentially has a fast response to intermittent renewable electricity, although low pressure absorbent-enhanced Haber-Bosch processes are also expected to have fast responses to load variations. Low-temperature thermochemical ammonia synthesis is expected to be a more feasible alternative to intermittent decentralized ammonia synthesis than plasma-catalytic ammonia synthesis due to its superior energy efficiency.

Techno-economic feasibility study on the application of downdraft gasifier in small-scale red clay bricks industries

2021 ◽  
Author(s):  
Murugan Paradesi Chockalingam ◽  
Navaneethakrishnan Palanisamy ◽  
Saji Raveendran Padmavathy ◽  
Edwin Mohan ◽  
Beno Wincy Winsly ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Economic Feasibility ◽  
Small Scale ◽  
Red Clay ◽  
Downdraft Gasifier ◽  
Clay Bricks

scholarly journals Resources, Production Scales and Time Required for Producing RNA Vaccines for the Global Pandemic Demand

Vaccines ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
Zoltán Kis ◽  
Cleo Kontoravdi ◽  
Robin Shattock ◽  
Nilay Shah
Keyword(s):  
Production Process ◽  
Messenger Rna ◽  
Vaccination Campaign ◽  
Vaccine Dose ◽  
Economic Feasibility ◽  
Small Scale ◽  
Production Scale ◽  
Working Volume ◽  
Global Demand ◽  
The Impact

To overcome pandemics, such as COVID-19, vaccines are urgently needed at very high volumes. Here we assess the techno-economic feasibility of producing RNA vaccines for the demand associated with a global vaccination campaign. Production process performance is assessed for three messenger RNA (mRNA) and one self-amplifying RNA (saRNA) vaccines, all currently under clinical development, as well as for a hypothetical next-generation saRNA vaccine. The impact of key process design and operation uncertainties on the performance of the production process was assessed. The RNA vaccine drug substance (DS) production rates, volumes and costs are mostly impacted by the RNA amount per vaccine dose and to a lesser extent by the scale and titre in the production process. The resources, production scale and speed required to meet global demand vary substantially in function of the RNA amount per dose. For lower dose saRNA vaccines, global demand can be met using a production process at a scale of below 10 L bioreactor working volume. Consequently, these small-scale processes require a low amount of resources to set up and operate. RNA DS production can be faster than fill-to-finish into multidose vials; hence the latter may constitute a bottleneck.

scholarly journals Techno-Economic Feasibility Study of Renewable Power Systems for a Small-Scale Plasma-Assisted Nitric Acid Plant in Africa

Processes ◽  
2016 ◽  
Vol 4 (4) ◽  
pp. 54 ◽  
Author(s):  
Aikaterini Anastasopoulou ◽  
Sughosh Butala ◽  
Bhaskar Patil ◽  
John Suberu ◽  
Martin Fregene ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Power Systems ◽  
Feasibility Study ◽  
Economic Feasibility ◽  
Small Scale ◽  
Acid Plant ◽  
Renewable Power

Economic performance of organic vs conventional vegetables production in Gaza strip

2014 ◽  
Vol 2 (2) ◽  
pp. 9-18
Author(s):  
Ahmed Abu Shaban
Keyword(s):  
Organic Farming ◽  
Gaza Strip ◽  
Farming System ◽  
Organic Production ◽  
Economic Feasibility ◽  
Production Costs ◽  
Economic Potential ◽  
Vegetable Crops ◽  
Gross Margin ◽  
Lower Production

Organic farming has achieved significant growth in developing countries. However, it is still in some areas such as Gaza strip at embryonic stage. Introduction and promotion of organic farming would need more information about economic feasibility of shifting from the existing conventional farms to organic farming system. This is the main aim of this study. Data was collected from 100 randomly selected farmers in southern area of Gaza strip using standard questionnaire. Additional focus group discussions were conducted for further qualitative analyses. Data was also collected from the organic farm of Safe Agriculture Association where vegetables are organically produced and marketed. Gross margin and comparative analyses were used to describe cost structure of conventional and organic production and to assess economic potentialities to shift to organic farming. Results varied among vegetable crops as some crops showed very high economic potential to shift to organic farming while other crops did not. Major reasons for crops with good potential were higher yield under organic farming, premium market prices and lower production costs. Major reasons for lower economic potential to shift were the significant lower yield and higher production costs. The study recommends further technical research to explore organic production techniques that allows for higher yield and lower production cost. The study also recommends further market research to investigate consumers' preferences and willingness to pay for organic products.

scholarly journals U.S. Kiwifruit Industry Model: Annual Supply and Monthly Demand

2000 ◽  
Vol 32 (3) ◽  
pp. 479-491
Author(s):  
Hikaru Hanawa Peterson ◽  
Lois Schertz Willett
Keyword(s):  
Empirical Analysis ◽  
Fruit Quality ◽  
Econometric Model ◽  
Economic Feasibility ◽  
Small Scale ◽  
The U.S

AbstractA dynamic econometric model of the U.S. kiwifruit industry provides a framework for empirical analysis of small-scale commodities, particularly those used by producers for diversification. Production and marketing processes are explained by annual and monthly components, respectively. Results confirm that plantings were speculative and that economic feasibility critically impacts acreage retention as the industry matures. Prices at alternative outlets and fruit quality in storage affect monthly shipments. Flexibilities of monthly f.o.b. prices imply elastic kiwifruit demand, and imports are found to be substitutes. The industry could increase its average annual gross revenue by marketing the crop earlier in the season.

scholarly journals Influence of Large Relative Tip Clearances for a Micro Radial Fan and Design Guidelines for Increased Efficiency

2020 ◽  
Author(s):  
Patrick H. Wagner ◽  
Jan Van herle ◽  
Lili Gu ◽  
Jürg Schiffmann
Keyword(s):  
Pressure Rise ◽  
Leading Edge ◽  
High Sensitivity ◽  
Design Guidelines ◽  
Tip Clearance ◽  
Small Scale ◽  
Blade Tip ◽  
Dynamics Simulations ◽  
Experimental Findings ◽  
Blade Tip Clearance

Abstract The blade tip clearance loss was studied experimentally and numerically for a micro radial fan with a tip diameter of 19.2mm. Its relative blade tip clearance, i.e., the clearance divided by the blade height of 1.82 mm, was adjusted with different shims. The fan characteristics were experimentally determined for an operation at the nominal rotational speed of 168 krpm with hot air (200 °C). The total-to-total pressure rise and efficiency increased from 49 mbar to 68 mbar and from 53% to 64%, respectively, by reducing the relative tip clearance from 7.7% to the design value of 2.2%. Single and full passage computational fluid dynamics simulations correlate well with these experimental findings. The widely-used Pfleiderer loss correlation with an empirical coefficient of 2.8 fits the numerical simulation and the experiments within +2 efficiency points. The high sensitivity to the tip clearance loss is a result of the design specific speed of 0.80, the highly-backward curved blades (17°), and possibly the low Reynolds number (1 × 105). The authors suggest three main measures to mitigate the blade tip clearance losses for small-scale fans: (1) utilization of high-precision surfaced-grooved gas-bearings to lower the blade tip clearance, (2) a mid-loaded blade design, and (3) an unloaded fan leading edge to reduce the blade tip clearance vortex in the fan passage.

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