Kiln Type Research Articles

Enriching IAM scenarios for effective pLCA integration: A clinker case study

Integrated assessment models are increasingly used to build prospective life cycle databases. While these models provide projections on an economy-wide scale, they can lack detail, with some industries aggregated at sector level and a technological resolution that tends to be too low for the demands of an LCA. This limitation hinders the accurate modelling of several industries in a prospective LCA. This paper aims to bridge the gap in detail between LCA and Integrated assessment models by means of an econometric model, using the cement industry as a case study. While this model sits outside of the integrated assessment model, it ensures consistency with the integrated assessment model's scenario by using data from the integrated assessment model to build its projections. The case study estimates the capital stock required, the fuel mix in the kiln, the most cost-effective kiln type and finally the capital stock composition. This was done for a baseline, moderate and climate stringent scenario, for the EU, USA and Canada. The projections of the model were integrated into a prospective life cycle assessment to determine the global warming potential of clinker production in the future. Results show an increase in alternative fuel use, especially for the EU. The use of natural gas increases for the USA and Canada but remains negligent for the EU. Kilns with carbon capture are adopted, if the carbon tax is high enough and the alternative fuel share is not too high.

Influence of kiln type on the production of lightweight aggregates

Influence of kiln type on the production of lightweight aggregates

Investigating the Impact of Shifting the Brick Kiln Industry from Conventional to Zigzag Technology for a Sustainable Environment

The brick kiln industry is one of the largest and most highly unregulated industrial sectors in developing countries. Most of the kilns use low-quality coal as primary fuel along with small quantities of bagasse, rice husk, and wooden chips. As a result of inefficient methods of combustion in conventional brick kilns, such as fixed chimney Bull’s trench kilns (FCBTKs), harmful pollutants are emitted in high quantities, which ultimately deteriorate the environment and are widely in operation in Pakistan. The most prominent harmful pollutants include carbon dioxide (CO2), carbon monoxide (CO), sulphur dioxide (SO2), black carbon (BC), and particulate matter less than 2.5 microns (PM2.5). Over the years, new technologies have been adopted by developed countries for the reduction of environmental burdens. One of these technologies is induced draught zigzag kilns (IDZKs), or zigzag kilns (ZZKs), technology, which effectively improves the combustion across the path of bricks stacked in a zigzag pattern. For the mass adoption of this technology, environmental assessment and comparison of both technologies is a crucial step. Both types of kiln sites are investigated for the analysis of their emissions and their environmental impact in this work. Carbon mass balance equations are used for the calculation of emission factors. Collected inventory data is then used for the life cycle assessment of both types of kilns using open LCA (version 1.10.3) and the Eco-invent database. According to the study, ZZK technology outperforms FCBTK in all aspects. The analysis of the specific energy consumption (SEC) of fired bricks for each kiln type reveals that ZZKs require 30% less energy than the conventional FCBTK. This implies that ZZKs demand lesser fuel than FCBTKs. The zigzag technology adoption scenario, in particular, can lead to approximately 30% lower CO2 emissions, which can be further reduced by up to 80% when taking into account black carbon (BC) emissions. Additionally, the adoption of zigzag technology can result in a 35% decrease in PM2.5 emissions. The study shows that adopting ZZK technology significantly reduces impact categories, such as particulate matter formation (PMF), photochemical oxidant formation (POF), and terrestrial acidification (TA) by 63%, 93%, and 95%, respectively.

Architecture and function of salt-producing kilns from the 8th to 18th century in the coastal Sundarbans mangrove forest, Central Ganges-Brahmaputra Delta, Bangladesh

Subsidence along the central coast of the Ganges-Brahmaputra Delta and a subsequent rapid burial by mangrove mud have preserved a hundred earthen kilns at 11 localities, exposed due to recent coastal erosion. The associated pottery indicates that the kilns were used for salt crystallization in brine pots mounted on perforated hotplates. Four kiln varieties were found at successive elevations. The kiln chamber walls and the basal charcoal layers were dated using thermoluminescence and radiocarbon dating respectively. The oldest kilns with a round outline, found at the lowest elevations, were operating in the early 8th to middle 9th century. Oval-shaped kilns, found at a 1-m higher elevation, were used from the mid-9th to early 10th century. After a 600-year long period without documented kilns, rectangular kilns with a lateral slot were built again at a 1-m higher land surface in the 16th and 17th century. The youngest kiln type consists of rectangular twin chambers dating from the late 16th to mid-18th century and occurs at 1.5 m below the present sediment surface. Architecture and functioning of these rectangular kilns are reconstructed, showing a multi-step procedure. This technique had been improved in the 19th century when pyramidal kilns were described in historic records.

Development of Ammonia Emission Factor for Industrial Waste Incineration Facilities Considering Incinerator Type.

In this study, the emission factor and concentration of ammonia from industrial waste incineration facilities were analyzed through actual measurements. The ammonia emission factor was calculated and the difference in ammonia emission factor for each type of incineration was confirmed through the Mann–Whitney U test. As a result of analyzing 279 samples, the NH3 emission factor of the SNCR facility of stoker types was 0.012 kgNH3/ton, and the NH3 emission factor of the SNCR facility of the rotary kiln methods was 0.014 kgNH3/ton. Additionally, the NH3 emission factor of this study was higher than the NH3 emission factor (0.003 kgNH3/ton) suggested by Kang’s study (0.009 kgNH3/ton) and EMEP/EEA (2006). There is a need to develop an NH3 emission factor that takes into account the characteristics of Korea, since it is largely different from the NH3 emission factor of EMEP/EEA. As a result of statistical analysis of the stoker type and the rotary kiln method, the null hypothesis that there is no difference between each type was adopted (p-value > 0.05), indicating that there was no statistical difference in the ammonia emission factors of the stoker type and the rotary kiln type.

Reduction of Iron Ore by Uncarbonized Biomass in a Rotary Kiln Type Furnace

Reduction of Iron Ore by Uncarbonized Biomass in a Rotary Kiln Type Furnace

Evaluating charcoal producers’ preferences for improved production systems in Marigat sub county, Baringo County

Many households in Kenya depend on charcoal as an important source of energy. However, overharvesting of trees and the use of inefficient technologies promote unsustainable charcoal production. Furthermore, high demand for charcoal from slow-growing indigenous species contributes to increased pressure in the drylands, threatening future supply and livelihoods. Recent studies have shown that Prosopis juliflora an invasive species introduced to arrest desertification equally produces quality charcoal. Also, improved technologies with more efficient carbonization rates have the potential to reduce not only the number of trees harvested but also quality of charcoal. Despite the existence of improved technologies, and the presence of fast-growing Prosopis juliflora, charcoal production remains unsustainable in Baringo County. This study used choice experiments (CE) to determine charcoal producers willingness to pay (WTP) for improved charcoal production system in Marigat sub-county.The attributes measured include charcoal quality, wood quality, P.juliflora growth trend and kiln type. Primary data was collected from a sample of 384 randomly selected charcoal producers using a semi-structured questionnaire. Study results indicate that charcoal producers were willing to pay more charcoal quality improvement which is associated with improved production systems and quality wood. However, they were not willing to pay for improved kilns. The findings suggest that the charcoal producers have a natural inclination to improved technologies with the study recommending charcoal producer association (CPA) membership as the first and efficient point of contact to adopt and use improved technologies.

Impact of South Asian brick kiln emission mitigation strategies on select pollutants and near-term Arctic temperature responses

The brick kiln industrial sector in South Asia accounts for large amounts of short-lived climate forcer (SLCF) emissions, namely black carbon (BC), organic carbon (OC), and sulfur dioxide (SO2; the precursor to atmospheric sulfate [SO4]). These SLCFs are air pollutants and have important impacts on both human health and the Arctic, a region currently experiencing more than double the rate of warming relative to the global average. Using previously derived Arctic equilibrium temperature response factors, we estimate the contribution to Arctic temperature impacts from previously reported emissions of BC, OC, and SO2 from four prevalent South Asian brick kiln types (Bull’s Trench [BTK], Down Draught [DDK], Vertical Shaft [VSBK], and Zig-zag). Net annual BC (115 gigagrams [Gg]), OC (17 Gg), and SO2 (350 Gg) baseline emissions from all four South Asian kiln types resulted in 3.36 milliKelvin (mK) of Arctic surface warming. Given these baseline emissions and Arctic temperature responses, we estimate the current and maximum potential emission and temperature mitigation considering two kiln type conversions. Assuming no change in brick production, baseline emissions have been reduced by 17% when considering current BTK to Zig-zag conversions and have the potential to decrease by 82% given a 100% future conversion rate. This results in a 25% and 119% reduction in Arctic warming, respectively. Replacing DDKs with VSBKs increases baseline SLCF emissions by 28% based on current conversions and has the potential to increase by 131%. This conversion still reduces baseline warming by 31% and 149%, respectively. These results show that brick kiln conversions can have different impacts on local air quality and Arctic climate. When considering brick kiln emissions mitigation options, regional and/or local policy action should consider several factors, including local air quality, worker health and safety, cost, quality of bricks, as well as global climate impacts.

Technological performance and effects of traditional grilling on the physicochemical characteristics and polycyclic aromatic hydrocarbon contamination of kilichi , a grilled meat produced in Niger

The physicochemical characteristics and chemical safety of two categories of grilled meat from Niger were assessed, using sun drying and optionally wood fire grilling processes. Contamination factors associated with the critical unit operations were identified and the technological parameters were monitored through these processes. Sixty samples were analyzed for dry matter, pH, and water activity. Polycyclic aromatic hydrocarbons were assessed using HPLC-FLD technique. No effect of the process on the duration of kilichi production was observed, whereas the yield of kilichi was significantly (p = .015) dependent on the process and kilichi category. Production of kilichi leads to losses of dry matter (yield <90%). All wood fire grilled samples were highly contaminated with BaP and PAH4, with concentrations exceeding up to 10 times the EU maximum limits set at 2 and 12 μg/kg, respectively. Kiln type, fire wood species, and processing practices were the critical factors for an improved quality of kilichi. Novelty impact statement The two main traditional processes of grilled meat production identified in Niger are characterized for one process, by sun drying and wood fire grilling of beef meat and for the second process by sun drying only, without wood fire grilling. Grilled meat obtained through the process not involving wood fire grilling has a level of PAHs contamination lower than the maximal limits for BaP (2 μg/kg) and PAH4 (12 μg/kg), whatever the category of grilled meat. All the wood fire grilled meat samples are highly contaminated with BaP and PAH4, exceeding up to 10 times the EU maximum limits for both BaP and PAH4.

2500 years of charcoal production in the Low Countries: The chronology and typology of charcoal kilns and their relation with early iron production

The study of archaeological remains of charcoal kilns is a fast growing field of research. The history and evolution of different types of (pre)historical charcoal production features is still poorly understood however. Based on a large number of radiocarbon dated charcoal kilns from Belgium and the Netherlands, covering c. 2500 years, a typology and chronology of charcoal kilns is presented. The oldest charcoal production features date to the late Iron Age, though many of these dates seem to suffer from an old-wood effect and might actually date to the Early Roman period. Both Iron Age and Roman period charcoal production is done in rectangular pit kilns. During the Early Middle Ages, there is a shift to circular pit kilns which become the dominant kiln type during the High Middle Ages. From c.1300 CE onwards, charcoal is no longer produced in pit kilns, but a new kiln type, i.e. the mound kiln is used. The size of the charcoal (pit) kilns decreases from the Roman period till c. 1300 CE when, with the use of mound kilns the volume of produced charcoal dramatically increases. These changes in kiln size most likely reflect changes in both the organisation, scale and technology of iron production in the Low Countries.

Regional microstructural characteristics between the body and glaze of ancient Chinese ceramics

Anorthite crystallization between the body and glaze of ancient ceramics has regional characteristics. According to the microstructural characteristics of the body and glaze, ancient Chinese ceramics can be mainly divided into four types: Yue kiln type, Longquan kiln type, Ding kiln type and Changsha kiln type. Anorthite crystallization is closely related to the elemental composition of the body and glaze. The microstructure of Minhou kiln ceramic chips shows that when the Al2O3 content of the body is high, fine feldspar crystals precipitated into the layer of molten glaze in contact with the body surface during firing. This unique microstructure can help identify some ceramics.

Characterization of thermal distribution in 50-Liter biochar kiln at different heating times

Biochar has been known to be an excellent soil amendment. However, the biochar yield and its quality are both affected by the process parameter, such as temperature and heating time, and the production method from kiln type used. Therefore, the objective of this work was to characterize the thermal distribution inside the 50-liter kiln at different heating times of the biochar production. The experiments on the kiln with a dimension of 500 mm × 380 mm (height × diameter) including the fuel core with diameter of 115 mm with 5 rows of 6.35 mm drill puncture diameters were conducted. The biochar was produced from 7 kg of agricultural waste corncob. The pyrolysis temperature increased with increasing heating time and it was controlled not exceeding 600 °C by adjusting the briquette fuel quantity. The results showed that the highest temperature was found at the fuel core and decreased in radial direction outwards to the kiln wall. The heating time showed effect on the thermal distribution as well as the biochar yield. The lower thermal gradient and the higher biochar yield were obtained at the higher heating time. The biochar yield would, however, decrease after optimal heating time due to the decomposition and degradation of biochar derived from corncob during the pyrolysis process. The production cost of biochar was also determined. These findings propose agriculturists the optimal heating time along with the production cost to facilitate the biochar production.

Black carbon, organic carbon, and co-pollutant emissions and energy efficiency from artisanal brick production in Mexico

Abstract. In many parts of the developing world and economies in transition, small-scale traditional brick kilns are a notorious source of urban air pollution. Many are both energy inefficient and burn highly polluting fuels that emit significant levels of black carbon (BC), organic carbon (OC) and other atmospheric pollutants into local communities, resulting in severe health and environmental impacts. However, only a very limited number of studies are available on the emission characteristics of brick kilns; thus, there is a need to characterize their gaseous and particulate matter (PM) emission factors to better assess their overall contribution to emissions inventories and to quantify their ecological, human health, and climate impacts. In this study, the fuel-, energy-, and brick-based emissions factors and time-based emission ratios of BC, OC, inorganic PM components, CO, SO2, CH4, NOx, and selected volatile organic compounds (VOCs) from three artisanal brick kilns with different designs in Mexico were quantified using the tracer ratio sampling technique. Simultaneous measurements of PM components, CO, and CO2 were also obtained using a sampling probe technique. Additional measurements included the internal temperature of the brick kilns, mechanical resistance of bricks produced, and characteristics of fuels employed. Average fuel-based BC emission factors ranged from 0.15 to 0.58 g (kg fuel)−1, whereas BC∕OC mass ratios ranged from 0.9 to 5.2, depending on the kiln type. The results show that both techniques capture similar temporal profiles of the brick kiln emissions and produce comparable emission factors. A more integrated inter-comparison of the brick kilns' performances was obtained by simultaneously assessing emissions factors, energy efficiency, fuel consumption, and the quality of the bricks produced.

Exposure to respirable silica among clay brick workers in Kathmandu valley, Nepal

ABSTRACTPrevious studies report high respirable silica exposures among clay brick workers globally; however, there are little data on exposures among workers in fixed chimney Bull's trench kilns, the predominant kiln type in Kathmandu valley, Nepal. We investigated respirable silica exposures among workers (N = 46) in five similar exposure groups (SEGs). Mean exposures were highest for red brick loading/carrying (331 μg/m3), followed by green brick stacking (223 μg/m3), fireman (102 μg/m3), coal crushing/carrying (92 μg/m3), and green brick molding (71 μg/m3). The average free silica content (13.8%) in the respirable dust fraction was similar to levels reported for clay brick workers employed in other types of kilns. Dust control measures and respiratory protection are recommended, with priority given to workers assigned to red brick loading and stacking and green brick stacking and carrying.

외열킬른형 열분해용융시설의 N2O 배출계수 개발

In this study, the NSUB2/SUBO emission factor of the facility was developed by measuring the kiln type pyrolysis melting facility. This used PAS (Photoacoustic Spectroscopy) method and measured the NSUB2/SUBO emission concentration. From March 2016 to April 2016, it was measured over a total of two times and NSUB2/SUBO concentrations were measured continuously for 24 hours using a 24 hour continuous measuring instrument (LSE-4405). The measured NSUB2/SUBO emission concentration of the pyrolysis melting facility was 0.263 ppm on average and the emission concentration distribution in the range of 0.013∼0.733 ppm was obtained. Therefore, the NSUB2/SUBO emission factor of the kiln-type pyrolysis melting facility was estimated to be 0.829 gN2O/ton-Waste. As a result of comparing the NSUB2/SUBO emission factor of the thermal kiln type pyrolysis melting facility and the previous study, previous studies were about 18 times higher. It is estimated that this is due to the difference of furnace temperature, oxygen concentration and denitrification facilities. It is considered that the study of the emission factor of pyrolysis melting facility is an important factor in improving the credibility of greenhouse gas inventory in waste incineration sector.

Biochar from "Kon Tiki" flame curtain and other kilns: Effects of nutrient enrichment and kiln type on crop yield and soil chemistry.

Biochar application to soils has been investigated as a means of improving soil fertility and mitigating climate change through soil carbon sequestration. In the present work, the invasive shrub "Eupatorium adenophorum" was utilized as a sustainable feedstock for making biochar under different pyrolysis conditions in Nepal. Biochar was produced using several different types of kilns; four sub types of flame curtain kilns (deep-cone metal kiln, steel shielded soil pit, conical soil pit and steel small cone), brick-made traditional kiln, traditional earth-mound kiln and top lift up draft (TLUD). The resultant biochars showed consistent pH (9.1 ± 0.3), cation exchange capacities (133 ± 37 cmolc kg-1), organic carbon contents (73.9 ± 6.4%) and surface areas (35 to 215 m2/g) for all kiln types. A pot trial with maize was carried out to investigate the effect on maize biomass production of the biochars made with various kilns, applied at 1% and 4% dosages. Biochars were either pretreated with hot or cold mineral nutrient enrichment (mixing with a nutrient solution before or after cooling down, respectively), or added separately from the same nutrient dosages to the soil. Significantly higher CEC (P< 0.05), lower Al/Ca ratios (P< 0.05), and high OC% (P<0.001) were observed for both dosages of biochar as compared to non-amended control soils. Importantly, the study showed that biochar made by flame curtain kilns resulted in the same agronomic effect as biochar made by the other kilns (P > 0.05). At a dosage of 1% biochar, the hot nutrient-enriched biochar led to significant increases of 153% in above ground biomass production compared to cold nutrient-enriched biochar and 209% compared to biochar added separately from the nutrients. Liquid nutrient enhancement of biochar thus improved fertilizer effectiveness compared to separate application of biochar and fertilizer.

3-41.間接キルン式ガス化による木質バイオマス発電について((12)燃焼等II,Session 3 バイオマス等)

3-41.間接キルン式ガス化による木質バイオマス発電について((12)燃焼等II,Session 3 バイオマス等)

Development of livestock waste burner for Stirling Engine

For on-site power generation by biomass fuel combustion of livestock waste and Stirling engine, we made two-kinds of combustor, oscillating kiln type and high-speed burner type, for effective thermal energy transfer to the Stirling engine. Then we estimated the burner from some point of view, as frame temperature, contamination, emission, heat transfer, ash treatment, easy operation, and etc.

Comparison of temperature field distribution between cement preclinkering technology and cement precalcining technology

Through the comparison of calcination conditions between cement preclinkering technology and cement precalcining technology, we studied the characteristics of temperature field distribution of cement preclinkering technology systems including cyclone preheater, preclinkering furnace, and rotary kiln. We used numerical simulation method to obtain data of temperature field distribution.Some results are found by system study. The ratio of tail coal of cement preclinkering technology is about 70%, and raw meal temperature can reach 1070 °C. Shorter L/D kiln type of preclinkering technology can obtain more stable calcining zone temperature. The highest solid temperature of cement preclinkering technology is higher than 80 °C, and high temperature region (>1450 °C) length is 2 times, which is beneficial for calcining clinker and higher clinker quality. So cement preclinkering technology can obtain more performance temperature filed, which improves both the solid-phase reaction and liquid-phase reaction.

The Concept, Design and Performance of a Novel Rotary Kiln Type Air-Staged Biomass Gasifier

Tar formation is the main bottleneck for biomass gasification technology. A novel rotary kiln type biomass gasification process was proposed. The concept design was based on air staging and process separation. This concept was demonstrated on a pilot scale rotary kiln reactor under ambient pressure and autothermic conditions. The pilot scale gasifier was divided into three different reaction regions, which were oxidative degradation, partial oxidation and char gasification. A series of tests was conducted to investigate the effect of key parameters. The results indicate that under optimum operating conditions, a fuel gas with high heat value of about 5500 kJ/Nm3 and gas production rate of 2.32 Nm3/kg could be produced. Tar concentration in the fuel gas could be reduced to 108 mg/Nm3 (at the gasifier outlet) and 38 mg/Nm3 (after gas conditioning). The cold gas efficiency and carbon conversion rate reached 75% and 78%, respectively. The performance of this gasification system shows considerable potential for implementation in distributed electricity and heat supply projects.