Gas Yield Research Articles

A Comprehensive Study of Biochar Yield and Quality Concerning Pyrolysis Conditions: A Multifaceted Approach

In this research, we investigated the yields of biochar, bio-oil, and synthesis gas under various pyrolysis conditions, as well as their impact on the elemental composition, FTIR, EDX, SEM, and HCV values of biochar. This study utilized three different pyrolysis temperatures (400 °C, 500 °C, 600 °C), two holding times (30 and 60 min), and two N2 gas flow rates (0.2 and 0.5 L min−1). We observed that an increase in pyrolysis temperature led to a decrease in the yields of biochar and bio-oil, while synthesis gas yield increased, as expected. Additionally, a higher gas flow rate resulted in a reduction of biochar yield from 34.07% to 32.72%. A longer residence time diminished the bio-oil yield but increased the synthesis gas yield. The FTIR, EDX, and elemental analysis of biochar produced at a pyrolysis temperature of 600 °C, with a 60-min holding time and a 0.2 L min−1 N2 gas flow rate, indicated maximized carbon content. Moreover, a more porous structure was observed at higher pyrolysis temperatures. The research also revealed that increases in pyrolysis temperature, residence time, and gas flow rate enhanced the energy content of the biochar.

Influence mechanisms of torrefaction on syngas production from bio-waste molten salt thermal treatment

The production of high-value syngas from bio-wastes through thermal conversion is a promising way to achieve carbon neutrality. In order to reduce the cost of the process, molten salt thermal treatment has been used for bio-wastes syngas production. Moreover, the removal of oxygen and water induced by torrefaction can effectively enhance the energy density of biomass, and the effect of these changes on the quality of syngas was widely investigated. This study proposed to torrefy bio-wastes and then produce syngas in molten NaNO3-NaNO2-KNO3 at 300 ℃. Results showed that the evaluation indices of syngas were improved, while the cold gas efficiency reached 44.02 % for beech wood torrefied at 280 ℃, and the syngas quality is equivalent to the products obtained by gasification of bio-wastes. The gas yield of the torrefied bio-wastes was increased by 8.08–45.23 % compared to the raw bio-wastes. Na+ and K+ in the molten salt catalyzed the cracking of propyl chains and ring opening of aromatic rings in lignin, resulting in a prominent enhancement in CO yield. Meanwhile, torrefaction could change the solid structure, leading to a delay in gas production, and torrefaction could also increase graphitization degree of char (C–C/C = C up to 50.72 % for SB-280), thus preventing the reaction proceeding. This study provided a new approach to enhance the content and quality of syngas from bio-wastes at low temperatures.

Pyrolysis and catalytic steam gasification of olive oil waste in two stages

A study of the pyrolysis and catalytic gasification of a waste from the extraction of olive oil has been carried out. The work objective was to characterize the solid and gaseous phases generated in the process for their possible utilization in energy generation. The experimental system consists of two cylindrical stainless steel reactors connected in series. A conventional pyrolysis is produced in the first reactor. In the second reactor, the gases and liquids generated in the first one pass through a dolomite catalytic bed where the cracking of the heavier components is produced. Also, in this second reactor, a steam stream is continuously introduced. The influence of temperature (500-700 ºC), quantity of catalyst (25-100 g) and steam flow rate (0-1.40 mL/min) has been determined. Also, the dolomite effectiveness as catalyst was evaluated For this motive, experiments, without reactivating dolomite, were carried out (0-6 runs), and the yields of solids, liquids and gases were determined. An increase in reaction temperature leads to a decrease in solid and liquid yield and to an increase in the gas phase yield. The presence of catalyst and the quantity of the same, originate an important decrease in the liquid phase yield and a high increase in the gas phase yield, especially important in the case of hydrogen. On the other hand, the catalyst is very stable and does not lose activity during at least six cycles of reaction. The presence of steam, increase the yield of hydrogen, but the increase of the steam flow rate, do not generate significant changes in the products distribution.

Two-stage fluidized bed gasification enhanced with oxidative pyrolysis for low-tar producer gas from biomass

Oxidative pyrolysis of fuel was adopted to configure an advanced two-stage fluidized bed gasification system, aiming to produce low-tar producer gas efficiently. A series of tests were carried out to investigate the effect of oxygen allocation in supply on gasification of pine chips in terms of both efficiency and producer gas quality. Compared with the case without pre-oxidation, coupling oxidative pyrolysis increased gas volume fraction of CO, CH4, and CnHm while decreasing that of CO2 and H2 in the produced gas. Further analysis showed that adopting oxidative pyrolysis reduced fuel gas yield, but the tar in the produced gas was lighter. The generated tar is easily transformed into small-molecule combustible gas by the catalytic action of hot char, thus increasing the calorific value of product gas. The long-term operation of the pilot plant presents a great steady continuous running with a minimum tar content in the producer gas of 1.3 g/Nm3. The above-mentioned results thus well verified the technical advantage and feasibility of the two-stage fluidized bed gasification with oxidative pyrolysis.

Simulation of waste tire gasification in bubbling fluidized bed by Aspen: Contribution ratio analysis

Waste tire gasification in a bubbling fluidized bed is a promising thermochemical conversion technology that not only utilize waste tire but also produce energy. To reveal the gasification performance of waste tire in a bubbling fluidized bed, two Aspen models were developed to simulate the effect of gasification agent types (such as air, steam, carbon dioxide and their mixtures), considering chemical reactions that reached thermodynamic equilibrium (CRTM) or were controlled by kinetics (CRK). The simulated gas compositions (H2, CO, CO2 and CH4) and lower heating value (LHV) were compared with experimental data under various operating conditions. The results showed that CRK model exhibited much better performance than the CRTM model. These two models were further utilized to analyze the effect of gasification agent type on gas composition and LHV. The contribution ratios of different chemical reactions were detailed analyzed, such as hydrogen combustion, carbon monoxide combustion, methane combustion, carbon combustion, steam gasification, water gas shift reaction and carbon dioxide gasification. The established Aspen model for waste tire gasification in a bubbling fluidized bed could be served as a guideline for selecting operation conditions to achieve high hydrogen composition, carbon conversion, and gas yield.

Energy Recovery from Municipal Solid Waste through Co-Gasification Using Steam or Carbon Dioxide with Olive By-Products

The valorization of untreated municipal waste (MSW) biochar for energetic uses, through its co-gasification with olive stone (OST) biochar under a steam or carbon dioxide atmosphere, was investigated. The experiments were conducted in a fixed bed unit and a thermal analysis–mass spectrometer system. The thermal behavior, reactivity, conversion, product gas composition, syngas yield and energy potential were determined, while the influence of the fuel’s internal structure, chemical functional groups and operating conditions were examined. The concentrations of H2 and CO2 in the product gas mixture under a steam atmosphere were increased with steam/biochar ratio, while that of CO was reduced. At a steam/biochar = 3 H2 yield, the higher heating value and conversion for the OST were 52.8%, 10.8 MJ/m3 and 87.5%; for the MSW, they were 44.4%, 9.9 MJ/m3 and 51.5%, whereas for their blend, they were 50%, 10.6 MJ/m3 and 76.6%, respectively. Under a carbon dioxide atmosphere, the reactivity and conversion of the OST biochar (84%) were significantly higher as compared with the MSW biochar (50%). The higher heating value of the product gas was 12.4–12.9 MJ/m3. Co-gasification of the MSW with OST (in proportions 30:70) resulted in the enhanced reactivity, conversion, syngas yield and heating value of product gas compared with gasification of solely MSW material.

Biomass gasification in rotary kiln integrated with a producer gas thermal cleaning unit: An experimental investigation

In this work, gasification of hazelnut shells grains is carried out in a bench-scale rotary kiln by using air as gasifying agent at 800 °C. The producer gas is directly treated in a thermal cleaning unit operating at 800–1100 °C with the aim to reduce the load of contaminants. The producer gas cleaning by thermal methods is usually studied by using model compounds, whilst herewith the behavior of a real producer gas is investigated. Results indicate that at high temperature CO2 reacts with tar and particulate to generate CO, thereby improving the quality of producer gas in terms of heating value, producer gas yield and contaminants content. Benzene is the most abundant organic contaminant of the producer gas, the concentration of which is significantly reduced upon thermal treatment. For the first time, a bench-scale rotary kiln gasifier with lignocellulosic biomass as feedstock is integrated with a thermal cleaning unit, providing experimental evidences about the suitability of rotary kiln for air gasification of lignocellulosic biomass and its integration with a thermal unit. The proposed approach could find application also when other types of gasifier are adopted, although a parametric study should be carried out in order to fully understand the reaction mechanism of contaminant removal and to find optimal operation conditions, also as a function of biomass feedstock features.

Investigating the Role of Byproduct Oxygen in UK-Based Future Scenario Models for Green Hydrogen Electrolysis

Water electrolysis for hydrogen production with renewable electricity is regularly studied as an option for decarbonised future energy scenarios. The inclusion of byproduct electrolytic oxygen capture and sale is of interest for parallel decarbonisation efforts elsewhere in the industry and could contribute to reducing green hydrogen costs. A deterministic hydrogen electrolysis system model is constructed to compare oxygen inclusion/exclusion scenarios. This uses wind and solar-PV electricity generation timeseries, a power-dependent electrolysis model to determine the energy efficiency of gas yield, and power allocation for gas post-processing energy within each hourly timestep. This maintains a fully renewable (and therefore low/zero carbon) electricity source for electrolysis and gas post-processing. The model is validated (excluding oxygen) against an existing low-cost GW-scale solar-hydrogen production scenario and an existing hydrogen production costs study with offshore wind generation at the multi-MW scale. For both comparisons, oxygen inclusion is then evaluated to demonstrate both the benefits and drawbacks of capture and utilisation, for different scenario conditions, and high parameter sensitivity can be seen regarding the price of renewable electricity. This work subsequently proposes that the option for the potential utilisation of byproduct oxygen should be included in future research to exemplify otherwise missed benefits.

Optimization of coal chemical process parameters and energy saving and emission reduction based on genetic algorithm

Abstract Coal is an important energy resource. How to utilize it efficiently and cleanly is a hot topic nowadays. In the coal gasification process, the process parameter indexes have a significant impact, and the uncertainty of these factors will lead to a decrease in the quality of gas production. Therefore, in this paper, the uncertainty of process parameters is considered, and Aspen plus software with the Monte Carlo method is used to simulate the coal chemical process and measure the effect of uncertainty of process parameters on the yield of the coal gasification process. On this basis, in addition, coal flow rate, pressure, and steam/oxygen are taken as the process parameters and optimized, and three sets of multi-objective optimization models are established with gas calorific value, gasification efficiency, and gas yield, respectively, which are solved by improved multi-objective genetic algorithm based on crossover operator and variational operator to obtain Pareto curves, so as to adjust the parameter values according to the actual needs. The results show that the fluctuation of pressure has a big influence on the carbon conversion rate and gasification efficiency, and the carbon conversion rate and gasification efficiency can be made more stable by controlling the change of pressure. The improved genetic algorithm NSGA-II can reach the actual optimal objective function value in both high and low iteration times, providing the required parameters for the decision maker, and the optimal program results in TEC of 402,758 kW and CO2 content of 0.12%, which is effective in energy saving and emission reduction.

Unravelling the kinetics, isotherms, thermodynamics, and mass transfer behaviours of Zeolite Socony Mobil - 5 in removing hydrogen sulphide resulting from a dark fermentative biohydrogen production process.

Research into the speciation of sulfur and hydrogen molecules produced through the complex process of thermophilic dark fermentation has been conducted. Detailed surface studies of solid-gas systems using real biogas (biohydrogen) streams have unveiled the mechanisms and specific interactions between these gases and the physicochemical properties of a zeolite as an adsorbent. These findings highlight the potential of zeolites to effectively capture and interact with these molecules. In this study, the hydrogen sulphide removal analysis was conducted using 0.8 g of the adsorbent and at various reaction temperatures (25-125 °C), a flow rate of 100 mL min-1, and an initial concentration of approximately 5000 ppm hydrogen sulphide. The reaction temperature has been observed to be an essential parameter of Zeolite Socony Mobil - 5 adsorption capacity. The optimum adsorption capacity attains a maximum value of 0.00890 mg g-1 at an optimal temperature of 25 °C. The formation of sulphur species resulting from the hydrogen sulphide adsorption on the zeolite determines the kinetics, thermodynamics, and mass transfer behaviours of Zeolite Socony Mobil - 5 in hydrogen sulphide removal and Zeolite Socony Mobil - 5 is found to improve the quality of biohydrogen produced in thermophilic environments. Biohydrogen (raw gas) yield was enhanced from 2.48 mol H2 mol-1 hexose consumed before adsorption to 2.59 mol H2 mol-1 hexose consumed after adsorption at a temperature of 25 °C. The Avrami kinetic model was fitted for hydrogen sulphide removal on Zeolite Socony Mobil - 5. The process is explained well and fitted using the Temkin isotherm model and the investigation into thermodynamics reveals that the adsorption behaviour is exothermic and non-spontaneous. Furthermore, the gas molecule's freedom of movement becomes random. The adsorption phase is restricted by intra-particle diffusion followed by film diffusion during the transfer of hydrogen sulphide into the pores of Zeolite Socony Mobil - 5 prior to adsorption on its active sites. The utilisation of Zeolite Socony Mobil - 5 for hydrogen sulphide removal offers the benefit of reducing environmental contamination and exhibiting significant applications in industrial operations.

Compost Amendment Enhances Leaf Gas Exchange, Growth, and Yield in Water-challenged ‘Crimson Giant’ Red Radish (Raphanus sativus L.)

Red radish is a nutritious root vegetable crop that has a short production cycle. Water deficit limits plant productivity, affecting its quantity and quality. Compost amendment offers a potential solution to mitigate water deficit effects. This study assessed the impact of compost manure rates (0%, 50%, 75%, and 100%) and irrigation treatments (40%, 60%, 80%, and 100% of evapotranspiration) on ‘Crimson Giant’ red radish production. Significant differences in growth and quality were observed among these treatments. Compost rates of 75% and 100% improved leaf gas exchange, plant growth (leaf count, fresh weight, dry weight, and area; stem length), root development, total yield (root fresh weight, dry weight, diameter, and length), and root quality (vitamin C and total soluble solid and titratable acidity). The 100% compost and 100% irrigation combination achieved the highest yields. Under water deficit, applying 75% or 100% compost with 80% irrigation conserved 20% of water while maintaining radish output. Overall, compost amendment effectively enhanced red radish growth and production under water deficit.

Process modelling of waste tyre pyrolysis for gas production using response surface methodology

The search for cleaner and renewable energy sources coupled with the need for environmental protection has necessitated the conversion of municipal solid wastes to energy sources. In this study, the pyrolysis of waste tyres in a fixed-bed reactor was carried out in a bid to generate non-condensable gases. The influence of process variables such as sample weight, reaction temperature, and reaction time were modelled and optimized using the central composite design of the response surface methodology. Based on the central composite design of the response surface methodology, the R2, adjusted R2 and predicted R2 values of 0.968, 0.941 and 0.750 respectively, indicated that the model properly fitted the experimental data. This implied the accuracy of the model prediction. The maximum predicted gas yield of 10.212 wt% was estimated under optimal conditions with desirability of 0.697, a dimensionless value indicating the closeness of the combination of input variables to the desired values for the response variables. The gases obtained upon pyrolysis of waste tyres can serve as a source of hydrocarbon gases in the petroleum and petrochemical industry.

Comparative microwave catalytic pyrolysis of cellulose and lignin in nitrogen and carbon dioxide atmospheres

In this paper, a cleaner pyrolysis strategy combining microwave heating, catalyst and carbon dioxide was explored for converting biomass components into higher quality products. Catalytic pyrolysis was more favorable for the decomposition and conversion of complex biomass structures. For furfural residue pyrolysis, potassium sulfate contained in sample served as the main catalytic component. Potassium sulfate promoted the increase of phenols in bio-oil. Notably, carbon dioxide atmosphere promoted the decomposition of substances and exerted a significant effect on biomass pyrolysis, which increased bio-oil yield and declined gas yield. When the pyrolysis atmosphere was changed from nitrogen to carbon dioxide, the ID/IG ratio decreased from 1.07 to 0.74, indicating that carbon dioxide decreased defect structure in biochar. Carbon dioxide enriched the porous structure and surface roughness of biochar. Also, carbon dioxide as a carrier gas was found to be more effective than nitrogen in improving the heating values of biochar and the acidity of bio-oil under carbon dioxide was lower than that under nitrogen, which was conducive to the subsequent utilization of biochar and bio-oil. Carbon dioxide promoted the production of alcohols, alkenes, and alkanes in bio-oil. Beneficially, the interaction of cellulose and lignin inhibited the release of hydrogen chloride. At last, this study also provides insights into the mechanism of catalyst and CO2 on biomass microwave pyrolysis.

Achieving climate neutrality in coal mining regions through the underground coal gasification

Coal mining regions face significant challenges in transitioning towards climate neutrality due to their dependence on fossil fuel extraction. This research explores the potential of underground coal gasification (UCG) technology as a pathway towards climate neutrality in these regions. UCG involves converting coal in-situ into syngas, a cleaner-burning fuel, while mitigating greenhouse gas emissions. The study investigates the material-thermal parameters of the gasification process using the MTB SPGV software and analyzes the gas concentration and producer gas yield parameters in the “Stepova” Mine field of SE “Lvivvuhillia”. Additionally, technological solutions for achieving climate neutrality through carbon dioxide (CO2) utilization are proposed, focusing on pre-separation of CO2 from producer gas obtained during UCG. A technological scheme for CO2 utilization is presented, outlining the steps from gas extraction to storage and utilization in underground spaces. The proposed method offers a promising approach to mitigate CO2 emissions and optimize resource utilization in coalmining regions, contributing to global efforts for environmental sustainability and climate action.

Co-gasification behavior and products distribution of wet sewage sludge and corn stalks: Effect and mechanism analysis of self-moisture utilization

Wet sewage sludge (WSS) self-moisture gasification is a promising route for H2-rich syngas production. This research investigated the co-gasification of WSS and corn stalks (CS), focusing on the effects of self-moisture content. Thermogravimetric analysis of the pyrolysis of the mixture (WSS:CS = 40:60 wt%) revealed that the reactions followed a three-parallel-reaction model. The co-gasification process was performed to compare the effects of self-moisture and external steam used as gasification agents, respectively. The results showed that the self-moisture gasification led to higher H2 yields (0.057–0.11 L/g), gas yields (0.19–0.21 L/g), and specific gas energy (2.62–2.72 MJ/kg) than those in external steam gasification (0.055–0.090 L/g, 0.16–0.18 L/g and 2.32–2.52 MJ/kg, respectively). Additionally, self-moisture gasification also resulted in lighter tar with primarily light organic acids (28.0%), and char with weaker aromatic structure features, attributed to longer reaction time during diffusion of pyrolysis products. Overall, this study provided theoretical foundations for the high-value exploitation of WSS.

Improving the Quality of Bio-oil Using the Interaction of Plastics and Biomass through Copyrolysis Coupled with Nonthermal Plasma Processing.

Bio-oil produced from the pyrolysis of biomass is chemically complex, viscous, highly acidic, and highly oxygenated. Copyrolysis of biomass and plastics can enhance oil quality by raising the H/C ratio, leading to improved biofuel properties. In this work, copyrolysis of polystyrene and biomass was passed to a second-stage dielectric barrier discharge nonthermal plasma reactor with the aim to further improve the product bio-oil. Pyrolysis of the polystyrene and biomass produces volatiles that pass to the second stage to undergo cracking and autohydrogenation reactions under nonthermal plasma conditions. There was a synergistic interaction between biomass and polystyrene in terms of overall oil and gas yield and composition even in the absence of the nonthermal plasma. However, the introduction of the nonthermal plasma produced a marked increase in monocyclic aromatic hydrocarbons (e.g., ethylbenzene), whereas polycyclic aromatic compounds decreased in concentration. Most notably, the influence of the plasma markedly reduced the quantity of oxygenated compounds in the product oil. It is suggested that the unique reactive environment produced by the plasma involving high-energy electrons, excited radicals, ions, and intermediates increases the interaction of the polystyrene and biomass pyrolysis volatiles. Increasing input plasma power from 50 to 70 W further enhanced the effects of the nonthermal plasma.

Co‐generation and GHG emission from agricultural waste based on pyrolysis/gasification: Experimental and LCA approaches

AbstractIn this study, co‐generation from rice straw based on pyrolysis and gasification was studied by experimental and modeling approaches. Pyrolysis experiment results show that improving pyrolysis temperature will benefit the yield of gas and bio‐oil, while reducing the yield of bio‐char. The BET (Brunauer, Emmett, and Teller) surface area of bio‐char reached a maximum of 143.26 m2/g when the temperature was increased to 550°C. For co‐generation in this study, an optimized pyrolysis temperature of 500°C was selected. With respect to gasification, air equivalence ratio (ER) largely influenced the syngas yield and composition. At ER = 0.25, the concentration of H2 and CO reached a maximum of 17.8 wt% and 16.2 wt%. Based on the experimental results, an Aspen Plus model was built to evaluate the mass and energy balance during co‐generation. Furthermore, a life cycle assessment method was used to evaluate the greenhouse gas emission during co‐generation process initialed from rice straw planting. Results show that the greenhouse gas emission intensities of the two co‐generation systems were 2.92 and 3.51 g CO2/MJ respectively, which were much lower than traditional fossil fuels.

Plastics as a reburning fuel: Pyrolysis at reburning temperatures and NO-reburning by simulated pyrolysis gas

Using waste plastics as a reburning fuel is promising for both reducing NOx emissions and managing plastic waste. To gain a better understanding of the chemistry involved in plastic reburning, pyrolysis products of different types of plastics at typical reburning temperatures (900–1200 °C) were investigated experimentally, and the reburning performance of simulated plastic pyrolysis gases was studied through experiments and chemical kinetic modeling. The plastics involved in the pyrolysis experiments included high-density polyethylene (HDPE), polypropylene (PP), polyamide 6 (PA6), and acrylonitrile–butadiene–styrene copolymer (ABS). HDPE exhibited the highest hydrocarbon gas yield (up to ∼ 70 wt% at 900 °C) while ABS had the lowest gas yield (<20 wt%) among the four plastics at the investigated temperatures. The hydrocarbon gas was composed mainly of methane, ethylene, and acetylene, with ethylene decreasing and acetylene increasing with temperatures rising from 900 to 1200 °C. Hydrogen cyanide was found to be the dominant gaseous nitrogen-containing compound for PA6 and ABS. Solid byproducts such as soot were generated at pyrolysis temperatures exceeding 1100 °C, leading to a reduction of the gas yield for all plastics. This indicates a potentially important contribution of heterogeneous NO reduction mechanisms during plastic reburning at high temperatures. Concerning the homogeneous NO reduction, reburning experiments using simulated plastic pyrolysis gases composed of methane, ethylene, and/or acetylene were carried out at 700–1200 °C in a flow reactor with an initial NO concentration of 1000 ppm and an excess air ratio λ of 0.7. Results for the simulated plastic pyrolysis gases showed NO reduction efficiencies ranging from 30 % to 46 % within the temperature range 950–1200 °C. The presence of acetylene in the simulated pyrolysis gas mixtures appears to facilitate NO reduction. A detailed chemical kinetic model applied to simulate the experiments gave a reasonable prediction of the NO reduction and revealed the important role of the ketenyl radical in removing NO.

Microscopic mechanism for CO2-assisted co-gasification of polyethylene and softwood lignin: A reactive force field molecular dynamics study

Co-gasification of biomass and waste plastic to produce syngas and value-added products is an attractive technology for renewable energy utilization and waste disposal. CO2 as a gasifying agent has received much attention as it can act as carbon source and oxidant in the reaction. In this paper, the feasibility and characteristics of CO2-assisted co-gasification of polyethylene and softwood lignin were explored. Simulation results showed that the lignin macromolecule began to decompose through C–O–C bond breaking and the PE chain gradually decomposed through C–C bond breaking. CO2-assisted co-gasification showed a negative synergistic effect on gas yield at the early stage, which delayed the reaction, but showed a positive synergistic effect at the late stage. The reaction between CO2 and carbon-containing fragments greatly promoted CO production. The hydrogen and hydrocarbon radicals from PE were actively involved in H2 and hydrocarbon gas production. Compared with O2-assisted co-gasification, the CO2-assisted and CO2/O2-assisted co-gasification yielded more CO, hydrocarbon gases and combustible gases and increased the lower heating value of gas product. This work sheds light on the underlying mechanisms of CO2-assisted co-gasification of polyethylene and softwood, and would be helpful for the development of this technology.

Gas exchange and yield of yellow passion fruit under different irrigated depths, planting hole volumes, and hydroretentive polymer application

Passion fruit cultivation relies on irrigation to increase yields in the semiarid of northeastern Brazil. Water scarcity is one of the factors that most affect crop physiology, leading to lower yields. Therefore, this study aimed to assess the influence of planting hole volume and application of a hydroretentive polymer on physiological and productive aspects of irrigated yellow passion fruit cv. BRS GA1 in the Northeast semi-arid region of Brazil. The experiment was conducted in randomized blocks, in a split-plot design 2 × (2 × 2). Treatments consisted of irrigation depths (100% and 70% of the crop's evapotranspiration requirement - ETc), planting hole volumes (64 dm3 and 128 dm3), and soil with and without application of hydroretentive Polymer (1.5 g dm3), with four replicates and three plants per plot. The analyzed variables included chlorophyll a and b indices, gas exchange, and yellow passion fruit yield. The findings showed that hydroretentive polymer application to the soil increases chlorophyll content and gas exchange in yellow passion fruit. Moreover, photosynthetic rates were not limited by a 30% reduction in irrigation depth and increased in plants grown in 128-dm3 planting holes with hydroretentive polymer. Based on yield results, irrigation depths can be reduced to 70% of the ETc by applying hydroretentive polymer in 64-dm3 planting holes.