scholarly journals PTG-HEFA Hybrid Refinery as Example of a SynBioPTx Concept—Results of a Feasibility Analysis

2019 ◽  
Vol 9 (19) ◽  
pp. 4047 ◽  
Author(s):  
Franziska Müller-Langer ◽  
Katja Oehmichen ◽  
Sebastian Dietrich ◽  
Konstantin M. Zech ◽  
Matthias Reichmuth ◽  
...  

Limited alternative fuels for a CO2-neutral aviation sector have already been ASTM certified; synthetic paraffinic kerosene from hydrotreated esters and fatty acids (HEFA-SPK) is one of these—a sustainable aviation fuel. With the hypothesis to improve the greenhouse gas (GHG) balance of a HEFA plant by realizing the required hydrogen supply via electrolysis—power to gas (PTG)—an exemplary SynBioPTx approach is investigated in a comprehensive feasibility study, which is, regarding this comparatively new approach, a novelty in its extent. About 10 scenarios are analysed by technical, environmental, and economic aspects. Within the alternative scenarios on feedstocks, electricity supply, necessary hydrogen supply, and different main products are analysed. For different plant designs of the hybrid refinery, mass and energy balances are elaborated, along with the results of the technical assessment. As a result of this environmental assessment, the attainment of at least 50% GHG mitigation might be possible. GHG highly depends on the renewability grade of the hydrogen provision as well as on the used feedstock. One important conclusion of this economic assessment is that total fuel production costs of 1295 to 1800 EUR t−1 are much higher than current market prices for jet fuel. The scenario in which hydrogen is produced by steam reforming of internally produced naphtha proves to be the best combination of highly reduced GHG emissions and low HEFA-SPK production costs.

Author(s):  
Ausilio Bauen ◽  
Niccolò Bitossi ◽  
Lizzie German ◽  
Anisha Harris ◽  
Khangzhen Leow

Aviation fuel demand is expected to continue to grow over the next decades and continue to rely heavily on kerosene fuel for use in jet engines. While efficiency and operational improvements are possible ways to reduce GHG emissions, decarbonisation will need to heavily rely on low carbon kerosene drop-in alternatives. Currently, alternative fuels make up a very small share of fuel used in aviation, but their commercialisation is making good progress. Hydrogen offers a longer term alternative fuel option but requires aircraft design and fuelling infrastructure changes. Electrification is emerging as an option for providing propulsion in aircraft, either in pure form in small aircraft or in hybrid mode in larger aircraft. This paper reviews the status, challenges and prospects of alternative fuels and electrification in aviation.


2021 ◽  
Vol 13 (8) ◽  
pp. 4479
Author(s):  
Rafael Villa ◽  
Andrés Monzón

Business to consumer e-commerce (B2C) has increased sharply in recent years driven by a growing online population and changes in consumer behavior. In metropolitan areas, the “Amazon effect” (online retailers’ vast selection, fast shipping, free returns, and low prices) has led to an increased use of light goods vehicles. This is affecting the rational functioning of the transport system, including a high degree of fragmentation, low load optimization, and, among other externalities, higher traffic congestion. This paper investigates the potential of a metro system, in a big city like Madrid, to provide delivery services by leveraging its existing carrying capacity and using the metro stations to collect parcels in lockers. It would be a new mixed distribution model for last-mile deliveries associated with e-commerce. To that end, the paper evaluates the cost and impacts of two alternative scenarios for managing the unused space in rolling stock (shared trains) or specific full train services (dedicated trains) on existing lines. The external costs of the proposed scenarios are compared with current e-commerce delivery scenario (parcel delivery by road). The results show that underground transport of parcels could significantly reduce congestion costs, accidents, noise, GHG emissions, and air pollution.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1539
Author(s):  
Karolina Wojtacha-Rychter ◽  
Piotr Kucharski ◽  
Adam Smolinski

The article evaluates the reduction of carbon dioxide emission due to the partial substitution of coal with alternative fuels in clinker manufacture. For this purpose, the calculations were performed for seventy waste-derived samples of alternative fuels with variable calorific value and variable share in the fuel mixture. Based on annual clinker production data of the Polish Cement Association and the laboratory analysis of fuels, it was estimated that the direct net CO2 emissions from fossil fuel combustion alone were 543 Mg of CO2 per hour. By contrast with the full substitution of coal with alternative fuels (including 30% of biomass), the emission ranged from 302 up to 438 Mg of CO2 per hour, depending on fuel properties. A reduction of 70% in the share of fossil fuels resulted in about a 23% decrease in net emissions. It was proved that the increased use of alternative fuels as an additive to the fuel mix is also of economic importance. It was determined that thanks to the combustion of 70% of alternative fuels of calorific value from 15 to 26 MJ/kg, the hourly financial profit gain due to avoided CO2 emission and saved 136 megatons of coal totaled an average of 9718 euros. The results confirmed that the co-incineration of waste in cement kilns can be an effective, long-term way to mitigate carbon emissions and to lower clinker production costs. This paper may constitute a starting point for future research activities and specific case studies in terms of reducing CO2 emissions.


Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 705
Author(s):  
Arnaldo Walter ◽  
Joaquim Seabra ◽  
Jansle Rocha ◽  
Marjorie Guarenghi ◽  
Nathália Vieira ◽  
...  

International civil aviation strives to significantly reduce its greenhouse gas (GHG) emissions, and the use of Sustainable Aviation Fuels (SAF) is an alternative for such purpose. However, for an alternative fuel to be considered SAF, some conditions must be met, and production must be certified for sustainability. This paper presents an assessment of the necessary conditions for the sustainable production of these biofuels in Brazil. It is based on a geospatial publicly available database (SAFmaps) that was built with the aim of providing information to stakeholders who would be interested in the production of SAF. The geographic scope corresponds to an area that is about half of the country. The case studies reported in this paper are related to four crop-based feedstocks (eucalyptus, soybean, sugarcane, and corn), which could be used for SAF production, according to three certified routes (FT, HEFA, and ATJ) (Fischer–Tropsch, Hydroprocessed Esters and Fatty Acids and Alcohol to Jet); in total, six potential production sites were assessed. For each crop, the detailed assessment is based on estimates of suitability for biomass production, yields, and costs. The assumptions made allowed us to explicitly analyse the risk of deforestation (production could only occur with displacement of pastures) and the necessary preservation of sensitive biomes and of legally protected areas, in addition to observing the restrictive conditions imposed by CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation). To reduce GHG emissions, transporting biomass over long distances was assumed to be only by rail or pipeline. In addition, we address alternatives to minimise the risks associated with induced land-use change (iLUC) and to reduce impacts on the landscape. The results show that the production of SAF through the ATJ route, using ethanol produced from sugarcane and corn, requires less land. Economic assessment was outside the scope of this paper.


Ecosystems ◽  
2021 ◽  
Author(s):  
Jan Oestmann ◽  
Bärbel Tiemeyer ◽  
Dominik Düvel ◽  
Amanda Grobe ◽  
Ullrich Dettmann

AbstractFor two years, we quantified the exchange of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) at two different large-scale Sphagnum farming sites. At both, peat extraction left a shallow layer of highly decomposed peat and low hydraulic conductivities. One site was characterized by preceding multi-annual inundation and irrigated by ditches, while the other one was inoculated directly after peat extraction and irrigated by ditches and drip irrigation. Further, GHG emissions from an irrigation polder and the effect of harvesting Sphagnum donor material at a near-natural reference site were determined. GHG mitigation potentials lag behind the results of less decomposed sites, although our results were also affected by the extraordinary hot and dry summer 2018. CO2 exchanges ranged between -0.6 and 2.2 t CO2-C ha−1 y−1 and were mainly influenced by low water table depths. CH4 emissions were low with the exception of plots with higher Eriophorum covers, while fluctuating water tables and poorly developing plant covers led to considerable N2O emissions at the ditch irrigation site. The removal of the upper vegetation at the near-natural site resulted in increased CH4 emissions and, on average, lowered CO2 emissions. Overall, best plant growth and lowest GHG emissions were measured at the previously inundated site. At the other site, drip irrigation provided more favourable conditions than ditch irrigation. The size of the area needed for water management (ditches, polders) strongly affected the areal GHG balances. We conclude that Sphagnum farming on highly decomposed peat is possible but requires elaborate water management.


2021 ◽  
Vol 9 (4) ◽  
pp. 415
Author(s):  
George Mallouppas ◽  
Elias Ar. Yfantis

This review paper examines the possible pathways and possible technologies available that will help the shipping sector achieve the International Maritime Organization’s (IMO) deep decarbonization targets by 2050. There has been increased interest from important stakeholders regarding deep decarbonization, evidenced by market surveys conducted by Shell and Deloitte. However, deep decarbonization will require financial incentives and policies at an international and regional level given the maritime sector’s ~3% contribution to green house gas (GHG) emissions. The review paper, based on research articles and grey literature, discusses technoeconomic problems and/or benefits for technologies that will help the shipping sector achieve the IMO’s targets. The review presents a discussion on the recent literature regarding alternative fuels (nuclear, hydrogen, ammonia, methanol), renewable energy sources (biofuels, wind, solar), the maturity of technologies (fuel cells, internal combustion engines) as well as technical and operational strategies to reduce fuel consumption for new and existing ships (slow steaming, cleaning and coating, waste heat recovery, hull and propeller design). The IMO’s 2050 targets will be achieved via radical technology shift together with the aid of social pressure, financial incentives, regulatory and legislative reforms at the local, regional and international level.


2021 ◽  
Author(s):  
Saara Lind ◽  
Marja Maljanen ◽  
Merja Myllys ◽  
Mari Räty ◽  
Sanna Kykkänen ◽  
...  

<p>Agricultural soils are a significant source of greenhouse gas (GHG) emissions. To study these emissions, we are currently building three research platforms that consist of full eddy covariance instrumentation for determination of net ecosystem carbon dioxide exchange and fluxes of methane and nitrous oxide. These platforms will be completed with supporting weather, plant and soil data collection. Two of our platforms are sites on organic soils with a thick peat layer (>60 cm) and the third one is on a mineral soil (silt loam). To study the role of the grassland management practises at these sites, we have initiated ORMINURMI-project. Here, we will characterise the effects of ground water table (high vs. low), crop renewal methods (autumn vs. summer) and plant species (tall fescue vs. red glover grass) on greenhouse gas budgets of grass production. Also effect on yield amount and nutrient quality will be determined. In this presentation, we will present the preliminary data collected at these research platforms and our plans for the use of these data in the coming years.</p>


Author(s):  
Fábio C. Barbosa

Freight rail carriers have been continuously challenged to reduce costs and comply with increasingly stringent environmental standards, into a continuously competing and environmentally driven industry. In this context, current availability and relative abundance of clean and low cost non conventional gas reserves have aroused a comprehensive reevaluation of rail industry into fuel option, especially where freight rail are strongly diesel based. Countries in which rail sector is required to play an important role in transport matrix, where fuel expenditures currently accounts for a significant share of operational costs, like Australia, Brazil, United States and other continental countries, can be seen as strong candidates to adopt fuel alternatives to diesel fueled freight railways. Moreover, from an environmental perspective, the use of alternative fuels (like natural gas) for locomotive traction may allow rail freight carriers to comply with emission standards into a less technologically complex and costly way. In this context, liquefied natural gas (LNG) fueled freight locomotives are seen as a strong potential near-term driver for natural gas use in rail sector, with its intrinsic cost and environmental benefits and with the potential to revolutionize rail industry much like the transition from steam to diesel experienced into the fifties, as well as the more recent advent of use of alternating current diesel-electric locomotives. LNG rail fueled approach has been focused on both retrofitting existing locomotive diesel engines, as well as on original manufactured engines. Given the lower polluting potential of natural gas heavy engines, when compared to diesel counterparts, LNG locomotives can be used to comply with increasingly restrictive Particulate Matter (PM) and Nitrogen Oxides (NOx) emission standards with less technological complexity (engine design and aftertreatment hardware) and their intrinsic lower associated costs. Prior to commercial operation of LNG locomotives, there are some technical, operational and economic hurdles that need to be addressed, i.e. : i) locomotive engine and fuel tender car technological maturity and reliability improvement; ii) regulation improvement, basically focused on operational safety and interchange operations; iii) current and long term diesel - gas price differential, a decisive driver, and, finally, iv) LNG infrastructure requirements (fueling facilities, locomotives and tender car specifications). This work involved an extensive research into already published works to present an overview of LNG use in freight rail industry into a technical, operational and economical perspective, followed by a critical evaluation of its potential into some relevant freight rail markets, such as United States, Brazil and Australia, as well as some European non electrified rail freight lines.


Author(s):  
Andrew Corber ◽  
Nader Rizk ◽  
Wajid Ali Chishty

The National Jet Fuel Combustion Program (NJFCP) is an initiative, currently being led by the Office of Environment & Energy at the FAA, to streamline the ASTM jet fuels certification process for alternative aviation fuels. In order to accomplish this objective, the program has identified specific applied research tasks in several areas. The National Research Council of Canada (NRC) is contributing to the NJFCP in the areas of sprays and atomization and high altitude engine performance. This paper describes work pertaining to atomization tests using a reference injection system. The work involves characterization of the injection nozzle, comparison of sprays and atomization quality of various conventional and alternative fuels, as well as use of the experimental data to validate spray correlations. The paper also briefly explores the application viability of a new spray diagnostic system that has potential to reduce test time in characterizing sprays. Measurements were made from ambient up to 10 bar pressures in NRC’s High Pressure Spray Facility using optical diagnostics including laser diffraction, phase Doppler anemometry (PDA), LIF/Mie Imaging and laser sheet imaging to assess differences in the atomization characteristics of the test fuels. A total of nine test fluids including six NJFCP fuels and three calibration fluids were used. The experimental data was then used to validate semi-empirical models, developed through years of experience by engine OEMs and modified under NJFCP, for predicting droplet size and distribution. The work offers effective tools for developing advanced fuel injectors, and generating data that can be used to significantly enhance multi-dimensional combustor simulation capabilities.


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