Analysis of a Solar-Aided Natural Gas Cogeneration Plant Applied to the Textile Sector

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Juan Sebastián Zuleta Marín ◽  
Eduardo Konrad Burin ◽  
Edson Bazzo
Keyword(s):  
Natural Gas ◽  
Steam Generator ◽  
Internal Combustion Engines ◽  
Net Present Value ◽  
Hot Water ◽  
Saturated Steam ◽  
Base Case ◽  
Promising Alternative ◽  
Chilled Water ◽  
Hybrid Concept

Abstract Two combined cooling heating power (CCHP) plant layouts are proposed to supply the electricity, heat, and cooling energy demands of textile industries. In the first scenario, natural gas fueled internal combustion engines are integrated with a heat recovery steam generator (HRSG) and a hot water absorption chiller to produce electricity, saturated steam, and chilled water for air conditioning purposes. In the second concept, a linear Fresnel solar field is integrated with the same CCHP to provide fuel economy during the sunny hours. The proposed plants were compared with a base case scenario in which electricity is imported from the grid, saturated steam is provided by a natural gas steam generator (NGSG), and chilled water is provided by electric chillers. Simulations were performed considering mass and energy conservation equations, information provided by equipment manufacturers and typical meteorological year (TMY) data sets for three different locations. The economic performance of plants was evaluated by calculating the net present value (NPV), the internal rate of return (IRR), and the discounted payback period (DPP) of investments. As an important result, a great potential for reducing the fuel consumption and CO2 emissions of hybrid concept was identified. However, the high investment of Fresnel collectors coupled with low natural gas prices showed the proposed hybrid concept as economically unfeasible. Nevertheless, it is expected that hybrid systems will have an important role once Fresnel technology costs are continuously declining and solar energy appears as a promising alternative for the sustainable transition to a low carbon future.

Detonation development from a hot spot in methane/air mixtures: Effects of kinetic models

2020 ◽  
pp. 146808742094461
Author(s):  
Jingyi Su ◽  
Peng Dai ◽  
Zheng Chen
Keyword(s):  
Natural Gas ◽  
Kinetic Models ◽  
Reaction Front ◽  
Internal Combustion Engines ◽  
Hot Spot ◽  
Thermal Sensitivity ◽  
Front Propagation ◽  
Low Carbon ◽  
Promising Alternative ◽  
Detonation Development

Natural gas is a promising alternative fuel which can be used in internal combustion engines to achieve low carbon emission and high thermal efficiency. However, at high compression ratio, super-knock due to detonation development might occur. In this study, the autoignitive reaction front propagation and detonation development from a hot spot were investigated numerically and the main component of natural gas, methane, was considered. The objective is to assess the performance of different kinetic models in terms of predicting hot spot–induced detonation development in methane/air mixtures. First, simulations for the constant-volume homogeneous ignition in a stoichiometric methane/air mixture were conducted. The ignition delay time, excitation time, critical temperature gradient, thermal sensitivity and reduced activation energy predicted by different kinetic models were obtained and compared. It was found that there are notable discrepancies among the predictions by different kinetic models. Then, hundreds of one-dimensional simulations were conducted for detonation development from a hot spot in a stoichiometric CH4/air mixture. Different autoignition modes were identified and the detonation regimes were derived based on the peak pressure and reaction front propagation speed. It was found that even at the same conditions, different propagation modes can be predicted by different kinetic models. The broadest detonation development regime was predicted by the reduced GRI mechanism, while a relatively narrow regime was predicted by the recent kinetic models such as FFCM-1 and Aramco 3.0. The present results indicate that super-knock prediction strongly depends on the kinetic model used in simulations. Therefore, significant efforts should be devoted to the development and validation of kinetic models for natural gas at engine conditions.

scholarly journals Thermodynamic and Economic Feasibility of Energy Recovery from Pressure Reduction Stations in Natural Gas Distribution Networks

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4453 ◽  
Author(s):  
Piero Danieli ◽  
Gianluca Carraro ◽  
Andrea Lazzaretto
Keyword(s):  
Natural Gas ◽  
Energy Recovery ◽  
Internal Combustion Engines ◽  
Large Scale ◽  
Net Present Value ◽  
Energy Content ◽  
Distribution Networks ◽  
Economic Feasibility ◽  
Pressure Reduction ◽  
Gas Distribution

A big amount of the pressure energy content in the natural gas distribution networks is wasted in throttling valves of pressure reduction stations (PRSs). Just a few energy recovery systems are currently installed in PRSs and are mostly composed of radial turboexpanders coupled with cogeneration internal combustion engines or gas-fired heaters providing the necessary preheating. This paper clarifies the reason for the scarce diffusion of energy recovery systems in PRSs and provides guidelines about the most feasible energy recovery technologies. Nine thousand PRSs are monitored and allocated into 12 classes, featuring different expansion ratios and available power. The focus is on PRSs with 1-to-20 expansion ratio and 1-to-500 kW available power. Three kinds of expanders are proposed in combination with different preheating systems based on boilers, heat pumps, or cogeneration engines. The goal is to identify, for each class, the most feasible combination by looking at the minimum payback period and maximum net present value. Results show that small size volumetric expanders with low expansion ratios and coupled with gas-fired heaters have the highest potential for large-scale deployment of energy recovery from PRSs. Moreover, the total recoverable energy using the feasible recovery systems is approximately 15% of the available energy.

scholarly journals Financial viability and environmental aspects in the selection of energy sources for sanitary hot water (SHW) and heated swimming pools

2019 ◽  
pp. 46-70
Author(s):  
Angeles Longarela-Ares
Keyword(s):  
Natural Gas ◽  
Alternative Energy ◽  
Net Present Value ◽  
Renewable Energy Sources ◽  
High Energy ◽  
Point Of View ◽  
Hot Water ◽  
Energy Sources ◽  
Financial Viability ◽  
Viability Analysis

Sustainability and energy efficiency are topics of great interest, especially in the sports facilities management sector due to the high energy costs. One of the MOST Relevant costs is derived from the consumption of domestic hot water (DHW) and swimming pool. The objective of This work is to study new ways to manage and reduce costs through the These valuation of the use of traditional and renewable energy sources and the Necessary investment to Contribute to the promotion of a more sustainable vision of business management. Four alternative energy installations (Natural Gas, Biomass, Solar Thermal Combined With Natural Gas or Biomass) are Proposed, it is verified Which is more suitable in terms of financial viability and one of them is selected. For This purpose, we start from a hypothetical companycase and a 20-year forecast of the energy consumption, the costs and initial investment of each alternative is made; viability analysis are performed With the Net Present Value (NPV) and the results are Obtained Compared. The Conclusion Is That The most Appropriate solution, from a financial point of view, for sports centers similar to the company-case and With the Considered Circumstances, is the installation of Biomass, an option That, in Addition, can be Considered respectful With the environment.

A phenomenological model for the description of unburned hydrocarbons emission in ultra-lean engines

2021 ◽  
pp. 146808742110050
Author(s):  
Enrica Malfi ◽  
Vincenzo De Bellis ◽  
Fabio Bozza ◽  
Alberto Cafari ◽  
Gennaro Caputo ◽  
...  
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Pollutant Emissions ◽  
Average Error ◽  
Combustion Engines ◽  
Nitric Oxides ◽  
Lean Burn ◽  
Fuel Charge ◽  
Unburned Hydrocarbons ◽  
Model Reliability

The adoption of lean-burn concepts for internal combustion engines working with a homogenous air/fuel charge is under development as a path to simultaneously improve thermal efficiency, fuel consumption, nitric oxides, and carbon monoxide emissions. This technology may lead to a relevant emission of unburned hydrocarbons (uHC) compared to a stoichiometric engine. The uHC sources are various and the relative importance varies according to fuel characteristics, engine operating point, and some geometrical details of the combustion chamber. This concern becomes even more relevant in the case of engines supplied with natural gas since the methane has a global warming potential much greater than the other major pollutant emissions. In this work, a simulation model describing the main mechanisms for uHC formation is proposed. The model describes uHC production from crevices and flame wall quenching, also considering the post-oxidation. The uHC model is implemented in commercial software (GT-Power) under the form of “user routine”. It is validated with reference to two large bore engines, whose bores are 31 and 46 cm (engines named accordingly W31 and W46). Both engines are fueled with natural gas and operated with lean mixtures (λ > 2), but with different ignition modalities (pre-chamber device or dual fuel mode). The engines under study are preliminarily schematized in the 1D simulation tool. The consistency of 1D engine schematizations is verified against the experimental data of BMEP, air flow rate, and turbocharger rotational speed over a load sweep. Then, the uHC model is validated against the engine-out measurements. The averaged uHC predictions highlight an average error of 7% and 10 % for W31 and W46 engines, respectively. The uHC model reliability is evidenced by the lack of need for a case-dependent adjustment of its tuning constants, also in presence of relevant variations of both engine load and ring pack design.

scholarly journals The Efficiency of Large Hole Boring (MSP) Method in the Reduction of Blast-Induced Vibration

2021 ◽  
Vol 11 (4) ◽  
pp. 1814
Author(s):  
Min Seong Kim ◽  
Sean Seungwon Lee
Keyword(s):  
Urban Areas ◽  
Cost Effective ◽  
Base Case ◽  
Large Hole ◽  
Promising Alternative ◽  
Geological Information ◽  
Drill And Blast ◽  
Smooth Blasting ◽  
Alternative Designs ◽  
Blasting Method

Drill and blast is the most cost-effective excavation method for underground construction, however, vibration and noise, induced by blasting, have been consistently reported as problems. Cut blasting has been widely employed to reduce the blast-induced problems during underground excavation. We propose that the large hole boring method using the state-of-the-art MSP (Multi-setting smart-investigation of the ground and pre-large hole boring) machine (“MSP method”) can efficiently improve vibration reduction. The MSP machine will be used to create 382 mm diameter empty holes at the tunnel cut area for this purpose. This study assessed the efficiency of the MSP method in reducing blast-induced vibration in five blasting patterns using a cylinder-cut, which is a traditional cut blasting method. The controlled blasting patterns using the MSP method demonstrated up to 72% reduction in blast-induced vibration, compared to the base case, Pattern B, where only cylinder-cut and smooth blasting method were applied. Therefore, the MSP method proves to be a promising alternative for blasting in sensitive urban areas where non-vibration excavation techniques were initially considered. Geological characteristics of 50 m beyond the excavation face can be acquired through the proposed real-time boring data monitoring system together with a borehole alignment tracking and ground exploration system. The obtained geological information will be a great help in preparing alternative designs, and scheduling of construction equipment and labour during the tunnel construction.

scholarly journals Solar Integrated Anaerobic Digester: Energy Savings and Economics

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4292
Author(s):  
Lidia Lombardi ◽  
Barbara Mendecka ◽  
Simone Fabrizi
Keyword(s):  
Anaerobic Digestion ◽  
Natural Gas ◽  
Economic Analysis ◽  
Thermal Energy ◽  
Economic Feasibility ◽  
Solar Thermal ◽  
Base Case ◽  
Economic Sustainability ◽  
Solar Thermal Energy ◽  
Solar Integration

Industrial anaerobic digestion requires low temperature thermal energy to heat the feedstock and maintain temperature conditions inside the reactor. In some cases, the thermal requirements are satisfied by burning part of the produced biogas in devoted boilers. However, part of the biogas can be saved by integrating thermal solar energy into the anaerobic digestion plant. We study the possibility of integrating solar thermal energy in biowaste mesophilic/thermophilic anaerobic digestion, with the aim of reducing the amount of biogas burnt for internal heating and increasing the amount of biogas, further upgraded to biomethane and injected into the natural gas grid. With respect to previously available studies that evaluated the possibility of integrating solar thermal energy in anaerobic digestion, we introduce the topic of economic sustainability by performing a preliminary and simplified economic analysis of the solar system, based only on the additional costs/revenues. The case of Italian economic incentives for biomethane injection into the natural gas grid—that are particularly favourable—is considered as reference case. The amount of saved biogas/biomethane, on an annual basis, is about 4–55% of the heat required by the gas boiler in the base case, without solar integration, depending on the different considered variables (mesophilic/thermophilic, solar field area, storage time, latitude, type of collector). Results of the economic analysis show that the economic sustainability can be reached only for some of the analysed conditions, using the less expensive collector, even if its efficiency allows lower biomethane savings. Future reduction of solar collector costs might improve the economic feasibility. However, when the payback time is calculated, excluding the Italian incentives and considering selling the biomethane at the natural gas price, its value is always higher than 10 years. Therefore, incentives mechanism is of great importance to support the economic sustainability of solar integration in biowaste anaerobic digestion producing biomethane.

Natural gas as a promising alternative fuel for passenger cars

2003 ◽  
Vol 2 (2) ◽  
pp. 184 ◽  
Author(s):  
Alia A. Shakour ◽  
Ahmed A. El-Abssawy ◽  
Yasser H. Ibrahim
Keyword(s):  
Natural Gas ◽  
Alternative Fuel ◽  
Passenger Cars ◽  
Promising Alternative

Effects of Natural Gas Compositions on Engine In-Cylinder Process

2015 ◽  
Vol 1092-1093 ◽  
pp. 498-503
Author(s):  
La Xiang ◽  
Yu Ding
Keyword(s):  
Natural Gas ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Engine Performance ◽  
Maximum Temperature ◽  
Maximum Pressure ◽  
Test Bed ◽  
Promising Alternative ◽  
Natural Gas Engines ◽  
Lower Maximum

Natural gas (NG) is one of the most promising alternative fuels of diesel and petrol because of its economics and environmental protection. Generally the NG engine share the similar structure profile with diesel or petrol engine but the combustion characteristics of NG is varied from the fuels, so the investigation of NG engine combustion process receive more attentions from the researchers. In this paper, a zero-dimensional model on the basis of Vibe function is built in the MATLAB/SIMULINK environment. The model provides the prediction of combustion process in natural gas engines, which has been verified by the experimental data in the NG test bed. Furthermore, the influence of NG composition on engine performance is investigated, in which the in-cylinder maximum pressure and temperature and mean indicated pressure are compared using different type NG. It is shown in the results that NG with higher composition of methane results in lower maximum temperature and mean indicated pressure as well as higher maximum pressure.

scholarly journals Effect of Hot-Water Blanching Pretreatment on Drying Characteristics and Product Qualities for the Novel Integrated Freeze-Drying of Apple Slices

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hai-ou Wang ◽  
Qing-quan Fu ◽  
Shou-jiang Chen ◽  
Zhi-chao Hu ◽  
Huan-xiong Xie
Keyword(s):  
Electron Microscopy ◽  
Freeze Drying ◽  
Hot Water ◽  
The Novel ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Drying Characteristics ◽  
Promising Alternative ◽  
Freeze Dried ◽  
Apple Slices

The effect of hot-water blanching (HWB) on drying characteristics and product qualities of dried apple slices with the novel integrated freeze-drying (NIFD) process was investigated by comparing with 3 different FD methods. Compared with the NIFD process without HWB pretreatment (VF-FD), the NIFD process with HWB pretreatment (HWB-VF-FD) resulted in a significantly higher mass loss and more sufficient freezing in vacuum-frozen samples, significantly higher rehydration ratio (RR), higher shrinkage ratio (SR), smaller Vitamin C (VC) content and lower hardness and better apparent shape in freeze-dried samples, and fewer change to the color of the dried or rehydrated samples (p<0.05). Compared with the conventional FD process with HWB pretreatment (HWB-PF-FD), HWB-VF-FD cost significantly less processing time and FD time and obtained significantly higher RR (p<0.05), almost the equivalent SR, VC content, and hardness, and similar appearance in dried samples. The microstructure of apple cell tissues was analyzed by transmission electron microscopy and scanning electron microscopy to interpret the above differences in drying characteristics and product qualities. The results suggested that the NIFD process of apple slices with HWB pretreatment was a promising alternative method to decrease drying time, achieve similar product quality, and simplify the process steps of the conventional FD technology.

Undersaturated Hydrocarbon Reservoir Waterflooding: A simulation Approach to Performance Assessment

2021 ◽  
Author(s):  
Adekunle Tirimisiyu Adeniyi ◽  
Miracle Imwonsa Osatemple ◽  
Abdulwahab Giwa
Keyword(s):  
Oil Recovery ◽  
Net Present Value ◽  
Oil Production ◽  
Base Case ◽  
Present Value ◽  
Sweep Efficiency ◽  
Recovery Method ◽  
Solution Approach ◽  
Hydrocarbon Reservoir

Abstract There are a good numbers of brown hydrocarbon reservoirs, with a substantial amount of bypassed oil. These reservoirs are said to be brown, because a huge chunk of its recoverable oil have been produced. Since a significant number of prominent oil fields are matured and the number of new discoveries is declining, it is imperative to assess performances of waterflooding in such reservoirs; taking an undersaturated reservoir as a case study. It should be recalled that Waterflooding is widely accepted and used as a means of secondary oil recovery method, sometimes after depletion of primary energy sources. The effects of permeability distribution on flood performances is of concerns in this study. The presence of high permeability streaks could lead to an early water breakthrough at the producers, thus reducing the sweep efficiency in the field. A solution approach adopted in this study was reserve water injection. A reverse approach because, a producing well is converted to water injector while water injector well is converted to oil producing well. This optimization method was applied to a waterflood process carried out on a reservoir field developed by a two - spot recovery design in the Niger Delta area of Nigeria that is being used as a case study. Simulation runs were carried out with a commercial reservoir oil simulator. The result showed an increase in oil production with a significant reduction in water-cut. The Net Present Value, NPV, of the project was re-evaluated with present oil production. The results of the waterflood optimization revealed that an increase in the net present value of up to 20% and an increase in cumulative production of up to 27% from the base case was achieved. The cost of produced water treatment for re-injection and rated higher water pump had little impact on the overall project economy. Therefore, it can conclude that changes in well status in wells status in an heterogenous hydrocarbon reservoir will increase oil production.

Sign in / Sign up

Export Citation Format

Share Document