Utilization Of Alternative Fuels Research Articles

Integrated carbon assessment for sludge-derived concrete: Modelling and a comparative study

Concrete, a cornerstone of modern construction, bears a significant responsibility for global carbon emissions due to its energy-intensive pyroprocessing processes and the direct carbon emissions associated with limestone decomposition. With increasing global of awareness environmental sustainability, the imperative to decarbonise concrete production is becoming evident. Recent research highlights the significance of producing eco-friendly "green" concrete by incorporating treated alum sludge, a by-product of drinking water treatment often discarded in landfills, within the framework of sustainable construction. This research endeavours to develop a comprehensive model for the integrated carbon assessment of sludge-derived concrete products. By conducting scenario and sensitivity analyses, the study explores the decarbonisation potentials and quantifies the impacts of diverse variables on carbon output across the entire lifecycle of concrete products. These variables encompass supply chain dynamics, cement replacement ratio, carbon intensity of local grid mix, and the utilization of alternative fuels. Findings reveal that in comparison to general purpose (GP) cement production, sludge treatment has the potential to achieve an impressive 83.48% reduction in carbon emissions. Moreover, a modest 10% substitution of cement with treated sludge would contribute to 9.07% overall carbon reduction. The transition to full renewable energy consumption holds the potential for a remarkable 41.97% carbon reduction, while the integration of photovoltaic (PV) electricity and biogas heating offers a substantial 30.57% carbon reduction in the manufacturing of sludge-derived concrete. Nonetheless, supply chain alterations demonstrate limited impacts, given the prevalence of locally sourced raw materials and the low embodied carbon contents of transportation-intensive ingredients such as sand and aggregate. Despite discernible progress achieved through cement substitution and renewable energy penetration, full carbon neutrality remains an elusive goal.

Design and Thermo-Economic Analysis of an Integrated Solar Field Micro Gas Turbine Biomass Gasifier and Organic Rankine Cycle System

A micro gas turbine (MGT) is an advanced technology with a simple structure and fast load response. It represents a good choice for the next generation of distributed power systems, where fossil fuels are going to be largely replaced by biofuels and renewable sources. In this context, this work aims to investigate and compare the performance of gradually more complex energy systems integrating a micro gas turbine plant: simple cogenerating asset, integrating a solar field, presence of a gasifier, and the addition of a bottoming ORC. In all cases, a thermo-economic analysis has been carried out for an application in the agricultural sector. Agricultural waste can be used to create a syngas as fuel for MGT through a gasifier, promoting the utilization of carbon-neutral alternative fuels to reduce harmful emissions. The authors considered the electrical and thermal needs of a hypothetical agri-food company to build the electrical and thermal load curves. The new and more complex cogeneration plant, designed by using the Thermoflex 30 software, leads to an increase in electrical power, recovered thermal power, overall electrical efficiency, carbon neutrality, and cogeneration indexes. In particular, the presence of the solar field promotes a reduction in fuel consumption as well as greater heat input to the thermal unit. The addition of a bottoming ORC system increases the electrical power by 36.4%, without significantly penalizing the thermal unit. Moreover, thanks to the gasifier that offsets the fuel reduction costs, through an economic analysis of the entire plant, a payback time of the investment of less than 4 years is obtained.

Comparative analysis of waste tire pyrolysis oil and gasoline as low reactivity fuel in RCCI engine

ABSTRACT The utilization of alternative fuels in internal combustion engines has gained significant attention due to concerns about energy security and environmental sustainability. Waste tire pyrolysis oil (WTPO) is a potential alternative fuel that can be produced from waste vehicle tires through a pyrolysis process. In this study, the possible use of WTPO in a diesel engine operating under Reactivity Controlled Compression Ignition (RCCI) mode was investigated. In the study, the use of WTPO as a low-reactivity fuel in RCCI engines is examined, highlighting the importance of innovative approaches to alternative fuels with varying reactivity levels for effective combustion control and emission reduction. In the experimental work, WTPO was tested at different energy rates of 15%, 30%, and 45% into the intake port using the PFI system, while conventional diesel fuel was injected directly into the cylinder by the CRDI system. The tests were carried out under different engine load conditions while maintaining a constant engine speed of 2400 rpm. The performance, combustion, and emission characteristics of the engine were analyzed and compared between WTPO and conventional gasoline fuel as LRF. The study results show that using WTPO in RCCI operation with sustainable ringing intensity leads to significant increases in Brake Thermal Efficiency (BTE) compared to gasoline usage, with BTE increments of up to 5%, 3.3%, and 6.3% observed with increasing engine load. Furthermore, WTPO usage in RCCI engines effectively reduced hydrocarbon (HC) emissions, addressing a significant issue, and maintaining the known benefits of reactivity-controlled combustion. These findings suggest that WTPO can be utilized as a viable low-reactivity fuel in RCCI engines with acceptable performance, combustion, and emission characteristics.

Assessment of cruise ship decarbonization potential with alternative fuels based on MILP model and cabin space limitation

Alternative fuels are expected to play an increasingly crucial role in the decarbonization of the shipping industry. Previous studies have explored the possibility of ship integrated energy systems that use alternative fuels for emission reduction in a cost-efficient manner. However, the various navigation loads and strict space limitations of ships are usually overlooked when designing the ships' energy systems. To fill this gap, a two-stage optimization model is proposed for designing ship integrated energy systems that incorporate alternative fuels, which incorporates internal combustion engines, fuel cells, energy storage technologies, and other relevant equipment. The model captures the ship's volume and weight limitations for alternative fuel applications, and a large cruise ship sailing in Oceania and the Caribbean is selected as a case study. The application feasibilities of four mainstream alternative fuels, i.e., hydrogen, ammonia, methanol, and natural gas, have been compared with the conventional diesel power system considering the impact of future trends of fuel cost and emission-related policies. The results indicate that more than 60% of greenhouse gas emissions can be reduced by replacing conventional fossil fuels with alternative fuels. Meanwhile, alternative fuel applications are economically competitive when compared to conventional diesel power systems, considering the growing technology readiness level of fuel production and fuel cells. Overall, this study is expected to provide guidance for the utilization of alternative fuels for ships and to identify the optimal ship integrated energy systems solutions.

Theoretical Investigations on utilization of alternative fuels in an IDI diesel engine under dual fuel mode

The study explores the impact of ammonia and DME on the combustion / performance characteristics and exhaust emissions of a dual-mode IDI diesel engine without making any major alterations to the engine. Fortran-77 programming is used to develop a computer simulation program. The findings show that blending in dual mode raises pre and main chamber temperatures and pressures, as well as IMEP and BP, but lowers BSEC as ammonia substitution increases from 5% to 25%. Blending (diesel + ammonia) increases BP by 15.93 percent, 37.25 percent, and 72.42 percent in dual mode at 20%, 40%, and 60% NG substitutions respectively and blending (diesel + DME) increases BP by 17.79 percent, 40.17 percent, and 76.99 percent in dual mode at 20%, 40%, and 60% NG substitutions respectively

Process compatible desulfurization of NSP cement production: A novel strategy for efficient capture of trace SO2 and the industrial trial

Cement industry contributes to more and more SO2 emission due to utilization of alternative raw materials and fuels, whereas the available calcium-based dry flue gas desulfurization (FGD) technologies present low efficiency due to slow reversible de-SO2 reactions and short gas-solid contact time in the preheater. In the present study, the SO2 capture potentials of CaCO3, CaO, and Ca(OH)2 in the preheater environment were maximized by introducing V2O5-based catalyst and selecting optimal reaction temperature, and the de-SO2 mechanism was extensively discussed. The results showed that the de-SO2 efficiency of calcium-based adsorbents increased by 10–57 times as SO2 was effectively oxidized to SO3 in the presence of V2O5-based catalyst, then maximum de-SO2 efficiency of 75.5% was achieved using Ca(OH)2 and V2O5-CeO2 at 600 °C. Furthermore, CaCO3 assisted by V2O5-CeO2 also had a de-SO2 efficiency of 65.6%. Subsequently, a novel process compatible FGD technology was designed to maximize the de-SO2 ability of raw meal in the preheater by adding V2O5-based catalyst and humidification, the SO2 concentration of flue gas reduced from 1000 mg/Nm3 to less than 100 mg/Nm3 in the industrial-scale trial, as more sulfur was solidified into clinker in the form of alkali sulfate without reducing its properties. This novel process compatible de-SO2 strategy is of real significance for reducing SO2 emission of cement industry at low economic cost.

Ammonia-based green corridors for sustainable maritime transportation

Decarbonizing maritime transportation will require huge investments in new technologies and infrastructure for the production, distribution, and utilization of alternative marine fuels. In this context, the concept of green shipping corridors has been proposed, where a green corridor refers to a major shipping route along which low- and zero-carbon maritime transportation solutions are provided. In this work, we conduct a global analysis of green shipping corridors by designing a network of alternative fuel production sites, transportation links, and bunkering ports that can support a large fraction of the global marine fuel demand. We choose green ammonia to be the alternative fuel as it has received significant attention as a potential carbon- and sulfur-free marine fuel that can be produced entirely from renewable resources. Our study identifies the most suitable locations for producing and bunkering green ammonia, examines the trade-off between ammonia production and transportation costs, and highlights the extent to which local reduction in production cost can lead to a competitive advantage in a future green ammonia market. We also demonstrate the value of our global network optimization, which considers many shipping routes simultaneously, in capturing potential synergies and trade-offs across different routes and regions. This work provides insights that can help inform decisions in establishing future green shipping corridors around the world.

Study on cool flame radical index and oxygen concentration dependence of oxygenated fuels

The growing utilization of alternative fuels has sparked an interest in understanding the combustion characteristics of oxygenated fuels at low temperature. Cool flame extinction limits provide direct measures of the low-temperature reactivity of fuels and critical information for advanced low-temperature combustion engine design. This paper investigates the effects of fuel and oxygen concentrations on the extinction limits of diffusion cool flames for oxygenated fuels, including dimethyl ether, methyl decanoate, and 1-dodecanol in an atmospheric counterflow burner. The cool flame radical indexes of these oxygenated fuels are developed by isolating the thermal and transport effects from the chemical contribution to diffusion cool flame extinction. The results show that the ranking of low-temperature reactivities of long carbon chain oxygenated fuels, compared with n-alkane, is ether > n-alkane > alcohol > ester for a similar carbon number. Furthermore, due to the critical role of multiple oxygen addition reactions in the low-temperature chemistry, the relationship between the cool flame extinction limit and the oxygen concentration is also explored. The results show that the cool flame extinction limits of the oxygenated fuels are proportional to a nth power of the oxygen concentration, [O2]n, due to the combined effects of multiple oxygen addition reactions and the negative temperature coefficient in low-temperature chemistry. Additionally, the measured n number of 1-dodecanol is found to be larger than 2, which suggests the existence of the third oxygen addition reactions in low-temperature chemistry for large alcohols.

Renewable Energy System: Alternative Fuel Usage in the Energy Market of the US Public Transportation System

The U.S. transportation sector is the second largest energy consumer in 2020 with about a 35% usage rate. However, the sector accounted for the largest proportion (29%) of the total greenhouse gas emissions in 2019. Compared with the use of personal automobiles, public transportation is believed to be cost-effective and provides low emissions, which tends to reduce the need to travel long distances and lower the carbon footprints of transit operations. This study examined the impact of alternative fuels (various blends of biodiesel, hydrogen, methanol, and ethanol) versus conventional fuels on greenhouse gas emissions in the U.S. public transit system. The research was anchored by three regression models to analyze the joint and individual impact of both conventional fuel and alternative fuel. Secondary data were extracted from the American Public Transit Association 2021 Fact Book, the U.S. Bureau of Transportation Statistics, and the Inventory of U.S. Greenhouse Gas Emissions and Sinks 1999-2019 (EPA 2021). The descriptive statistics, correlation, and stationarity tests were established on the variables, and the regression models were estimated using ordinary least squares. The findings revealed that while conventional fuel expands the flow of carbon emissions, alternative fuel is a drag on the total emissions from public transportation. However, it was concluded that the utilization of alternative fuels in the U.S. transportation industry is still very low, thus there is a need to put all machinery in motion to embrace this fuel type to reverse climate change issues, especially in the public transit system.

LNG Bunkering Dynamics: An Exploratory Study for Türkiye

United Nations’ decarbonization and greenhouse gas reduction targets are to be achieved through the utilization of alternative fuels globally. LNG is a viable alternative for mitigating maritime transport-related greenhouse gas emissions. This study investigates LNG bunkering supply chain development in Türkiye. Semi-structured interviews with bunkering supply chain representatives were conducted to explore phenomena. The results of the research provided a pathway to establish a new supply chain for alternative marine fuels. The research findings indicate that collaboration and setting a regulatory framework are vital for supply chain development.

Effect of biomethane substitution on combustion noise and performance of a dual fuel common rail direct injection diesel engine

AbstractRising pollution levels and stringent emission regulations have raised the requirement for the utilization of alternative green fuels as a sustainable energy source for engine applications. The economic and environmental benefits of using biomethane or renewable natural gas (>95% methane) in diesel engines have made it a promising solution. Sound levels caused by combustion noise, however, is an area of concern in the early stages of engine development process, and to the best of our knowledge studies related to the impact of gaseous fuel energy share on combustion noise in dual fuel diesel engines have not been reported in the literature. In the present work, experimental research on the combustion noise of a biomethane augmented dual fuel common‐rail direct injection (CRDI) diesel engine has been carried out with a correlational design of its performance and combustion characteristics at various engine operating conditions. Comparative results on combustion and performance characteristics of different fuel compositions at various engine loads revealed that there is a better utilization of gaseous fuel at full load conditions resulting in improved power output and reduced heat transfer losses. Cylinder pressure spectra derived from recorded in‐cylinder pressure were used for carrying out the quantitative analysis of sound levels. The results suggested that an increment in methane share is effective in controlling the sound pressure levels to 95 dB (at 1.5 Newton‐meter [Nm] and 13.5 Nm loading conditions) and it is lower than the diesel‐only operational levels at all loading conditions.

Mechanisms by which smoothelin-like protein 1 reverses insulin resistance in myotubules and mice

Insulin resistance (InR) is manifested in skeletal muscle by decreased insulin-stimulated glucose uptake due to impaired insulin signaling and multiple post-receptor intracellular defects. Chronic glucose-induced insulin resistance leads to the activation of Ser/Thr kinases and elevated phosphorylation of insulin receptor substrate 1 (IRS1) on Ser residues. Phosphorylation of IRS1 triggers the dissociation of IRS1 and its downstream effector, phosphatidylinositol 3-kinase. In the present study, we provide evidence for the insulin-sensitizing role of smoothelin-like protein 1 (SMTNL1) that is a ligand-dependent co-regulator of steroid receptors, predominantly the progesterone receptor. SMTNL1 was transiently overexpressed in insulin-resistant C2C12 myotubes. A proteome profiler array revealed that mTOR and Ser/Thr kinases were SMTNL1-dependent signaling pathways. In the presence of progesterone, overexpression was coupled to decreased Ser phosphorylation of IRS1 at Ser307, Ser318, and Ser612 residues. SMTNL1 also induced the expression and activity of the p85 subunit of PI3K. SMTNL1 regulated the expression of PKCε, which phosphorylates IRS1 at Ser318 residue. SMTNL1 also regulated ERK1/2 and JNK, which phosphorylate IRS1 at Ser612 and Ser307, respectively. Real-time metabolic measurements of oxygen consumption rate and extracellular acidification rate revealed that SMTNL1 improved glycolysis and promoted the utilization of alternative carbon fuels. SMTNL1 also rescued the mitochondrial respiration defect induced by chronic insulin exposure. Collectively, SMTNL1 plays a crucial role in maintaining the physiological ratio of Tyr/Ser IRS1 phosphorylation and attenuates the insulin-signaling cascade that contributes to impaired glucose disposal, which makes it a potential therapeutic target for improving InR.

A numerical study on methanol steam reforming reactor utilizing engine exhaust heat for hydrogen generation

Internal combustion engines are used in most vehicles around the world to power the transport sector. Efficiency improvement, emission reduction, and utilization of alternative fuels are the main aspects of current IC engine research. Hydrogen-enhanced combustion proved to be one of the efficient ways to achieve such goals. But the problem lies in the storage of hydrogen for the transportation sector, and on-board fuel reforming is a promising option for solving this issue. It deals with transforming a suitable liquid fuel (methanol) into an H2-rich gas using a catalytic conversion process. For sustaining the reforming reaction, the required heat energy is taken from engine exhaust waste heat, this process is known as thermochemical recuperation. Number of studies on the reformers utilized for on-board hydrogen generation using engine exhaust heat are limited in the literature. The present study investigates the performance of a reactor that uses the exhaust gas heat energy for sustaining the reforming reaction. A numerical analysis was performed over a selected reactor where exhaust gases were flowing at one side, while on the other, the reforming reaction was taking place with the help of heat provided by high-temperature exhaust gases. A packed bed-type reactor was chosen for the current study and a parametric study was conducted where the effects of various operating parameters on both reacting and heating sides on the reactor's performance were investigated. It was found that temperature was the most influential inlet parameter among others. Steam/Carbon ratio and flow configuration had a negligible effect on the hydrogen yield as well as methanol conversion. Reactant inlet velocity increment revealed a significant drop in methanol conversion as it reduces the residence time for reforming reaction in the catalyst zone.

Single-Pulse Shock Tube Experimental and Kinetic Modeling Study on Pyrolysis of a Direct Coal Liquefaction-Derived Jet Fuel and Its Blends with the Traditional RP-3 Jet Fuel.

A basic understanding of the high-temperature pyrolysis process of jet fuels is not only valuable for the development of combustion kinetic models but also critical to the design of advanced aeroengines. The development and utilization of alternative jet fuels are of crucial importance in both military and civil aviation. A direct coal liquefaction (DCL) derived liquid fuel is an important alternative jet fuel, yet fundamental pyrolysis studies on this category of jet fuels are lacking. In the present work, high-temperature pyrolysis studies on a DCL-derived jet fuel and its blend with the traditional RP-3 jet fuel are carried out by using a single-pulse shock tube (SPST) facility. The SPST experiments are performed at averaged pressures of 5.0 and 10.0 bar in the temperature range around 900–1800 K for 0.05% fuel diluted by argon. Major intermediates are obtained and quantified using gas chromatography analysis. A flame-ionization detector and a thermal conductivity detector are used for species identification and quantification. Ethylene is the most abundant product for the two fuels in the pyrolysis process. Other important intermediates such as methane, ethane, propyne, acetylene, and 1,3-butadiene are also identified and quantified. The pyrolysis product distributions of the pure RP-3 jet fuel are also performed. Kinetic modeling is performed by using a modern detailed mechanism for the DCL-derived jet fuel and its blends with the RP-3 jet fuel. Rate-of-production analysis and sensitivity analysis are conducted to compare the differences of the chemical kinetics of the pyrolysis process of the two jet fuels. The present work is not only valuable for the validation and development of detailed combustion mechanisms for alternative jet fuels but also improves our understanding of the pyrolysis characteristics of alternative jet fuels.

Use of Isothermal and Isoperibolic Calorimetry to Study the Effect of Zinc on Hydration of Cement Blended with Fly Ash.

Increasing utilization of secondary raw materials and alternative fuels results in increasing contents of metals in cements. Zinc is one of these elements. It comes to cement with secondary raw materials such as slag or fly ash or by the utilization of used tires as an alternative fuel. Zinc ions significantly prolong the hydration process in cement. This work deals with the influence of zinc ions in the form of very poorly soluble ZnO salt and easily soluble ZnCl2 and Zn(NO3)2 on the hydration of cement blended with fly ash. Zinc was dosed in the range of 0.05%, 0.1%, 0.5% and 1% of cement weight. The effect of zinc on hydration was monitored by isothermal and isoperibolic calorimetry. A 15% addition of fly ash to cement mainly causes further retardation of hydration reactions due to the reactions of fly ash particles with Ca2+ ions from cement. The strongest effect on the hydration retardation from all investigated compounds showed in ZnO as it dissolves very slowly. On the contrary, for the dosage of 1% of zinc in the form of ZnCl2 significant acceleration of hydration occurred. In this work, a synergistic effect on the prolongation of hydration with a combination of cement, zinc and fly ash was demonstrated. The lengths of induction periods were assessed from detected calorimetric curves and from these lengths the curves were gained by fitting with the exponential function. Final products were next analyzed using X-ray diffraction.

A novel technology for liquefied synthetic natural gas production powered by renewable electricity: Process development and impact analysis on vehicular transportation

Overgeneration of wind energy conversion systems represents a grid issue, limiting the growth of renewable energy utilization. Alternative fuels utilization such as liquefied natural gas is emerging as a new market with a big potential in freight transport. In order to mitigate wind energy production curtailment, a power to liquefied synthetic natural gas process is proposed. Solid oxide electrolyser and catalytic methanation integrated system is applied to produce hydromethane. After a dehydration step in a temperature swing adsorption unit, low temperature gas upgrading techniques are applied for the first time to hydromethane mixture. Liquified synthetic natural gas is produced, meeting grid injection and endothermic engines requirements after regasification. A higher energy efficiency with respect to the application of traditional technologies is achieved. Plant configuration was optimized for internal thermal and chemical energy recovery and exploitation, achieving an overall electrical to chemical efficiency of about 50%. A case study was analyzed for the Irpinia (Italy) territory, strongly affected by wind energy overgeneration. Impact on local transport infrastructure was assessed through well-to-wheel analysis, considering the use of produced liquified synthetic natural gas in heavy duty vehicles. Greenhouse gas avoided emissions are expected to correspond to 7.1% of the vehicular emissions related to local traffic statistics for 2016.

Effect of intake manifold design on the mixing of air and bio-CNG in a port-injected dual fuel diesel engine

The awareness for an effective utilization of renewable energy and alternative fuels has been increasing. As alternative fuels, both liquid and gaseous biofuels have huge resources. A bio-CNG is a form of biogas with increased methane content. The present study comprises the development of intake manifold with the port fuel injector and investigate the mixing characteristics of air and bio-CNG. The aim of the study is to analyse the effect the R/D ratio on the flow behaviour and mixture formation of air and bio-CNG. The four configurations of intake manifold are investigated. The ratio of radius of curvature of manifold bend (R) to the diameter of manifold (D) is varied as 1, 1.5, 1.75 and 2. The port fuel injector for bio-CNG induction is placed at 200 mm from the manifold. The objective is to optimize the intake manifold to deliver the homogeneous mixture of air and bio-CNG inside the engine cylinder. As the bio-CNG is new age fuel, being produced to reduce the import of conventional CNG, the work for optimization of port injector and intake manifold are hardly available. The geometries are made in PTC-Creo 3.0, followed by CFD simulation in ANSYS Fluent. The different configurations are analysed for the comparison of the parameters such as, pressure, velocity, turbulence kinetic energy, helicity and mass fraction of CH4. The results show that the distribution of bio-CNG near the outlet of the manifold is uniform and homogeneous for the manifold with R/D ratio of 1.75 and 2.

Use of Gasoline, LPG and LPG-HHO Blend in SI Engine: A Comparative Performance for Emission Control and Sustainable Environment

The rising global warming concerns and explosive degradation of the environment requires the mainstream utilization of alternative fuels, such as hydroxy gas (HHO) which presents itself as a viable substitute for extracting the benefits of hydrogen. Therefore, an experimental study of the performance and emission characteristics of alternative fuels in contrast to conventional gasoline was undertaken. For experimentation, a spark ignition engine was run on a multitude of fuels comprising of gasoline, Liquefied petroleum gas (LPG) and hybrid blend of HHO with LPG. The engine was operated at 60% open throttle with engine speed ranging from 1600 rpm to 3400 rpm. Simultaneously, the corresponding performance parameters including brake specific fuel consumption, brake power and brake thermal efficiency were investigated. Emission levels of CO, CO2, HC and NOx were quantified in the specified speed range. To check the suitability of the acquired experimental data, it was subjected to a Weibull distribution fit. Enhanced performance efficiency and reduced emissions were observed with the combustion of the hybrid mixture of LPG with HHO in comparison to LPG: on average, brake power increased by 7% while the brake specific fuel consumption reduced by 15%. On the other hand, emissions relative to LPG decreased by 21%, 9% and 21.8% in cases of CO, CO2, and unburned hydrocarbons respectively. Incorporating alternative fuels would not only imply reduced dependency on conventional fuels but would also contribute to their sustainability for future generations. Simultaneously, the decrease in harmful environmental pollutants would help to mitigate and combat the threats of climate change.

Valorization of Sewage Sludge via Gasification and Transportation of Compressed Syngas

A significant challenge in the utilization of alternative gaseous fuels is to use their energy potential at the desired location, considering economic feasibility and sustainability. A potential solution is a compression, transportation in pressure tanks, and generation of electricity and heat directly at the recipient. In this research, the potential for generating syngas from abundant waste substrates was analyzed. The sewage sludge (SS) was used as an example of a bulky and abundant resource that could be valorized via gasification, compression, and transport to end-users in containers. A model was developed, and theoretical analyses were completed to examine the influence of the calorific value of the syngas produced from the SS gasification (under different temperatures and gasifying agents) on the efficiency of energy transportation of compressed syngas. First, the gasification simulation was carried out, assuming equilibrium in a downdraft gasifier (reactor) from 973–1473 K and five gasifying agents (O2, H2, CO2, water vapor, and air). Molar ratios of the gasifying agents to the (SS) C ranged from 0.1–1.0. The model predicted syngas composition, lower calorific values (LHV) for a given molar ratio of the gasification agent, and compressibility factor. It was shown that the highest LHV was obtained at 0.1 molar ratio for all gasifier agents. The highest LHV (~20 MJ∙(Nm3)−1) was obtained by gasification with H2 and the lowest (~13 MJ∙(Nm3)−1) in the case of air. Next, the available syngas volume in a compressed gas transportation unit and the stored energy was estimated. The largest syngas volume can be transported when O2 is used as a gasifying agent, but the highest amount of transported energy was estimated for gasification with H2. Finally, the techno-economic analyses showed that syngas from SS could be competitive when the energy of compressed syngas is compared with the demand of an average residential dwelling. The developed syngas energy transport system (SETS) concept proposes a new method to distribute compressed syngas in pressure tanks to end-users using all modes of transport carrying intermodal ISO containers. Future work should include the determination of energy demand for syngas compression, including pressure losses, heat losses, and analysis of the influence of syngas on storage and compression devices.

Techno-economic assessment of alternative fuels in second-generation carbon capture and storage processes

Several technical methods are currently discussed to meet the objectives of the United Nations Framework Convention on Climate Change 21st Conference of the Parties, Paris, France (Paris Agreement) in terms of carbon dioxide (CO2) concentration in the Earth’s atmosphere. In addition to efficiency improvements, reduction of energy consumption, and the utilization of renewable energy sources, the application of carbon capture and storage (CCS) technologies seems to be unavoidable. Whereas all these measures aim on the reduction of CO2 that is being newly released, there is the approach to remove CO2 from the atmosphere that has already been emitted. This can be achieved by the utilization of bioenergy in CCS processes. Within this paper, the utilization of alternative fuels in two second-generation CCS processes is assessed. In this regard, chemical looping combustion (CLC) and calcium looping (CaL) are two promising technologies. Both processes have proven their feasibility already in semi-industrial scale. The assessment includes three different types of fuel namely coal, biomass, and solid recovered fuel (SRF). The analysis is twofold: first, a heat and mass balance calculation reveals the specific CO2 emissions of each power system; second, a cost analysis points out the feasibility from an economic point of view. The highest CO2 removal can be achieved by a biomass-fired CLC unit (− 696 gCO2/kWhe). Furthermore, it was found that the co-combustion of SRF even at moderate co-firing rates allows for noteworthy improved economics of the CCS system. Therefore, the utilization of waste-derived fuels in the context of CCS processes should be put more into focus in future research activities.