Conventional Combustion Research Articles

Experimental investigation on spray and flame characteristics of a marine diesel engine with single and double injection

Multiple injection is one of the advanced technologies employed in modern diesel engines to improve combustion efficiency, reduce pollutant emissions, and minimize combustion noise. The application of multiple injection in marine diesel engines differs from its use in vehicles or heavy-duty engines, as it is not commonly combined with Exhaust Gas Recirculation (EGR). However, there is a scarcity of studies specifically examining the combustion characteristics of medium-speed marine diesel engines utilizing multiple injection. Given the large space scale of marine diesel engine, a constant volume chamber with a visible diameter of 240 mm was used, and an injector with a nozzle diameter of 0.465 mm was employed in the experiment. The spray development and combustion process were recorded by Mie-scattering and flame natural luminosity imaging respectively. Both conventional and double injection combustion processes were analyzed in detail. The results show that although the liquid phase spray does not fully penetrate to the cylinder wall in marine diesel engines, the flame penetrates to the cylinder wall rapidly, the flame burns near the wall almost throughout the entire combustion duration. The combustion characteristics of the double injection are significantly different, the flame propagation speed of the pilot and main injection fuel is one-third to one-half of that of a single injection with a long duration. For single injection spray with long injection duration, the flame penetration velocity is determined by the sequential ignition velocity of the fuel. While the flame penetration velocity for sprays with short injection duration mainly depends on the jet penetration velocity. The investigation on the impact of dwell time, fuel distribution, and injection pressure on the combustion process of double injection also provides valuable insights for optimizing multiple injection strategies.

Enhanced radiation heat transfer performance of Alumina-Spinel composite sphere with hollow structure for rapidly ultra-high temperature thermal storage/release process

Heat storage technologies for high temperatures have recently been gaining increasing attention. For heat storage applications at high temperatures, such as industrial regenerative burner systems, the impact of radiant heat transfer on the efficiency of rapid heat storage and release cannot be ignored. Hence, the development of heat storage materials with high infrared radiation absorption is of great significance for energy saving and CO2 emission reduction. Consequently, this study innovatively proposes an advanced composite heat storage material, composited by alumina and a Fe-Co-Mn-Al spinel, with the aim of improving absorptivity. A medium-entropy approach is employed to improve IR absorptivity of alumina. Through the strategic adding of various transition metal oxides, the radiative absorptivity of the alumina material in the 600–1200 °C range increased from an initial 0.2 to an impressive 0.8, provided that doping additives remain below 10 wt%. The high-temperature heat storage material balances cost, heat recovery efficiency and thermal stability. In addition, the heat storage material is prepared as a hollow sphere to further enhance the heat storage density of rapid heat storage/release and reduce cost. Multi-scale numerical simulations are carried out to reveal the heat transfer enhancement mechanisms of modified materials and hollowing. radiative modification can significantly increase the heat storage and release capacity, especially at ultra-high temperatures above 1000 °C. Experimental evaluations using an actual regenerative burner further confirmed the heat recovery performance of this novel heat storage sphere. Comparing with conventional regenerative burner system, heating power remarkably increased by 24.6 %, and the heat storage density of packed bed improved by 16.7 %. This study promises to significantly improve the efficiency of rapid heat recovery at high temperature.

Structural, Characterization, And Morphological Properties Of Copper Nanoparticles From Opuntia Ficus Indica Plant

AbstractOne of the most recent areas of interest in current nanotechnologies and nanosciences is the use of biomaterials in the manufacturing of nanoparticles. More and more research is being carried out on environmentally friendly methods to create metal oxide nanoparticles (NP), with the intention of preventing any potential risks associated with harmful substances for a safe and healthy environment. In this study, Copper Oxide (CuO) is synthesized utilizing Opuntia ficus‐indica as the plant extract using a Microwave Combustion Technique (MCM) and its comparison against the Conventional Combustion Method (CCM) are investigated. The synthesized CuO nanoparticles were characterized using X‐ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT‐IR), Scanning Electron Microscopy (SEM), and Energy Dispersive X‐ray Analysis (EDX) analysis. Photoluminescence spectroscopy was undertaken to acquire emission and absorption spectra and determine defects in the structures of all synthesized nanopowder samples. The antibacterial activity of the CuO nanoparticles was evaluated in‐vitro using gram‐negative and gram‐positive bacteria (Bacillus subtilis, Staphylococcus aureus). Enhanced anti‐bactericidal activity was shown against Gram‐negative bacteria compared to Gram‐positive bacteria. Through these findings, the use of CuO using Opuntia ficus indica extracts is hereby shown to be a cost‐effective and environmentally friendly alternative and that can be used in a variety of applications.

The application challenge of electric vehicles

The growing demand for sustainable transportation has prompted an accelerated transition toward electric vehicles (EVs) as a promising solution to mitigate the environmental impact of conventional internal combustion engine (ICE) vehicles. This research analyzes the key challenges and technologies associated with EVs, aiming to produce insights into this rapidly evolving field. The challenges surrounding EVs encompass various aspects, including limited driving range, lack of access to electric vehicle charging stations (EVCS), charging times for EVs, and safety considerations. To overcome these challenges, several technological advancements have emerged. Battery technology has advanced to extend the driving range per charge of an electric vehicle. Various models and algorithms to study the EVs charging station placement problem (EVCSPP) have been proposed to find the optimal location to build the charging stations. The advancement of extreme fast charging (XFC) technology and the intelligent transport system (ITS) shorten the charging time to improve the practicality of EVs adoption. Furthermore, the EVs charging standard and risk management have been introduced to ensure a secure charging system. By addressing these challenges and leveraging innovative technologies, a comprehensive and sustainable charging network can be realized, facilitating the transition towards a cleaner and greener transportation system.

Impact of engine control variables on low load combustion efficiency and exhaust emissions of a methane-diesel dual fuel engine

A conventional diesel engine when operated in the reactivity-controlled compression ignition (RCCI) combustion strategy faces challenges of high total hydrocarbon (THC) and carbon monoxide (CO) emissions leading to poor combustion efficiency at low engine loads. The oxides of nitrogen (NOx) versus smoke trade-off, encountered in conventional diesel combustion, is replaced by the NOx-THC trade-off in the RCCI operation. This work focuses on addressing the NOx-THC trade-off issue by systematically investigating the effects of engine control variables, such as, fuel injection timing, exhaust gas recirculation (EGR) and intake throttling, on a light duty compression ignition engine running in a methane-diesel dual fuel mode. The engine is operated at a load of 3 bar gross indicated mean effective pressure and at a speed of 1500 rev/min. Based on relationships identified between engine control variables, combustion parameters, emissions and engine performance, a bottom-up approach is used to combine the control variables synergistically to improve the NOx-THC trade-off. A combination of advanced start of injection timing of diesel (−35 degree crank angle (°CA) after top dead centre), 50% premix ratio and 55% EGR levels along with the end of port fuel injection of methane in the middle of the intake stroke (−270°CA), has resulted in a ∼34 percentage points (from 56% to 90%) improvement in combustion efficiency and a ∼9.5 percentage points improvement in thermal efficiency compared to the baseline low load dual fuel operation while maintaining good combustion stability. THC emission is reduced from 105 to ∼25 g/kWh whilst maintaining low levels of NOx (<0.3 g/kWh).

A free piston engine generator powered hybrid wheel loader with independent electric drive

Series hybrid powertrain is a practical way for wheel loader electrification. Conventional internal combustion engine (ICE) technique is mature but the efficiency is limited. Free piston engine generator (FPEG) is regarded as a promising technology that can be applied as decarbonized range extenders attributed to its high thermal efficiency and ultimate fuel flexibility. In this study, a FPEG-based series hybrid powertrain is proposed for wheel loaders to reduce fuel consumption. Multiple FPEG units are parallel connected to power the electric powertrain. The optimal unit commitment of the FPEG set is investigated via dynamic programming. A rule-based strategy called discrete power follower (DPF) is proposed. The influence of FPEG unit number on powertrain performances is studied. Energy efficiency comparison between the FPEG-based and the ICE-based series hybrid powertrains is carried out. Results show that the fuel consumption of the proposed FPEG-based series hybrid powertrain is 10.5 % lower than the ICE-based powertrain. The mean efficiency of wheel loader powertrain improves from 31.7 % to 35.1 %.

Study on Flow and Heat Transfer Characteristics of 25 kW Flameless Combustion in a Cylindrical Heat Exchanger for a Reforming Processor

Flameless combustion has advantages such as low pollution and uniform temperature in the combustion chamber, making it an excellent option for heat exchangers. Previous studies have focused solely on the flameless combustion phenomenon, without considering its interaction with the target being heated. In this study, we conducted experimental and computational fluid analyses on a cylindrical reformer for reverse air injection flameless combustion. Typically, small-scale reformers of 10 kW or less are coaxial triple-tube cylindrical reformers. In contrast, multitubular reformers are used for larger-scale applications, since the heat transfer rate in single-burner cylindrical reformers decreases sharply as the scale increases. Flameless combustion, with high heat transfer efficiency, helps overcome the limitation of premixed burner. Compared with conventional premixed burners, flameless burner decreases the combustion gas outlet temperature by 30% at 25 kW while reducing energy consumption by 24% (owing to the high heat transfer rate) for a given cooling fluid outlet temperature. Furthermore, it is shown that introducing a ring at the combustion chamber exit can enhance combustion gas recirculation. The experimental result was confirmed through computational fluid analysis. It is concluded that for reverse air injection flameless combustion, the combustion gas recirculation rate in the combustion chamber is strongly related to the heat transfer.

Thermoacoustic stabilization of a sequential combustor with ultra-low-power nanosecond repetitively pulsed discharges

This study demonstrates the stabilization of a sequential combustor with Nanosecond Repetitively Pulsed Discharges (NRPD). Sequential combustors offer advantages such as enhanced fuel flexibility and broader operational range compared to the conventional combustors. However, thermoacoustic instabilities limit their potential. While passive control strategies like Helmholtz dampers have been utilized, active control methods have been hindered by the lack of robust actuators for harsh conditions with sufficient control authority. This study demonstrates successful suppression of instabilities using NRPD in a lab-scale atmospheric sequential combustor, even at low plasma power (1.1 W, about 1.5×10−3 percent of thermal power of 73.4 kW). We also examine the effect of pulse repetition frequency and plasma generator voltage on NO emissions and the sequential flame topology. Notably, higher plasma power can further enhance suppression, albeit with a slight increase in NO emissions. However, the highest plasma power in our study (81 W, 1.1×10−1 percent of flame thermal power) shows a slight improvement in acoustic suppression while significantly elevating NO emissions. Intriguingly, specific plasma parameter combinations can excite another acoustic mode, necessitating further exploration for optimized control. This pioneering study highlights the potential of ultra-low-power plasma-based thermoacoustic control in sequential combustors, paving the way for enhanced stability and performance.

A review of electric vehicle hosting capacity quantification and improvement techniques for distribution networks

AbstractThe electrification of the transport sector to control the carbon footprint has been gaining momentum over the last decade with electric vehicles (EVs) seen as the replacement for conventional internal combustion engines. Economic incentives, subsidies, and tax exemptions are also paving the way for rising EV penetration in the power distribution networks. However, the exponential EV adoption requires careful technical and regulatory analysis of traditional networks to satisfy the network reliability constraints. Therefore, it would be vital to find EV hosting capacity (HC) limits of networks from a multifaceted approach involving various market players, mainly distribution system operators and EV owners. This review provides a systematic categorization of EV hosting capacity evaluation and improvement methods, thus enabling researchers and industry personnel to navigate the advancing landscape of EVs. This novel framework extends beyond the theoretical implication of diverse objective functions and HC improvement methods to the actual numerical values of EV HC across varying geographical settings. Therefore, this unique synthesis of varying aspects of EV HC facilitates the in‐depth understanding of the integration of sustainable energy and transport sector.

Holistic performance evaluation of a turbofan featuring pressure gain combustion for a short-range mission

Aviation is at the center of public interest because of its environmental impact, such as noise and pollutant emissions. Evolutionary technologies are not expected to be sufficient to contribute significantly to the 2050 CO2 emissions reduction targets. This could change if the constant pressure combustion of the Joule cycle could be replaced with a constant volume combustion (pressure gain combustion, PGC). However, PGC comes with a major drawback of a periodic, highly unsteady process that potentially reduces the stability and efficiency of the adjacent compressor and turbine. Furthermore, changes to the secondary air system (SAS) are required since the driving force of SAS stems from the pressure loss in the conventional combustor. Despite the lasting prevalence of pressure gain combustion, there is no whole system analysis taking into account not only the beneficial aspects of PGC, but also the detrimental effects on the SAS and turbo components. To close that gap, a zero-dimensional whole engine model is created. That model accounts for the individual effects of PGC. A comprehensive design methodology identifies optimum engine specifications for a short-range mission. By comparing the results of the PGC turbofan to a conventional turbofan, an SFC improvement of 3.3% was identified.

A Review on Control Methods of SEPIC Converters

In recent years, electric vehicles have witnessed a surge in popularity due to their energy-saving and eco-friendly attributes. Unlike conventional internal combustion engine vehicles, electric vehicles exhibit superior performance and operational efficiency. Within the realm of modern electric vehicles, power electronic circuits, notably including DC-DC converters, play a pivotal role. Among these converters, single- ended primary-inductor converters (SEPIC) find extensive use in scenarios where minimizing input and output ripple currents is essential. The primary objective of this project is to conceive and put into action advanced controllers for SEPIC converters, catering to a diverse range of applications, encompassing battery-powered devices, solar energy systems, and LED lighting systems. Key Words: DC-DC converter, SEPIC converter, PID, SMC, ASMC, Fuzzy logic Control.

Comparative life cycle assessment of battery-electric and diesel underground mining trucks

The mining sector is currently confronted with an energy market and evolving regulatory landscape that exerts pressure on the industry to consistently enhance its strategies and decision-making in support of sustainable practices. Traditionally, the ore is transported using heavy-duty trucks powered by diesel engines which have been identified as a primary contributor to environmental degradation. An emerging and technologically advanced solution of considerable interest is the implementation of battery-electric trucks, which still generates some uncertainty about its actual impact on the environment. The primary hypothesis under investigation is that battery-electric vehicles have significantly lower environmental impacts than conventional combustion vehicles. Thorough research is needed to bridge this knowledge gap and robustly understand the environmental effects of these technologies in the mining context. This study uses Life Cycle Assessment to evaluate the potential environmental impacts of battery-electric trucks compared to diesel trucks in a theoretical underground mine. The study analyses the environmental impacts around three main stages: the raw material supply for the manufacture of the vehicles, the energy supply (electricity or diesel fuel), and other indirect impacts associated with the operation of both types of trucks. The characterization methodology used is the ReCiPe2016 Midpoint (Hierarchical) using open-access software OpenLCA v1.10.3 for the impact assessment. The functional unit selected is one ton of material transported over 1 km. Our results for the baseline Chilean scenario indicate that diesel trucks have a considerably greater environmental impact in two of the five categories studied: global warming potential and stratospheric ozone depletion. The energy supply is the ‘hotspot’ for the electric truck life cycle, while the diesel truck life cycle has the operation and the energy supply as the main environmental impact sources due to the upstream and direct emissions associated with diesel supply and combustion, respectively. However, when considering particulate matter formation and water consumption, electric trucks exhibit higher impacts due to the technologies employed for generating the electricity used to charge their batteries. Furthermore, the environmental profile of the electric truck improves considerably when renewable sources of electricity substantially substitute coal in the electricity mix, as projected in the Chilean policy context. The main novelty of this study is that it is the first initiative comparing a battery-electric truck with a diesel truck considering an approach to the underground operation reality for the mining sector.

Review on Microfluidic Technology Based Synthesis of Fe-based Nanoparticles for Catalyst in Fuel Cell

Conventional combustion based energy generations, reliant on fossil fuels, poses significant environmental harm. In contrast, fuel cells offer an efficient and eco-friendly energy conversion method, capable of integrating with renewable sources and contemporary energy carriers to support sustainable development and energy security. Consequently, fuel cells are considered the promising energy conversion devices of the future. However, extensive research reveals that the cost of catalysts constitutes the most substantial portion of the overall fuel cell cost. To tackle this cost constraint, considerable advancements have been achieved in the development of cost-effective, precious metal-free electrocatalysts. Common methods for the preparation of metal nanomaterials (NPs) have more stringent requirements, lower deposition efficiency and higher costs. In addition, conventional preparation methods without precisely control of reagent concentration, mixing and temperature during the preparation process, makes it difficult to obtain the same results with poor reproducibility, restricting the industrial fabrication of high performance nanomaterials. Microfluidic reactors have advantages of efficient mixing, high heat and mass transfer, low reagent consumption, precise control of reactant components, residence time, reaction temperature and other parameters. They can also be coupled with multi-step reactions, greatly reducing the preparation time while obtaining composite nanomaterials with excellent dimensional homogeneity. In this review, we mainly discuss the microfluidic technology-based synthesis of PGM-free catalyst used in fuel cell.

Predicting the performance and emissions of an HCCI-DI engine powered by waste cooking oil biodiesel with Al2O3 and FeCl3 nano additives and gasoline injection – A random forest machine learning approach

This study presents a novel method for predicting the performance and emissions of a Homogeneous Charge Compression Ignition-Direct Injection (HCCI-DI) engine fuelled by waste cooking oil biodiesel (WCOB) blended with Aluminum oxide (Al2O3) and Ferric chloride (FeCl3) nano additives and premixed with gasoline. The test fuels considered were pure diesel, WCOB, B50 (a 50–50 blend of diesel and WCOB), and the nano-additives at concentrations of 50 ppm and 100 ppm. All experiments were performed on a 4.4 kW HCCI-DI engine operating at 1500 rpm. The results revealed that, utilization of WCOB showed a substantial reduction in emissions. Hydrocarbon (HC), carbon monoxide (CO) and smoke emissions decreased by 54.17 %, 50 %, and 22.69 %. Nevertheless, oxides of nitrogen (NOx) emissions increased by 18.32 %. When introducing gasoline (20 %) as a premix in HCCI-DI engines, a favourable shift in emission and efficiency metrics was observed. The brake thermal efficiency (BTE) increased 4.23 %. Moreover, NOx and smoke emissions decreased by 4.3 % and 39.21 %. Furthermore, compared to conventional diesel-fueled combustion, the integration of the nano additives manifested promising results. After introducing Al2O3 into neat fuel, The BTE improved by 11.27 % for direct injection (DI) combustion and 18.31 % for HCCI-DI combustion. Additionally, there was a marked decrease in exhaust emissions. FeCl3 nano additive into the test fuel significantly reduced HC, CO, and smoke emissions. Furthermore, the random forest machine learning approach demonstrated an extensive accuracy in forecasting both engine performance and emissions for the HCCI-DI engine. The innovative combination of cutting-edge machine learning techniques and combustion technology used. This model to understand the complicated correlations between input parameters and engine outputs and account for the system's intrinsic non-linearities and interactions. This dramatically improves standard prediction approaches, often assuming linear correlations or disregarding variable interdependencies.

HCCI technology using hydrogen energy and artificial intelligence

The principle of a HCCI engine is to inject a mixture of fuel and air into the cylinder and allow it to self-ignite under a high compression ratio. Unlike traditional gasoline and diesel engines, the mixture in the HCCI engine is homogeneous and does not require an ignition system to ignite it. The air-fuel mixture in the cylinder is burned completely by compressing. It makes effective use of fuel. The structure is simpler than a conventional internal combustion engine. HCCI engine has a huge application prospect in many fields. Among them, the automobile is one of the biggest parts. However, some applications have not been widely used. Although the HCCI engine has so many advantages, as this study has discussed, many of its drawbacks are still serious, such as the difficulty in controlling the parameters in the combustion and work process, resulting in the theoretical process being difficult to realize fully. The stringent environmental constraints of HCCI engines, the scarcity of suitable fuels and the significantly lower lifetime of HCCI engines than conventional engines pose significant obstacles to their practical use. This study presents the idea of using artificial intelligence system-assisted control system to accurately control HCCI engines in real time, which has shown great potential in HCCI engine misfire detection and HCCI engine initial burn time prediction.

Experimental investigation of the co-combustion of LPG-hydrogen blends on LPG-fueled systems

The need for sustainable and less pollutant heating solutions has started an energy transition process. Some of the short-term alternatives proposed are based on the use of hydrocarbon-hydrogen blends in conventional combustion systems. In this work, LPG-H2 blends are studied in (a) a gas heater, (b) a water heater and (c) a porous media burner. Thermal and emission behavior, as well as thermal efficiency, are studied for different fractions of H2 in the fuel blend. Stable combustion was sustained for H2 volume fractions up to (a) 44%, (b) 68% and (c) 58%, for the above-mentioned appliances, respectively. Both gas and water heaters showed an overall reduction in thermal efficiency and temperatures as H2 presence was increased. On the other hand, higher temperatures, and thermal efficiencies, along with a 30% reduction in CO emissions were registered for the porous media burner for large H2 fractions in the fuel blend. In conclusion, the technical feasibility of adding H2 to the LPG feed lines of conventional combustion systems was demonstrated, through the stable operation of the 3 appliances studied.

Development of a novel subgrid combustion model for buoyant turbulent diffusion flames

A novel approach is presented to incorporate finite rate reactions in modeling of turbulent diffusion flame, with the existence of unresolved flamelets inside the CFD grid cells taken into account. This approach, called SCM (subgrid combustion model), is applied in large eddy simulations of the UMD line burner flames. With the global kinetic parameters fitted for the measurement data and detailed simulations of autoignition in stoichiometric methane-air mixture, as well as for the extinction strain rate in the opposed non-premixed jets, the SCM model is shown to replicate the mean temperature profiles in unsuppressed flame with mean total heat release of 50 kW. For flame suppression via dilution of the oxidizer flow by nitrogen, the lift-off and extinction of non-anchored flame are predicted in agreement with the experimental data. The SCM is designed as a tool to allow for the finite rate kinetics effects in large eddy simulations of buoyant turbulent diffusion flames, with the focus on weakly turbulent regions, in which applicability of conventional combustion models is limited.

Large eddy simulation of spray and combustion characteristics of biodiesel and biodiesel/butanol blend fuels in internal combustion engines

Biofuel is a crucial renewable and environmentally friendly energy source for addressing greenhouse gas emissions and other energy-related issues. Biodiesel and butanol, among alternative biofuels, possess complementary physical and chemical properties, offering multiple possibilities for their use in existing internal combustion engines. However, biodiesel’s distinctly different physical and combustion properties from conventional diesel fuels make its combustion process substantially different. The complex composition of biodiesel presents significant challenges in accurately simulating its spray combustion characteristics. This paper presents a systematic evaluation of six single-component surrogate fuel models and a five-component model for the prediction of biodiesel spray characteristics under various conditions using large-eddy simulation (LES). The results show that single-component surrogate fuel models can only predict the gaseous penetration of biodiesel but not the liquid-phase penetration. A five-component fatty acid methyl ester surrogate fuel model is proposed, demonstrating an accurate simulation of biodiesel spray evaporation characteristics under different conditions. Based on the five-component evaporation model, LES is utilized to examine three strategies of biodiesel/butanol-fueled internal combustion engines: direct injection of pure biodiesel in conventional diffusion-controlled combustion (CDC) engines, direct injection of biodiesel–butanol blend in CDC engines, and biodiesel/butanol reactivity-controlled compression ignition (RCCI) engines. The simulation results are validated against engine experiment results, showing that the five-component model can successfully predict spray and combustion characteristics in internal combustion engines. The RCCI concept can significantly reduce NOx emissions; however, CO and UHC emissions are higher than in the CDC engines due to incomplete combustion in the fuel-lean butanol/air mixture.

Carbon emissions reduction potentiality for railroad transportation based on life cycle assessment

This study addresses the comparative carbon emissions of different transportation modes within a unified evaluation framework, focusing on their carbon footprints from inception to disposal. Specifically, the entire life cycle carbon emissions of High-Speed Rail (HSR), battery electric vehicles, conventional internal combustion engine vehicles, battery electric buses, and conventional internal combustion engine buses are analyzed. The life cycle is segmented into vehicle manufacturing, fuel or electricity production, operational, and dismantling-recycling stages. This analysis is applied to the Beijing-Tianjin intercity transportation system to explore emission reduction strategies. Results indicate that HSR demonstrates significant carbon emission reduction, with an intensity of only 24 %–32 % compared to private vehicles and 47 %–89 % compared to buses. Notably, HSR travel for Beijing-Tianjin intercity emits only 24 % of private vehicle emissions, demonstrating the emission reduction benefits of transportation structure optimization. Additionally, predictive modeling reveals the potential for carbon emission reduction through energy structure optimization, providing a guideline for the development of effective transportation management systems.

Development of high-strength and durable coal char-based building bricks

Pyrolysis coal char is a byproduct of the coal industry and causes undesirable environmental issues from conventional coal combustion and gasification. This paper presents a novel approach to utilize coal char for manufacturing new and environmentally friendly building bricks. The effects of sand, silica fume (SF), superplasticizer (SP), air-entraining admixture (AE), and graphene oxide (GO) on the properties of char-based bricks, including heat of hydration, thermogravimetric and differential thermal analysis, microstructures, density, and compressive strength, are investigated. A new treatment method using hydrophobic liquid in a vacuum condition is proposed to improve the durability of char bricks, which is evaluated based on water absorption and freeze-thaw (F-T) cycles. The experimental results indicate that the new bricks with 40% char content have a good compressive strength performance of 49.2–52.5 MPa, which compares favorably to conventional clay bricks with compressive strength of 10–20 MPa. Adding AE and GO slightly increases and decreases the compressive strength at 28 days, respectively. Moreover, the proposed treatment method significantly improves the durability of char bricks. The treated char bricks exhibit a boiling water absorption of ≤2.3%, which is 90% lower than that of untreated char bricks. The untreated and treated char bricks can achieve 22 and 120 F-T cycles, respectively. Overall, this study presents a promising approach to repurpose coal char and produce sustainable building bricks with high compressive strength and durability.