Conventional Steam Research Articles

Greenhouse gas offsets distort the effect of clean energy tax credits in the United States

Abstract Prominent clean energy tax credits in the United States (U.S.) could drive large expenditures that materially increase greenhouse gas (GHG) emissions if their implementing regulations assign negative values to avoided GHG emissions and allow projects to offset other supply chain emissions on this basis. Most notably, we find that assigning negative GHG intensities to biogenic- and fossil-origin methane feedstocks and allowing such feedstocks to be blended with natural gas could support about 35 million metric tonnes of gray hydrogen production per year under the Section 45V tax credit. These practices would come at a taxpayer cost of ∼$1 trillion over 10 years of tax credit eligibility and cause excess emissions of ∼3 billion tonnes carbon dioxide-equivalent (CO2e) above scenarios that impose strict methane controls. Both the clean hydrogen (Section 45V) and clean electricity (Section 45Y) production tax credits use life cycle emissions criteria to direct potentially trillions of dollars in federal tax expenditures. Life cycle analysis is a decision support tool that is increasingly prominent in energy and environmental policies, but it is not an objective, quantitative calculator. Seemingly minor choices about life cycle system boundaries and baseline assumptions, such as whether unabated methane emissions are assumed to continue indefinitely, have gigatonne-scale effects on expected GHG outcomes. We find that risks are more significant for hydrogen than clean electricity due both to the scale of feedstock availability relative to market size and tax credit value relative to commodity prices. Methane feedstocks that are inappropriately assigned negative emissions intensity could dominate U.S. hydrogen production via conventional steam methane reformation, preventing the innovation-oriented 45V tax credit from encouraging development of higher-cost electrolysis technology. For both tax credits, if eligibility rules qualify emitting technologies based on offsets, long-lived facilities would have no incentive to continue offsetting once tax credit incentives end, risking lock-in of methane-based infrastructure.

Towards a Greener Future: Sustainable Innovations in the Extraction of Lavender (Lavandula spp.) Essential Oil

Lavender is one of the most appreciated aromatic plants, with high economic value in food, cosmetics, perfumery, and pharmaceutical industries. Lavender essential oil (LEO) is known to have demonstrative antimicrobial, antioxidant, therapeutic, flavor and fragrance properties. Conventional extraction methods, e.g., steam distillation (SD) and hydro-distillation (HD), have been traditionally employed to extract LEO. However, the low yield, high energy consumption, and long extraction time of conventional methods have prompted the introduction of novel extraction technologies. Some of these innovative approaches, such as ohmic-assisted, microwave-assisted, supercritical fluid, and subcritical water extraction approaches, are used as substitutes to conventional extraction methods. While other methods, e.g., sonication, pulsed electric field, and cold plasma, can be used as a pre-treatment that is preceded by conventional or emerging extraction technologies. These innovative approaches have a great significance in reducing the energy consumption, shortening the extraction time, and increasing the extraction yield and the quality of EOs. Therefore, they can be considered as sustainable extraction technologies. However, the scale-up of emerging technologies to an industrial level should also be investigated from the techno-economic points of view in future studies.

Characteristics and control methods of high-pressure in-situ combustion by heavy oil reservoir

With the increase of buried depth, the in-situ combustion (ISC) of deep heavy oil reservoirs faces the problems of unclear high-pressure oxidation mechanism and high risk, and the conventional steam injection method cannot guarantee the effect. Taking Lukeqin Oilfield in Xinjiang, China, as an example, the oxidation characteristics of heavy oil under different pressures are analyzed by thermal analysis and combustion tube experiments, and the feasibility of high-pressure ISC is analyzed. The control method of high-pressure ISC in the field is obtained by numerical simulation. The results show that high pressure advances the oxidation stages of crude oil and accelerates the advance rate of the combustion front. The temperature of the combustion front is increased by more than 300 °C, but the combustion stability becomes worse. The activation energy and pressure of each oxidation stage show a power function decreasing relationship. High-pressure low-oxygen ISC reduces the ignition threshold temperature, and the combustion is stable and continuous, which is feasible in the development of deep heavy oil reservoirs. When the oxygen content is 8%, the combustion of high-pressure ISC is stable, the recovery rate is increased by 8%.

Economic and Environmental Impact Analysis of Innovative Peeling Methods in the Tomato Processing Industry

Peeling is a key step in the industrial production of canned peeled tomatoes, vital for optimizing efficiency, yield, product quality, waste reduction, and environmental impact. This study presents a comparative assessment of the economic and environmental impacts of adopting innovative peeling technologies, including infrared (IR), ohmic heating-assisted lye (OH-lye), and ultrasound-assisted lye (US-lye) peeling, relative to conventional steam and lye peeling methods. Focusing on a medium-sized Italian tomato processor, the impacts of these methods on productivity, water and energy consumption, wastewater generation, and environmental footprint using Life Cycle Assessment (LCA) methodology, were evaluated. Findings indicated that adopting IR, OH-lye, and US-lye methods enhanced peelability (ease of peeling > 4.5) and increased production capacity by 2.6–9.2%, while reducing solid waste by 16–52% compared to conventional steam and lye methods. LCA results showed IR as the most environmentally favorable method, followed by steam, OH-lye, and US-lye, with conventional lye peeling being the least sustainable. OH-lye and IR methods also significantly reduce water and energy use, while US-lye shows higher demands in these areas. Additionally, OH-lye and IR methods require little or no NaOH, minimizing chemical consumption and wastewater production, which offers notable environmental and cost advantages. Overall, this preliminary study underscores economic and environmental potential for novel peeling technologies, encouraging industry consideration for adoption.

Perovskite Anode for SOFCs Running on Dry Reforming of CH4

Dry reforming of biogas, which contains methane and carbon dioxide, for use as fuel in Solid Oxide Fuel Cells (SOFCs) can achieve superior efficiency and carbon neutrality compared to conventional steam reforming. In this study, we investigated Sr1-xLaxTi1-yRuyO3 (SLTRO) perovskite cathode materials for SOFCs with high electrical conductivity and excellent catalytic activity for dry reforming. La+3 doping on the Sr+2 site of the basic SrTiO3 (STO) perovskite material enhanced electronic conductivity, while simultaneous exsolution of Ru+4 doped on the Ti+4 site at high temperatures facilitated the formation of numerous Ru nanoparticles on the surface. The SLTRO cathode material with exsolved Ru nanoparticles exhibited high catalytic activity for dry reforming, with methane conversion rates of 85% and carbon dioxide conversion rates of 83% at the SOFC operating temperature of 700°C. Notably, it maintained a degradation rate of less than 1%/1000 hours without carbon deposition during dry reforming operation at 700°C for over 1000 hours. Additionally, we will report the electrochemical properties and performance of SOFC cells equipped with SLTRO cathodes. Figure 1

Performance evaluation of a steam generation system using a novel semi-open heat pump for waste heat recovery in dyeing industry

Performance evaluation of a steam generation system using a novel semi-open heat pump for waste heat recovery in dyeing industry

The characteristics of steam chamber expanding and the EOR mechanisms of tridimensional steam flooding (TSF) in thick heavy oil reservoirs

The characteristics of steam chamber expanding and the EOR mechanisms of tridimensional steam flooding (TSF) in thick heavy oil reservoirs

Optimizing the extraction of essential oil yield from Pistacia lentiscus oleo-gum resin by superheated steam extraction using response surface methodology

Pistacia lentiscus L. is an aromatic plant containing a significant percentage of essential oil (EO) used in fragrance, pharmaceuticals, cosmetics, and the food industry. The purpose of this work is focused on the optimization of Pistacia lentiscus L. oleo gum resin EO yield extracted by superheated steam extraction (SHSE) by response surface methodology, including extraction parameters of particle size (0. 5 − 1 mm), temperature (140–180 °C) and time (90–150 min). The optimum conditions for Pistacia lentiscus L. EO extracted by SHSE were found to be (particle size: 0.75 mm, time: 120 min and temperature: 160 ℃) which produced the highest EO yield of 5.7%. A regression model was developed, demonstrating a robust quadratic correlation with an R2 value of 0.9991, making it suitable for predictions. Furthermore, the yield of Pistacia lentiscus L. EO extracted by SHSE was compared with the conventional steam and hydro distillation techniques. The study revealed that SHSE yielded higher quantities of EO than other extraction methods. GC-MS analyzed the chemical composition of Pistacia lentiscus L. EO. The predominant compound of Pistacia lentiscus L. EO was determined to be α-pinene, while the other identified compounds include trans-verbenol, verbenol, cis-verbenone, camphene, β-myrcene, d-limonene, cymene, α-myrtenol, α-campholenal, α-copaene, and α-thujene, whose content differed according to different extraction techniques. Overall, superheated steam extraction is an efficient technique for extracting Pistacia lentiscus L. essential oil that enhances EO yield, requiring less time for extraction.

Design and Optimization of a Chemical Looping Hydrogen Production System Using Steam Reforming for Petrochemical Plants.

Industrial pollution is a significant environmental concern, and researchers are seeking solutions to minimize its impact. Chemical looping combustion is an efficient technique to decrease CO2 emissions. This study delves into its application within petrochemical plants for hydrogen production. In addition to its high efficiency in hydrogen production, this method yields pure CO2 and nitrogen. The design features four reactors utilizing iron and nickel metals as oxygen carriers. A model in Aspen Plus was developed to simulate this design and evaluate its performance. Aspen Plus uses RGIBBS submodel which works based on minimization of the Gibbs free energy. The research findings indicate that this design significantly boosted the hydrogen production rate from 3380 kmol/h in conventional steam reforming reactors and 4258 kmol/h in the three-reactor chemical looping combustion setup to 4408 kmol/h. Lowering the temperatures of the iron and nickel fuel reactors, as well as the iron steam reactor, reducing the airflow rate, and increasing the pressure of the iron steam reactor all led to increased hydrogen production. Conversely, changing the pressure of the nickel fuel reactor had minimal impact. The inlet steam flow rate exhibited a nonlinear effect, initially increasing and then decreasing the hydrogen production rate.

On the Role of Anions in Solid Catalysts with Ionic Liquid Layer (SCILL) for the Selective Hydrogenation of Highly Concentrated Acetylene Streams.

Electric plasma assisted pyrolysis of methane represents a highly promising greener alternative to produce ethylene from biogas and renewable energies compared to conventional steam cracking of naphtha. The mediocre performance of typical Pd-Ag catalysts for the downstream purification of the substantially higher concentrated acetylene impurities (≥15 vol.-%) in those ethylene streams via selective hydrogenation is yet limiting economic interest. Following the concept of solid catalysts with ionic liquid layer (SCILL), we have modified an intrinsically non-selective palladium catalyst with imidazolium based ionic liquids varying among 10 different anions and investigated them in this reaction. The best performing [C4C1IM][MeSO4]-SCILL reaches an outstanding average ethylene selectivity over 20 h on-stream of 82 % at full acetylene conversion without any sign of deactivation, clearly outperforming conventional Pd-Ag catalysts. By varying parameters like ionic liquid (IL) loading, temperature, feed gas composition, cations, and by using XPS for surface analysis we could gain a very comprehensive understanding of the underlying mechanisms that reduce the competing over-hydrogenation and oligomerisation side-reactions.

Steam cracking in a semi-industrial dual fluidized bed reactor: Tackling the challenges in thermochemical recycling of plastic waste

Steam cracking in a semi-industrial dual fluidized bed reactor: Tackling the challenges in thermochemical recycling of plastic waste

Research on the radioactive safety of industrial steam supplied by PWR nuclear power plant

Research on the radioactive safety of industrial steam supplied by PWR nuclear power plant

Thermo-economic and environmental analyses of supercritical carbon dioxide Brayton cycle for high temperature gas-cooled reactor

Thermo-economic and environmental analyses of supercritical carbon dioxide Brayton cycle for high temperature gas-cooled reactor

Mathematical modeling for the production performance of cyclic multi-thermal fluid stimulation process in layered heavy oil reservoirs

Mathematical modeling for the production performance of cyclic multi-thermal fluid stimulation process in layered heavy oil reservoirs

A cradle-to-gate life cycle assessment for clean hydrogen gas production pathway using the CeO2/Ce2O3-based redox thermochemical cycle

A cradle-to-gate life cycle assessment for clean hydrogen gas production pathway using the CeO2/Ce2O3-based redox thermochemical cycle

Comprehensive assessment and energetic-exergetic performance optimization of a new solar thermal electricity system based on Scheffler-type receivers combined with screw-type volumetric machines

Comprehensive assessment and energetic-exergetic performance optimization of a new solar thermal electricity system based on Scheffler-type receivers combined with screw-type volumetric machines

Optimization of a novel hydrogen production process integrating biomass and sorption-enhanced reforming for reduced CO2 emissions

Optimization of a novel hydrogen production process integrating biomass and sorption-enhanced reforming for reduced CO2 emissions

Extraction of Origanum onites L. using an industrial-type microwave-assisted distillation (MWAD) system: Increasing energy saving and essential oil yield compared to conventional steam distillation

Extraction of Origanum onites L. using an industrial-type microwave-assisted distillation (MWAD) system: Increasing energy saving and essential oil yield compared to conventional steam distillation

Transcritical CO2 mixture power for nuclear plant application: Concept and thermodynamic optimization

Transcritical CO2 mixture power for nuclear plant application: Concept and thermodynamic optimization

Innovative Technology of Continuous-Steam Distillation with Packed Column to Obtain Essential Oil-Differentiated Fractions from Mexican Lime (Citrus aurantifolia)

Continuous distillation (CD) by steam is a patented emerging technology that allows us to obtain essential-oil fractions from citrus juices. It presents benefits such as reducing steam consumption by 50%, lowering environmental impact, and, by its design, obtaining fractions enriched in terpenic and oxygenated compounds that can be further processed. The CD of essential oils from Mexican lime juice (Citrus aurantifolia) was studied and the results were compared with conventional steam distillation (batch) in terms of steam consumption, extraction yield, chemical composition, and quality of the essential oils. Different steam flows were used: distillation without a packed column (sc); with packed column (cc); and steam flows of 10, 15, and 20 mL/min with a reflux ratio of 0.5, 1, and 2, respectively. CD was superior in terms of composition, extraction energy savings (0.63 kg steam/kg juice with 1.39 kg steam/kg juice in the conventional), and the extraction yield recovery efficiency was >90%. Gas chromatography-mass spectrometry analysis of the extracted essential oils indicated that the use of CD with a column increases the fractionation of volatile compounds. The result of this study demonstrates that CD can be used as an alternative method to extract the essential oil from lime or any citrus fruit, obtaining differentiated fractions in aroma and composition.