Gas Volume Research Articles

Flow rate measurements of slug flow by pressure differences of a venturi tube with a swirler

When the elongated bubbles and liquid slugs of slug flow alternately flow through a throttling element, the strong random fluctuations of pressure difference leads to low accuracy of online measurement of gas-liquid flow rates. In this paper, slug flow is converted into an annular flow before entering a venturi tube using a swirler, and the pressure fluctuation amplitude of the gas-liquid two-phase flow is greatly reduced, and the linear correlation between the pressure difference and the gas-liquid flow rates is more significant. The effects of gas-liquid flow rates on the axial pressure difference ΔPs across the swirler, the radial pressure difference ΔPr on a cross-section downstream of the swirler and the axial pressure difference ΔPo of the venturi tube were studied under the condition of 40%–82% gas volume fraction. The square root of the pressure difference increases linearly with the liquid/gas flow rate, and the empirical correlations between the square root of the pressure differences and the gas-liquid flow rates are established. By combining the empirical correlations in pairs, three flow rates measurement models of slug flow based on double pressure differences are established. When ΔPo and ΔPs are used as the measurement parameters of flow rates, the relative errors of liquid-phase flow rate and gas-phase flow rate are below ±2% and ±15%, respectively. When ΔPo and ΔPr are used as the measurement parameters of flow rates, the relative errors of liquid-phase flow rate and gas-phase flow rate are below ±3% and ±15%, respectively. It provides high-precision, low-cost and non-radioactive two-phase flow measurement technology for oil-gas gathering and transportation.

Impact of Depth on Underground Hydrogen Storage Operations in Deep Aquifers

Underground hydrogen storage in geological structures is considered appropriate for storing large amounts of hydrogen. Using the geological Konary structure in the deep saline aquifers, an analysis of the influence of depth on hydrogen storage was carried out. Hydrogen injection and withdrawal modeling was performed using TOUGH2 software, assuming different structure depths. Changes in the relevant parameters for the operation of an underground hydrogen storage facility, including the amount of H2 injected in the initial filling period, cushion gas, working gas, and average amount of extracted water, are presented. The results showed that increasing the depth to approximately 1500 m positively affects hydrogen storage (flow rate of injected hydrogen, total capacity, and working gas). Below this depth, the trend was reversed. The cushion gas-to-working gas ratio did not significantly change with increasing depth. Its magnitude depends on the length of the initial hydrogen filling period. An increase in the depth of hydrogen storage is associated with a greater amount of extracted water. Increasing the duration of the initial hydrogen filling period will reduce the water production but increase the cushion gas volume.

Enforcing accurate volume conservation in VOF‐based long‐term simulations of turbulent bubble‐laden flows on coarse grids

AbstractThis study proposes two different strategies to enforce accurate volume conservation in volume‐of‐fluid (VOF)‐based simulations of turbulent bubble‐laden flows on coarse grids. It is demonstrated that, without a correction, minimal volume errors on a time‐step level, caused by the under‐resolution of the interface, can accumulate to significant deviations from the intended flow conditions despite the comparably good volume conservation properties of the geometric VOF method. In particular, large volume errors are observed for challenging setups combining coarse grid resolutions and comparably high Reynolds and Eötvös numbers. The problem is reinforced for long‐term simulations in periodic domains, which are often performed to collect flow statistics of bubbly flows. The first proposed volume conservation method simply corrects the volume error of a bubble by uniformly adding or removing the respective amount of gas volume in the interface cells. The second proposed method performs an additional reconstruction and advection step of the VOF field using a non‐divergence‐free velocity field, which can be interpreted as a slight dilatation or contraction of the bubble. A comparison between the global flow statistics as well as the individual bubble dynamics for both volume conservation methods reveals that the results are quasi‐identical for a number of challenging test cases, while the gas volume is accurately conserved. The proposed methods allow to perform numerical simulations of freely deformable bubbles in turbulent flows for setups that have previously been out of reach for this numerical framework.

Effects of different thawing methods on physical and physicochemical properties of frozen dough and quality of corresponding steamed bread

The thawing method is critical for the final quality of products based on the frozen dough. The effects of ultrasound thawing, proofer thawing, refrigerator thawing, water bath thawing, ambient thawing, and microwave thawing on the rheology, texture, water distribution, fermentation characteristics, and microstructure of frozen dough and the properties of steamed bread were investigated. The results indicated that the ultrasound thawing dough had better physicochemical properties than other doughs. It was found that ultrasound thawing restrained the water migration of dough, improved its rheological properties and fermentation capacity. The total gas volume value of the ultrasound thawing dough was reduced by 21.35% compared with that of unfrozen dough. The ultrasound thawing dough displayed a thoroughly uniform starch-gluten network, and an enhanced the specific volume and internal structure of the steamed bread. In conclusion, ultrasound thawing effectively mitigated the degradation of the frozen dough and enhanced the quality of steamed bread.

Programmable intratumoral drug delivery to breast cancer using wireless bioelectronic device with electrochemical actuation

ABSTRACT Objective Breast cancer is a global health concern that demands attention. In our contribution to addressing this disease, our study focuses on investigating a wireless micro-device for intratumoral drug delivery, utilizing electrochemical actuation. Microdevices have emerged as a promising approach in this field due to their ability to enable controlled injections in various applications. Methods Our study is conducted within a computational framework, employing models that simulate the behavior of the microdevice and drug discharge based on the principles of the ideal gas law. Furthermore, the distribution of the drug within the tissue is simulated, considering both diffusion and convection mechanisms. To predict the therapeutic response, a pharmacodynamic model is utilized, considering the chemotherapeutic effects and cell proliferation. Results The findings demonstrate that an effective current of 3 mA, along with an initial gas volume equal to the drug volume in the microdevice, optimizes drug delivery. Microdevices with multiple injection capabilities exhibit enhanced therapeutic efficacy, effectively suppressing cell proliferation. Additionally, tumors with lower microvascular density experience higher drug concentrations in the extracellular space, resulting in significant cell death in hypoxic regions. Conclusions Achieving an efficient therapeutic response involves considering both the characteristics of the tumor microenvironment and the frequency of injections within a specific time frame.

Determination of internal gas losses during cyclic operation of an underground gas storage using identification modeling

An identification modeling method is proposed that makes it possible to determine of in-situ gas losses during the cyclic operation of underground gas storages (UGS) facilities and, on its basis, a preliminary estimate of in-situ gas losses during the cyclic operation of a particular tectonic block of the Galmaz UGS facility is predicted. It has been established that the main part of in-situ gas losses is the volume of gas that has diffused into the formation waters.

Thermal Runaway Characteristics and Gas Analysis of LiNi0.9Co0.05Mn0.05O2 Batteries

Layered ternary materials with high nickel content are regarded as the most promising cathode materials for high-energy-density lithium-ion batteries, owing to their advantages of high capacity, low cost, and relatively good safety. However, as the nickel content increases in ternary layered materials, their thermal stability noticeably decreases. It is of paramount importance to explore the characteristics of thermal runaway for lithium-ion batteries. In this study, two high-nickel LiNi0.9Co0.05Mn0.05O2 batteries were laterally heated to thermal runaway in a sealed chamber filled with nitrogen to investigate the thermal characteristics and gas compositions. The temperature of the battery tabs was measured, revealing that both batteries were in a critical state of thermal runaway near 120 degrees Celsius. A quantitative analysis method was employed during the eruption process, dividing it into three stages: ultra-fast, fast, and slow; the corresponding durations for the two batteries were 3, 2, 27 s and 3, 3, 26 s. By comparing the changes in chamber pressure, it was observed that both batteries exhibited a similar continuous venting duration of 32 s. However, the pressure fluctuation ranges of the two samples were 99.5 and 68.2 kPa·m·s−1. Compared to the other sample, the 211 Ah sample exhibited larger chamber pressure fluctuations and reached higher peak pressures, indicating a higher risk of explosion. In the experimental phenomenon captured by a high-speed camera, it took only 1 s for the sample to transition from the opening of the safety valve to filling the experimental chamber with smoke. The battery with higher energy density exhibited more intense eruption during thermal runaway, resulting in more severe mass loss. The mass loss of the two samples is 73% and 64.87%. The electrolyte also reacted more completely, resulting in a reduced number of measured exhaust components. The main components of gaseous ejections are CO, CO2, H2, C2H4, and CH4. For the 211 Ah battery, the vented gases were mainly composed of CO (41.3%), CO2 (24.8%), H2 (21%), C2H4 (7.4%) and CH4 (3.9%), while those for the other 256 Ah battery were mainly CO (30.6%), CO2 (28.5%), H2 (21.7%), C2H4 (12.4%) and CH4 (5.8%). Comparatively, the higher-capacity battery produced more gases. The gas volumes, converted to standard conditions (0 °C, 101 kPa) and normalized, resulted in 1.985 L/Ah and 2.182 L/Ah, respectively. The results provide valuable guidance for the protection of large-capacity, high-energy-density battery systems. The quantitative analysis of the eruption process has provided assistance to fire alarm systems and firefighting strategies.

Possible physical mechanisms of the high echogenicity of lipid coated nanobubbles

Lipid coated nanobubbles (NBs) have attracted a great level of interest as ultrasound (US) contrast agents due to their ability to extravagate through leaky tumor vasculature. Their linear resonance frequency is in the range of ∼50 M Hz–200 MHz, leading to confusion over their observed strong contrast in diagnostic US frequencies. By solving the Marmottant model, the dynamics of uncoated and lipid coated NBs and microbubbles (MBs) are studied over the frequency and pressure ranges (6–12 MHz, 0.1–1.2 MPa) generally used in diagnostic US. A novel bifurcation analysis in tandem with the analysis of the frequency component of the scattered pressure are conducted. Results show that despite the increased linear resonance frequency and viscous damping due to the lipid shell, buckling and rupture of the shell enhances the generation of the 2nd and 3rd harmonic resonances at pressures as low as 0.2 MPa, not observed with uncoated NBs. The generation of the harmonic resonances are concomitant with an abrupt increase in the 2nd and 3rd harmonic frequency component of the scattered pressure with their pressure threshold (PT) increasing with decreasing NBs size. For the same gas volume, and above the PT, the maximum non-destructive 2nd and 3rd harmonic powers of NBs can become higher than the 2–4 μm MBs. Similar to the lower subharmonic pressure threshold of MBs, the dynamic variation of the NBs effective surface tension due to buckling and rupture may be the potential reason behind the observed harmonic echogenicity.

Fire-Extinguishing Dibromomethane Mixtures with Fluorinated Alkanes for Fire and Explosion Protection of Oil and Gas Industry Facilities

The high fire hazard level is specific to the oil and gas industry due to the circulation of large volumes of flammable gases and liquids. To ensure fire protection at the oil and gas industry facilities, automated gaseous fire extinguishing is widely used. The main fire-extinguishing agents in automated gaseous fire-extinguishing systems are refrigerants HFC 23, 125, 227еа, FC 318c, and fluorinated ketone FK 5-1-12. Upon the adoption of the international agreements on combating global warming, most fluorinated gaseous fire-extinguishing agents currently used for fire extinguishing fell under restrictions. The article indicates the importance of refrigerants HFC 23, 125, 227еа, and FC 318c, whose production volume must be reduced by 85 % by 2036 to ensure the required level of fire and explosion protection of oil and gas industry facilities. A method to reduce the volumes of used fluorinated alkanes by producing highly efficient fire-extinguishing mixtures, one of the components of which is an agent of high global warming potential (GWP) and the other is a chemical compound with a short atmospheric lifetime, has been proposed. Dibromomethane, which fully meets the latest environmental requirements, is to be considered a short-lived component. Based on the well-known kinetic data, the rates of elementary chemical reactions generated in the flame of the methane-oxygen mixture when contacting with refrigerants HFC 23, 227еа, and dibromomethane, have been calculated and compared. The efficiency of using dibromomethane to increase the fire-extinguishing efficiency of refrigerants HFC 23 and 227еа has been substantiated. An experimental determination of the minimum fire-extinguishing efficiency of the generated mixed compositions is conducted to confirm the correctness of theoretical calculations. The obtained mixed gaseous fire-extinguishing agents enable the reduction of the volume of high global warming potential refrigerants by 1.5–2 times. It has been also demonstrated that the obtained mixed compositions have no toxic impact on a human.

Investigations on affinity law under gas–liquid conditions in multistage radial and mixed-flow multiphase pumps

Affinity laws have been widely used in pump design and simulation under high-temperature and corrosive conditions. By applying such laws, it is possible to shorten development cycles and reduce test costs. However, current applications of affinity laws are still limited to liquid conditions. In this paper, expressions for affinity laws and their applicability are investigated for multistage radial and mixed-flow multiphase pumps under gas–liquid conditions. A high-pressure (30 MPa) gas–liquid experimental platform is constructed, and three-stage and 25-stage radial pumps and a 15-stage mixed-flow pump are investigated, with specific speeds of 107 and 216. With gas compressibility taken into account, the gas–liquid two-phase flow rate, head, and power, and the corresponding dimensionless hydraulic coefficients, are defined for multiphase pumps. The deterioration of gas–liquid pressurization performance is found to be divided into three processes with different dynamic mechanisms, corresponding to three flow patterns. The inlet gas volume fraction of pump is used to judge dynamic similarity. At the same inlet gas volume fractions λ1 = λ2, when the gas–liquid flows in two pumps have the same flow pattern, dynamic similarity will be satisfied. The affinity law that is established shows good applicability to the three-stage radial multiphase pump, with goodness of fit R2 larger than 0.9 for the two-phase Ψm–Φm and Πm–Φm performance curves. Finally, experimental results indicate that the affinity law also has good applicability to multiphase pumps with different stage numbers and blade structures under gas–liquid conditions.

Air Quality and Health Impacts of Onshore Oil and Gas Flaring and Venting Activities Estimated Using Refined Satellite-Based Emissions.

Emissions from flaring and venting (FV) in oil and gas (O&G) production are difficult to quantify due to their intermittent activities and lack of adequate monitoring and reporting. Given their potentially significant contribution to total emissions from the O&G sector in the United States, we estimate emissions from FV using Visible Infrared Imaging Radiometer Suite satellite observations and state/local reported data on flared gas volume. These refined estimates are higher than those reported in the National Emission Inventory: by up to 15 times for fine particulate matter (PM2.5), two times for sulfur dioxides, and 22% higher for nitrogen oxides (NOx). Annual average contributions of FV to ozone (O3), NO2, and PM2.5 in the conterminous U.S. (CONUS) are less than 0.15%, but significant contributions of up to 60% are found in O&G fields with FV. FV contributions are higher in winter than in summer months for O3 and PM2.5; an inverse behavior is found for NO2. Nitrate aerosol contributions to PM2.5 are highest in the Denver basin whereas in the Permian and Bakken basins, sulfate and elemental carbon aerosols are the major contributors. Over four simulated months in 2016 for the entire CONUS, FV contributes 210 additional instances of exceedances to the daily maximum 8-hr average O3 and has negligible contributions to exceedance of NO2 and PM2.5, given the current form of the national ambient air quality standards. FV emissions are found to cause over $7.4 billion in health damages, 710 premature deaths, and 73,000 asthma exacerbations among children annually.

Design of ammonia leakage online monitoring system based on tunable diode laser absorption spectroscopy

A real-time online ammonia volume fraction monitoring system based on tunable diode laser absorption spectroscopy (TDLAS) is designed to meet the demand for ammonia gas leakage monitoring in ammonia-fueled ships. The system uses a 1, 512 nm distributed-feedback (DFB) laser as the light source and a 5 m high-temperature Boss-Gas-Cell as the absorption cell. By applying a 4 Hz scan signal and a 31.4 kHz modulation signal to the laser current, the effective absorption signal of the gas is transferred to the high-frequency band, then the second harmonic (2f) signal about gas volume fraction is extracted by a digital lock-in amplifier from the gas absorption signal, and ammonia volume fraction can be calculated from the amplitude of 2f signal. The test results show that the ammonia detection accuracy in the range of 0-500 ppm can reach ±1% FS, the response time is less than 30 s, and the system measurement repeatability is less than 1%, which meets the needs of ammonia leakage monitoring in ammonia-fueled vessels.

DETERMINATION OF THE CAPACITY OF PIPELINES TRANSPORTING LIQUID PRODUCTS, DEPENDING ON THE THERMOBARIC CONDITIONS

The article discusses the issues of calculating the capacity of pipelines through which liquid hydrocarbon products are transported, depending on thermobaric conditions. These calculations are important for such urgent tasks of pipeline transport practice as carrying out an inventory and establishing the fact of illegal withdrawal of oil/oil products from the pipeline. The work provides a fundamental equation of the state of the stopped pipeline, in consideration of which the focus of attention is on changing the geometric capacity of the pipeline depending on the change in temperature and pressure of the pumped medium. When considering the change in volume, from the classical equations of mechanics, refined dependencies were obtained for two cases: underground and above-ground laying. A comparison of the obtained relationships has been made, in which it has been found that a number of effects such as a change in gas volume and a temperature factor «mask» the effect of leakage/illegal sampling, preventing their identification from the pressure/temperature change data. An analytical explanation of the processes occurring in the shut down pipeline will allow further quantification of the uncertainties that arise, which will facilitate the decision and allow adjustments to be made to the software used.

Method of controlling the volume of combustion products at different boiler loads

Purpose. Development of a method for controlling the volume of combustion products at different load of boiler equipment. Achieving the objective may allow controlling the flue gas temperature and, consequently, the efficiency to increase it. Methodology. Control of the flue gas volume value on the basis of determining the appropriate composition of the fuel gas mixture. Findings. The effect of flue gas temperature increase at use of fuel gases of lower calorific value and increase in ballast gases quantity is revealed. The latter can be the air used as an oxidising agent at its considerable excess. The mechanism of such an effect due to the increase in the quantity and velocity of flue gases is suggested. A parameter determining the volume of flue gases produced per unit calorific value of various fuel gases is proposed. On the basis of this parameter the method for calculating the composition of the mixture of different gases to ensure the constancy of the flue gas volume at variable load is proposed Originality. On the example of the results of verification thermal calculation the change in flue gas temperature and efficiency value is considered. The non-standard character of their change is revealed. In contrast to the case of using fuel gas of constant composition with increasing load, the temperature of flue gases remained close to constant, and the value of efficiency increased. Practical value. The obtained results indicate the possibility of controlling the flue gas temperature and boiler efficiency at a given load. This allows one, unlike the case of using fuel gas of constant composition, to increase the efficiency exactly at maximum load avoiding getting into the condensate mode at minimum load. There is a possibility to save fossil gas and, consequently, to reduce the greenhouse share in CO2 emissions.

Statistical Analysis and Modeling of the CO2 Series Emitted by Thirty European Countries

In recent decades, an increase in the earth’s atmospheric temperature has been noticed due to the augmentation of the volume of gases with the greenhouse effect (GHG) released into the atmosphere. To reduce this effect, the European Union’s directives indicate the action directions for reducing these emissions, among which carbon dioxide (CO2) recorded the highest amount. In this context, the article analyzes the CO2 series reported in 1990–2021 by 30 European countries. The Kruskal-Wallis test rejected the hypothesis that the series comes from the same underlying distribution. The Anderson-Darling test rejected the normality hypothesis for seven series out of thirty, and Sen’s procedure found a decreasing trend slope only for 17 series. ARIMA models have been built for all individual series. Grouping the series (by the k-means and hierarchical clustering) provided the base for building the Regional series (RegS), which describes the CO2 pollution evolution over Europe. The advantage of this approach is to provide the synthetic image of the regional evolution of the CO2 emission volume (mt), incorporating information from 30 series (one for each country) in only one—RegS. It is also shown that selecting the number of clusters involved in building RegS and assessing their stability is essential for the model’s goodness of fit.

Redispatch Model for Real-Time Operation with High Solar-Wind Penetration and Its Adaptation to the Ancillary Services Market

Modern electrical power systems integrate renewable generation, with solar generation being one of the pioneers worldwide. In Latin America, the greatest potential and development of solar generation is found in Chile through the National Electric System. However, its energy matrix faces a crisis of drought and reduction of emissions that limits hydroelectric generation and involves the definitive withdrawal of coal generation. The dispatch of these plants is carried out by the system operator, who uses a simplified mechanism, called “economic merit list” and which does not reflect the real costs of the plants to the damage of the operating and marginal cost of the system. This inefficient dispatch scheme fails to optimize the availability of stored gas and its use over time. Therefore, a real-time redispatch model is proposed that minimizes the operation cost function of the power plants, integrating the variable generation cost as a polynomial function of the net specific fuel consumption, adding gas volume stock restrictions and water reservoirs. In addition, the redispatch model uses an innovative “maximum dispatch power” restriction, which depends on the demand associated with the automatic load disconnection scheme due to low frequency. Finally, by testing real simulation cases, the redispatch model manages to optimize the operation and dispatch costs of power plants, allowing the technical barriers of the market to be broken down with the aim of integrating ancillary services in the short term, using the power reserves in primary (PFC), secondary (SCF), and tertiary (TCF) frequency control.

Design improving the quality of natural gas volume measurement with G1.6÷G25 meters by optimizing their metrological verification

Design improving the quality of natural gas volume measurement with G1.6÷G25 meters by optimizing their metrological verification

A Review on Anthropogenic Biomass Burning: Emission of Aerosol Pollutants, Impact on Climate Change, Human Health and its Mitigation Strategies

Biomass burning is a complex process, encircling chemical and physical responses covering, transmission of mass and warmth. A large number of investigations were accumulated on the significant emissions from various kinds of anthropogenic biomass burning in the recent decade. In India, an increasing trend of biomass burning is an important cause to release a large volume of reactive gases with other impurities and intensify the level of invisible particles into the troposphere, which affects humans health and leads to the probable alteration of the weather and global climate. The present review looks at the interpretations for a diverse investigation of distinct body and monitoring interventions, pertinent to our country, relating to the significance of particulate matter emissions, sources of aerosols and their health implications. This study also discusses numerous persuaded investigations, conducted on the impact of aerosol, attributed to climate change and also points out precise matters such as spatio-temporal variability of fire occurrences detected in India. Furthermore, the present study reveals that substantial quantities of data, along with a variety of enhanced simulation models and investigational validations, are essential for the development of efficient mitigation strategies with the objective of protecting the environment of the Indian Peninsula.

Pyrolysis characteristics and product distribution of oil sludge based on radiant heating.

It needs to be improved the conversion efficiency and stable operation of conventional pyrolysis with high-temperature flue gas heating (HFH). Herein, a new radiative heating (RH) pyrolysis method is proposed. Experimental studies are carried out on a self-made radiation pyrolysis pilot plant to investigate the effects of different factors (pyrolysis final temperature, residence time, and carrier gas volume) on product distribution. The results show that with the increase of pyrolysis temperature, the yield of the gas phase consistently increases, and the proportion of CH4 and H2 in the pyrolysis gas reaches 62.31% at 700°C. The yield of the liquid phase increases and then decreases. The recovery rate of pyrolysis oil achieves 68.07% when the pyrolysis temperature is 600°C with main components of ketones and unsaturated hydrocarbon compounds. The yield of the solid phase consistently decreases. The RH in this work generates more pyrolysis gas in the pyrolysis process and alleviates the effects of fouling layers on the continuous operation of the equipment which has guiding significance for the efficient resource utilization of oil sludge.

Evaluation of Partial Replacement of Barley Grain with Heated Potato Processing By-products in the Diet of Dairy Cows Using an In vitro Gas Production Technique

Background: The increasing urban population requires more dairy product (meat and milk) production; therefore, using agricultural sector by-products as animal feedstuffs has found double importance.
 Objective: The effects of replacing barley grain with heated potato slices (HPS) and French fries waste (FFW) in iso-energetic total mixed dairy cow rations on cumulative gas production and in vitro DM degradability were evaluated using in vitro techniques.
 Methods: Seven experimental dairy cow total mixed rations (TMR) were formulated based on partial replacing barley grain with HPS or FFW, including Control: a diet containing 16% (DM basis) barley grain as one of the main sources of non-forage carbohydrates; 5 HPS: a diet containing 11% barley grain and 5% HPS; 10 HPS: a diet containing 6% barley grain and 10% HPS; 15 HPS: a diet containing 1% barley grain and 15% HPS; 5 FFW: a diet containing 11% barley grain and 5% FFW; 10 FFW: a diet containing 6% barley grain and 10% FFW; 15 FFW: a diet containing 1% barley grain and 15% FFW. Two in vitro gas production approaches were conducted separately to measure the production of gas volumes and dry matter (DM) degradability at 2, 4, 6, 12, 24, 36, and 48 hours of incubation.
 Results: After 48 h of incubation, the gas production volume varied between 174 and 197 ml/g DM, with the highest value observed with control and the lowest value with FFW treatments (P < 0.05). Also, the gas production rate for the insoluble fraction varied from 0.031 to 0.054 ml/h and was higher for HPS treatments than for control and FFW treatments (P < 0.05). After 48 h of incubation, DM degradability was significantly lower for the control than other treatments. DM effective degradability, with a passage rate of 0.05 h−1, found to be higher for FFW and HPS treatments compared with the control. Moreover, the rate of the B fraction degradation was significantly lower for the control (0.14 % h−1) than for treatments.
 Conclusion: The heated potato processing by-products could be replaced with barley grain by 15% in the diet of dairy cows without having negative effects on ruminal fermentation.