Vapor Recovery Research Articles

Optimization of energy-exergy efficiencies of an advanced cold energy utilization system in liquefied natural gas filling station

In this study, a novel cold energy utilization configuration of liquefied natural gas is presented for liquefied-compressed natural gas filling station by combining gasoline vapor recovery, power generation and blood freeze-drying. Aspen Plus software is employed for modeling, and the simulation results are compared with the published literature to verify the accuracy. Based on the analysis of gasoline vapor condensation temperature, when the condensation temperature is −30.2 °C, −59.8 °C and −114 °C in turn, the recovery efficiency can be guaranteed more than 95%, and the energy consumption is the most competitive. Subsequently, the influence of evaporator and turbine outlet pressure on the performance of the power generation subsystem is studied by thermodynamic analysis. Then, the genetic algorithm is applied to determine the optimal binary mixtures, and the optimization results exhibit that the maximum net power output and exergy efficiency reach 154.6 kW and 28.96%, respectively. Meanwhile, the equivalent output power of gasoline vapor recovery subsystem and blood freeze-drying subsystem are 139.14 kW and 305.53 kW, respectively. The economic analysis demonstrates that the design payback period is only 6.3 years, providing a new idea for reasonable utilization of cold energy in liquefied-compressed natural gas station.

Analysis of the vaporization processes in the vehicle fuel tank. New equation for determining the vapor amount

Introduction (problem statement and relevance). Hydrocarbon emissions from vaporizationtank fuel contribute significantly to the total emissions of hazardous substances from vehicles equipped with spark ignition engines. To meet the established standards for limiting hydrocarbon emissions caused by evaporation, all modern vehicles use fuel vapor recovery systems, the optimal parameters of which require the availability and application of mathematical models and methods for their determination.The purpose of the research was to develop a model of vapor generation processes in the car fuel tank and a methodology for determining the main quantitative parameters of the vapor-air mixture.Methodology and research methods. The analysis of the processes of vapor generation in the fuel tank was carried out. It was shown that the mass of hydrocarbons generated in the steam space was directly proportional to its volume and did not depend on the amount of fuel in the tank.Scientific novelty and results. New analytical dependences of the vaporization amount on the saturated vapor pressure, barometric pressure, initial fuel temperature and fuel heating during parking have been obtained.Practical significance. A formula was obtained to estimate the temperature of gasoline boiling starting in the tank, depending on the altitude above sea level and the volatility of gasoline, determined by the pressure of saturated vapors. Using the new equations, the vaporization analysis in real situations (parking, idling, refueling, explosive concentration of vapors) was carried out.

Cryogenic Vapor Recovery Unit for Light Fractions of Hydrocarbon Fuel

Cryogenic Vapor Recovery Unit for Light Fractions of Hydrocarbon Fuel

Improving the Performance of Composite Hollow Fiber Membranes with Magnetic Field Generated Convection Application on pH Correction.

The membranes and membrane processes have succeeded in the transition from major technological and biomedical applications to domestic applications: water recycling in washing machines, recycling of used cooking oil, recovery of gasoline vapors in the pumping stations or enrichment of air with oxygen. In this paper, the neutralization of condensation water and the retention of aluminum from thermal power plants is studied using ethylene propylene diene monomer sulfonated (EPDM-S) membranes containing magnetic particles impregnated in a microporous propylene hollow fiber (I-PPM) matrix. The obtained membranes were characterized from the morphological and structural points of view, using scanning electron microscopy (SEM), high resolution SEM (HR-SEM), energy dispersive spectroscopy analysis (EDAX) and thermal gravimetric analyzer. The process performances (flow, selectivity) were studied using a variable magnetic field generated by electric coils. The results show the possibility of correcting the pH and removing aluminum ions from the condensation water of heating plants, during a winter period, without the intervention of any operator for the maintenance of the process. The pH was raised from an acidic one (2–4), to a slightly basic one (8–8.5), and the concentration of aluminum ions was lowered to the level allowed for discharge. Magnetic convection of the permeation module improves the pH correction process, but especially prevents the deposition of aluminum hydroxide on hollow fibers membranes.

Process system analysis on oil processing facility and economic viability from oil well-to-tank

Hydrocarbon processing from extraction to the final product is an important aspect that needs an optimised technology for consumption-led market growth. This study investigated real data from the oil processing facility and analysed the simulation model for the entire crude oil processing unit based on the process system engineering aspect using Aspen HYSYS. The study mainly emphasises the process optimisation in processing the hydrocarbon for the maximum yield of the product with less energy consumption. The investigation also includes a thorough economic analysis of the processing facility. The datasets for oil properties are obtained from a modern petroleum refinery. The investigation comprises of varying transient conditions, such as well shutdowns using three oil reservoirs (low, intermediate, and heavy oil). The impact of various conditions, including process heating, well shutdown, oil combinations, presence of water on the production, is analysed. The results indicate that the factors involving crude oil processing are significantly affected by the process conditions, such as pressure, volume, and temperature. The vapour recovery unit is integrated with the oil processing model to recover the separator's gas. The optimisation analysis is performed to maximise the liquid recovery with Reid vapour pressure of 7 and minimum water content in oil around 0.5%. Economic analysis provided an overall capital cost of $ 9.7 × 106 and an operating cost of $2.1 × 106 for the process configuration. The model results further investigate the constraints that maximise the overall energy consumption of the process and reduce the operational cost.

ONLINE FIXED TANK VOLATILE ORGANIC CONTENT QUANTIFICATION USING MACHINE LEARNING

Tank emission calculation is typically performed offline, and manual data gathering from various tanks could be a timely and inefficient task. This paper presents iCON’s first principal process simulation software to perform tank emission quantification by leveraging its extensive database of all process simulation models and chemical components’ physical properties. Hence, a lot of operation cost is saved by eliminating the need for inventory sampling activity for each tank. This paper also will discuss online tank emission work processes to make them sustainable. iCON Tank Emission complies with the United States Environmental Protection Agency (USEPA) Compilation of Air Pollutant Emission Factors (AP-42) Fifth Edition Chapter 7 Liquid Storage Tanks that covers fixed roof tanks (vertical and horizontal) and floating roof tanks (internal, external, and domed) with a respective combination of the roof, shell, rim seal, fittings and breather vent settings. It is also linked to the monthly Malaysian Climate Condition covering domestic municipals’ temperature (minimum and maximum), Solar Irradiance Factor, and wind speed that improve the tank emission calculation accuracy. iCON Tank Emission lets users calculate thousands of tank emissions simultaneously by using iCON Machine Learning feature and displays the monthly and yearly summary reports for report standardisation among multiple business units. The simulation convergence time is instantaneous, making it time efficient for HSE engineers to perform strict monthly calculations and reporting online. Case studies and whatif scenarios could also be run to reduce tank emission via the introduction of vapour recovery and optimising tank mechanical parameters, i.e., type of rim seal, colour, and fittings selection. iCON Online Tank Emission links the iCON model with real-time plant information data for real-time tank emission calculation, transparent to management and regulators. The findings from this compositional first principle thermodynamic base tank emission simulation study are considered more efficient, faster, and cheaper than the conventional method.

Energy Conservation in The Petroleum Industry: Process Heat Integration for a Vapour Recovery Unit Using The Pinch Technology.(Dept.P)

Energy Conservation in The Petroleum Industry: Process Heat Integration for a Vapour Recovery Unit Using The Pinch Technology.(Dept.P)

Refueling emission of volatile organic compounds from China 6 gasoline vehicles

Vehicular refueling emission is a potential source of urban atmospheric volatile organic compounds (VOCs) that is not well understood and controlled. China 6 vehicles have been equipped with the onboard refueling vapor recovery (ORVR) system to cut down refueling emissions, while the emission characteristics and reduction effectiveness are rarely reported. In this study, we conducted laboratory tests to measure the refueling emissions from ten China 6 vehicles and three China 5 vehicles (refueling-emission-uncontrolled, REU) and developed an inventory in a typical middle-sized Chinese city (Langfang) to explore the emission reduction resulted from relevant policies. Compared with headspace vapor and refueling vapor from REU vehicles, the emission profiles for China 6 vehicles are consist of considerably higher proportions of small alkanes and alkenes (C2-C3) and lower proportions of C6-C8 hydrocarbons. Such differences indicate that the headspace vapor profiles are incapable of representing the refueling emission for China 6 vehicles. The market-share-weighting emission factors (EFs) of total hydrocarbons (THCs) and total VOCs for China 6 vehicles are 11.2 mg/L and 6.4 mg/L, respectively, corresponding to control efficiency of approximately 98.8% compared with the REU vehicles. Based on the real-world EFs and the fuel consumption in Langfang, a refueling emission inventory with high spatiotemporal resolution is developed. The total refueling emission of THCs in Langfang is approximately 190.6 tons in 2018 and will likely decline to 25.0 tons in 2035. The implementation of the ORVR will contribute to 90% of the refueling emission reduction in 2035.

Risk assessment of workers' exposure to BTEX and hazardous area classification at gasoline stations.

Vaporization of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds pollutes the air and causes health hazards at gasoline stations. This study revealed the risk of BTEX exposure according to the hazardous area classification at gasoline stations. The risk assessment of gasoline workers from a representative group of 47 stations, which followed the United States Environmental Protection Agency-IRIS method of assessing BTEX exposure, was expressed as the hazard index (HI). A result of matrix multipliers of the hazardous exposure index and fire possibility from flammable gas classified hazardous area-I and area-II at the fuel dispensers. BTEX concentrations were actively sampled in ambient air and a flammable gas detector was used to measure the flammability level. Results showed that the BTEX concentrations from ambient air monitoring were in the range of 0.1-136.9, 8.1-406.0, 0.8-24.1 and 0.4-105.5 ppb for benzene, toluene, ethylbenzene, and xylene, respectively, which exceeded the NIOSH exposure limit of 100 ppb of benzene concentration. The risk assessment indicated that five stations reached an unacceptable risk of worker exposure to BTEX (HI>1), which correlated with the numbers of gasoline dispensers and daily gasoline sold. The risk matrix classified hazardous area-I at 4 meters and hazardous area-II at 4-8 meters in radius around the fuel dispensers. This study revealed the hazardous areas at gasoline stations and suggests that entrepreneurs must strictly control the safety operation practice of workers, install vapor recovery systems on dispenser nozzles to control BTEX vaporization and keep the hazardous areas clear of fire ignition sources within an eight-meter radius of the dispensers.

Improving the economic efficiency of vapor recovery units at hydrocarbon loading terminals

The article discusses effective ways to reduce the cost of operating vapor recovery units and increase the financial result of their operation. The first method is based on regulation of the power-on time of the installation. The second method is based on using the potential energy of the fluid flow of the gravity section to supply the system equipment with energy. The potential savings on VRU maintenance will reduce the risks of payback of installations. The proposed methods will have a significant impact on society, as the possibility of a wider distribution of installations that protect the environment from emissions of volatile organic compounds into the atmosphere will become available.

Research on Decision Methods for Technical Solutions Based on Grey-correlation degree to Vapor Recovery of Refined Oil Terminals

In the process of decision on technical solution to vapor recovery of refined oil terminals, the grey-correlation analysis (GCA) is introduced to optimise technical solutions by building a multi-target decision model and using the sequencing of weighted grey-correlation degree (GCD) of evaluation solution as judgment criteria, to determine the priorities of solutions, and the effectiveness of the decision method is verified by a practical example.

Water vapor recovery device designed with interface local heating principle and its application in clean water production

The characteristic of the device is to realize the synchronization of sewage treatment and clean water production. The existence of superhydrophobic BiOBr layer selectively removes surface oil slick and degrades dissolved pollutants.

Evaluation of Pollutant Emissions into the Atmosphere during the Loading of Hydrocarbons in Marine Oil Tankers in the Arctic Region

Emissions of volatile organic compounds into the atmosphere when loading oil or petroleum products into tankers are strong environmental pollutants. Given the increase in oil transport by sea and the development of Arctic routes, humanity faces the task of preserving the Arctic ecosystem. Vapor recovery units can limit the emissions of volatile organic compounds. However, it is necessary to estimate the emissions of oil and petroleum products vapors. This article offers two methods for estimating emissions of volatile organic compounds. In the analytical method, a mathematical model of evaporation dynamics and forecasting tank gas space pressure of the tanker is proposed. The model makes it possible to estimate the throughput capacity of existing gas phase discharge pipeline systems and is also suitable for designing new oil vapor recovery units. Creating an experimental laboratory stand is proposed in the experimental method, and its possible technological scheme is developed.

Carbon Nanoporous Adsorbents Prepared from Walnut Shell for Liquefied Natural Gas Vapor Recovery in Cryogenic Storage Systems

Carbon Nanoporous Adsorbents Prepared from Walnut Shell for Liquefied Natural Gas Vapor Recovery in Cryogenic Storage Systems

Sol–Gel Synthesis of High‐Density Zeolitic Imidazolate Framework Monoliths via Ligand Assisted Methods: Exceptional Porosity, Hydrophobicity, and Applications in Vapor Adsorption

AbstractMonolithic ZIF‐8 and ZIF‐67 adsorbents are synthesized at room temperature using a novel, ligand‐assisted method. Despite reductions in crystallinity within some of the samples, monolithic zeolitic imidazolate frameworks (ZIFs) have superior volume‐relative microporosity, total porosity, and surface areas relative to their particulate counterparts due to increased density. Samples synthesized using a single modulator, n‐butylamine, have a hierarchical porosity resulting in improved adsorption capacities in mid‐ to high‐ sorbate pressure regions. ZIF‐67 monoliths produced through mixed‐modulator synthesis, n‐butylamine and 1‐methylimidazole, are almost entirely microporous. Vapor adsorption isotherms find that, whilst their amorphous content results in increased water uptake, monolithic ZIFs are found to possess higher surface and adsorption hydrophobicity than traditional non‐polar adsorbents. Cosorption measurements with a common VOC toluene, under humid conditions, find that these monolithic ZIF samples outperform powder equivalents, with the mixed‐modulator ZIF‐67 monolith capturing 28% more VOC compared to the powder ZIFs studied due to its superior volumetric efficiency. This study provides insights into the benefits of modulator‐based tuning of porosity within monolithic ZIFs which, combined with their hydrophobicity, may facilitate their application for industrial organic vapor recovery or indoor air cleaning, where efficient hydrophobic adsorbents which can operate in humid environments are essential.

Performance Analysis of Membrane Separation Process for Water and Heat Recovery from Flue Gas

Membrane separation process can simultaneously recover water vapour and waste heat from flue gases, which has great potential for water and energy savings. Composite ceramic nanoporous membrane is one of the emerging technologies showing the good performance of water vapour and waste heat recovery from the flue gas of power plants. However, the flue gas has great property changes along a flue resulting in a dramatic performance change of membrane separation. Current experimental studies couldn’t provide enough experience to explore the performance of membrane modules in a wide range of working conditions and structure configuration. In this paper, a calculation model is established based on thermodynamic mechanisms of membrane separation process to simulate the performance of ceramic membrane modules under different structure configuration and working conditions. Three cases are conducted to analyse the effects of module configuration and parameter selection in a ceramic membrane module. Results show that a ceramic membrane module placed before the desulphurisation tower can recover more heat, while after the desulphurisation tower it can recover more water. There would be an optimal tube diameter and an optimal tube spacing for water recovery under specific working conditions. These results show great adaptability of the calculation model and could guide the system design of membrane separation modules in water vapour and waste heat recovery.

EVALUATION OF THE EFFECTIVENESS OF THE COMBINED MEMBRANE-EJECTOR VAPOUR RECOVERY SYSTEM

Currently, the most common way to reduce hydrocarbon losses from evaporation at oil and petroleum products storage facilities is to use pontoons and floating roofs. However, vapour recovery systems can achieve a greater degree of loss reduction. Membrane vapour recovery units, that are widespread in Europe, are still not in use in Russia, although their high effectiveness is noted in some sources. Another promising way to reduce losses is to use ejector vapour recovery units. The article substantiates the use of combined membrane-ejector vapour recovery units: a methodology for calculating the effectiveness of such devices is proposed and an analysis of the influence of various parameters of membrane-ejector systems on the degree of reduction of gasoline losses during oil tank filling is made.

Production and evaluation of properties of waste-based carbon adsorbent

This paper focuses on the study of the production method, evaluation of quality indicators and application of adsorbents based on wood and common polymer wastes. The co-pyrolysis technique of polyethylene, polypropylene, polyethylene terephthalate and other polymers with sawdust at the weight ratio of 1:1 and 1:2 and temperature 370−500 °C is used for the production of adsorbents. Influence of polymer and wood type on the product quality is discussed. For the composition of birch wood and polypropylene, linear models for the yield estimation and indicators of the porous structure of adsorbents, based on the experiment planning method, are proposed, which allow us to forecast their quality under the joint influence of their production factors. The adsorbent at 500 °C was also characterized by optical and electron microscopy, X-ray fluorimetry, infrared spectrometry and low-temperature nitrogen adsorption method: its surface area (Brunauer–Emmett–Teller) is 435 m2/g, surface area of micropores (t-plot) is 316 m2/g; the average pore diameter is 1.93 nm; the total pore volume is 0.20 cm3/g. The sample at 370 °C has maximal volume of pores sorbing 0.662 cm3/g of benzene and 0.703 cm3/g of tetrachlormethane and expressed hydrophobic properties; these values are superior to those of birch activated carbon twice. Its use for the vapor recovery of benzene from the airflow was evaluated, which showed its high activity (322 mg/g) and superiority over commercial activated carbon. An approximate ecological and economic evaluation of this adsorbent production has been carried out, demonstrating its profitability and environmental effectiveness.

Summary of VOCs Treatment Technology in Product Oil Depot

With the continuous development of social industry and economy, environmental problems are increasingly prominent. The problem of VOCs emission treatment needs to be solved. This paper introduces the source and harm of oil vapor produced in oil depot, and expounds the treatment measures of VOCs. The treatment measures of storage tank are introduced. The principle and research progress of four kinds of recovery processes are described. The development mode and research direction of VOCs treatment in oil depots in the future are prospected, the importance of oil vapor recovery is pointed out, and the recovery technology of VOCs should be developed in the direction of intelligence, integration, miniaturization and energy saving.

Методика прогнозирования степени улавливания паров углеводородов при абсорбции

Over the years of practical use of absorption, various methods for calculating absorbers have been developed. Among others, the calculation of mass transfer processes was created based on the use of a so-called mass transfer coefficient β, showing how much mass of the target substance passes from the gas phase to the liquid one through a surface area unit per time unit. To determine β, empirical equations are used depending on their validity for a particular type of absorber and operating conditions given. However, these calculations are relatively complex and fail to be applicable to whatever absorber design used. The calculations of phase transitions using phase equilibrium constants do not depend on the design features of the equipment where mass transfer occurs. However, to date, the phase equilibrium theory has been applied to calculate the separation of a multicomponent mixture under no air condition; therefore, it could not be used to predict phase transitions when a gas-air mixture contacts a liquid absorber. Based on the theory of phase transitions, the authors developed a simplified method for predicting the degree of oil vapor recovery at absorption. The technique was successfully tested through calculating the efficiency of the jet absorption unit used to recover oil vapor. Also, the installation performance at absorbent replacement was simulated. The replacement of easily volatile oil used as a working fluid with oil of a lower saturated vapor pressure was shown to significantly increase the degree of hydrocarbon vapor recovery. The possibility of applying the technical solution is limited with the following conditions: low-volatile liquids used as absorbent cannot be highly viscous and have a high pour point; their quality should not deteriorate when absorbing oil vapor; the cost of replacing the working fluid should be reasonable.