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A tiltable box-type solar cooker was designed and fabricated to meet the cooking needs of a typical family of five in Sana'a, Yemen, which is currently experiencing an energy crisis as a result of the war that has been ongoing since 2015. The production cost of the cooker is US$74, which is affordable to Yemenis. The first figure of merit (F1), second figure of merit (F2), cooking power, and maximum stagnation temperature were found experimentally to be 0.1354 °Cm2/W, 0.4934, 63.53 W, and 172.75 °C, respectively. A numerical simulation with a solar load model was performed using ANSYS-FLUENT Academic 2019 R3 to study the temperature distribution and solar heat flux inside the cooker. The solar beam direction and radiation were considered via the solar load model using two methods: by defining the experimental data as the input and by using ANSYS-FLUENT's solar calculator. The simulation results were validated by comparison with experimental results in the form of temperature measurements, and good agreement was observed between the numerical and experimental results with a maximum error of 3.29%.

The disposal of kitchen waste (KW) from households associated with the increasing population is an alarming environmental concern with the release of greenhouse gases additional to the large landfill spaces requirement. An experimental rig was developed to characterize the torrefaction process of banana peels (BP) and stale bread (SB) in a microwave-heated reactor. The new approach to enhance the microwave irradiation absorption was investigated by adding charcoal bed. The KW materials were upgraded successfully into torrefied product fuel with up to 31% elevation in the heating value compared to the raw materials. However, the significant reduction in mass and the amount of energy consumed during the torrefaction have a direct effect on the economic evaluation of the product. For domestic production of solid fuels, 0.058 $/kg production cost was achieved for both types of KW which is significantly lower than the current market prices for charcoal in Malaysian markets.

Biodiesel and vegetable oil suffer from higher viscosity and boiling point resulting in poor atomization and evaporation rate compared to diesel fuel additional to the lower heating value which negatively affect the stability of flame. The unsteady heat release rate from flame provides unique pressure wave signature that can be captured as acoustic wave. A pressurized combustion chamber was developed and connected to a vehicular turbocharger to test combustion stability and emissions of wide range of liquid biofuels. Biodiesel and blends of palm oil/diesel from 10% (Vol.%) up to 100% pure palm oil (i.e. P10-P100) were investigated and compared to diesel as the benchmark fuel. Microphone probes at the chamber inlet and outlet were used to capture the acoustic signals to be analyzed through the Fast Fourier Transform (FFT) using MATLAB program. The analysis of the acoustic signals revealed distinguishable deviation patterns between diesel and other biofuels which showed close resemblance to the carbon monoxide (CO) emission patterns at the same operating pressures. Biodiesel was comparable to P20, while increasing palm oil blend resulted in higher deviation. Chamber pressure also showed positive effect on combustion stability and reduced the deviation between diesel and other biofuels.

Externally fired gas turbine (EFGT) is one of the few power generation configurations capable of utilizing biomass in its solid form without any additional equipment to convert it to liquid or gas. Due to its high thermal output capability for drying applications, EFGT is one of the most suitable configurations for the off-grid rural areas in Malaysia with abundant biomass waste and high demand of heat for crops drying. The main downside of EFGT is the necessity for high temperature heat exchanger which compromises the system feasibility due to the high cost and other technical challenges. This can be eliminated by the addition of steam in a configuration known as humid air turbine (HAT), thus, limiting the required temperature and allowing for the use of common low-temperature heat exchanger types. Several mono-tube steam boiler designs were compared to fulfil the required steam flow rate of 2 kg/min for the available EFGT system. Counter-flow design was found to be more suitable with its higher efficiency. The boiler was characterized experimentally at output steam flow rate range of 0.4-2 kg/min using off-cut waste wood from furniture industry. Maximum achieved boiler efficiency and specific fuel consumption were 73% and 0.29 kg/kWh, respectively.

New type of shaft-inside-shaft friction high-speed power turbine coupling was investigated. Experimental test rig was developed to evaluate the new coupling (case C) and compare its performance with conventional bush couplings without absorber pads (case A) and with absorber pads (case B). Two accelerometers were used for the vibration analysis, and for each case, signals were recorded for the angular vibration on the alternator casing and for displacement axial vibration on the platform. Vibration signals were analysed through the fast Fourier-transform frequency spectrum in the range of 0–2.5 kHz. Higher shaft speed of 13,037 rpm was achieved with the new coupling compared to 6885 and 8056 rpm for cases A and B, respectively, indicating significant reduction in friction losses. Unbalance, looseness and misalignment faults were analysed through the harmonic frequencies 1X-5X for the three cases. The severity of misalignment was examined by the 2X/1X ratio on the alternator and the platform. The new coupling suffered from high misalignment at low rotating speeds, but showed superior performance above 4000 rpm.

Producer gas (PG) flameless combustion in a premixed cyclone combustor was investigated experimentally and numerically. The experiment was carried out over different premixed charges of air/fuel mixture and inlet nozzle diameters under PG fuel input power up to 80 kW. Exhaust temperature was above 1050 K for the whole operating range with CO emission below 0.08 Vol.% and NOx emission of 420 ± 30 ppm. Swirl flow field, internal hot flue gas recirculation, and temperature distributions inside the combustor were numerically studied. The numerical results were validated by the experimental data and it confirmed the achievement of temperature uniformity throughout the combustion volume when operated under flameless combustion mode. The reaction regime of PG flameless combustion was further analyzed with respect to turbulent scale characteristics. The present PG flameless combustions were typified by both moderate Damkohler and Karlovitz numbers, falling into the Flamelets in eddies regime.

In this study, three different methods for high quality solid fuel production were tested and compared experimentally. Oil palm empty fruit bunches, mesocarp fibers, palm kernel shells and rubber seeds shells were treated using thermal (TC), hydrothermal (HTC) and vapothermal (VTC) carbonization. All thermochemical methods were accomplished by using a custom made batch-type reactor. Utilization of novel single reactor equipped with suspended internal container provided efficient operation since both steam generator and raw materials were placed inside the same reactor. Highest energy densification was achieved by VTC process followed by TC and HTC processes. The heating value enhancement in VTC and TC was achieved by the increase in fixed carbon content and reduction in volatile matter. The formation of the spherical components in HTC hydrochar which gave a sharp peak at 340 °C in the DTG curves was suggested as the reason that led to the increment in energy content.

The global demand for utilization of renewable fuels in gas turbines has been on the increase to secure a sustainable, and pollution free environment. In this paper, the reviewed studies were on different liquid biofuels production methods such as the catalytic conversion of biomass, gasification, pyrolysis and transesterification. The review also included different studies on directly fired gas turbine (DFGT) and externally fired gas turbine (EFGT) utilizing biomass and liquid biofuels. Furthermore, this study elucidated the use of biofuels in clean combustion methods scalable to gas turbines such as colourless distributed combustion (CDC), high temperature air combustion (HiTAC), moderate or intensive low oxygen dilution (MILD) combustion and catalytic combustion. The discussion included the effect of different input parameters associated with the clean combustion systems that have influence on the attainment of ultra-low emissions of NOx and CO under premixed and non-premixed modes. As for the fuel types, biodiesel is one of the most studied biofuel in gas turbine especially in small-scale micro gas turbine (MGT) engines. The materials for the path of hot gas, types of fuels, heat recovery and cogeneration techniques are the variables, found to be affecting the performance of the DFGT. As for the EFGT, the high temperature heat exchanger with its lower turbine inlet temperature of 700–900 °C is generally the main limiting factor for this technology. The paper concluded by highlighting relevant and recent findings, thereby proposes a further research to improve the versatility in the utilization of liquid biofuels in gas turbines.

The upgrade of wet biomass sources into char presents a big challenge and is deemed as a non-feasible process in many cases using the conventional thermal carbonization. Hydrothermal carbonization (HTC) and vapothermal carbonization (VTC) are promising techniques for wet biomass carbonization since no pre-drying is required. Two types of wet biomass waste materials were investigated, bagasse (BG) and lime peel (LP), with moisture content of 67% and 78%, respectively. Experimental test rig was developed to study the effects of HTC and VTC processes on the raw materials in terms of product properties and combustion characteristics. For HTC process, water-to-biomass (W/B) ratio showed a significant effect on the product heating value with 10.2% difference for BG and 6.6% for LP through the W/B tested range. On the other hand, VTC process provided a significantly higher elevation in heating value up to 33% and 32% for BG and LP, respectively, compared to 20% and 16% for the HTC process.

Syngas produced from fixed bed gasifier suffers from high inert diluents (N2+ CO2) in the range of 60–65 vol.%. Hence, higher energy is required for syngas external compression making this concept less profitable for small scale micro gas turbine (MGT) applications. A new method was proposed in this study to eliminate the external compression of syngas by inducing air−syngas mixture directly through the MGT's compressor. Turbocharger based MGT with pressurized cyclone combustor (PCC) were developed to evaluate the new concept experimentally. Annular tube heat recovery unit (HRU) was developed to utilize the exhaust thermal power for hot air production. Stable syngas combustion was achieved with air-fuel ratio in the range of 3.3–4.1. NOx and CO emissions were below 250 ppm and 15 ppm respectively, with turbine inlet temperature below 700 °C. The natural aspiration of syngas directly from the gasifier was sufficient to run the MGT at low pressure ratio of 0.4 barg, but it was not enough to generate any electrical output. Hot air thermal output was 34 kW with overall system efficiency including the gasifier of 37.8%.

Biomass as carbon-neutral fuel is a promising alternative to mitigate global warming problems. Biomass conversion into producer gas (PG) through air gasification allows the co-firing of PG burners with fossil fuel burners in boilers for large scale power generation. However, PG is highly diluted with nitrogen which reduces the heating value resulting in significantly higher PG flow, eliminating the possibility of using conventional compact gas burner designs. To burn the low-grade PG, special design for the combustor is required. Novel combustor design which combined three theories of swirl vane, cyclonic and staged combustion to facilitate PG combustion in compact geometry was elaborately investigated. Flow hydrodynamics and combustion characteristics of low-grade PG were studied using ANSYS-FLUENT simulation software. Design of Experiments (DOE) method was applied to optimize the design of the combustor geometry. The arrangement of simulations was designed based on the instruction of DOE. The optimum geometry design of combustor was 500 mm combustor length, 150 mm combustor diameter, 60° swirl vane angle and 0.4 secondary inlets position to total combustor length ratio. The combustor achieved optimum performance of 1965 K outlet temperature, 18 ppm CO emissions and 33 ppm NOx emissions at slight lean condition with equivalence ratio of 0.9.

The recovery of low grade waste heat for power generation is getting more attention due to its large magnitude in the industrial sector. Commonly proposed solutions include Organic Rankine Cycle (ORC), transcritical carbon dioxide (T-CO 2 ) cycle and Kalina cycle but with complex architectures. Special type Stirling liquid piston engines such as the Fluidyne and thermo-fluid oscillator can also recover low grade waste heat below 150 °C with simple construction. In this study, a novel two-phase thermo-fluid engine with single chamber and diaphragm was developed and tested experimentally. The engine was characterized at different heat source temperatures ranging from 50 °C up to 100 °C and maximum pressure in the range of 1.2–2 bar. Highest indicated efficiency was 10.3% compared to 25.5% Carnot efficiency with maximum indicated power of 70 W at 10 RPM engine speed. A crankshaft mechanism was installed with flywheel and rope brake dynamometer to measure engine brake power. Maximum brake power measured was about 0.4 W at 8 RPM due to the high friction losses in the power delivery mechanism.

Micro-gas turbines (MGT) are small-scale independent and reliable distributed generation systems that offer potential for saving energy and reducing carbon monoxide (CO) emissions. They are expected to play a vital role in future energy supplies for remote locations with or without grid connections. In this paper, a design and development of a combustion chamber for micro-gas turbine was performed by SOLID-WORKS and computational fluid dynamics (CFD) ANSYS-FLUENT simulation software. Different chamber geometries were used to simulate with species transport and non-premixed combustion models to determine the optimum chamber design. The best chamber geometry adopted after optimization was 50 mm flame holder diameter, 60 cm chamber height, having 4 holes of 6, 8 and10 mm with dead zone between the combustion zone and dilution zone. A two-stage MGT was developed based on vehicular turbochargers to test the chamber. The experimental test of the chamber with liquefied petroleum gas (LPG) fuel resulted in a stable combustion with CO emission below 100 ppm and turbine inlet temperature below 900 °C.

Torrefaction is known as mild pyrolysis process occurring at temperature range of 200–300 °C. Torrefied biomass can be co-fired directly with coal in boilers without any fuel pre-treatment, thus, increasing its economic value over raw biomass significantly. An experimental rig was developed to characterize the torrefaction process of wood pellets in a new gasifier-torrefier. Temperature of the syngas exiting the gasifier is about 300–400 °C which is sufficient for biomass torrefaction. Biomass torrefaction process is fully characterized based on biomass bed height and temperature, residence time and heating value of the torrefied product. Temperature profiles inside the torrefaction reactor were recorded for different air flow rates of 9, 12, 15 and 18 m 3 /h. The process has achieved about 10–40% and 5% enhancement in heating value of torrefied biomass and syngas respectively.

CO2 gasification of biomass is a promising candidate for the reduction of carbon footprint with the added benefit of improving syngas quality by eliminating N2 dilution. Further enhancement of syngas quality is proposed in this study by incorporating the water shift reaction to increase H2 concentration. Oil palm shell (OPS) as one of the major agriculture waste sources in Malaysia was investigated. Microwave assisted steam-CO2 gasification was characterized in the temperature range of 700–850 °C and steam/CO2 ratio in the range of 0.014–0.043. Surface composition and morphology of char were examined at different temperatures using scanning electron microscope and energy dispersive spectrometry (SEM/EDS). Optimum operation was achieved at steam/CO2 ratio of 0.028 and 850 °C with 92% and 85% CO2 and char conversions, respectively. Increasing steam flow at maximum temperature increased the H2/CO ratio by 22% and syngas heating value by 6%. Statement of novelty The effect of steam addition on Boudouard reaction and active sites on oil palm shell char micro-pore-structure, absorption of microwave irradiation and CO2-syngas conversion were characterized.

Syngas production using double throat downdraft gasifier was characterized through full gas production range of 25–250 m3/h. The gasifier was able to produce ignitable syngas in a wide range of air fuel (AF) equivalence ratio (λ) of 0.3–0.4. Syngas combustion stability was characterized in a cyclone combustor. Stable combustion was achieved from lean fuel air (FA) equivalence ratio condition (φ = 0.49) to the rich combustion limit (φ = 1.25). Thermal power from the combustor was recovered by an annular tube heat exchanger to demonstrate a simple and efficient way of hot air production from biomass fuels. The hot air production configuration was characterized and the optimum operation condition was found to be at (φ = 0.68) lean combustion. This configuration can produce 36 kWth of hot air with overall efficiency of 46% and NOx and CO emissions below 140 ppm.

Producer gas from biomass gasification is plagued by the presence of tar which causes pipe blockages. Thermal and catalytic treatments in a microwave reactor have been shown to be effective methods in removing tar from producer gas. A question arises as to the possibility of enhancing the removal mechanism by adding water into the reactor. Toluene and naphthalene were used as tar models in the present study with N 2 as the carrier gas followed by the use of simulated producer gas. Thermal treatment with various amount of water was added at temperatures in the range of 800–1200 °C. The tar removal efficiency obtained 95.83% at the optimum temperature of 1200 °C for naphthalene in for toluene 96.32% at 1050 °C at water to tar ratio (W/T) of 0.3. This study shows that the removal of tar by microwave irradiation with water addition is a significant and effective method in tar cracking.

The conflict in Yemen in 2015 has resulted in a total lack of diesel fuel supply to many major cities that resulted in disruption to many public services and utilities. This trans-disciplinary two-phase project was initiated by the Small and Micro Enterprise Promotion Service to study the production of biodiesel from waste cooking oil (WCO) from a techno-economic point of view. The first phase of the project included a lab scale biodiesel investigation to determine the optimum production conditions. The biodiesel fuel product was analyzed, in addition to a performance comparison between diesel and biodiesel on a small compression ignition gen-set. The second phase included a feasibility study for small and medium scale biodiesel production facilities from WCO based on the current economic situation in Yemen.

Energy crises is one of the major causes for the economic decline in Yemen since large portion of the invested capital is spent on standalone small-scale low efficiency electrical generators. This goes not only for the industrial sector, but also for the simple citizens to provide some of their basic electrical requirements. The establishment of Marib gas turbine (GT) station as the first gas turbine based plant in Yemen in 2009 has slightly reduced the gap between power requirement and consumption. Marib power plant consists of three GT units of 163 MWe nominal net output per unit with additional 400 MWe in the second phase of the project. However, its high potential is wasted by using the simple GT cycle without any enhancement method such as combined or even recuperative cycles. Additional to the high altitude of its location that dropped significantly its efficiency down to 29 %. Thus, around 71 % of the fuel thermal power is discharged to the ambient as a waste. This study investigates one of the enhancement methods for Marib GT plant without any major modification on the current configuration of the station. The study showed that the rise in ambient temperature in summer could cause a power output degradation up to 0.6 % per 1°C. Thus, the addition of fogging inlet air cooling system was found to be one of the simplest and economical solutions. A mathematical model is developed to determine the impact of ambient conditions (i.e. temperature and humidity), on turbine performance. The developed mathematical model is verified with on-site operation data from Marib power plant. The results showed that Marib gas turbine power plants have excellent potential for fog operation with Evaporative Cooling Potential of 11.5 - 24 ºC. The results also showed a significant enhancement in turbine performance after using the fogging system with additional output power boost up to 30 MWe.

Gas turbines provide large portion of the global power generation as well as the carbon footprint. Utilizing biomass in gas turbines in externally fired gas turbine (EFGT) configuration is a promising option for the reduction of greenhouse emissions. However, only few experimental EFGT studies have been reported due to the technical difficulties and high cost associated with the development of high temperature heat exchanger for the system. An experimental turbocharger-based EFGT test-rig was developed in previous study. However, the low turbine inlet temperature (TIT) below 700 °C provided by the heat exchanger was not adequate for the turbine start-up. In this study, the heat exchanger was redesigned using annular tube configuration and eight tube sizes were compared. The optimum heat exchanger design elevated TIT up to nearly 900 °C and the turbine was able to operate at self-sustaining mode in the pressure range of 0.2–0.25 bar.

In this paper, the hydrodynamic flow inside an internally circulating fluidized bed (ICFBG) was characterized using experimental and three-dimensional computational fluid dynamics (CFD) models. Eulerian-Eulerian model (EEM) incorporating the kinetic theory of granular flow was implemented in order to simulate the gas–solid flow. A full-scale plexiglass cold flow experimental model was built to verify simulation results prior to the fabrication of the gasifier. Six parameters were manipulated to achieve the optimum design geometry: fluidization flow rate of the draft tube (Qdt), aeration flow rate of the annulus (Qan), initial bed static height (Hbs), draft tube height (Hdt), draft tube diameter (Ddt), and orifice diameter (Dor). The investigated parameters showed strong effect on the particle flow characteristics in terms of the pressure difference (ΔP) and solid circulation rate (Gs). The predicted results by simulation for the optimum case were in close agreement with experimental measurements with about 5% deviation. The results show that the ICFBG operated stably with the maximum Gs value of 86.6 kg/h at Qdt of 350 LPM, Qan of 150 LPM, Hbs of 280 mm, Hdt of 320 mm, Ddt of 100 mm, and Dor of 20 mm.

Combustion inefficiencies and high pollutants emissions keep motivating researchers to enhance combustion technology. Producer gas fuel from biomass gasification with its low heating value and high CO content requires a special combustor design for efficient burning. Porous media burner (PMB) has been widely investigated and proven to be well suited for low heating value fuels lean combustion. This study aims at performance investigation of PMB fueled by producer gas from biomass gasification. A downdraft gasifier system along with a PMB burner and heat recovery unit has been developed. The PMB comprises two layers of 10 mm and 20 mm diameter upper and lower alumina spheres packed, respectively. With PG heating value of about 5 MJ/m3, lean to ultra lean stable combustion was achieved with equivalence ratios (Φ) in the range of 0.33

Externally fired heat engines were used widely since helium the industrial revolution using dirty solid fuels for example coal, due to the lack of refined fuels. However, with the availability of clean fuels, external firing mode was abandoned, except for steam power plants. Lately, with the global trend moving towards green power production, the idea of the external fired system has captured the attention again especially externally fired gas turbine (EFGT) due to its wider range of power generation and the potential of using environment friendly renewable energy sources like biomass. In this paper, a wide range of thermal power sources utilizing EFGT such as concentrated solar power (CSP), fossil, nuclear and biomass fuels are reviewed. Gas turbine as the main component of EFGT is investigated from micro scale below 1 MW e to the large scale central power generation. Moreover, the different high temperature heat exchanger (HTHE) materials and designs are reviewed. Finally, the methods of improving cycle efficiency such as the externally fired combined cycle (EFCC), humidified air turbine (HAT), EFGT with fuel cells and other cycles are reviewed thoroughly.

A two-stage micro gas turbine (MGT) with low speed generator was developed to operate fully on producer gas (PG) from a pressurized downdraft gasifier without any auxiliary fossil fuel. It is an efficient and environment friendly system for hot air production for any industrial drying process. For the Low heating value PG combustion, a pressurized cyclone combustor (PCC) was designed and optimized using computational fluid dynamics simulation. The system was characterized experimentally with liquefied petroleum gas (LPG) and PG fuels in dual-fuel mode and then with pressurized PG in single-fuel mode. The system as a combined heat and power (CHP) has achieved an overall efficiency of about 58% with 35 kW th hot air production as thermal output of the system.

Air-blown gasifier suffers from lower heating value of producer gas (PG) compared to steam gasification, but at the expense of the addition of steam boiler for the latter. The performance of an air-blown double walled downdraft biomass gasifier was characterized experimentally. Air fogging unit was added to the annulus of the gasifier allowing for superheated steam to be generated as additional oxidizer. Steam-to-biomass (S/B) ratio has been introduced to investigate the optimum amount of injected water needed to produce the optimum quality of PG. Comparisons were made on the composition and heating value of PG with and without water injection which were analysed and calculated with the aid of gas chromatograph. Highest heating value of PG was 4.72 MJ/Nm3 at S/B ratio of 0.2 which corresponded to about 10% increment. Various S/B ratios were investigated in this study in the range of 0.1–0.3. However, as S/B ratio exceeded 0.25, it resulted adversely to the quality of PG. The effect of water injection on tar contamination in PG was also investigated. Tar reduction was proportional to the amount of the injected water resulting in about 8% reduction at maximum S/B ratio corresponding to 0.65 g/m3 tar yield.

Micro gas turbine (MGT) is an efficient alternative to costly generation and transmission of electricity especially in combined heat and power (CHP) for remote areas applications. In this study, an optimum geometry of a flame holder of MGT combustion chamber was determined in terms of height and diameter using solid works and ANSYS fluent. To determine and optimise the flame holder geometry, species transport and non-premix with radiation models were used in ANSYS fluent. Optimisation process was performed to select the best geometry of flame holder that produces lowest CO emission. The flame holder was divided in to three zones namely; pre-mix, combustion and dilution zones respectively. The test parameters applied during simulation include: the diameter of holes, number of rows per zone, heat flux through convective heat transfer, percentage excess air and location of dead zone. Optimum diameter of holes for the zones was found out to be 6, 8 and 10 mm with each having four rows of holes. In addition, 60 cm height and 2 inches diameter of flame holder showed a well distributed flame contours. The application of heat flux under radiation model reveals an acceptable CO emission of 102 ppm and average temperature of 1218 °C for the diesel fuel used.

The combustion difficulties for low heating value (LHV) gases derived from biomass fuels via a gasification process have led to more investigations into LHV gas combustors. Cyclone combustors provide good air/fuel mixing with long residence times. In this study, a small-scale pressurized cyclone combustor (PCC) was designed and optimized using computational fluid dynamics (CFD) simulation. The PCC, along with a turbocharger-based, two-stage microturbine engine, was first characterized experimentally with liquefied petroleum gas (LPG) fuel and then with both LPG and LHV gas derived from biomass in dual-fuel mode. The combustor achieved ultra-low CO and NOx emissions of about 5 and 7 ppm, respectively, for LPG fuel and of about 55 and 12 ppm, respectively, in dual-fuel mode at the maximum second-stage turbine speed of 26,000 rpm with stable turbine operation.

Recently, there has been wide-ranging research on the idea of biomass fuel powered externally firing micro gas turbines; but only a small subset of these studies has used experimental work to evaluate the systems. These systems have not yet been employed in Malaysia for applications in thermal energy or power generation. The objective of this study is to determine the performance of a stainless steel high-temperature heat exchanger, which was built to transfer thermal power from a biomass gasifier-combustor to the pure air turbine working fluid. The study is based on experimental work using different air blower capacities as an air supply. The heat exchanger achieved 694 °C turbine inlet temperature with an average effectiveness of 62.5%.

The concept of external fired micro gas turbine (EFMGT) using biomass fuels is getting more attention in the last two decades. However, most of the studies were conducted using computer simulation to evaluate the EFMGT systems with a lack of experimental studies. A small scale EFMGT was developed using a vehicular turbocharger as a micro gas turbine. Different micro turbine startup methods were experimentally investigated with maximum turbine inlet temperature and pressure of about 694 °C and 2.1 bar, respectively. The difficulties experienced during the turbocharger engine startup process are reported in this paper. Driving the turbocharger shaft from the compressor side using the air flow hydraulic power was not a sufficient method for the EFMGT unlike the directly fired turbine. The only proven turbine startup method for the EFMGT is the mechanically driven turbine shaft.