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Development of the multigeneration plants based on the simultaneous production of water and energy can solve many of the current problems of these two major fields. In addition, the integration of fossil power plants with waste heat recovery processes in order to prevent the release of pollutants in the environment can simultaneously cover the environmental and thermodynamic improvements. Besides, the addition of a carbon dioxide (CO2) capturing cycles with such plants is a key issue towards a sustainable environment. Accordingly, a novel waste heat recovery-based multigeneration plant integrated with a carbon dioxide separation/liquefaction cycle is proposed and investigated under multi-variable assessments (energy/exergy, financial, and environmental). The offered multigeneration system is able to generate various beneficial outputs (electricity, liquefied CO2 (L-CO2), natural gas (NG), and freshwater). In the offered system, the liquified natural gas (LNG) cold energy is used to carry out condensation processes, which is a relatively new idea. Based on the results, the outputs rates of net power, NG, L-CO2, and water were determined to be approximately 42.72 MW and 18.01E+03, 612 and 3.56E+03 kmol/h, respectively. Moreover, the multigeneration plant was efficient about 32.08% and 87.72%, respectively, in terms of energy and exergy. Economic estimates indicated that the unit product costs of electricity and liquefied carbon dioxide production, respectively, were around 0.0466 USD per kWh and 0.0728 USD per kg-CO2. Finally, the total released CO2 was about 0.034 kg per kWh. According to a comprehensive comparison, the offered multigeneration plant can provide superior environmental, thermodynamic, and economic performances compared to similar plants. Moreover, there was no need to purchase electricity from the grid.

The parallel processes involved in the production of refinery fuel gas, liquid petroleum gas (LPG), propylene, and polypropylene, occurring in thirteen refinery units, are modeled by the use of a Generalized Net (GN) apparatus. The modeling of the production of these products is important because they affect the energy balance of petroleum refinery and the associated emissions of greenhouse gases. For the first time, such a model is proposed and it is a continuation of the investigations of refinery process modelling by GNs. The model contains 17 transitions, 55 places, and 47 types of tokens, and considers the orders of fuel gas for the refinery power station, refinery process furnaces, LPG, liquid propylene, and 6 grades of polypropylene. This model is intended to be used as a more detailed lower-level GN model in a higher-level GN model that facilitates and optimizes the process of decision making in the petroleum refining industry. [ABSTRACT FROM AUTHOR]

Waste tires are also known as "black pollution", and pose significant risks to human health and ecosystems. The pyrolysis process can recover valuable products such as natural gas, oil, and pyrolysis carbon black (CBp), with CBp being the most important one. However, CBp from waste tires has a high degree of particle aggregation and low oil absorption value, making it difficult to further utilize. In this work, we propose a novel method to activate CBp by simulated fuel gas, which fully utilizes exhaust gas resources and enables the reuse of resources. The simulated fuel gas, composed of a mixture of N2 and CO2, was used to investigate the effects of activation temperature (700–1000 °C), activation time (2–5 h), flow rates (30–50 mL·min−1), and the content of CO2 in the simulated fuel gas (10%-90% (volume)) on increasing the specific surface area. The samples were analyzed using XRD, SEM, N2 adsorption/desorption, and Raman shift. The results indicate that the hybrid atoms and carbon atoms in CBp can absorb enough energy to open the closed pores, allowing the activator to fully react with CBp. This work demonstrates a feasible approach to improve the high value-added utilization of cracked carbon black. [ABSTRACT FROM AUTHOR]

Objective The aim is to recycle C3+ and H2 in refinery fuel gas to improve economic benefits. Methods Through the analysis and comparison of the fuel gas from different sources, the hydrogen-rich and high-level C3+ fuel gas are found out. Then the process of H2 recycling is optimized and the area of dehydrogenation membrane is increased so as to improve the amount of H2 recovery. The absorption and stabilization system of catalytic unit and coking unit is used to recover C3+ in fuel gas. Results The total investment of technological transformation is 3.2 million yuan, this can recover 12. 3×10³ tons of C3+ components per year, increase the benefits by 30 million yuan per year, recover H2 10, 5X 106 m³ per year, and reduce the cost of H2 production by 12 million yuan per year. Conclusions This scheme makes full use of the existing absorption and stabilization system and the existing dehydrogenation system of the refinery to expand the capacity, it has the advantages of less investment, good benefit and quick efficiency, and great significance for the high-quality development of Yumen Refining and Chemical Plant. [ABSTRACT FROM AUTHOR]

Since carbon dioxide (CO2) has a more substantial impact on climate change, it must be recycled to slow down global warming. In this work, wet impregnation (at a 3 wt.% concentration), drying, and calcination processes were used to synthesise calcium oxide-loaded carbon beads (CaO/CB). In order to produce Ca/CB (catalyst) from the CaO/CB, hydrogen gas was employed for the reduction process. Then, the obtained Ca/CB were used in a packed bed reactor (PBR) to produce carbon monoxide (CO) as a fuel gas from CO2 by thermocatalytic gasification process. The experiments were conducted with non-catalysed CB and the Ca/CB catalyst from 100 to 900 °C and 100 to 300 °C, respectively. The current study reveals that Ca reactive sites on Ca/CB have significantly higher gasification activity than the non-catalysed CB for CO2 reduction. The samples (CB and CaO/CB) were thoroughly characterised by N2 adsorption and desorption isotherms, FESEM with EDX, XRD, TG-DSC, and FTIR spectroscopy. Also, gas chromatography was used to verify the reactant and product species qualitatively and quantitatively. Compared with regular CB, Ca/CB has a maximum CO2 conversion and CO yield of 50.7% at 150 °C. In contrast, CO formation began to occur above 300 °C using regular CB. For this, the PBR was operated with CO2 on a CB-filled and catalyst-filled (Ca/CB) reactive zone at a 100 mL/min flow rate under the same circumstances. These findings lead to the hypothesis that the kinetic barrier for converting CO2 to CO can be overcome by Ca/CB. [ABSTRACT FROM AUTHOR]

In this study, the effect of gasifying agent and bed material on the performance of the co-gasification of a mixture of coal, plastic waste, and wood was investigated. The experimental runs were carried out in a lab-scale bubbling fluidized bed reactor utilizing air, oxygen-enriched air, a mixture of air and steam, and a mixture of oxygen and carbon dioxide as reactant gases, while silica sand, olivine, and a mixture of olivine and dolomite as bed materials were used. The results indicated that both gasifying agent and bed material strongly affect the gas composition and, as a consequence, the process performance. In particular, the test with oxygen-enriched air and silica sand provided a producer gas with the highest heating value (9.32 MJ/Nm3), while the best performance in terms of gas yield (2.98 Nm3/kg) and tar reduction (−94.5%) was obtained by utilizing the air/steam mixture and olivine. As regards tar composition, it was observed that the most abundant and recalcitrant tar substance groups are naphthalenes and PAHs. On the other hand, phenols and furans appear to be the most sensitive groups to the effect of gasifying agent and bed material. [ABSTRACT FROM AUTHOR]

The processing of coal tar pitch (CTP) to produce clean fuel gas and carbon black (CB) is studied in a plasma reactor equipped with a direct-current plasma torch. The composition of the gas produced and energy costs were estimated theoretically for the CTP pyrolysis and gasification processes by two oxidants, namely oxygen and water vapor. We have found that the main gaseous compounds obtained in the pyrolysis and gasification processes are hydrogen (H2), carbon monoxide (CO), and very often carbon dioxide (CO2). For the pyrolysis case, the mean value of the synthesis gas concentration reaches a major value of 98 vol.% (H2 – 81 vol.%, CO – 17. vol.%). However, only 23% of the initial CTP is transformed into gas phase at 1100 K and its content increases up to 37.4% at a temperature of 3000 K. For oxygen gasification, the syngas quantity is little less compared to the pyrolysis case and attains 96.6 vol.% (H2 – 26.5 vol.%, CO – 70.1 vol.%) for T > 1100 K. An intermediate syngas content for the water steam gasification is 97.8 vol.% (with H2 – 55.8 vol.% and CO – 42.0 vol.%). The CB produced was composed of well-defined spherical particles of 30-nm size. Furthermore, it is composed of carbon (98.2%), and followed by oxygen (1.8%) with a surface area of 97 m2 g−1. The thermal plasma system shows high efficiency in conversion of CTP into high-value-added products. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The growth in demand for the production of heat and electricity requires an increase in fuel consumption by power equipment. At the moment, the most demanded thermal equipment for construction and modernization is gas turbine units. Gas turbines can burn a variety of fuels (natural gas, synthesis gas, methane), but the main fuel is natural gas of various compositions. The use of alternative fuels makes it possible to reduce CO 2 and NO x emissions during the operation of a gas turbine. Under conditions of operation of thermal power plants at the wholesale power market, it becomes probable that combined cycle power units, designed to carry base load, will start to operate in variable modes. Variable operation modes lead to a decrease in the efficiency of power equipment. One way to minimize or eliminate equipment unloading is to install an electrolysis unit to produce hydrogen. In this article the technology of "Power to gas" production with the necessary pressure at the outlet of 30 kgf/cm2 (this pressure is necessary for stable operation of the fuel preparation system of the gas turbine) is considered. High cost of hydrogen fuel during production affects the final cost of heat and electric energy, therefore it is necessary to burn hydrogen in mixture with natural gas. Burning a mixture of 5% hydrogen fuel and 95% natural gas requires minimal changes in the design of the gas turbine, it is necessary to supplement the fuel preparation system (install a cleaning system, compression for hydrogen fuel). In addition, the produced hydrogen can be stored, transported to the consumer. For the possibility of combustion of a mixture of natural gas and hydrogen fuel in a gas turbine the methodology of calculation of thermodynamic properties of working bodies developed by a team of authors under the guidance of Academician RAS (the Russian Academy of Sciences) V.E. Alemasov has been adapted, resulting in a program that allows to obtain an adequate mathematical model of the gas turbine. The permissible range of the working body temperature is limited to 3000 K. This paper presents the developed all-mode mathematical model of a gas turbine. On the basis of mathematical modeling of a gas turbine, a change in the main energy and environmental characteristics is shown depending on the composition of the fuel gas. Adding 5% hydrogen to natural gas has little effect on the gas turbine air treatment system, the flow rate remains virtually unchanged. CO 2 emissions decrease, but there is an increase in the amount of H 2 O in the turbine exhaust gases. [ABSTRACT FROM AUTHOR]

In various industries, hydrogen is used as the main raw material, as an auxiliary material, and/or as a fuel. Oil refining and petrochemical enterprises consume up to 50 % of the hydrogen produced. A promising method is proposed for hydrogen production, which consists in preliminary thermolysis of heavy oil stock, followed by catalytic conversion of steam-gas products, which makes it possible to reduce hydrogen production cost. The method will allow greater degree of feedstock processing and expansion of refinery feedstock base. [ABSTRACT FROM AUTHOR]

The parallel processes involved in the production of refinery fuel gas, liquid petroleum gas (LPG), propylene, and polypropylene, occurring in thirteen refinery units, are modeled by the use of a Generalized Net (GN) apparatus. The modeling of the production of these products is important because they affect the energy balance of petroleum refinery and the associated emissions of greenhouse gases. For the first time, such a model is proposed and it is a continuation of the investigations of refinery process modelling by GNs. The model contains 17 transitions, 55 places, and 47 types of tokens, and considers the orders of fuel gas for the refinery power station, refinery process furnaces, LPG, liquid propylene, and 6 grades of polypropylene. This model is intended to be used as a more detailed lower-level GN model in a higher-level GN model that facilitates and optimizes the process of decision making in the petroleum refining industry.

In this study, char-supported metal composites (0.2Ni-RHC, 0.2Fe-RHC and 0.2Co-RHC) were prepared via impregnation and subsequent microwave heating method, which were used as both microwave absorbers and catalysts for in-situ microwave-induced pyrolysis of pine sawdust, aiming to obtain high-quality fuel gas based on the interaction of microwave radiation and metal active sites in catalysts. The results showed that well-dispersed nanoparticles were generated in the three catalysts, which were firmly anchored on the matrix of the char support by several layers of graphitic carbon. The catalysts exhibited excellent microwave absorbing properties, a rapid heating rate was achieved which realized the temperature rise from room temperature to 800 °C within 110 s 0.2Fe-RHC exhibited the best catalytic performance among these three catalysts, with a high gas yield of 73.4% and low solid and bio-oil yield of only 4.1% and 13.6%, respectively. The yield of H 2 and CO increased from 137.7 to 190.6 mL/g and from 241.2 mL/g to 393.9 mL/g compared with that of pure RHC. The microwave heating behavior and the catalytic activity of char-supported Fe catalyst were also influenced by the loading amount of Fe. [Display omitted] • Biochar-supported metal composites were prepared as catalysts and microwave absorbers. • Porous biochar support with well dispersed metal nanoparticles were obtained. • The catalysts can be heated to 800 °C within 1.5 s by microwave heating. • The gas yield reached 73.4% with H 2 and CO yield of 190.6 and 393.9 mL/g for 0.2Fe-RHC. • Excessive Fe loading reduced the catalytic activity of biochar-supported Fe catalysts. [ABSTRACT FROM AUTHOR]

Zero valent iron (Fe0) water remediation studies, over the last 40 years, have periodically reported the discovery of CnH2n+2 in the product water or product gas, where n = 1 to 20. Various theories have been proposed for the presence of these hydrocarbons. These include: (i) reductive transformation of a more complex organic chemical; (ii) hydrogenation of an organic chemical, as part of a degradation process; (iii) catalytic hydrogenation and polymerisation of carbonic acid; and (iv) redox transformation. This study uses wastewater (pyroligneous acid, (pH = 0.5 to 4.5)) from a carbonization reactor processing municipal waste to define the controls for the formation of CnH2n+2 (where n = 3 to 9), C3H4, and C3H6. A sealed, static diffusion, batch flow reactor, containing zero-valent metals [181 g m-Fe0 + 29 g m-Al0 + 27 g m-Cu0 + 40 g NaCl] L−1, was operated at two temperatures, 273–298 K and 348 K, respectively. The reactions, reactant quotients, and rate constants for the catalytic formation of H2(g), CO2(g), C3H4(g), C3H6(g), C3H8(g), C4H10(g), C5H12(g), C6H14(g,l), and C7H16(g,l), are defined as function of zero valent metal concentration (g L−1), reactor pressure (MPa), and reactor temperature (K). The produced fuel gas (422–1050 kJ mole−1) contained hydrogen + CnHy(gas), where n = 3 to 7. The gas production rate was: [1058 moles CnHy + 132 moles H2] m−3 liquid d−1 (operating pressure = 0.1 MPa; temperature = 348 K). Increasing the operating pressure to 1 MPa increased the fuel gas production rate to [2208 moles CnHy + 1071 moles H2] m−3 liquid d−1. In order to achieve these results, the Fe0, operated as a "Smart Material", simultaneously multi-tasking to create self-assembly, auto-activated catalysts for hydrogen production, hydrocarbon formation, and organic chemical degradation (degrading carboxylic acids and phenolic species to CO2 and CO). [ABSTRACT FROM AUTHOR]

The NOx produced from industrial facilities is a serious environmental problem in China. In this work, the NOx emission from the combustion of natural gas in the sidewall burner was investigated by using CFD method. To achieve the low NOx emission, the sidewall burner structure was optimized involving the width of the primary premixed gas outlet, the secondary fuel gas nozzles number and angular spacing. The mixing rate of fuel gas and air could be improved by increasing the width of primary premixed gas outlet, and the lowest NOx emission of 32.8 ppm was achieved at the width of 8 mm. The NOx emission was remarkably reduced with the increasing of nozzles number, where 28.33 ppm of NOx emission and 357.35 ppm of CO were obtained at four nozzles. The combustion performance and NOx emission was improved as well as NOx emission was reduced at the angular spacing of 55°, compared to that of 30°, 35°, 40°, 45°, 50°, and 60°. [ABSTRACT FROM AUTHOR]

PURPUSE. This article describes the possibility of burning natural gas from different fields in a stationary power gas turbine General Electric 6FA. METHODS. Currently, gas turbine technologies are one of the most stably developing areas related to the modernization of generating equipment. At present, modernization of power plants is underway both with gas turbine units and with units in the combined-cycle power unit in the Republic of Tatarstan. The conducted studies allow us to evaluate the effect of the component composition of the fuel on the performance of a gas turbine. Comparative studies make it possible to evaluate changes in the energy characteristics of a gas turbine operating as part of a combined cycle gas turbine unit. RESULTS. The study shows that changes in the fuel composition have an impact on the energy characteristics of a gas turbine plant (efficiency, air consumption). Work with a deviation of the Wobbe index is not permissible. The deviation of the Wobbe index for the city of Zainsk is 5.29%, therefore, when installing a gas turbine it is necessary to change the setting of the fuel system. For synthesis gas, the deviation of the Wobbe index was 22.23%, the use of this fuel is unacceptable without changing the design and setting of the fuel system, since the throughput of the fuel system is not designed for a flow rate of 27.8 kg/s. The smallest values of the amount of CO2, NO, O2 in the composition of the combustion products are achieved on the fuel gas of the city of Kazan. CONCLUSION. The use of synthesis gas as the only fuel is undesirable when operating a gas turbine in a combinedcycle unit, since the calorific value of the flue gases when operating on synthesis gas is minimal and amounts to 94.3 MW, which will affect the operation of the steam turbine.

Hypothesis: Aerogels are new nanostructured materials that have attracted much attention in recent decades. In the meantime, polymeric aerogels have found special applications due to their lightness and cost-effectiveness. In this study, the carbon aerogels were used to filter the gases from fossil fuels. The challenge of this research is to try to increase the efficiency of gas separation, which is proportional to the surface area and structure of the separator.Methods: Carbon nanocomposite aerogel was made using pre-polymeric material with a high specific surface area and with nanostructure morphology during carbonization process at temperatures 600 and 1200°C. Novolac resin was selected for its low cost and solubility in alcohols as a polymer matrix in sol-gel polymerization. Expanded graphite due to its unique properties and relatively good distribution and for reaction with novolac was used as reinforcement. In this study, a sample with a distribution of fine colloids was selected by examining the distribution of carbon aerogel colloids by combining different percentages of novallac solid in primary sol. Again, by examining the size of the cavities, the production of the aerogel was made by combining the selected precursor composition with four percentages of expanded graphite. Then, the samples were pyrolized at two different temperatures. In the following, the effect of expanded graphite nanoparticles and degree of crystallinity of carbon nanocomposite aerogel on the filtration efficiency of gases from fossil fuels was investigated. To evaluate the effect of different crystallinity of aerogel, carbon aerogels were prepared at temperatures of 600 and 1200°C with different degree of crystallinity. Findings: The results of this study showed that samples of carbon aerogel with 0.75% wt expanded graphite and pyrolized at 1200°C showed 40% higher carbon dioxide absorption efficiency than pure samples.

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Several pyrolysis plants have been developed and commercially operated to produce fuel oil from plastic waste. By contrast, only a few examples of fuel-gas production plants have been reported. This study investigates the feasibility of fuel-gas production from plastic waste using a bench-scale pyrolysis plant by analyzing the material and energy balances of the plant. As part of a waste-to-fuel-gas project for substituting natural gas used in cogeneration equipment, this study examines the material and energy balances during operation of an externally heated rotary kiln reactor.The scale-up simulation of a 200-kg/h plant was performed based on the operation results obtained for a 2-kg/h plant using polypropylene and laminates of polypropylene with polyethylene terephthalate as feedstock. Based on the 200-kg/h plant estimates, the amount of fuel generated as fuel gas, fuel-gas consumed, and excess fuel gas used for supplying electricity to a factory using a cogeneration system equaled 3.86 × 107, 1.49 × 107, and 2.42 × 107 MJ/year, respectively, in terms of the lower heating value. The excess fuel could be used as a natural-gas substitute in cogeneration systems. In cases where a fuel-gas production system with 200-kg/h capacity costs less than USD 2,467,000, the pyrolysis-based fuel production is considered economically beneficial compared to the current treatment methods owing to the associated cost savings of up to approximately USD 177,000/year realized by ensuring substitution of 2.42 × 107 MJ/year of natural gas.

Zero valent iron (Fe0) water remediation studies, over the last 40 years, have periodically reported the discovery of CnH2n+2 in the product water or product gas, where n = 1 to 20. Various theories have been proposed for the presence of these hydrocarbons. These include: (i) reductive transformation of a more complex organic chemical; (ii) hydrogenation of an organic chemical, as part of a degradation process; (iii) catalytic hydrogenation and polymerisation of carbonic acid; and (iv) redox transformation. This study uses wastewater (pyroligneous acid, (pH = 0.5 to 4.5)) from a carbonization reactor processing municipal waste to define the controls for the formation of CnH2n+2 (where n = 3 to 9), C3H4, and C3H6. A sealed, static diffusion, batch flow reactor, containing zero-valent metals [181 g m-Fe0 + 29 g m-Al0 + 27 g m-Cu0 + 40 g NaCl] L−1, was operated at two temperatures, 273–298 K and 348 K, respectively. The reactions, reactant quotients, and rate constants for the catalytic formation of H2(g), CO2(g), C3H4(g), C3H6(g), C3H8(g), C4H10(g), C5H12(g), C6H14(g,l), and C7H16(g,l), are defined as function of zero valent metal concentration (g L−1), reactor pressure (MPa), and reactor temperature (K). The produced fuel gas (422–1050 kJ mole−1) contained hydrogen + CnHy(gas), where n = 3 to 7. The gas production rate was: [1058 moles CnHy + 132 moles H2] m−3 liquid d−1 (operating pressure = 0.1 MPa; temperature = 348 K). Increasing the operating pressure to 1 MPa increased the fuel gas production rate to [2208 moles CnHy + 1071 moles H2] m−3 liquid d−1. In order to achieve these results, the Fe0, operated as a “Smart Material”, simultaneously multi-tasking to create self-assembly, auto-activated catalysts for hydrogen production, hydrocarbon formation, and organic chemical degradation (degrading carboxylic acids and phenolic species to CO2 and CO).

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)