Studies of Gas Emissions and Performance of Stoves Using Biomass

In this article,we evaluated the energy performance parameters and gas emissions to identify which of the stoves studied performs best,and the biomass char briquettes with less emission.Biomass char briquettes from peanut shells,cashew nut shells,and corn cobs were produced using wheat flour as a binder.The binder rate was set at 9%and 10%.Based on the energy performance parameters,it was highlighted that the char briquette from corn cob with 9%binder(Char_CC_9%)has the best energy performance,followed by the char briquette from peanut shells with 9%binder(Char_PNS_9%),and lastly,the char briquette from cashew nut shells with 10%binder(Char_CNS_10%).The average energy efficiency of the“jambar”stove was 15.68%,while that of the“Malgache”stove was 12.41%.The average specific fuel consumption of the“jambar”stove was 0.12 kg of fuel per kilogram of water while that of the“Malgache”stove was 0.15 kg of fuel per kilogram of water.In terms of gaseous emissions,CO(carbon monoxide)concentrations were very high for char briquettes from corn cobs,with a CO emission factor of 0.40 g/min and NOx emission factor of 9.79 mg/min.For char briquettes from cashew nut shells,CO and NOx emission factors were respectively 0.30 g/min and 5.32 mg/min.The lowest average concentrations were obtained with char briquettes from peanut shells with a CO emission factor of 0.25 g/min and NOx 3.98 mg/min.

Natural Solar Drying and Charcoal Production by Pyrolysis of Empty Shells of Cocoa Pods Using a Carbonisation Stove Fitted with a Chimney

The world’s production of cocoa highly has grown since 1960.In West Africa,the production reached about 3,000,000 tons in 2012.More than 50%of the world’s production of cocoa comes nowadays from Côte d’Ivoire and Ghana and Côte d’Ivoire is the biggest producer.After harvesting,the empty shells,considered as non-useful wastes,are abandoned in the fields where they become a source of pollution.That yields millions of tons of biomass that can be converted into charcoal,instead of being sources of pollution.In the present work,the drying kinetics of the empty wet shells were studied.Then,charcoal production by pyrolysis of those empty shells of cocoa pods was performed,using a carbonisation stove fitted with a chimney.The study showed that the empty shells have a high moisture content.The different phases of the drying were observed.The study compared the drying rates and the diffusion coefficients of a small sample and a big sample.Two experiences of carbonisation of the empty shells were successfully carried out.For the first experiment,the pyrolysis temperatures were recorded and the charcoal mass efficiency calculated.For the second experiment,the temperatures were higher and the result was colored charcoals.The colorations disappeared after some hours.

Mathematical Model of Combustion in Blunt Annular Ceramic Burner

The computer simulation of the combustion process in blast furnace(BF) stove has been studied by using the k-ε-g turbulent diffusion flame model.The combustion process in blunt annular ceramic burner was calculated by using the software.The profiles of gas and air velocity,temperature of the combustion products,concentration of the components,and the shape and length of the flame during combustion have been researched.Compared with the original annular ceramic burner,the new design of the blunt one improves the mixing of the gas and the air significantly,and shortened the length of the flame.

Sillimanite, Kyanite and Andalusite in China and Their Applications Part II: Their Applications in Refractories to Improve Resistance to Creep and Thermal Shock

As a second part under the title, this paper introduces the applications of sillimanite group minerals (SGM) in refractory products for hot blast stove, blast furnace, torpedo, hot metal mixer, etc., with emphases on their uses in the low creep and thermal shock resistant bricks for tuyere and iron notch of blast furnace and checker brick and ceramic burner of hot blast stove, taking use of their phase transformation to form primary mullite and secondary mullite, accompanied by volume expansion. The developed SGM containing refractories have found wide uses in major domestic iron and steel making plants to meet the requirements of longer service life, higher service temperature and intensified operations.

Development and Assessment of Thermoacoustic Generators Operating by Waste Heat from Cooking Stove

This paper presents the development and assessment of two low-cost, travelling wave, thermoacoustic generators operating by waste heat energy from cooking stove. One powered by waste heat from a propane-driven stove, the other powered by waste heat from a wood-burning stove. The propane-driven thermoacoustic generator was successfully demonstrated to produce approximately 15 watts of electricity using a commercial audio loudspeaker. The wood-burning thermoacoustic generator was successfully constructed and tested to generate a maximum of 22.7 watts of electricity under a pressurised condition. The latter has a high potential to be used by over 1.5 billion people in rural communities for applications such as LED lighting, charging mobile phones or charging a 12V battery. A comprehensive power assessment of the propane-driving generator as well as the development and performance assessment of the wood-burning generator are described throughout this article.

Influencing Factors of Properties of Castables for Hot Blast Stove Pipes

In order to prolong the service life of castables for hot blast stove pipes,effects of SiO2 micropowder addition and aggregate kind on properties of castables for hot blast stove pipes,and properties of silica sol bonded castables were researched using homogenized bauxite,andalusite particles,andalusite fines,white fused corundum fines,α-Al2O3 micropowder,pure calcium aluminate cement,SiO2 micropowder,and silica sol as starting materials. The results show that：（1） as SiO2 micropowder addition increases,the shrinkage rate of fired specimens increases; BD increases firstly,reaches the highest at 4 mass%,and then decreases; CMOR and CCS of all specimens increase gradually; so the appropriate SiO2 micropowder addition is 4 mass%;（2） the specimens with bauxite aggregate have better CCS and volume stability,but specimens with andalusite aggregate have better thermal shock resistance;（ 3） for castables for hot blast stoves using silica sol as binder,the addition of pure calcium aluminate cement can decrease the linear change rate after treatment at 1 400℃ and can slightly enhance CCS and CMOR,but has very little influence on AP and BD; and the introduction of citric acid worsens the thermal shock resistance of specimens.

Development of Anti-Creep Andalusite-Based Bricks for Blast Furnace Stove

Secondary nudlitization and mineral phase compositions of reacting andalusite of different gain sizes with fine alumina powders are studied. By adopting reasonable process technology to control nudlitization behavior during firing, good anti-creep andalusite bricks have been developed.

Resistance characteristics of the ball packed-bed regenerator of the new-type swirl flow hot blast stove

A renovation project of miniaturization and high efficiency is provided for the hot blast stove .The experimental data tested feasibility of the new-type swirl flow hot blast stove. The normal and hot state experiments have been done through changing the angle of gas entering into the regenerator. Factors influencing pressure drop have been studied and analyzed. The experimental results can be formulated in the form of the Ergun equation. The regression equation is obtained. And two modified coefficients are offered to the regenerator pressure drop of the new-type swirl flow hot blast stove.

The Microwave Sintering Technology andIts Application in the Synthesis of ZrB_2

The principles and features of microwave sintering, the application in refractories and synthesis methods of ZrB2 are reviewed. The synthesis results of ZrB2 by thermit deoxidate method show that production price of ZrB2 can be effectively lowered through microwave synthesis. It will expand the application of ZrB2 in refractories.

The influence of particle size on the thermal performance of coal and its derived char in a Union stove

For low-income communities in South Africa,coal is the most common solid fuel which is burnt in a variety of devices,including imbaulas and cast-iron stoves.The present work was conducted with the aim of determining the effect of the fuel particle size on the performance of coal,typically sourced in low-income households in townships in South Africa,and to subsequently compare the performance with a feed char of a common cast iron stove.Four fuel particle sizes of 15,20,30,and 40 mm,as well as a composite of the sizes were tested at 550C,against their untreated coal analogues to evaluate the thermal performance of each fuel.The thermal performance assessment metrics are ignition time,water boiling time,heat transfer and combustion efficiencies,while CO and CO_(2)emissions were measured for the calculations of CO/CO_(2)ratios.Ignition times were found to decrease from coals to chars and to decrease with increasing particle size.The effects of fuel type on the water boiling time were only observed in the later stages of the burn cycle,with the char boiling a 2 L batch of water in an average 24 min,while the coals reported an average boiling time of 20 min.Heat transfer efficiencies showed no significant variation with fuel type or particle size,with the average efficiency for the coals and that of the chars being around 66%.The fuels’performance was better gauged by the combustion efficiency,which was found to improve marginally from the coal fuels to the chars,and to increase with increasing particle size.Results from this testwork could contribute to the performance inventories from the combustion of domestic coal mined in South Africa in a typical cast iron stove which is used in informal settlements.

Practice of improving the hot blast temperature for the 2500 m^3 BF

A high blast temperature is an effective measure that improves pulverized coal injection （PCI）and energy consumption,decreases the cost of blast furnaces （BF）. Apart from using technology such as the increased vault temperature of the hot-blast stove, the increased temperature of the waste gas, the preheating of combustion air and gas, and fully closed mixed air valves, other measures, such as using an oxygen-enriched blast stove, burning high heating value converter gas, increasing the number of stove changes to reduce the time needed for stove blasts, were taken to increase the blast temperature of the 2 500 m3 BF in recent years. The blast temperature of the 2 500 m3 BF was continuously increased in these years. The monthly average temperature of the 2 500 m3 BF reached 1 158℃, with the highest blast temperature reaching 1 195 ℃ in 2006. This technique of increased blast temperatures has reached an advanced level in China.

Technology Progress of Refractories for Iron Making in China

This paper reviews the present development situation of refractories for iron making system in China, which includes blast furnace, hot blast stove and coke dry quenching, etc. Varieties and performances of refractories used by the top steel and iron groups such as Baosteel, Wuhan I＆S Group and Anshan I＆S Group for iron making were exemplified and concerned problems were analyzed, together with solutions and suggestions for future refractories R＆D work.

Innovative Fuel Energy Saving Practices among the Small Farming Households, Ethiopia

Many studies have indicated that traditional cooking stoves are inefficient and their use leads to the acceleration of deforestation, the decline of land productivity, subsequently triggering climate changes and human health problems. On the other hand, the introduced ＂improved cooking stoves＂ also have their own disadvantages. Therefore, the case study was conducted aiming to study the rationale of using traditional stoves and document the innovative biomass energy saving practices of the community. The research studied two pilot areas in rural community with different agro-ecology and farming systems. Moreover, individual and focus group discussions were conducted among women households using transect and random sampling. The f＇mdings indicate that use of traditional stoves is dominant practice due to flexibility, simplicity and multi-functionality. Moreover, the biomass fuel use is integral part of the fanning system, socio-cultural framework and habits and customs of local community. The study has documented local innovation practices of biomass energy saving by improving stoves and chimney, combining different crops in food cooking, improving local beer processing, shifting crop-land to woodland. Moreover, the study reveals that the enclosure of communal forests due to the modem extension services is attributed with long distance travel to collect fuel wood, leading to conflicts and declines livelihood diversity of the poor population. Hence, consideration of local initiatives in development of appropriate and sustainable technology is essential.

Development of Thermal Shock Resistant and Low Creep Bricks for Hot Blast Stove

The paper describes the ries with high thermal shock development of brick seresistance and low creep rate for hot blast stove, including research target and research plan on the basis of analysis on how to enhance the thermal shock resistance and to lower creep rate of the bricks. Efforts have been made on the selection of starting materials such as corundum, mullite, andalusite and sillimanite etc., together with some measures taken on multi-grade formulation, homogenizing of the matrix of bricks and addition of some special additives. The results indicated that the bricks were with characteristics such as higher thermal shock resistance of 〉 30 cycles under quenching in water from 1000℃, and creep rate of 0. 2 under 1400℃ for 20 -50hrs with load of 0.2 MPa. Now a series of products of this kind have been developed and produced. The application of the products in Wuhan Iron and Steel Co. showed very prospective results. Now most of domestic large sized blast furnaces say ≥- 1000m^3, including those of Baoshan Iron and Steel Co. , have selected the series products made by Gongyi No. 5 Refractories Head Factory（GYWN） for their hot blast stoves.

Development of Andalusite Bricks for Hot Blast Stove

Low-creep andalusite bricks are characterized by high refractoriness under load, good anti-creep property, high mechanical strength, low porosity, good thermal shock resistance, etc. In this study, low-creep andalusite brick specimens were investigated in the lab using mullite, bauxite and andalusite. Andalusite with the different particle sizes were used in the experiment and the specimen with the best property was selected us the production standard. In addition, the industrial produced low-creep andalusite bricks were compared with other low-creep bricks. The results show that the developed low-creep andalusite bricks is an excellent material for hot blast stove.

Heat Transfer Validation and Comparative Evaluation of Biochar Yield from Pyrolysis Cook Stove

The developing world still largely depends on biomass, such as wood, animal dung and agricultural waste for domestic fuel sources that are typically burned in traditional stoves. Ethiopia has different biomass resource for biochar production, through pyrolysis cook stove co-producing biochar. Coffee husks are the major solid residues from the handling and processing of coffee in the study area. This study was to evaluate the biochar co-producing pyrolysis cook stove with respect to heat transfer through the bed and biochar yield. From allothermal type of pyrolysis cook stove, the stove design was selected for both the computational fluid dynamic （CFD） simulation and experimental measurements. ANSYS 14.5 was used for CFD simulation of the wood combustion. The production of biochar from coffee husk, corncob and sawdust at different heating times, bed and stove surface temperature were undertaken. Bulk density, pH and surface area of the biochar were measured. While good agreement between simulation and experimental result was obtained in the conduction phase during pyrolysis, deviation between the two on account of the effect of volatile gas in changing the temperature trend within the biomass bed was noticed. Within the biomass type, the maximum mean biochar yield （38.91%） was seen from coffee husk. In the case of different stove designs, the minimum mean biochar yield （27.11%） was found from normal Anila stove. The pH of biochar is found to be significantly affected by the type of biomass （9.83 mean for corncob and coffee husk, 6.43 mean for sawdust）, heating time （9.19 mean for 90 min and 8.01 mean for 30 min） and stove type （9.52 mean for normal Anila and 8.01 mean for flangeless Anila continuous feeding type）. In fact, the type of biomass is observed to significantly affect the bulk density and surface area ofbiochar.

Numerical calculation of flow and heat transfer process in the new-type external combustion swirl-flowing hot stove

It is clarified that the important method to improve the blast temperature ofthe small and the middle blast furnaces whose production is about two-thirds of total sum of Chinafrom 1000℃ to 1250-1300℃ is to preheat both their combustion-supporting air and coal gas. The airtemperature of blast furnaces can be reached to 1250-1300℃ by burning single blast furnace coal gasif high speed burner is applied to blast furnaces and new-type external combustion swirl-flowinghot stove is used to preheat their combustion-supporting air. The computational results of the flowand heat transfer processions in the hot stove prove that the surface of the bed of the thermalstorage balls there have not eccentric flow and the flow field and temperature field distribution iseven. The computational results of the blast temperature distribution are similar to thosedetermination experiment data. The numerical results also provide references for developing anddesigning the new-type external combustion swirl-flowing hot stoves.

Performance of a Score-Stove with a Kerosene Burner and the Effect of Pressurization of the Working Fluid

Score-StoveTM a clean-burning cooking stove that also generates electricity was tested using a pressurized kerosene burner. The Score-Stove works on the principle of thermo-acoustics to gen- erate small-scale electricity. The device having hot-end, cold-end and regenerator acts in a way similar to a stirling cycle generating acoustic power, which is then converted to electricity using a linear actuator. It can supply small power for applications such as LED lighting, mobile phone charging and radios particularly in rural areas without grid electricity as well as improving house- hold air pollution. After assessing the needs of the rural communities through a survey, tea-stalls and small restaurants owners were identified as clients with the most potential of using the stove in Bangladesh. Bangladesh University of Engineering and Technology ((BUET) modified a Score- Stove to use both wood and a pressurized kerosene burner of a design that is widely used for cooking in rural areas of Bangladesh. The design was adapted to meet performance needs such as: heating rate, cooking efficiency, energy distribution, electric power generation, exhaust emissions and time taken to boil water using standardized water boiling tests. Performance was also compared with conventional (non-electrically generating) stoves that use a pressurized kerosene burn- er. The Score-Stove performance was then evaluated while increasing the pressure of the sealed working fluid (air in this case) from atmospheric to about 1.4 bar. The pressurization was found to almost double the power generation. An arrangement for utilizing cooling water waste heat was also devised in order to improve the thermal performance of the stove by 18%. Technical deficiencies are documented and recommendations for improvements and future research in order to obtain wider end-user acceptance are made.

An Opportunity to Switch Energy Sources in Institutions in the Kilimanjaro Region, Tanzania and Benefit from Carbon Finance under the Sustainable Land Management Project

The sustainable land management (SLM) project is seeking to engage with public institutions to explore the possibility of using the energy-switch principle presented by the carbon market to reduce emissions from inefficient use of biomass energy and discharge of human waste into the environment. Such a switch will be a triple-win situation that improves the natural environment, reduces deforestation, and provides avenues for revenue generation. As such, it commissioned a study of the pattern of energy consumption in the institutions and the type of cooking stoves they employ. Results show that firewood (51%) is the most widely used fuel because of availability, affordability, and reliability. The study also found that 56% of the institutions use energy-saving stoves, which is an opportunity that the project can seize to encourage use of alternatives sources of energy as opposed to biomass. In addition, 88% of the institutions expressed willingness to switch to biogas for cooking. This is yet another opportunity for scaling up the dissemination of renewable sources of energy in the region. Better adoption and wider use of renewable energy sources will take place when innovative financing mechanisms are devised to cover the high upfront cost of installing renewable energy systems. This has been one of the main barriers to scaling up the use of renewable in the region.

Exposure to Emissions from Kerosene Cooking Stoves and the Pulmonary Health Status of Women in Olorunda Community, Ibadan, Nigeria

Exposure to high PM10 by women and children for hours on a daily basis in poor ventilated kitchen may lead to respiratory morbidity among this vulnerable group. In Nigeria, data on the levels of air pollutants associated with kerosene stove combustion are very scarce. Like-wise little had been documented on the pulmonary health of women exposed to kerosene stove emission. This study was carried out to measure the levels of kerosene combustion emissions within kitchen environments and also assess the pulmonary function status of the exposed women at baseline. Particulate matter (PM10) and gaseous emissions (GE) were measured in six purposively selected clusters of regular kerosene stove users (KSU) using gravimetric sampler and gas monitors, respectively and their values compared with WHO guideline limits. 167 randomly selected KSU were surveyed to elicit their socio demographic features. A spirometer was used to assess the lung function status (FEV1) of 72 KSU in six neighbourhood kitchen clusters. Data were analysed using descriptive statistics, and Pearson’s correlation tests. Respondents’ mean age was 38 + 12.9 years. Mean duration of exposure to GE was 18.9 + 9.8 years. Mean PM10 was 248.1 + 14.1 μg/m3 and ten folds higher than WHO guideline limit of 25 μg/m3. Mean GE in ppm were: CO (0.00), CO2 (200.1 + 12.4), SO2 (0.01 + 0.00) and NO2 (0.00). Mean FEV1 among KSU was 2.0 + 0.5 litres which was significantly lower than the mean predicted value of 2.7 ± 0.5 litres. There was a negative correlation between PM10 and FEV1 (r = -0.7539, p > 0.05). Safer cooking methods and practices to obviate health hazards are advocated.