Gas Plant Research Articles

Application of innovative methodology for risk assessment and inspection methods on example of small experimental biomass gasification unit

Application of Innovative methodology for risk assessment and inspection methods is the result of a long-term work in the field of Risk-Based Inspection. As such, it was successfully applied on oil and gas facilities in the Middle East. As an example of its versatility, application will be shown on small experimental biomass gasification plant utilized for the purpose of combined heat and power generation, built in Serbia in the middle of the past decade. Throughout the analysis both active and passive damage mechanisms will be identified as well as barriers thus enabling the creation of a system that documents the dynamics of the damage mechanisms and installed barriers.

Criteria for Enhanced Monitoring and Control Plans for a Waste Gasification Plant

Abstract The Environmental Monitoring Plan (EMP) and the Monitoring and Control Plan (MCP) are key documents required respectively in Environmental Impact Assessment (EIA) procedures and in the Integrated Environmental Authorization (IEA) for activities subjected to this procedure. Both documents aim at preventing impacts on the environment and human health and/or quickly taking actions if anomalous levels of pollutants are found in the environment. Trentino is an Italian region located in the Alps characterized by high population density in its valleys, complex terrain and, thus, a low level of dispersion of the atmospheric pollutants. The research carried out in Trentino in the last two decades has allowed identifying innovative monitoring approaches to point out issues that conventional methodologies could not detect. The present paper provides the key elements of an EMP that must be included in the EIA of a waste gasification plant. The paper proposes unconventional monitoring campaigns to guarantee a more efficient control of the areas influenced by the plant before, during and after its construction. The paper also discusses key aspects of an MCP for plants that are subjected to IEA. The final aim is to make this paper a reference document to 1) evaluate new projects of waste combustion plants, 2) suggest alternative monitoring methodologies to investigate the role of specific pollutants in peculiar contexts, and 3) prescribe a specific surveillance plan in the case of a plant that is subjected to IEA. Considerations on differences with conventional plants were also included.

Criteria for the Assessment of Health Risk from a Waste Gasification Plant

Abstract In mountainous regions, the atmospheric dispersion of air pollutants is limited by complex terrain morphology. Trentino (a province located in the Italian Alps) is characterized by a high population density, highly developed agriculture and farming, and the presence of civil and industrial activities, whose emissions tend to be trapped inside the valleys. These conditions translate into exposure levels that are potentially higher than other geographical contexts (e.g., flat or coastal regions). The academic research carried out in Trentino since 2005 has produced a series of publications on topics related to the risk for health derived from waste management and other activities. These publications has focused on: 1) the evaluation of the emissions of organic pollutants from the waste sector; 2) the monitoring of persistent organic pollutants (POPs) in various environmental matrices; 3) a methodology to carry out a comprehensive health risk assessment considering all the relevant exposure routes in an area; 4) the role of the local diet in the exposure of a population to POPs; 5) methodologies to define new regulatory limit values for dioxin and hexavalent chromium; and 6) the role of dispersion modeling in assessing the exposure to air pollutants. The present paper will review these publications and provide a reference document to evaluate new project proposals that require a health risk assessment and facilitate the work of proponents, clarifying the requirements of a health risk assessment. The paper will refer to waste gasification, but the considerations expressed in this paper may apply to other activities.

Power to gas plant for the production of bio-methane: Technoeconomic optimization

In this work, a power to bio-methane plant in which the biogas is produced from an anaerobic digester plant and the hydrogen is generated by using an electrolysis unit powered by a renewable plant (photovoltaic or wind-based), is designed and sized. The plant sizing is carried out by applying a techno-economic multi-objective black box optimization approach. A numerical code, built by using the Matlab software package, is used to evaluate components sizes and to assess plant costs. This code is implemented in an optimization workflow developed in the modeFRONTIER environment. This approach allows to identify the optimal size of the plants components with the aim of maximizing the annual bio-methane producibility and minimizing its levelized cost. The results show that for a low-price electricity scenario (45 €/MWh) the minimum levelized cost of bio-methane (LCOBM), equal to 84.6 €/MWh, is obtained adopting the PV-based configuration. On the contrary, considering an high-price scenario (135 €/MWh), the minimum LCOBM is obtained for the Wind-based plant and is equal to 34.9 €/MWh.

The ecological response and distribution characteristics of microorganisms and polycyclic aromatic hydrocarbons in a retired coal gas plant post-thermal remediation site.

Thermal remediation is one of the most common approaches of removing organic pollutants in the retired contamination sites. However, little is known about the performance of bacterial community characteristics after in situ thermal remediation. In this study, the ecological response and spatial distributional characteristics of microorganisms and polycyclic aromatic hydrocarbons (PAHs) were investigated using a high throughput sequencing method in a retired coal gas plant site after in situ thermal remediation in Nanjing, China. Combination of Venn, clustering-correlation heatmap and two - factor correlation network analysis revealed that, microbial communities were obviously affected and classified by soil depths, temperature, and contamination level, respectively. The common and endemic microorganisms of each group were identified. The relative abundances of Thermaerobacter, Calditerricola, Brevibacillus, Ralstonia and Rhodococcus (aerobic bacteria) gradually declined with the increase of soil depth, while those of Bacillus, Fictibacillus, Paenibacillus, Rheinheimera presented opposite tendency. Some thermophilic degradation bacteria of PAHs, including Thermaerobacter, Calditerricola, Bacillus, Rhodococcus, unclassified_p__Firmicutes, Arthrobacter and Deinococcus, were identified and increased in the abundance at heavily polluted sites. Additionally, Proteobacteria, Bacteroidota, Deinococcota, Chloroflexi, Acidobacteriota, and Actinobacteriota showed negative response to the increase of soil depth, temperature and pollution level, while Firmicutes presented a positive response. This implied that Firmicutes has better stress resistance and adaptability to thermal remediation condition. The key environmental factors affecting microorganism composition and distribution were Temperature, Total nitrogen, Oxidation-Reduction Potential, Organic matters, and PAHs concentrations, which explains the dominant driving mechanism of soil depth, temperature, and contamination level on microbial characteristics in thermal remediation site. Our study could contribute to a better understanding of the resilience and adaptation mechanisms of microbial community at the contaminated site after the in situ thermal remediation.

Quantitative Risk Assessment Approach to a Dynamic Safety Evaluation: Skikda’s Coastal City Liquefied Gas Plant

Quantitative Risk Assessment Approach to a Dynamic Safety Evaluation: Skikda’s Coastal City Liquefied Gas Plant

Gas production in the Czech Republic yesterday, today and tomorrow

The Czech Republic is one of the most advanced countries in the world in the field of gas industry. The production of gas from coal started here as early as 1847 and has been developing intensively since then. Initially, the gas was used to light the streets, which is why it was referred to as town gas. Soon its use also spread to other areas, e.g. for heating water and housing heating, but also for washing clothes and almonds and a number of other activities. A significant change occurred in the middle of the 20th century, when the process of coal gasification was developed, which began to replace the less effective methods of gas production with carbonization. The first pressurized gas plant in Bohemia was put into operation during the 2nd world war in Záluží near Litvínov and supplied gas not only to local chemical plants, but also to large cities in its vicinity via a high-pressure gas pipeline. Other pressurized gas plants were located in the 1950s in Úžín and in the early 1970s in Vřesová. The production of town gas in the Czech Republic at that time reached a volume of almost 4 billion m3/a. The construction of the transit gas system from the Soviet Union to mainland Central and Western Europe and its commissioning in the first half of the 1970s meant a gradual decline in the production of town gas and its replacement by natural gas. Therefore, the pressurized gas plants were gradually taken out of operation. The last gas plant in Vřesová ceased operation in the summer of 2020. However, gas production technologies are still being developed in the Czech Republic. Several devices for gasification of bio-mass and devices intended for gasification of various al-ternative fuels have been implemented. The interruption of natural gas supplies from Russia in the summer of 2022 has again revived interest in these technologies, especially in industrial enterprises with high gas consumption in technological processes.

Theoretical technical–economic comparison of hybrid energy for gas and solar concentration plants in the Region of Antofagasta Chile

Electricity demand from mining industry in Chile will increase up to 34 % in the next 10 years. The Antofagasta region has several mining operations and gas pipelines, in addition to being an area with very high solar resource availability. This study focuses on reviewing hybridization alternatives for combined cycle plants with concentrating solar generation technologies. In this work a techno-economic analysis of two alternative small scale hybridized solar-combined cycle technologies is developed, a solarized combined cycle with STP and a solarized combined cycle with PTC. To perform the solar concentration systems simulations, TRNSYS software was used for PTC, and Solstice software for STP system, while the thermodynamic simulation for the combined cycle system was developed using EES software. The LCOE was calculated for all plants considering a fuel cost of 66 USD/MWh. LCOE obtained for combined cycle is 202 USD/MWh, while LCOE for combined cycle with STP integration is 149 USD/MWh, and LCOE for combined cycle with PTC integration is 197USD/MWh. The lowest LCOE is achieved with the STP integration, since part of the fuel that feeds the combined cycle is replaced by solar energy, avoiding the emission of 16,603 tons of CO2.

Dictamnus albus L’ a Ait. Ekstrelerin PC-12 ve SHSY-5Y Hücre Hatlarında Toksik Etkilerinin Değerlendirilmesi ve Antioksidan Aktivitesinin Araştırılması

This study investigated the antioxidant and cytotoxic properties of the Dictamnus albus L. plant grown in Türkiye. The aerial parts and roots of the plant were evaluated qualitatively in terms of chemical content. Total phenol and flavonoid amounts were calculated by spectrophotometric methods, antioxidant activity was tested with DPPH and ABTS radical scavenging activity assay. In addition, cell viability determination in PC-12 and SHSY-5Y cell lines was evaluated by performing MTT (3-4,5-dimethyl-thiazolyl-2,5-diphenyltetrazolium bromide) test. According to the results, both parts of the plant gave negative results in the tannin, cyanogenetic glycoside, anthraquinone, cardiac glycoside, and anthocyanoside identification tests, while they gave positive results in the alkaloid, coumarin, saponin, carbohydrate identification tests. While the total amount of phenol was calculated as 77.13 ± 5.73 mgGAE gexracts-1 in the extract prepared with methanol from the aerial parts of the plant (D.A Herba), it was calculated as 43.81 ± 9.49 mgGAE gexracts-1 in the extract prepared from the roots (D.A Root). The total flavonoid content could only be calculated in the D.A Herba extract (19.11 ± 0.16 mgCA gextract-1). Although the DPPH radical scavenging effect of the extracts was higher in D.A Herba extract, the ABTS radical scavenging effects were found similar in both D.A Herba and D.A Root extracts. According to the toxicity test, D.A Root extract reduced the viability below 50% (43.17 ± 3.44%) at 500 µg mL-1, but D.A Herba extract was found to be more toxic at the same concentration with 19.53 ± 0.183% in the PC-12 cell line. However, D.A. Herba and D.A.Root extract increased cell proliferation in the SHSY-5Y cell line at 3.25 µg/mL concentrations with 122.87±6.29 and 112.78±7.00%, respectively. The results suggest that D. albus may be a promising candidate for the new phytopharmaceuticals due to its neuroprotective effects.

A novel strategy for process optimization of a natural gas liquid recovery unit by replacing Joule–Thomson valve with supersonic separator

The natural gas liquid recovery is an important process in a gas plant to correct hydrocarbon dew point and earn profit. In this study, a natural gas liquid recovery unit operated based on the Joule–Thomson process was investigated and its performance was optimized. To improve the system performance, the plant configuration and intermediate pressure ratio were defined as the variables and maximization of the natural gas liquid recovery rate and maximization of exergy efficiency were defined as the objective functions. To improve the plant performance, the amount of natural gas liquid recovery rate should be increased. To achieve this goal, several scenarios for the intermediate pressure ratio and three new configurations were proposed for the investigated gas plant. In the proposed configurations, the supersonic separators with optimized structures were used instead of the Joule–Thomson process. It was observed that all three proposed configurations improved the natural gas liquid recovery rate compared to the existing configuration. For example, by installing two supersonic separators instead of second and third stage Joule–Thomson valve + low temperature separator, at the optimal operating condition, the natural gas liquid recovery rate increased about 390%. The influence of the intermediate pressure ratio on the phase envelope diagram, exergy efficiency, dew point depression and natural gas liquid recovery rate was also investigated. By comparing the influence of intermediate pressure ratio and modifying the plant configuration on the objective functions, it was observed that the system performance can be further improved by modifying the plant configuration.

CARBON FOOTPRINT COMPARATIVE ANALYSIS FOR EXISTING AND PROMISING THERMAL POWER PLANTS

The power production industry is the main greenhouse gas emitter that makes its contribution to global warming. The greenhouse gas emission takes place in fuel production, transportation, and combustion. A prospective method for emission mitigation is the transition to organic fuel-burning facilities with small emissions by capturing carbon dioxide. Power consumption on the carbon dioxide capture remarkably reduces the efficiency of these facilities, which leads to increasing of fuel consumption and greenhouse gas emission because of the larger fuel production and transportation. Based on the material balance method, taking into account system effect of changes in efficiency and amount of fuel consumed, the paper estimated the carbon footprint over a twenty-year lifecycle for following thermal power plants types: combined cycle and oxy-fuel combustion plants for both natural gas and coal with internal gasification. It is shown that the transition to oxygen-fuel plants can reduce the carbon footprint near 90% for natural gas and near 75% for coal. The study also demonstrates the positive effect of carbon capture and storage system implementation for reducing carbon footprint near 75% for natural gas and near 70% for coal.

Voltage and frequency regulation in smart grids via a unique Fuzzy PIDD2 controller optimized by Gradient-Based Optimization algorithm

This paper proposes a maiden intelligent controller design that consists of a Fuzzy Proportional–Integral–Derivative–Double Derivative (FPIDD2) controller whose parameters are fine-tuned using the Gradient-Based Optimization algorithm (GBO). The proposed FPIDD2 regulator is employed as a secondary regulator for stabilizing the combined voltage and frequency loops in a two-area interconnected power system. It has been shown that the GBO optimization algorithm outperforms other optimization strategies such as the Chimp Optimization Algorithm (ChOA), the Whale Optimization Algorithm (WOA), and the Gorilla Troops Optimization algorithm (GTO). The proposed FPIDD2 controller is tested in a conventional two-area power system. Then, the investigation is expanded to a two-area hybrid system, with each area comprising a mix of traditional (thermal, gas, and hydraulic power plants) and renewable generation units (wind and solar power). Additionally, the proposed controller takes into account system nonlinearities (such as generation rate limitations, governor deadband, and communication time delays), system uncertainties, and load/renewables fluctuations. In the two tested systems, the dynamic responses of each system demonstrate that FPIDD2 has a superior ability to attenuate the deviations in voltage and frequency in both areas of the system. In the studied conventional system, the proposed FPIDD2 controller is compared with a PID controller tuned by the Multi-Objective Non-Linear Threshold Accepting Algorithm (MONLTA), which has been presented in the literature, and a Fuzzy PID (FPID) controller tuned by GBO. In the investigated hybrid system, the suggested FPIDD2 regulator is compared to a GBO-tuned Integral Derivative-Tilted (ID-T) controller and FPID controller. As a fitness function (FF) for the GBO, the criteria of minimizing the integral time absolute error (ITAE) are applied. The results are presented in the form of MATLAB/SIMULINK time-domain simulations.

Analisa kebocoran line warming up high pressure boiler feed pump menggunakan metode root cause and failure analysis di Pembangkit Listrik Tenaga Gas & Uap Grati

The reliability of the Grati Gas And Steam Power Plant equipment is highly maintained to support the operational readiness of the generation. The feed water system at the Grati Gas And Steam Power Plant is one of the most important factors, especially in the feed water pump equipment. One of the pumps that is highly reliable is the High Pressure Boiler Feed Water Pump which is used as a tool for supply feed water to the Heat Recovery Steam Generator. However, from the recap data of disturbances in the Grati Gas And Steam Power Plant, leaks often occur in the system, precisely in the line warming up which serves to provide flow to the standby High Pressure Boiler Feed Water Pump and comes from the backflow of the High Pressure Feed Water Header to the Discharge side of the pump. Analysis related to the leak is very necessary in order to minimize losses due to the occurrence of the disturbance using the Root Cause And Failure Analysis method to eliminate the main disturbance causing the leak. The research variables used include the independent variable: regulating the pump discharge opening, the dependent variable: flow rate and valve warming up opening and the controlled variable: standby pump temperature and pump operating temperature. By conducting a series of trials setting the discharge valve opening of the High Pressure Boiler Feed Water Pump starting from 80%, 85%, 90%, 95% and 100%. The results of these tests can be concluded that the greater the opening of the pump discharge valve, the higher the speed and flow rate, while the pump discharge pressure will decrease.

A multi-task learning approach for chemical process abnormity locations and fault classifications

The fault classification of chemical processes based on supervised learning generally demands for enough labeled fault samples, which represents a big challenge for practical engineering issues. In the industrial field, when capturing an appearance of process abnormities, human operators usually take account of correlations of relevant variables so as to locate process variables associated with the abnormity before further classifying or diagnosing the corresponding faults. In this context, accurate abnormity localizations can be an effective help for classifying the fault type. Nowadays, deep learning based fault classifications have been extensively studied and widely circulated in the literature. However, the existing approaches rarely concern the supporting role of abnormity locations for fault classifications. Motivated by this observation, this paper proposes a multi-task learning (MTL) based convolutional neural network (CNN) model for concurrent abnormity locations and fault classifications for chemical processes. Specifically, fault samples are labeled with both abnormal variable locations and fault categories before constructing a multi-task learning CNN classifier performing an auxiliary task, abnormity locations, and a primary task, fault classifications. In addition, dynamic task weights are assigned to facilitate task contributions. This method can enjoy effectively reducing the necessary amounts of labeled fault samples in achieving satisfactory fault classification performances. Experiments are carried out on the TE process simulation platform and an industrial coal gasification plant along with comparisons with conventional fault classification methods, verifying the effectiveness of the proposed method.

Features of Studying Coating Strength and Methods Increasing Its Indicators with Plasma Spraying Working Bodies of Gas Turbine Engines and Plants

Features of Studying Coating Strength and Methods Increasing Its Indicators with Plasma Spraying Working Bodies of Gas Turbine Engines and Plants

Effect of Protection on Guy Wire Related to Corrosion Defects

Guy wires are a powerful mechanical tool used widely in all industries. Most of the applications are employed in supporting tall structures such as antenna, communication towers, transmission lines, electric poles, and erecting flare stacks on an oil and gas platform or plant. Severe wind events such as tornadoes are the primary failurein transmitting line structure in many places worldwide. So, this research aims to investigate the effect of different types of guy wire on corrosion defects. There are many lay and strand design types in the production of guy wire. The two most common are the 7-wires and 19-wires lay. There are four samples with four conditions: the first sample is not protected with any material, the second is protected by lubrication using WD-40, the third is protected using rubber hose casing, and the last is protected by a combination of both lubrication and rubber hose casing technique. The result shows that the sample protected by a combination of lubrication and rubber hose casing has no corrosion defect.

Eulerian computational fluidisation modelling using OpenFOAM applied to a semi-industrial fluidised bed reactor and pilot plant application

Simulations of a fluidised bed reactor for gasification of municipal solid refuse-derived fuel were performed using OpenFOAM software. Firstly, evaluation was made of a simplified gas-solid two-phase model, considering sand and air as the components, according to a transient Eulerian-Eulerian approach. A scale-up study was also performed to obtain thermal-fluid dynamic parameters. Then, a real dimensions non-reacting model was developed, based on the experimental information from a semi-industrial gasification plant with capacity for processing 7.1 t day−1 of municipal refuse-derived fuel, producing 16.9 t day−1 of syngas. The fluidising regime was mapped for different inlet conditions, at 1,123 K, with air velocities ranging from 0.01 to 1.25 m s−1, and the continuous operation of the reactor was analysed, where in the solid particles packing remained at approximately 88% from maximum, with bed height of 2.05 m. The results were in good agreement with data available in the scientific literature, and the computational model was able to provide consistent results when compared to the experimental information for the semi-industrial reactor. The authors’ major remark was the hability of this computational model in obtaining consistent results from simulations of the semi-industrial scale reactor, with good prediction of the internal fluid dynamics characteristics.

Modelling and validation of energy systems with dynamically operated Power to Gas plants for gas-based sector coupling in de-central energy hubs

Participants of the COP 26 summit have agreed to limit global temperature rise to 1.5 K by 2050. Out of the many strategies envisaged to meet the targets of COP 26, the ‘Sector Coupling’ process aims to use renewable electricity in residential heating, chemical industry, and transportation sectors. Several studies predict that de-central energy systems will play a significant role in the future. Among the proposed sector coupling strategies in de-central energy systems, the Power to Gas (PtG) process producing chemical energy carriers like Substitute Natural Gas (SNG) from renewable power is gaining acceptance. Numerical models of de-central energy systems are needed to analyse sector coupling under fluctuating renewable energy generation and changing gas demand. This study introduces a numerical model of a decentral energy system that includes a novel methanation concept developed at the Engler Bunte Institut of KIT called 3 Phase Methanation. Here, H2 from electrolysis and CO2 from DAC or other biomass-based sources are passed through a slurry bubble column reactor. The slurry is a suspension of the catalyst in a liquid heat transfer medium where the heat of the reaction is dissipated. The 3-Phase methanation process is modelled in this study using the axial dispersion method. Earlier studies describing experimental campaigns conducted on the pilot plant in KIT have proven that the reactor core is nearly isothermal with stable product gas compositions even if the load changes are instantaneous. In this study, it is shown that the numerical model can replicate the experimental results. Following modelling and validation, the numerical model of the PtG plant is integrated with the other components to simulate the de-central energy system. The simulation results demonstrate the dynamic output of all the components and, in particular, the response provided by the PtG plant. This model can be adapted to simulate sector coupling in future de-central energy systems and analyse aspects like long-term energy storage, GHG minimisation and cost-optimal operation.

Multi-criteria evaluation and optimization of a new multigeneration cycle based on solid oxide fuel cell and biomass fuel integrated with a thermoelectric generator, gas turbine, and methanation cycle

Recently, due to increasing concerns about the reduction of fossil energies reserves and environmental crises, the development of more efficient and low-emission systems has become necessary. An alternative energy system should be able to improve the efficiency of energy production, have a reasonable investment cost and be environmentally friendly. The current research developed a multi-criteria evaluation method of a new multigeneration cycle (MGC) based on a solid oxide fuel cell (SOFC) and biomass fuel. In the planned MGC, the SOFC is fed by syngas from the biomass gasification process. To reduce environmental hazards, a fraction of the carbon dioxide was recycled for reutilization in the aforementioned process. A gas turbine and a thermoelectric generator (TEG) were employed to produce electrical energy and an absorption chiller was embedded to produce cooling. The output heat of the fuel cell was utilized for heating purposes. A part of the electricity produced was feed into the electrolysis cycle to produce hydrogen. Excess hydrogen was combined with carbon dioxide released from the MGC in a synthesis cycle to reduce pollutant emissions by producing methane. A thermodynamic-conceptual, exergoeconomic and environmental evaluation of the MGC was developed. The optimization based on the genetic algorithm to maximize performance and minimize the cost of the MGC was also developed. The results obtained from the optimization indicate that the proposed MGC can compete with most biomass-driven systems. Besides, the amount of carbon dioxide released can be significantly reduced compared to conventional coal, natural gas and petroleum-driven power plants.

On the green hydrogen production through gasification processes: A techno-economic approach

Green hydrogen rises in the world energy scenario as one of the most promising non-carbon-based fuels capable of replacing fossil fuels. Biomass gasification is emerging as a cleaner and sustainable process of producing green hydrogen. Green hydrogen can be obtained by resorting to different biomass gasification processes. Moreover, techno-economic studies are essential to determining the viability of these processes and are missing in the literature. The novelty of this study is the identification of the gasification process that produces the highest hydrogen yields and the presentation of the viability conditions for three gasification plants aiming to produce green hydrogen. The methodology followed is based on the development of three models of biomass gasification processes (conventional, plasma, and supercritical water) in Aspen Plus® to estimate maximum hydrogen yields through a parametric study. The economic study was conducted based on economic indicators (net present value and payback) to assess the viability of each gasification process for green hydrogen production. The results suggest that supercritical water gasification is the most suitable process for hydrogen production, with hydrogen yields of 0.844 Nm3/kgbiomass. Hydrogen yields of 0.828 Nm3/kgbiomass, and 0.758 Nm3/kgbiomass were achieved for the conventional gasification and plasma gasification processes, respectively. From the economic assessment, it was concluded that none of the gasification processes are viable under the determined optimal operating conditions. A sensitivity analysis, however, revealed that conventional gasification is viable for steam-to-biomass ratios <3. Process intensification techniques were applied, revealing that supercritical water gasification can be viable for feed concentrations between 15 and 25%. A minimum selling price of 7 €/kg, 10 €/kg, and 13 €/kg were obtained for green hydrogen generated by the conventional, supercritical water, and plasma gasification processes, respectively. The results obtained in this study are of paramount importance for the hydrogen economy. However, this research should be supplemented by further intensifying the gasification processes in order to bring green hydrogen production costs down to a more competitive level.