Product Gas Flow Research Articles

Techno-Economic Assessment of an Off-Grid Biomass Gasification CHP Plant for an Olive Oil Mill in the Region of Marrakech-Safi, Morocco

A substantial number of off-grid olive oil mills in Morocco are powered by diesel-fired generators, which hugely contribute to air pollution and greenhouse gas emissions. In this research work, a biomass gasification combined heat and power (CHP) plant fueled with local by-products was explored as a renewable alternative to electrify off-grid olive oil mills in this country. The case study considered a gasification CHP plant with a rated power of 80 kWe, in order to enable adaptation of the producer gas flow rate to abrupt changes in the power generation unit under dynamic operation. A downdraft gasifier and a producer gas conditioning unit were modeled under steady state operation using Cycle-Tempo, while the power generation unit was modeled in the Thermoflex simulation environment under partial and full load operation. Olive cake pellets and olive pruning chips were evaluated as biomass feedstock, with moisture contents ranging from 5% to 20% (wet basis). The results from the simulation of the gasification CHP plant showed net electrical efficiencies and CHP efficiencies around 18% and 35%, respectively. Finally, a profitability assessment of the gasification CHP plant was developed for 2 months of continuous operation, together with a sensitivity analysis. The results for the baseline scenario reveal a payback period of 7–8 years and a 68.5% accumulated profit based on the capital investment, which suggest that biomass gasification CHP plants can represent an economically feasible and sustainable solution for the electrification of off-grid areas in Morocco.

Generating electricity from palm waste by gasification technique coupled with externally fired gas turbine: a case study

ABSTRACT Recently, renewable energy sources have become an encouraging solution to the availability and environmental problems arising from using fossil fuels for energy production. The article’s goal is to provide a reliable and doable path toward producing electricity from biomass by using palm waste (fronds, empty fruit bunches, and trunks). The system is simulated using Cycle-Tempo software. Waste was gasified at 800°C using a downdraft fixed-bed reactor to produce syngas. After that, a producer gas flow of around is sent to an externally fired gas turbine (EFGT), where it is promptly burned at atmospheric pressure to produce electricity. According to the simulation’s outcomes, palm fronds are the waste that worked best as a feedstock, and an estimated 390 kW of electric power could be generated by the externally fired gas turbine with a 19% electrical efficiency. The producer gas had a good molecular composition (H2 15.02%, CO 18.1%, CH4 1.25%, CO2 10.79%, H2O 8.17%, and N2 46.08%), a low heating value of up to (4.16 MJ/kg), a gasification efficiency of 77%, and a CHP efficiency of 61%. A comparison of the findings with previously published literature revealed that the proposed technology allows for the production of syngas with a satisfactory composition from palm fronds.

Integration of Electromagnetic Geophysics Forward Simulation in Coupled Flow and Geomechanics for Monitoring a Gas Hydrate Deposit Located in the Ulleung Basin, East Sea, Korea

We investigate the feasibility of electromagnetic (EM) geophysics methods to detect the dissociation of gas hydrate specifically from a gas hydrate deposit located in the Ulleung Basin, East Sea, Korea via an integrated flow-geomechanics-EM geophysics simulation. To this end, coupled flow and geomechanics simulation is first performed with the multiple porosity model employed, where a mixed formulation with the finite volume (FV) and finite element (FE) methods are taken for the flow and geomechanics, respectively. From the saturation and porosity fields obtained from the coupled flow and geomechanics, the electrical conductivity model is established for the EM simulation. Solving the partial differential equation of electrical diffusion which is linearized using the 3D finite element method (FEM), the EM fields are then computed. For numerical experiments, particularly two approaches in the configuration for the EM methods are compared in this contribution: the surface-to-surface and the surface-to-borehole methods. When the surface-to-surface EM method is employed, the EM is found to be less sensitive, implying low detectability. Especially for the short term of production, the low detectability is attributed to the similarity of electrical resistivity between the dissociated gas (CH4) and hydrate as well as the specific dissociation pattern within the intercalated composites of the field. On the other hand, when the surface-to-borehole EM method is employed, its sensitivity to capture the produced gas flow is improved, confirming its detectability in monitoring gas flow. Hence, the EM geophysics simulation integrated with coupled flow and geomechanics can be a potential tool for monitoring gas hydrate deposits.

Utilization of Spiked Pepper (Piper aduncum L.) as Feedstock for Gasification

The massive spread and growth of invasive alien plant species (IAPS) such as Piper aduncum L. (PA) endanger the natural ecosystem. Utilizing their woody biomass as feedstock through gasification to produce renewable energy can reduce risk and provide better incentives to rural communities. Heating value (HV), fixed carbon (FC), volatile combustible matter (VCM), and ash content were used to compare PA with five other tree species – namely, Calliandra calothyrsus L. (CC), Gliricidium sepium L. (GS), Broussonetia papyrifera L. (BP), Eucalyptus marginata L. (EM), and Eucalyptus urophylla L. (EU) – as fuel for gasification. The effects of particle size (ps), air volumetric flow rate (υair), and carbonization and their interactions to cold gas efficiency (CGE), producer gas flow rate (υsyngas), and specific gasification rate (SGR) were also studied. The economics and environmental impact of spiked pepper as feedstock were evaluated by hypothetically putting up a 100 kWe gasification plant in the Upper Bauyan Watershed serving 138 households. With an electrical efficiency of 17.1%, the plant would need 990 tons of PA. Feedstock supply would be adequate even after 20 yr of operation since biomass growth rate would be faster than consumption rate. The computed carbon dioxide (CO2) emissions annually for harvesting was 9.72 tons (shelterwood method) – 781.11 tons for gasification and electrical production against direct combustion, which theoretically emits 1,729.73 tons annually. Financial analysis indicated a profitable investment with a positive net present value of PHP 6,240,257.08 or USD 122,358 (USD 1 = PHP 51), IRR of 12%, payback period of 6.97 yr, and levelized cost of electricity (LCOE) of PHP 8.90 (USD 0.17). Overall, the study indicates the economic feasibility and ecological soundness of utilizing PA as feedstock provided that silvicultural management is applied in replanting indigenous trees in eradicated lands. This method can also be effective in restoring the landscape of affected watersheds.

THE INFLUENCE OF THE PERFORATION DENSITY AND DAMAGED ZONE PERMEABILITY ON A GAS WELL PRODUCTION

The exploitation of wellbore condensate deposits must be carried out in such a way that both water and condensate from the productive layer are not entrained during extraction. That is precisely why the article analyzes the effect of the density of perforations of the productive layer on the amount of extracted gas. The effect of the area affected by the drilling on the produced gas flow is also studied. After 50 years since the first use of the mechanical realization of the perforations of the productive layers of the gas wells, there is little data regarding the influence of the perforation geometry of a gas well, namely the way of communication between the production layer and the borehole, on its production. The aim of this paper is to simulate the operation of the well for different values specific to the drilling mode, highlighting its production. The problem is addressed by nodal analysis. The numerical simulators were used to simulate the flow of the mixture through the layer-well system and respectively through the mixture pipe.

Modelling of Physical Method for Tar Elimination from Producer Gas at Low Temperature

Combining a methanation step with biomass gasification requires an intensive tar removal process that reduces its content down to 1 mg/Nm3. In this paper, low temperature processes are suggested for treating tar and reducing its content to the acceptable limit. However, the gas must be pre-treated prior to the low temperature process in order to reduce its temperature, its moisture content and the heavy tar fraction. Two water scrubbers are placed prior to the low temperature tar removal process. Benzene and toluene remains in the producer gas after the scrubbers. Those two components can be valorised if separated from the producer gas at low temperature. The tar removal, at low temperature, induces the water vapour frosting remaining in the producer gas. The simultaneous frosting and condensation takes place over a cold plate. Modelling simultaneously the multi-component frost growth and condensation requires complex mathematical approach. A parametric study is completed to assess the impact of the wall temperature and the producer gas flow rate on the tar removal process function of time and plate length. Results showed that a wall temperature of -20 (C is required to lead to the benzene frost formation for an initial molar fraction of 0.024. After one hour, the thicknesses of benzene and ice frost layers reach 1.5 and 2.5 mm, respectively. Therefore, the heat transfer between the gas and the cold surface is reduced.

AN EFFECT OF SPRAY CONFIGURATION AND ADSORBENT MATERIAL ON PERFORMANCE OF THE SPRAY SCRUBBER IN THE DOWNDRAFT GASIFIER-ENGINE SYSTEM

The work aims to investigate an effect of spray configuration and adsorbent material on performance of wet scrubber in removing tar gravimetric in producer gas. The scrubber is installed at small scale downdraft gasifier-engine system and the tests are conducted in two sections. Firstly, the scrubber is tested using water adsorbent at various spray flow configurations to the producer gas flow (cross flow, counter flow, mixed flow). Secondly, the scrubber is tested using adsorbent of cooking oil and waste of engine lubricant at cross flow spray configuration. The performance of the scrubber investigated are temperature profile, log mean temperature difference, heat transfer rate, and tar removal effectiveness. For spray configuration test, the result shows that cross spray configuration (CrS) has the optimum performance. The CsS scrubber has the highest LMTD, heat transfer rate, and tar removal efficiency among others. The values are 29.8°C, 7.84 kW, and 0.43, accordingly. Meanwhile, the test using different adsorbent indicates adsorption property of the adsorbent plays an important rules in tar removal effectiveness of the scrubber. The removal effectiveness of the scrubber for using adsorbent of water, cooking oil, and engine lubricant are 0.43, 0.12, and 0.60, respectively.

The effect of Jatropha seed cake producer gas flow rates on a diesel engine operated on dual fuel mode at high engine speed

Jatropha seed cake is a byproduct of biodiesel production. The seed cake can be used to make a producer gas that can be fumigated into a diesel engine operated on dual fuel mode without major modification. This paper intends to investigate the impact of Jatropha seed cake-derived producer gas mass flow rate on the performance and emission characteristics of a diesel engine operated on a dual fuel mode at a high engine speed of 3,000 rpm. The results highlight that the maximum diesel replacement rate reached 60% at a 20 kg/h gas flow rate when the engine was operated at medium engine load. An increase in gas flow rate augments the diesel substitution rate but decreases the electrical-thermal efficiency (ETE). At 70% of the full engine load, the specific diesel consumption declined from 0.337 to 0.185 kg/kWh when the gas was increased from zero to 20 kg/h. At this engine load, the ETE sharply fell off from 25% to 10.6% and 6.6% when the gas flow rate increased from zero to 10 kg/h and 20 kg/h, respectively. The electrical specific fuel consumption and electrical specific energy consumption, exhaust hydrocarbon (HC), carbon monoxide (CO), and carbon dioxide (CO2) emissions were found to be higher with an increase in gas flow rate. Unlike dual fuel engine operation at medium speed, the nitrogen oxides (NOX) emissions were consistent with an increase in gas flow rate. Based on the empirical findings, the dual producer gas-diesel engine should be operated at high engine load but not at a high engine speed of 3,000 rpm with a maximum gas flow rate of 20 kg/h.

Effects of biodiesel blends and producer gas flow on overall performance of a turbocharged direct injection dual-fuel engine

ABSTRACTThis paper elaborates the experimentation on a Turbocharged Direct Injection engine using calophyllum biodiesel and producer gas. The objective of this study was to evaluate the performance and emission characteristics, at different gas flow rates keeping load constant. The result depicted a reduced efficiency of 4.2% and enhanced exhaust gas temperature of 12.2% at varying gas flow rates. Consider the emission analysis, smoke opacity 51.7%↓, nitric oxide 37.3%↓, carbon monoxide 17.7%↓ and hydrocarbon 35.9%↓ reduced for all test fuels at maximum load conditions, in contrast to single-fuel mode. Finally, it can be concluded that dual-fuel engines evolved as potential substitute for diesel.

The performance of turbocharged diesel engine with injected calophyllum inophyllum methyl ester blends and inducted babul wood gaseous fuels

The current investigation briefly elaborates usage of calophyllum inophyllum biodiesel and babul-derived gas on a turbocharged diesel engine operated in dual fuel mode taking into consideration two different phases of operation. Initially, the experimentation was to be carried out keeping the gas flow rate fixed at 21.58 kg/h with varying loading condition in contrast to the naturally aspirated mode. Secondly, the gas flow rate was varied for all the fuels with fixed optimal loading conditions at 3.77 kW. Meanwhile, the modified operating parameters such as injection timing (230bTDC), injection pressure (240 bar), combustion chamber (TrCC), nozzle hole geometry (4-hole) were kept constant throughout the set of experimentations. The present work describes the novelty of varying the gas flow rate techniques with modified engine parameters in order to discuss the overall performance, and emission and combustion behavior in contrast to conventional diesel fuel. The result concludes a lower thermal efficiency (BTE) for B20 + P gas (21.58 kg/h) of 2.7%↓ while higher exhaust gas temperature (EGT) and brake specific energy consumption (BSEC) of 3.7%↑ and 2.18%↑ at 3.77 kW than diesel + P gas. Additionally, considering emission analysis, carbon monoxide (CO), carbon dioxide (CO2), hydrocarbon (HC), nitric oxide (NO) and smoke opacity delivers a lower emission range for B20 + P gas of about 24.4%↓, 7.14%↓, 60.8%↓, 14.28%↓ and 42.8%↓ in comparison to diesel + P gas at optimal loading conditions. Moreover, varying the producer gas flow rate depicted a lower BTE and higher BSEC, EGT for B20 at maximum flow rate of 21.58 kg/h was 7.6%↓, 1.7%↑and 6.7%↑ in contrast to conventional fuel. Furthermore, CO, CO2, HC, NO and smoke opacity delivers a very low emission range of 15.2%↓, 8.42%↓, 20.5%↓, 29.6%↓ and 49.3%↓ in contrast to diesel fuel in dual fuel mode. Hence, considering the above discussion, engine with optimal load of 3.77 kW and gas flow rate of 21.58 kg/h along with modified engine parameters as discussed above enhanced the engine’s overall performance. This provides a freedom from using conventional resources resulting in both diesel fuel savings and energy security for future development.

Gasification of cotton stalk in a downdraft gasifier

ABSTRACTDemand of energy is ever increasing and sustainable form of energy supply is needed. Fossil fuels utilization causes a lot of environmental pollution. Biomass is a renewable, sustainable, and environment friendly form of energy and can be used to fulfill energy needs. Gasification of biomass can be employed to use it efficiently. In the present work, trials were performed on gasification of biomass in a downdraft gasifier. The specific biomass consumption was reasonably constant with a mean value of 0.462 kg/h for all gas flow rates. The temperature of the various zones increased as the producer gas flow rate increased. The temperature of the oxidation zone rose from 580 to 725°C with increase in the gas flow rate from 7 to 19 Nm3/h. The volume percentage of the CO and H2 rose somewhat with rise in gas flow rate. The producer gas calorific value was higher at higher gas flow rates. Tar content of the producer gas was lower than the permissible limits at all gas flow rates except for very low gasification rate. The particulate matter content in the gas was somewhat higher than the permissible limits. The gasifier efficiency ranged between 69.57% and 74.48% as the gas flow rate varied from 7 to 19 Nm3/h.

A major discovery in Permian volcanic rock gas reservoir exploration in the Sichuan Basin and its implications

Recently, a high-yield gas flow of 22.5 × 104 m3/d was achieved in the wildcat well Yongtan 1, deployed by PetroChina Southwest Oil and Gasfield Company, and an extrusive facies volcaniclastic gas reservoir was first discovered in the Sichuan Basin, which is a major breakthrough in the exploration of volcanic rock gas reservoirs. In order to further evaluate the exploration potential in Permian volcanic rock gas reservoirs in this basin, we systematically reviewed and summarized the exploration process of volcanic rocks in this study area, as well as the characteristics of gas reservoirs of well Yongtan 1, the controlling factors and modes of hydrocarbon accumulation. The following findings were obtained. (1) Over the past five decades of gas exploration of volcanic rocks, the change of exploration thought and progress in seismic prediction contribute to a major discovery in this study area, i.e., the well location deployment of Yongtan 1 was determined in the Jianyan area, where the volcanic anomalies of the Permian developed outbursts are well developed and the gas reservoir conditions are favorable. This also proves that another new gas exploration area in this basin was found. (2) From the data of Yongtan 1, we found high-quality volcanic porous reservoirs with a thickness of over 100 m developed in the Permian strata, the effusive volcanic rock types dominated by breccia and tuffaceous breccia, reservoir space composed of dissolution pores, interbreccia dissolution pores, and other pores, the porosity of which is 6.68%–13.22% and 10.26% on average, the permeability 0.01–4.43 mD and 2.35 mD on average. (3) This abnormally high pressure gas reservoir was buried 4500–6000 m deep underground with the middle formation pressure being 125.625 MPa and the pressure coefficient being up to 2.22. Methane content in the minor H2S-bearing produced gas flow reached up to 99.03%. (4) Volcanic rocks in the Jianyang–Zhongjiang–Santai area are developed, and they are adjacent to the Cambrian high-quality source rocks in the Deyang–Anyue rifting. The early extensional deep faults play a role in connecting source and storage. There are many sets of caprocks, such as the Upper Permian Longtan Formation and Lower Triassic layered thick paste rocks, providing conditions for forming large-scale tectonic–lithologic composite trap gas reservoirs, and the favorable exploration area reaches up to 6000 km2. In conclusion, this major discovery not only proves that Permian volcanic rocks in the Sichuan Basin has large potential for oil and gas exploration, but reaffirms the confidence in changing our exploration thought, speeding up new exploration zones and areas, and discovering more and bigger gas fields.

Performance prediction of a decentralized power plant (120 kWe) using a multi-particle model of a downdraft biomass gasification process

A one-dimensional model of a downdraft biomass gasifier is presented to investigate the effect of operating parameters on the performance of a power plant. The approach considers the biomass fed to the reactor by employing discrete particle size distribution (DPSD) to simulate the real operational conditions of a gasification power plant (120 kWe/400 kWth). Char production (byproduct) and producer gas (PG) flow are the targets of the model; the model has been validated using data from an industrial power plant (biomass consumption, pressure drop, and PG composition) with an average relative error of 1.8%. The model achieved stable and reliable results using DPSD for 16 different particle sizes. The increase in the mean biomass particle diameter (15–60 mm) diminished the PG power (363.8–285.3 kW) and the cold gas efficiency (CGE) (63.2–54.36%) because of low particle surface/volume ratio. When biomass moisture content increased (5–25 wt%), the PG power decreased (364.14–318.75 kW) because of low gasification temperature. Moreover, when the number of driven engines was increased from 2 to 5 (electric power), the CGE decreased (68.17–59.17%) due to the low residence time of the solid and gas phases, which inhibited the gasification reactions, in the reactor.

Mass, energy, and exergy analysis of the microgasification process in a top-lit updraft reactor: Effects of firewood type and forced primary airflow

Four representative firewood species from some Colombian regions were evaluated in a top-lit-updraft (TLUD) reactor under gasification regimes. The effect of primary airflow on the process was studied at three levels (20, 30, and 40 l/min) using the firewood species with the highest fuel value index (FVI; 9.8 MJ/cm3). The thermodynamic assessment of the microgasification process was characterized by means of response variables such as flame front velocity (Vff), maximum reaction temperature (Tmax), fuel/air equivalence-ratio (Frel), mass yields (gas-Ygas, char-Ychar, and tar-Ytar), cold gas efficiency (CGE), chemical exergy efficiency (CEE), and irreversibility (I). With regard to the influence of the firewood type, the performance of the process was mainly affected by physical properties, such as bulk density and hardness, which had a positive effect on both Frel and Ytar, with a 95% confidence level. On the contrary, Vff, Ychar, Ygas, CGE, CEE, and I decreased when the bulk density and hardness increased. With regard to the effect of the airflow, Vff and Tmax increased from 7.9 to 14.0 mm/min and from 724.9 °C to 838.3 °C, respectively, because the process tended to lead to combustion; however, CGE and CEE tended to slightly increase with the airflow because the producer gas flow increased.

Technical Parameters Modeling of a Gas Probe Foaming Using an Active Experimental Type Research

The present paper deals with a current and complex topic, namely - a technical problem solving regarding the modeling and then optimization of some technical parameters related to the natural gas extraction process. The study subject is to optimize the gas probe sputtering using experimental research methods and data processing by regular probe intervention with different sputtering agents. This procedure makes that the hydrostatic pressure to be reduced by the foam formation from the water deposit and the scrubbing agent which can be removed from the surface by the produced gas flow. The probe production data was analyzed and the so-called candidate for the research itself emerged. This is an extremely complex study and it was carried out on the field works, finding that due to the severe gas field depletion the wells flow decreases and the start of their loading with deposit water, was registered. It was required the regular wells foaming, to optimize the daily production flow and the disposal of the wellbore accumulated water. In order to analyze the process of natural gas production, the factorial experiment and other methods were used. The reason of this choice is that the method can offer very good research results with a small number of experimental data. Finally, through this study the extraction process problems were identified by analyzing and optimizing the technical parameters, which led to a quality improvement of the extraction process.

Performance and emissions characteristics of a direct injection diesel engine from compressing producer gas in a dual fuel mode

This research highlights the impact of compressed producer gas combined with diesel fuel in a dual fuel mode on performance and emission characteristics of a three-cylinder diesel engine connected to an AC generator. Producer gas was generated from a small downdraft gasifier using charcoal, and sent into the engine using a supercharger to increase the gas flow rate from 76 to 125 lpm. The engine speed was adjusted from 1,000 to 1,600 rpm, while operating at full load. All results of this investigation indicate that supercharging producer gas improved the diesel economy and engine performance characteristics, but it increased the amount of various pollutants. Engine performance testing results from compressing producer gas showed that the use of gas flow rates of 116 to 125 lpm increased the maximum diesel saving by 41%, electrical power by 1.88%, and thermal efficiency by 35.76% as compared to a diesel fuel only mode. Additionally, specific energy consumption decreased with increasing producer gas flow rate and engine speed. For measuring the emissions of the engine, exhaust gas temperature increased from 223 to 276 oC, CO2 emissions increased from 21.59 to 33.90%, CO emissions increased from 0.36 to 0.59%, HC emissions increased from 23 to 58 ppm, and smoke opacity increased from 4.00 to 6.07 K.m-1 compared with the diesel fuel only mode.

Experimental investigation of salmon blends and sesame wood chips as alternative fuel

ABSTRACTThe present investigation elaborates on the exhaust emission and diesel fuel savings from a multicylinder diesel engine operated in dual fuel mode utilizing salmon biodiesel and sesame wood generated producer gas at different loads (0, 2, 4, 6, 8, and 10 kW) under an optimum producer gas flow rate of 19.72 kg/h. The results of this investigation depicted that both nitric oxide and smoke emission were reduced, while carbon monoxide, carbon dioxide, and hydrocarbon emission increased for dual mode in contrast to single fuel operating mode. Increase in biodiesel blend percentage shows a reducing curve for all the emission parameters in comparison to diesel fuel for all test conditions in dual fuel mode. Therefore, for optimum producer gas flow rate of 19.72 kg/h, it might be inferred that sesame generated producer gas with salmon biodiesel may be able to substitute for the conventional diesel for reducing greenhouse emission without much engine modification.

Design, development and testing of small downdraft gasifiers for domestic cookstoves

The design methodology available in the literature for downdraft gasifiers of large capacity (∼40–600 kWth) is not directly applicable to very small sized gasifiers. In the present work, design and development of small downdraft gasifiers of 4 kWth and 2.5 kWth nominal capacities, for domestic cookstove application, have been carried out by non-linear extrapolation of data in literature for large gasifiers. The prototypes thus developed were found to give maximum gasification efficiency close to 80%. Extensive experimentation was conducted in the laboratory to study the effect of two operating parameters, viz., gasification air flow rate and the fuel particle size, on the performance of these gasifiers. The performance parameters studied included calorific value of the gas, gasification efficiency, air-biomass ratio and the hearth load.Through detailed analysis of the results, it has been shown that the two operating parameters affect the gasifier performance primarily through their impact on reactor temperature and the total particle surface area available for the reactions. This explains the observation of an optimal gasification air flow rate for best gasification efficiency.It is also shown that the producer gas flow rate varies linearly with gasification air flow rate for a wide range of operating conditions on different sizes of gasifiers. It is also seen that different sizes of the gasifiers can have a different hearth load corresponding to best efficiency.

Performance evaluation of premixed burner fueled with biomass derived producer gas

Energy consumption of liquefied petroleum gas (LPG) in ceramic firing process accounts for about 15–40% of production cost. Biomass derived producer gas may be used to replace LPG. In this work, a premixed burner originally designed for LPG was modified for producer gas. Its thermal performance in terms of axial and radial flame temperature distribution, thermal efficiency and emissions was investigated. The experiment was conducted at various gas production rates with equivalence ratios between 0.8 and 1.2. Flame temperatures of over 1200°C can be achieved, with maximum value of 1260°C. It was also shown that the burner can be operated at 30.5–39.4kWth with thermal efficiency in the range of 84 – 91%. The maximum efficiency of this burner was obtained at producer gas flow rate of 24.3 Nm3/h and equivalence ratio of 0.84.

Design of a partially aerated naturally aspirated burner for producer gas

This article presents a detailed methodology for the design of a partially aerated naturally aspirated burner used for combustion of the producer gas generated in a downdraft gasifier cookstove. The main difference between an LPG burner and producer gas burner is that the former uses a high velocity jet of gas at ambient temperature whereas the latter uses a low velocity, high mass flow rate, buoyant jet of gas at 100–300 °C. Due to the elevated temperatures, buoyancy force plays an important role in entraining combustion air into the burner for producer gas. This has been accounted for in the new methodology, developed based on the design procedure available in the literature for hydrocarbon fuels. A mathematical model for fluid flow and heat transfer through the burner has been developed to predict percentage of primary aeration in the burner at different producer gas flow rates. The pressure drops predicted by the model have been validated using experimental measurements. The predictions of the model have been used to corroborate the assumptions and heuristics used in the design methodology. The predictions have also been used to demonstrate the importance of considering buoyancy in burner design, by comparing with a burner designed ignoring buoyancy. With the use of the newly designed burner, the thermal efficiency of the gasifier cookstove was found to improve substantially. Carbon monoxide (CO) emissions from the cookstove using this burner were also found to be within the limits (<5 g/MJd) recommended in the Indian Standards for cookstoves.