Small-scale Pilot Plant Research Articles

Оценка токсичности не распространяющих горение сигнальных кабелей при пожаре в производственных помещениях

Currently, flame retardant materials made from polymers with flame retardant additives are widely used. However, the thermal effects of the fire on these materials from the point of view of the release of toxic gases are not sufficiently studied. The purpose of the article is an experimental assessment of the toxicity of the gaseous environment of a room during thermal decomposition of flame retardant signal cables used in the industrial premises and in the buildings with a massive presence of people. Experimental method is used for studying the process of formation of the hydrogen cyanide and carbon monoxide during thermal decomposition of the cable product samples in a small-scale pilot plant. The analysis of the obtained results was carried out. Density of the radiant heat flux incident on the cable surface, which is characteristic of a fire in a room, is modeled. Dependences are obtained concerning the partial densities of hydrogen cyanide and carbon monoxide, as well as the specific emission coefficients of these gases on the duration of experiments in the case of thermal decomposition of a modern flame retardant signal cable of the ng LS FR HF E1180 brand, the insulation of which is made of polymers with flame retardant additives. It is found that this cable under real fire conditions can release toxic compounds (carbon monoxide and hydrogen cyanide) in the concentrations exceeding their maximum allowable values during the evacuation of people from the premises. The obtained values of the specific mass coefficients of formation of CO and HCN, as well as the specific mass coefficient of O2 absorption, can be used in the mathematical models of the dynamics of fire hazards when calculating the time of blocking escape routes in the industrial premises, as well as in the buildings with a mass stay of people, where flame retardant signal cables are located.

Catalyst optimization in a catalytic flow reversal reactor for lean methane combustion

This paper describes a detailed catalyst configuration study for a catalytic flow reversal reactor for lean methane combustion using computational modelling. The design is based on the use of a platinum group metals catalyst in the form of a washcoated monolith. A small-scale pilot plant reactor is used as the basis for the study. The computational model is based on the fundamental conservation equations of mass and energy that are solved using the finite element method with commercial software. Extensive model validation is performed using experimental data previously obtained on the pilot plant system. It is found that catalyst activity and length of the reaction section play key roles in the stable operation and performance of the system. For methane feed concentrations above about 0.5% by volume, the catalyst activity plays a relatively small role. For concentrations down to about 0.2% both the catalyst activity and reactor length become increasingly important. The complete transient history of the reactor also plays an important role in determining whether or not a stable stationary state can be achieved for a given set of inlet conditions. Computational modelling is shown to be an extremely valuable tool for the design of the reactor system.

Enclosed trough solar thermal power plant with thermal energy storage and saltwater condenser in Al Khobar, Kingdom of Saudi Arabia

The preliminary design of a concentrated solar power (CSP) plant with thermal energy storage (TES) in Al-Khobar, Kingdom of Saudi Arabia is here presented. The specific conditions, in terms of environment, weather and sun irradiance, sand and dust, humidity, temperature, solar irradiance, clouds coverage, and proximity to the sea, are considered. A CSP parabolic trough (PT) with TES in a glass enclosure and a once-through saltwater condenser is selected to produce solar energy with the added value of dispatchability. The results of the simulation by using the System Advisor Model (SAM) software are proposed in detail. The manuscript presents the supporting experimental data, and the model development, validation, and application. The computation of the operation of a reference CSP PT with TES plant located in a drastically different environment, requiring specific components such as a glass enclosure and a once-through saltwater condenser, is trustworthy. A small-scale pilot plant is however suggested before moving to full-scale plant construction.

Bed cooling effects in solid particulate matter emissions during biomass combustion. A morphological insight

Considering recent environmental regulations, the need to adapt domestic biomass combustion systems to models that generate less emissions has gained relative importance. The present research proposes an analysis of the bed cooling effects on emission patterns, specifically focusing on the concentration, typology and morphological aspects of the released particles. The study was carried out by comparing the behaviour of a small-scale pilot plant with air stratification, with and without bed cooling. The results revealed an optimal behaviour of the facility with distributions of 30% primary-70% secondary air, accompanied by a significant decrease in emissions due to the reduction in the operating temperatures. More than 75% of the particles were retained in the bed on the cooled surfaces due to the effect of the prominent temperature gradient that was produced. Among the types of emitted particles (mostly with sizes below 0.1 μm), the presence of partial biomass degradation remnants was observed, representing three-quarters of the total collected matter. To a lesser extent, the presence of carbonaceous agglomerates was detected and usually in very compact clusters; however, in cases of high primary air supply, large amounts of immature soot were observed.

Intensified degradation of textile wastewater using a novel treatment of hydrodynamic cavitation with the combination of ozone

Abstract Ozone has been applied for the advanced treatment of textile wastewater containing a large number of indigestible dyes and other macromolecular organics. However, due to the poor mass transfer performance of ozone, the efficiency of ozonation was limited, resulted in high operating cost. In the present work, the degradation of dyes and real textile wastewater by hydrodynamic cavitation combined with ozone (HC + O3) was studied in a small-scale pilot plant operating at a capacity of 40 L. The treatment of single HC and HC + Air had minute dye removal within 180 min whereas the treatment of HC + O3 and single O3 could degrade the dyes effectively in 10 min. The removal efficiency of dyes followed the order HC + O3 > single O3 > HC + Air > single HC. The synergetic coefficient of HC + O3 was 1.33, which indicated that HC and O3 had noteworthy synergistic effect in the hybrid system. For the real textile wastewater, the removal rates of HC + O3 on COD, TOC, UV254 and color were 36%, 23%, 71% and 90% in 30 min, which was higher than the single treatment. The removal of UV254 and color showed that macromolecular organics and residual dyes were effectively degraded. Among these treatments, HC + O3 was the most energy-efficient. Therefore, HC + O3 could be used as a potential dye degradation technology and would have a promising engineering application value in the real textile wastewater advanced treatment.

Mathematical Model for the Removal of Essential Oil Constituents during Steam Distillation Extraction

Steam distillation is the conventional means by which oils are extracted in the flavour and fragrance industry. A mathematical model for the steam distillation extraction (SDE) of air-dried Ocimum basilicum (basil) leaves has been developed and tested using a small-scale pilot plant. The model predicts the removal of oil components from the plant matrix and subsequent transfer to the steam. It also accounts for the diffusional transfer of components within the leaf and the simultaneous convective transfer into the vapour phase while also respecting the individual components’ volatilities. It has been applied vertically on an element-by-element basis through the bed for a mixture of major and minor components. The proposed SDE model appears to be a good match between predicted values and the experimental data. The model predicts a faster initial extraction rate for components such as α-pinene and α-terpinene, possibly due to preferential extraction of light, volatile components present in larger quantities.

Design of a parabolic trough concentrated solar power plant in Al-Khobar, Saudi Arabia

The paper discusses the design options for a concentrated solar power plant in Al-Khobar, Saudi Arabia. The specific conditions, in terms of weather and sun irradiance, are considered, including sand and dust, humidity, temperature and proximity to the sea. Different real-world experiences are then considered, to understand the best design to adapt to the specific conditions. Concentrated solar power solar tower with thermal energy storage such as Crescent Dunes, or concentrated solar power solar tower without thermal energy storage but boost by natural gas combustion such as Ivanpah are disregarded for the higher costs, the performances well below the design, and the extra difficulties for the specific location such as temperatures, humidity and sand/dust that suggest the use of an enclosed trough. Concentrated solar power parabolic trough without thermal energy storage such as Genesis or Mojave, of drastically reduced cost and much better performances, do not provide however the added value of thermal energy storage and dispatchability that can make interesting Concentrated solar power vs. alternatives such as wind and solar photovoltaic. Thus, the concentrated solar power parabolic trough with thermal energy storage of Solana, of intermediate costs and best performances, albeit slightly lower than the design values, is selected. This design will have to be modified to enclosed trough and adopt a Seawater, Once-trough condenser. Being the development peculiar, a small scale pilot plant is suggested before a full-scale development.

Development of an aluminum compound casting process - Experiments and numerical simulations

The casting of liquid melt on a preheated substrate layer to produce a metallurgical compound represents a direct approach towards clad aluminum strips. To investigate this direct process route and the formation of a metallurgical bond at the interface, a small-scale pilot plant to cast pure aluminum on strips of aluminum alloy 7075 under controlled conditions was developed. Composite casting plates were produced at varying casting parameters (preheating temperature of the substrate, clad layer thickness, casting speed, melt temperature) and subsequently analyzed by metallographic means to classify the bond quality. Suitable thermal conditions for the melt flow in the casting device were found by numerical simulation using a commercial fluid flow and solidification software package. Additional meso- and micro-modeling of the casting and the bonding zone supported the understanding of the bonding mechanism. The heat transfer in the macro-model of the casting device was calibrated using measured temperatures obtained during compound casting experiments. A finer meshed two-dimensional meso-model of the casting device was derived from the macro-model to gain more accurate information about the temperature distribution in the vicinity of the bonding zone. This interface between the pure aluminum and the aluminum alloy was modeled in extremely high temporal and spatial resolution (micro-model) as temperatures are not accessible there by direct measurements. These simulation results show the time-resolved re-melting and re-solidification of the aluminum alloy during compound formation. The obtained simulation results correlate very well with electrochemically etched cross sections of cast bilayer aluminum strips. The experiments show that the oxide layer at the interface has to be removed completely during the casting process to obtain high quality compounds. The assumed mechanism of detachment and transport of the fractured oxide is shown schematically and necessary thermo-mechanical conditions for the removal of the oxide skin are discussed.

Design of a cw, low-energy, high-power superconducting linac for environmental applications

The treatment of flue gases from power plants and municipal or industrial wastewater using electron beam irradiation technology has been successfully demonstrated in small-scale pilot plants. The beam energy requirement is rather modest, on the order of a few MeV, however the adoption of the technology at an industrial scale requires the availability of high beam power, of the order of 1 MW, in a cost effective way. In this article we present the design of a compact superconducting accelerator capable of delivering a cw electron beam with a current of 1 A and an energy of 1 MeV. The main components are an rf-gridded thermionic gun and a conduction cooled beta= 0.5 elliptical Nb3Sn cavity with dual coaxial power couplers. An engineering and cost analysis shows that the proposed design would result in a processing cost competitive with alternative treatment methods.

Time-Dependent Desalination Tests for Small-Scale SWRO Pilot Plant Installed at Urla Bay, Turkey

In this work, performance data from a small-scale reverse osmosis (RO) plant based on seawater FilmTec spiral wound RO membranes for different periods of operation are presented and analyzed. A prototype RO set-up with a 2,200 L/d capacity was installed and operated at Urla Bay which was located in Izmir, Turkey. This study typically investigates RO performance in terms of permeate flux, salt and boron rejections. Thin-flm composite membrane-based RO technology was successfully used with this RO set-up, which gave an average salt rejection of more than 95%. It was found that over a period of 36 hours of continuous operation, the permeate flux decreased by approximately 4% of its initial value but salt rejection stayed nearly constant. In this study, long-term data were also compared with a full-capacity operation using two paralleled membranes and a lowered-capacity operation with a single membrane. The results show that the small-scale RO system was successfully operated to mimic typical large-scale RO plants installed for production of potable water.

Evaluation of virus reduction at a large-scale wastewater reclamation plant by detection of indigenous F-specific RNA bacteriophage genotypes

ABSTRACTEvaluating the reduction of virus load in water reclamation plants is important to ensuring the hygienic safety of the reclaimed water. A virus-spiking test is usually used to estimate virus reduction but is not practicable at large-scale plants. Thus, we evaluated virus reduction by ultrafiltration (UF) plus ultraviolet (UV) irradiation at a large-scale reclamation plant (1000 m3/d) by quantifying indigenous F-specific RNA bacteriophages (FRNAPHs). To detect the infectious FRNAPH, we used both plaque assay and integrated culture–reverse-transcription polymerase chain reaction combined with the most probable number assay, which can detect infectious FRNAPH genotypes. For comparison, we determined reductions of indigenous FRNAPHs and spiked MS2 at a small-scale pilot plant (10 m3/d) at the same time. Reductions by UF were not significantly different among the bacteriophages at pilot plants. This result suggests that indigenous bacteriophages could be used for evaluating virus reduction by UF at large-scale plants. Indigenous Genotype I (GI) FRNAPH showed the highest UV resistance, followed by GII, GIII, and GIV. The resistance of GI-FRNAPH was equivalent to that of spiked MS2. The reduction of the total infectious FRNAPHs determined by plaque assay was affected by the predominant FRNAPH genotype, presumably because of their different UV resistances. Our results reveal that indigenous GI-FRNAPH can be a good alternative indicator to spiked MS2 in view of virus reduction during water reclamation. The reclaimed water from our large-scale reclamation plant could be used for irrigation because the expected reduction (6.3 log10) of indigenous GI-FRNAPH achieved the Title 22 (>5 log10).

Экспериментально-теоретический подход к расчету концентраций моноксида углерода и показателя токсичности при пожаре в условно герметичном помещении

Introduction. In previous works, the authors proposed a new approach to the calculation of the concentration of toxic products of combustion. The approach is based on determination the volume average density of toxic gases at any given time by using their experimental dependences on the mean volume temperature. The accuracy of this approach depends heavily on the error of determining the heat losses coefficients in small-scale experimental setup and real full scale room. In this paper, using experimental data obtained on small-scale pilot plant, it is proposed a different approach, that uses the theoretical and experimental dependences between average volume densities of toxic gases and the mean volume density of oxygen. It is not necessary to determine the heat losses coefficient and also solve differential equations of the conservation laws of toxic gases masses. Materials and methods. Coniferous wood building materials, transformer oil and PVC sheath cables are considered as combustible materials. Theoretical and experimental methods of gas dynamics and heat and mass transfer are used to determine the parameters of gases mixture during free convection. Theory and calculation. A physical and mathematical model for calculating the mean volume density of carbon monoxide and toxic index for the combined effects of CO and O 2 during the combustion of solid and liquid substances and materials in conventionally hermetic volume of arbitrary sizes is proposed. The model is based on the integral method for calculating thermal and gas dynamics of fire in the room. Formulas for calculating the mean volume density of CO and toxicity index for mutual effect of the action of CO and O 2 are obtained. Results. Experimental dependencies of mean volume density of carbon monoxide and toxicity index from mean volume density of oxygen are obtained in a small-scale pilot plant. A comparison of the theoretical values of mean volume density of CO and toxicity index derived using the proposed formulas with experimental values is made. Discussion. It is shown that the volume average density of carbon monoxide and the toxicity index for the combined effects of CO and O 2 during combustion of solid and liquid materials in conventionally hermetic volume of arbitrary sizes can be calculated by using only the average volume oxygen density and specific coefficients of separation of CO and deleting O 2 . The resulting formulas for calculating the mean density of CO and toxicity index of the mutual influence of CO and O 2 do not contain the geometric sizes of the room and combustible materials surfaces and, therefore, are fair in both small-scale and large-scale fire in the room. Conclusions. The proposed physical and mathematical model allows calculation of mean volume density of CO and toxicity index for combined effects of CO and O 2 during fire in a real full-scale room without solving the differential equation of conservation law of carbon monoxide mass and using the experimental dependence between the mean volume densities of CO and O 2 and the calculated average volume density of O 2 .

Effective ways to modernize outdated coal heat power plants

An analysis of the state of equipment of 72 outdated coal HPP (heat power plants) of a total capacity 14.3 GW with steam parameters before the turbines pbefore ≤ 9 MPa, tbefore = 420–540°С was performed. The equipment is characterized by a considerably low efficiency factor, even if it were converted to burning the natural gas, and by increased release of harmful substances. However, on the most part of the considered HPP, the steam turbines, unlike the boilers, have thus far retained the operation applicability and satisfactory reliability of performance. The analysis has shown that it makes sense to effectively modernize the outdated coal HPP by transformation of their equipment into combined-cycle plant (CCP) with coal gasification, which has high economic and ecological indicators due to thermodynamic advantage of the combined cycle and simpler purification of the generator gas in the process under pressure. As the most rational way of this transformation, the one was recognized wherein—instead of the existing boiler (boilers) or parallel to it—a gasification and gas turbine system is installed with a boiler-utilizer (BU), from which steam is fed to the HPP main steam pipe. In doing this, the basic part of the power station equipment persists. In the world, this kind of reconstruction of steam power equipment is applied widely and successfully, but it is by use of natural gas for the most part. It is reasonable to use the technology developed at Heat Engineering Research Institute (HERI) of hearth-steam gasification of coal and high-temperature purification of the generator gas. The basic scheme and measures on implementation of this method for modernization of outdated coal HPP is creation of CCP with blast-furnace of coal on the basis of accessible and preserved HPP equipment. CCP power is 120 MW, input-output ratio (roughly) 44%, emissions of hazardous substances are 5 mg/МJ dust, 20–60 mg/МJ SO2, and 50–100 mg/МJ NOх. A considerable decrease of specific CCP cost is expected: down to approximately half compared to that of CCP with coal gasification created elsewhere abroad. Verification and debugging of accepted solutions can be carried out at a small-scale pilot plant.

Characterisation of residual char from biomass gasification: effect of the gasifier operating conditions

Char, together with tars, are the main wastes derived from biomass gasification. The removal of tars and the valorisation of char are necessary to avoid technical problems and to increase the overall efficiency of the gasification plant, respectively (both aspects encouraging the commercial implementation of biomass gasification systems). However, char properties may not be suitable for an easy valorisation. This work analyses the effect of the main gasifier operating conditions (relative biomass/air ratio, temperature and steam content of the gasifying agent) on the properties of char produced from gasification of dealcoholised marc of grape. Those properties allow both, to analyse the phenomena taking place during the conversion process and to assess potential applications (valorisation) of this waste. Gasification was carried out in a small-scale drop-tube pilot plant. Char characterisation includes structural, thermo-chemical and compositional analysis. Results show that an increase of the relative biomass/air ratio leads to a higher char production as well as to an increase in the extent of the carbonisation, which makes the char more aromatic and stable. Intermediate relative biomass/air ratios (∼3.5), indicate a trade-off between fuel conversion and char specific surface area. On the other hand, higher operating temperatures lead to a less reactive char as a consequence of a higher fuel conversion. All obtained chars have low specific surface area (<70 g/m2), which discourages their application as activated carbon without further activation. Inorganic elements have in general a high retention level in the carbonaceous matrix (∼70–80% for most compounds), which decreases at higher temperatures and/or lower steam content in the gasifying agent. The char could also be recirculated to the gasifier or to a combustor. However, the alkali index values of both the initial biomass and the gasification chars are far above the limit considered as troublesome, thus being likely to cause slagging and fouling problems.

Upgrading of heat carrier oil derived from liquid-phase pyrolysis via fluid catalytic cracking

Second generation biofuel technologies are well investigated to extend the amount of sustainable biofuels. One of the most important criterions for biofuels is their profitability. The bioCRACK process is a new and innovative biomass-to-liquid concept to produce advanced biofuels by liquid-phase pyrolysis. A refinery integrated pilot plant was built up at the OMV refinery in Schwechat (Austria) to provide data for up-scaling. The objective of this publication was to test the suitability of different processed heat carrier oils derived from the bioCRACK process as feedstock for the FCC process. Vacuum gas oil – a typical feedstock for fluid catalytic cracking – was used as heat carrier oil. Different case studies were evaluated, whereas spruce wood and wheat straw were used as feedstock for pyrolysis. All experiments were conducted in a fully continuous small scale pilot plant with internally circulating fluidized bed design. In general, the obtained results show a high conversion efficiency for all performed case studies. Thereby the yield of coke is increased a little. The investigation confirmed that the total fuel yield can be improved even more by additional hydrotreatment. It turned out that the use of a pre-hydrotreated vacuum gas oil for pyrolysis leads to the highest conversion level.

The purification of fermentatively produced hydrogen using membrane technology: a simulation based on small-scale pilot plant results

Hydrogen is known as one of the most promising energy carriers of the future. Its production in a sustainable manner is therefore an important step towards a competitive alternative to fossil energy sources. Dark fermentation is such a sustainable pathway, as hydrogen is produced via biotechnological conversion of biomass. But, the resulting hydrogen-rich gas from fermentation still needs to be upgraded, which can be done via membrane technology. In this work, an innovative small-scale process was developed, membrane modules were assembled and tested, and the purification method was simulatively investigated. The laboratory tests with pure gases showed that the utilized commercially available H2-selective membranes have an ideal H2/CO2-selectivity of 3.3, at the respective process conditions. When applying gas mixtures, the H2/CO2-selectivity was reduced. To further investigate the purification method, an Aspen Plus® gas permeation simulation model was used. The single-stage model was evaluated and it reflected the results from field and laboratory tests well. Furthermore, three different multi-stage setups were developed, simulated, and analyzed. The utilization of H2-selective material in a two-stage process resulted in a specific energy demand of 0.400 kWh/Nm3H2, but achieved no sufficient hydrogen purity. Compared to that, the use of CO2-selective membranes demanded only 0.296 kWh/Nm3H2. The recycle to feed ratio, as well as the H2-puriy of 95.5 vol% in the product was also in favor of the CO2-selective membranes compared to the commercially available H2-selective material.

Particle size control of detergents in mixed flow spray dryers

Particle size is a key quality parameter of a powder detergent as it determines its performance, the bulk density and the look and feel of the product. Consequently, it is essential that particle size is controlled to ensure the consistency of performance when comparing new formulations. The majority of study reported in the literature relating to particle size control, focuses on the spray produced by the atomisation technique. One approach advocated to achieve particle size control is the manipulation of the ratio of the mass slurry rate and mass flow rate of gas used for atomisation. Within this study, ratio control was compared with an automatic cascade loop approach using online measurements of the powder particle size on a small-scale pilot plant. It was concluded that cascade control of the mean particle size, based on manipulating the mass flow rate of gas, resulted in tighter, more responsive control. The effect of a ratio change varied with different formulations and different slurry rates. Furthermore, changes in slurry rate caused complications, as the impact on particle size growth in the dryer is non-linear and difficult to predict. The cascade loop enables further study into the effect of particle size on detergent performance.

Identification of Methyl Ester Content from Waste Cooking Oil Using Gas Chromatographic Method

Waste cooking oil has always been an environment problem in food factories and one method of effect disposing this oil without effecting the environment is to convert it to fatty acid methyl ester (FAME) using small scale pilot plant. The conversion of waste cooking oil with sodium hydroxide as a catalyst in conversional process at 22kHz speed. The reaction of time, molar ratio, speed, catalyst and amount of catalyst will be effect in FAME quality. The quality of biodiesel define is total ester content using gas chromatography. Gas chromatography analysis is a one of technique for identification and quantitation of compounds in a biodiesel sample. From biodiesel sample can identification of contaminants and fatty acid methyl ester. In this research biodiesel sample were analyses using a gas chromatography-flame ionization detector ( Perkin Elmer GC Model Clarus 500) equipped with a DB-5 HT capillary column ( 0.53mm x 5 m) J&amp;W Scientific. The analytic conditions for ester content were as follow by: column temperature used 2100C, temperature flame ionization detector (FID) of 2500C, pressure of 80kPa, flow carrier gas of 1ml/min, temperature injector of 2500C, split flow rate of 50ml/min, time for analysis 20 minute and volume injected of 1 μl. The ester content (C), expresses as a mass fraction in present using formula (EN 14103, 2003a) calculation. Conversion of triglyceride (TG) to FAME using conversional process obtained 96.54 % w.t with methanol to oil molar ratio 6:1, 1%w.t acid sulphuric and 1% w.t sodium hydroxide catalyst.

The (UP)Scaling of Renewable Energy Technologies: Experiences from The Austrian Biomass District Heating Niche

Abstract The successful diffusion of sustainable technologies is termed “upscaling” in the transition studies literature. This paper maintains that upscaling is an ambiguous notion that suggests that technology diffusion processes follow a linear trend from small-scale pilot plants to industrial-scale facilities. On the ground, however, socio-technical configurations are implemented at a variety of scales, simultaneously. These issues are demonstrated in this paper by analysing the historical development of the Austrian biomass district heating niche. Drawing on secondary statistical data and primary qualitative semi-structured interviews, it is possible to identify four generic socio-technical configurations or dominant designs that, in conjunction, shape the diffusion dynamics of this technology in Austria

Flame stability and OH and CH radical emissions from mixtures of natural gas with biomass gasification gas

In this work, a study about laminar premixed flames derived from the combustion of natural gas and producer gas (25 and 50% by volume) mixtures in an atmospheric burner was carried out. The producer gas was obtained from steam gasification process of dealcoholised marc of grape in a small-scale drop-tube gasification pilot plant, this solid fuel being an abundant biomass waste in Spain. These mixtures have different advantages such as replacing fossil fuels with renewable fuels, reducing NOx emissions and other advantages associated with the biomass consumption. The main objectives of this work are to delimitate the stability diagram of the different mixtures, to evaluate the potential of these mixtures to reduce NOx emission and to study the interchangeability of the gas mixtures used. The results obtained show that an increase in the producer gas amount (and therefore in the hydrogen content) makes possible a stable burner operation at leaner conditions, thus leading to lower combustion temperature and NOx emissions. OH and CH radical concentrations were measured by chemiluminescence to confirm the potential to reduce NOx emissions. The Wobbe index results show a possible interchangeability between natural gas and natural gas/producer gas mixtures below 37% vol. of producer gas.