Pyrolysis Unit Research Articles

Closed-loop organic waste management systems for family farmers in Brazil

ABSTRACT Family farmers in Brazil could diversify their sources of income and improve agriculture practices by adopting circular economy principles on their farms. Closed-loop technological systems can be used to manage organic waste and produce fertiliser and biogas thereby generating revenue. Anaerobic Digestion (AD) is a proven technology that can produce digestate (i.e. fertiliser) and biogas from organic waste, although digestate application in soil and crops without treatment can have adverse effects. However, in practice, there is a lack of knowledge about the benefits of recycling organic waste in farming communities in Brazil. Therefore, the main aim of this paper is to provide conceptual design configurations of closed-loop systems that manage organic waste and generate revenue for small farms in Brazil. A literature review of selected technologies and interviews with Brazilian family farmers were used to inform the components of the proposed conceptual designs. The proposed designs are based on circular economy principles, incorporating AD, pyrolysis for biochar, hydroponics and vermifiltration in various configurations. A complete closed-loop system consisting of a 7.5 m3 digester, pyrolysis unit, a combined hydroponic and vermifilter unit and a shredder is estimated to cost around USD$1600 (R$ 6600). The flexibility of the proposed systems has the potential to increase resilience and income for small-scale farmers, whilst encouraging good practices for waste management. The conceptual designs can be used as a basis for further research and development of small-scale organic waste management solutions in Brazil.

Experimental study on catalytic pyrolysis of plastic waste using low cost catalyst

Energy generation and utilization become an index of country development. The currently using conventional energy sources are depleting at faster rate, thereby researchers are searching for a viable alternative to generate the energy. The source should be compatible with the existing engines to run and sustain eco-balance. The two severe problems facing across the world are continuous raise of plastic usage and depletion of fossil fuels. The major hurdles with the plastic waste are disposal and recycling. The disposal for land filling may cause soil contamination, environmental disturbance due to incineration both are leads to social resistance. Pyrolysis is the one effective solution to resolve the plastic waste disposal is converting the energy a Though, pyrolysis is an effective approach to extract fuel oil from waste plastic, it suffers from expensive of catalysts. In the present work, an attempt has made to address it by utilizing low cost catalyst like fly ash for pyrolysis of HDPE and LDPE plastic. Experiments were conducted on pyrolysis unit by varying the mass fraction of catalyst at 5%, 10% and 15%. It is observed that yield of maximum at 5% and it is decline with the further addition of catalyst. In contra, increase in mass fraction of catalyst reduces the reaction temperatures as well as retention times. The physiochemical properties of collected oil were measured and compared against the diesel and gasoline fuels bides in polymerized links into usable form. It offers dual solution in environmental aspects and addressing the verge fossil fuels.

Технологии Изомалк-3 и Изомалк-3R для получения индивидуальных лёгких парафиновых углеводородов как сырья нефтехимических производств

The article discusses the new environmentally friendly catalytic technologies for processing butane cut, developed by SIE Neftehim LLC, giving wide opportunities for involving LPG in production of commercial value-added products. Development of petrochemical industry has created a demand for technologies and catalysts that enhance the economic efficiency of petrochemical products’ manufacturing and expand the feed base of petrochemical facilities without involving primary processing feeds. As the environmentally safe and economically effective solution, SIE Neftehim, LLC offers Isomalk-3 technology to produce maximum amount of isobutane, and Isomalk-3R technology to produce maximum amount of n-butane from isobutane cut. Application of Isomalk-3R technology expands the feed base for ethylene production due to isomerization of isobutane by-product to n-butane. N-butane is a valuable feed for pyrolysis units, providing high yields of ethylene, propylene, and n-butene used for polymer production. In turn, obtaining additional amounts of isobutane is possible due to application of n-butane to isobutane catalytic isomerization technology Isomalk-3. Isobutane cut produced in Isomalk-3 technology is notable for its high purity: the isobutane content may exceed 99 wt.%, it has no sulfur, nitrogen, chlorine, and oxygen impurities. Isobutane is in demand as the feed for production of alkylate, butyl rubber, oxygenates (MTBE and ETBE), isooctane. Isomalk-3 and Isomalk-3R processes do not require injection of chlorinating reagents, and the highly active catalytic system is resistant to poisons and impurities. Isomalk-3 and Isomalk-3R process designs are very similar, which allows integrating two units into one for alternate production of n-butane and isobutane.

PROCESSING OF WASTE COAL FINES WITHOUT ACCESS TO OXYGEN

The subject of research in this work is the processing of waste coal fines using a pyrolysis plant. The aim of the study is to obtain semi-coke and pyrolysis gas in the process of processing waste coal fines without oxygen. The process of thermochemical processing of coal fines is carried out by the principle of embedding a pyrolysis unit in a pyrolysis unit, or a second pyrolysis unit of a reduced size is installed inside the improved design of the pyrolysis unit using a specially withdrawn hole. To obtain the result of the study, the main pyrolysis unit, first, we will load the main pyrolysis unit with coal and then install the built-in (new) pyrolysis unit by preloading it with coal fines, and then we will make connections with the outlet pipe and fully load the main pyrolysis unit. We attach a distributor tee, a waste material container and a receiver for collecting pyrolysis gas to the outlet pipe. Experimental research is carried out on the coals of the Abshyr-ata and Kozho-kelen deposits, and for the reliability of the obtained research result, we will measure the main parameters of the studied coals until the final product is obtained. To obtain the result of the study, the main pyrolysis unit, first, we will load the main pyrolysis unit with coal and then install the built-in (new) pyrolysis unit by reloading it with coal fines, and then we will make connections with the outlet pipe and fully load the main pyrolysis unit. We attach a distributor tee, a waste material container and a receiver for collecting technical gas to the outlet pipe. Experimental research is carried out with coals of the Abshyr-ata and Kozho-kelen brands, and for the reliability of the obtained research result, we will measure the main parameters of the studied coal grades until the final product is obtained. With the help of this unit, the process of upgrading waste of coal fines and low-grade coals of Kyrgyzstan is carried out. The developed installation can be used in the heat and power industry of the Republic and research institutions.

Comparison of Pyrolysis Liquids from Continuous and Batch Biochar Production—Influence of Feedstock Evidenced by FTICR MS

Bio-oils from biomass pyrolysis can be a resource for upgrading to chemicals or fuels. Here, for the first time, we compare the composition of bio-oils produced from two feedstocks (wheat straw, softwood) in pyrolysis units of different mode of operation (continuous—rotary kiln vs. batch) using Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) in different ionization modes (APPI (+), ESI (+/−)). Our results demonstrate that the pyrolysis unit design had only a minor influence on the composition of bio-oils produced from low-mineral containing wood biomass. Yet, the wheat straw-derived bio-oil produced in the continuous unit comprised lower molecular weight compounds with fewer oxygen-containing functional groups and lower O/C and H/C ratios, compared to bio-oils from batch pyrolysis. Longer residence time of vapours in the heated zone in the rotary kiln and a higher mineral content in wheat straw resulted in increased catalytically-mediated secondary reactions that favoured further bio-oil decomposition. This work shows for the first time that it is possible to produce distinct bio-oils without the need for external catalyst addition, by matching reactor type/design and feedstock.

CLEARANCE OF SOLID HOUSEHOLD WASTE WITH THE RECEPTION OF ALTERNATIVE TYPES OF ENERGY CARRIERS

The research is devoted to improving the technology of obtaining alternative types of energy carriers by applying methods of pyrolysis of unclaimed types of solid domestic wastes of biological origin, which also allow solving the tasks of improving the ecological situation in the places of formation. The practical value and relevance of this research lies in the development of advanced technology for obtaining alternative fuels. The proposed pyrolysis unit allows producing gaseous and liquid hydrocarbons in a continuous cycle. In the atmosphere of the gasifying agent (air, oxygen, water vapor, carbon dioxide or their mixture), the gasification process is primarily performed in vortex reactors or fluidized bed furnaces at temperatures of 600-1100°C. Accordingly, the production (extraction) of AT from them requires pre-treatment, often quite serious: separation, grinding, mixing, drying, etc., which ultimately guarantees the consistency of its composition and quality.

Geospatial supply-demand modeling of lignocellulosic biomass for electricity and biofuels in the European Union

Bioenergy can contribute to achieving European Union (EU) climate targets while mitigating impacts from current agricultural land use. A GIS-based modeling framework (1000 m resolution) is employed to match biomass supply (forest and agricultural residues, complemented by lignocellulosic energy crops where needed) with biomass demand for either electricity or bio-oil production on sites currently used for coal power in the EU-28, Norway, and Switzerland. The framework matches supply and demand based on minimizing the field-to-gate costs and is used to provide geographically explicit information on (i) plant-gate supply cost; (ii) CO2 savings; and (iii) potential mitigation opportunities for soil erosion, flooding, and eutrophication resulting from the introduction of energy crops on cropland.Converting all suitable coal power plants to biomass and assuming that biomass is sourced within a transport distance of 300 km, would produce an estimated 150 TW h biomass-derived electricity, using 1365 PJ biomass, including biomass from energy crops grown on 6 Mha. Using all existing coal power sites for bio-oil production in 100-MW pyrolysis units could produce 820 PJ of bio-oil, using 1260 PJ biomass, including biomass from energy crops grown on 1.8 Mha. Using biomass to generate electricity would correspond to an emissions reduction of 135 MtCO2, while using biomass to produce bio-oil to substitute for crude oil would correspond to a reduction of 59 MtCO2. In addition, energy crops can have a positive effect on soil organic carbon in most of the analyzed countries. The mitigation opportunities investigated range from marginal to high depending on location.

Small-scale biochar production on Swedish farms: A model for estimating potential, variability, and environmental performance

Several small-scale pyrolysis plants have been installed on Swedish farms and uptake is increasing in the Nordic countries. Pyrolysis plants convert biomass to biochar for agricultural applications and syngas for heating applications. These projects are driven by ambitions of achieving carbon dioxide removal, reducing environmental impacts, and improving farm finances and resilience. Before policy support for on-farm pyrolysis projects is implemented, a comprehensive environmental evaluation of these systems is needed. Here, a model was developed to jointly: (i) simulate operation of on-farm energy systems equipped with pyrolysis units; (ii) estimate biochar production potential and its variability under different energy demand situations and designs; and (iii) calculate life cycle environmental impacts. The model was applied to a case study farm in Sweden. The farm’s heating system achieved net carbon dioxide removal through biochar carbon sequestration, but increased its impact in several other environmental categories, mainly due to increased biomass throughput. Proper dimensioning of heat-constrained systems is key to ensure optimal biochar production, as biochar production potential of the case farm was reduced under expected climate change in Sweden. To improve the environmental footprint of future biochar systems, it is crucial that expected co-benefits from biochar use in agriculture are realised. The model developed here is available for application to other cases.

How to trace back an unknown production temperature of biochar from chemical characterization methods in a feedstock independent way

Besides the feedstock composition, the highest treatment temperature (HTT) in pyrolysis is one of the key production parameters. The latter determines the feedstock’s carbonization extent, which influences physicochemical properties of the resulting biochar, and in consequence its performance in industrial and agricultural applications. The actual HTT of biomass is difficult to measure in a reliable manner in many large-scale pyrolysis units (e.g., rotary kilns). Therefore, producers and end-users often rely on unreliable or biased information regarding this key production parameter that affects biochar quality. Data from indirect chemical assessment methods of biochar’s carbonization extent correlate well with the highest treatment temperature. Therefore, this study demonstrates that the HTT can be accurately assessed posteriori and feedstock-independently via a simple-to-use model based on biochar characteristics related to the carbonization extent. For that purpose, 24 contrasting biochars from 12 different feedstocks produced in the most common production temperature range of 350−700 °C were analysed using 5 different established biochar chemical characterization methods. Then, experimental data was used to establish a multilinear regression model capable of correlating the HTT, which was successfully validated for external datasets. The correlation accuracy for biochars of various origin (lignocellulosic, manure) was satisfactorily high (R2adj. = 0.853, RSME =47 °C). The obtained correlation proved that the HTT can be predicted feedstock independently with the use of basic input data. It also provides a quick, simple, and reliable tool to verify the HTT of a given biochar.

Growth kinetic study of electrochemically active bacterium Shewanella putrefaciens MTCC 8104 on acidic effluent of jute stick pyrolysis

ABSTRACT Production of bioelectricity from waste streams using electrochemically active bacteria (EAB) has a great prospect. This article focuses on the assessment of the assimilation of acid-rich pyroliquid (APL), appearing from the waste stream of pyrolysis unit of jute stick, by one of EAB, Shewanella putrefaciens MTCC 8104. At the optimum temperature ( = 37°C) and pH ( = 4), the strain can assimilate up to 230 ppm of acetic acid per hour. Microscopic analysis indicates the presence of nanowires in the bacteria. Diauxic growth pattern is exhibited when both APL and whey are used as carbon sources. The minimum inhibitory concentration of acetic acid against S. putrefaciens has been determined to be 8000 ppm. Growth kinetics of the strain has been determined by using APL having acetic acid concentration between 100 and 7500 ppm, as carbon source. While the Monod model can explain the growth in the uninhibited zone, Wayman model has been proved to be the fittest by statistical analysis using the Akaike Information Criterion. The kinetic parameters μmax, Ks and Ki are 0.11 h−1, 13.17 and 75930.1 mg/L, respectively, with R 2 value of 0.977.

Catalytic conversion of pure glycerol over an un-modified H-ZSM-5 zeolite to bio-based aromatics

The catalytic conversion of pure glycerol to bio-aromatics (bio-BTX) over an un-modified H-ZSM-5 (SiO2/Al2O3 molar ratio of 23) via an ex-situ catalytic pyrolysis approach in a continuous tandem-micro reactor at a scale of 1 g glycerol h−1 was investigated. A BTX peak carbon yield of 28.1 ± 0.2 % was obtained at a pyrolysis temperature of 400 °C, catalytic upgrading temperature of 500 °C, atmospheric pressure and a WHSV of 1 h−1. About 70 % of the bound oxygen in glycerol was converted to water. The latter was mainly formed in the catalytic upgrading unit (70 %), though conversion of glycerol to other oxygenates with water formation was also observed in the pyrolysis unit. Catalyst deactivation occurs at a time scale of hours and is mainly due to coke deposition (12.0 wt.%) on the catalyst surface. An oxidative regeneration procedure to remove coke was applied and 5 cycles of reaction-regeneration were performed successfully, though a drop in activity was observed after each cycle due to irreversible catalyst deactivation. Characterization of the fresh, deactivated and regenerated catalysts by various techniques revealed dealumination of the H-ZSM-5 framework and resulted in a dramatic decrease in Brønsted acidity of the catalyst. Dealumination mainly occurred in the catalytic upgrading reactor and to a by far lesser extent during catalyst regeneration. This information is relevant for a better understanding of the process on a molecular level but also for scale-up studies, e.g. for the design of pilot plants.

Hydrogen Gas Production Simulation Utilizing Empty Fruit Bunch of Oil Palm Pyrolysis Unit by Steam Methane Reforming Process

We present a simulation of the hydrogen gas production by steam methane reformer unit utilizing empty fruit bunch (EFB) of the oil palm tree by using Aspen Plus. The oil palm empty fruit bunches, as biomass, is one that can be used as an alternative energy source to generate power. This paper aims to determine the amount of hydrogen gas (H2) can be obtained from five different EFBs samples, which are available as waste in the local area of Sumatera Utara Province. In the pyrolysis unit, the proximate and ultimate analysis of the EFB was introduced while developing the model in Aspen Plus simulation environment to get the syngas as a product from the pyrolysis process. The syngas out from the pyrolysis unit then going to a steam methane reformer unit to get hydrogen-rich gas. The results showed that, from five samples of EFBs, the H2 obtained in the range of 0.90 kg/hr to 1.70 kg/hr.

Sustainability assessment of activated carbon from residual biomass used for micropollutant removal at a full-scale wastewater treatment plant

Activated carbon (AC), used for removal of organic micropollutants in European wastewater treatment plants (WWTPs), is usually produced from non-renewable resources that need to be transported over long distances. Utilising local residual biomass as a raw material may be advantageous in terms of sustainability. This study investigated the environmental and energy balances of using biowaste and biomass from landscape management for micropollutant removal at a commercial scale WWTP. Both residual biomasses were processed using the integrated generation of solid fuel and biogas from biomass (IFBB) technique to obtain a press cake that was used as feedstock for AC production. The results showed a lower global warming potential (GWP) and cumulative energy demand in comparison to a fossil-based conventional AC Differences in GWP between residual and fossil ACs were enhanced when the end-of-life incineration step was considered, and residual AC had a lower social risk associated with its production. Energy efficiency of AC production was substantially increased by utilising waste heat generated in the pyrolysis process of biochar production and by using electricity generated in a combined heat and power plant using biogas from the methanation of IFBB press fluids. Converting residual biomass into activated carbon using IFBB and a state-of-the-art pyrolysis and activation unit along with energy recovery would improve WWTP sustainability and self-sufficiency in terms of the raw materials required.

Influence of biomass type on the composition of bio-oils from ablative fast pyrolysis

One of the easiest ways to minimize the overall costs of bio-oil production is to minimize biomass transportation and, thus, pyrolysis should be performed at or close to the biomass original location. Thus, we applied ablative fast pyrolysis (AFP), as the only potentially mobile pyrolysis unit, to convert residual lignocellulosic biomass into bio-oil. Four different biomass types were converted to bio-oils: beech and poplar wood, straw and miscanthus. To study reliably the influence of biomass type on bio-oil yields, physicochemical properties and composition, pyrolysis was carried out at a constant temperature of 550 °C. Titrations and spectroscopic methods were used for the characterization of the main oxygenate groups. GC–MS was used for the quantification of more than 120 volatile compounds. Such a thorough analytical study of AFP bio-oils, heretoforemissing in scientific literature, allowed us to reliably discuss the differences in bio-oils’ relative to the knowledge of biomass composition. Significant differences between the bio-oils were observed, with the lowest content of carboxylic and carbonyl groups in the straw bio-oil. The amount of carboxylic and phenolic groups in all the bio-oils was in the typical range observed for bio-oils unlike the carbonyls´ and levoglucosan content, which was lower than typical for bio-oils from other pyrolysis units.

Intensification of heat transfer by mixing in pyrolysis units during oil waste disposal

This article provides an overview of the most common mixing devices. Their advantages and disadvantages are presented, as well as a mathematical description of the heat transfer process. Revealed the most promising designs for mixing oil waste. The design of the developed mixing device is shown.

Deoxygenation of wheat straw fast pyrolysis vapors over Na-Al2O3 catalyst for production of bio-oil with low acidity

Catalytic upgrading of pyrolysis vapors from wheat straw over Na2CO3 impregnated γ-Al2O3 was studied as a promising route to biofuels. The Na species were homogenously distributed on the support and created a basicity of ~0.02 mmol CO2/g catalyst, at 80% lower catalyst acidity. Analytical pyrolysis using a micro-pyrolyzer showed that Na-Al2O3 particularly decreased the yield of acids via ketonization, which was confirmed by feeding carboxylic acid model compounds. The presence of Na decreased the coke yield and catalyzed the coke combustion, decreasing the combustion temperature by ~100 °C.Subsequently, 100 g Na-Al2O3 catalyst was tested in an ablative bench scale fast pyrolysis unit where ~5 kg of wheat straw was pyrolyzed and the vapors passed the catalytic reactor during six reaction/regeneration cycles. In agreement with the micro-pyrolyzer results, Na-Al2O3 was highly effective in reducing the acidity of the bio-oils. Total acid numbers (TAN) as low as ~1–4 mgKOH/g could be maintained up to high B:C ratios of ~13. For a given TAN, this allowed operating to higher B:C ratios and provided higher oil yields compared to using acidic catalysts such as γ-Al2O3 and HZSM-5 zeolite for vapor treatment. At bio-oil energy recoveries of ~60–70% relative to raw bio-oil, the deoxygenation was comparable to the acidic catalysts. Operation to higher B:C ratios allowed increasing the energy recovery to ~85% relative to the non-treated bio-oil while still obtaining a good deoxygenation performance of ~60%. Despite the hydrothermal conditions during reaction and oxidative regeneration, the activity of Na-Al2O3 was regained by coke combustion, the Na remained well dispersed on the support, and the catalyst maintained its capacity for CO2 adsorption at 500 °C after six reaction/regeneration cycles.

Meeting EU ELV targets: Pilot-scale pyrolysis automotive shredder residue investigation of PAHs, PCBs and environmental contaminants in the solid residue products

The EU’s publication of the 2017 End-of-Life Vehicle Recycling and Recovery results reported that the UK failed to meet its targets. The Commission’s data showed that the UK only achieved a rate of 94.1% falling short of the 95% target. The treatment of automotive shredder residue (ASR) using pyrolysis technologies offers a potential solution to this shortfall. The pyrolysis products could contribute to the target as well as supporting the circular economy package. However, there are questions about their hazardous nature and whether they qualify as secondary products. ASR, from a commercial plant, was processed through a pilot-scale pyrolysis unit, which separated the char into two fractions: coarse ≥0.1 mm and fine ≤0.1 mm. These were chosen as potential commercial products. Chars were produced from two processing temperatures of 800 and 1000 °C. These temperatures maximise gas production and produce the best “quality” char in terms of limiting organic contamination. It was found that the toxicity of the chars changed with both processing temperature and size fraction; with the maximum total PAHs concentration in the fine fraction at 800 °C. The coarse fractions were shown to be non-hazardous. It is suggested that some form of post-separation may be required to remove the hazardous component. The implication was that non-separated char could be classified as hazardous even if its overall characteristics were not, due to the role of dilution. If there were any questions about the status of the char this could prevent the use of ASR to meet the higher ELV target.

Waste timber pyrolysis in a medium-scale unit: Emission budgets and biochar quality

Pyrolysis of organic waste or woody materials yields a stable carbonaceous product that can be mixed into soil and is often termed “biochar”. During pyrolysis carbon-containing gases are emitted, mainly volatile organic carbon species, carbon monoxide and aerosols. In modern pyrolysis units, gases are after-combusted, which reduces emissions substantially. However, emission data for medium- to large-scale pyrolysis units are scant, both regarding gases, aerosols, heavy metals and polycyclic aromatic hydrocarbons (PAH).Making biochar from lightly contaminated waste timber (WT) is a promising waste handling option as it results in the potential valorization of such residues into e.g. sorbents for contaminant stabilization. For this process to be environmentally sustainable, emissions during the process need to be low and the resulting biochar of sufficient quality. To investigate both issues, we pyrolyzed three batches of WT and one reference batch of clean wood/leaves in a representative medium-scale pyrolysis unit (Pyreg-500, 750 t/year) with after-combustion of the pyrolysis gases, and measured the gas, aerosol, metal and PAH emissions, as well as the characteristics and contamination levels of the resulting biochar, including contaminant leaching.Mean emission factors for the WT were (g/kg biochar); CO = 7 ± 2, non-methane volatile organic compounds (NMVOC) = 0.86 ± 0.14, CH4 = 0, aerosols (PM10) = 0.6 ± 0.3, total products of incomplete combustion (PIC) = 9 ± 3, PAH-16 = (2.0 ± 0.2) · 10−5, As (most abundant metal) = (2.3 ± 1.9) · 10−3 and NOX = 0.65 ± 0.10. There were no significant differences in emission factors between the pyrolysis of WT and the reference respectively, except for PM10, NMVOC, and PAH-16, which were significantly lower for WT than for the clean wood/leaves. The WT biochar did not satisfy premium or basic European Biochar Certificate criteria due to high levels of zinc and PAH. However, leachable metal contents were <0.1% of total contents. Still, use of the WT-biochar without further improvement or investigation would be limited to ex situ use, not improving soil fertility or in situ remediation.

Recycling of product gas does not affect fast pyrolysis oil yield and composition

It has been reported that a deoxygenated bio-oil (ca. 0.12 kg kg−1 O on bio-oil basis) can be obtained simply by recycling the non-condensable gases (NCG) of biomass fast pyrolysis to a fluidized-bed reactor operated at atmospheric pressure [Mullen et al., 2013, Energy Fuels, 27, 3867–3874]. Such an unprecedented effect would (i) complicate the use of lab-scale research results obtained typically under inert gas (N2, He, Ar) atmosphere for the design of commercial scale pyrolysis units projected to utilize a recycle gas atmosphere (ii) obviate the need for catalytic pyrolysis or mild hydrotreatment processes. Considering these implications, further validation or refutation of the claimed deoxygenation effect of recycle gas atmosphere is needed.Therefore, fast pyrolysis experiments with pine wood were performed in a bench-scale fluidized bed reactor under N2 atmosphere, recycle gas atmospheres (75 % and 90 % recycle gas volume fraction) at reactor temperatures of 430 °C and 500 °C. Mass balances were obtained and the bio-oils were analyzed using GC/MS, GPC, elemental analysis and Karl Fischer titration. No significant differences were observed in product yield and bio-oil composition (e.g. oxygen content) when going from a nitrogen gas atmosphere to a recycle gas atmosphere for both pyrolysis temperatures.

Solution-Processed Amorphous Zinc Oxide Thin Film Transistor Based NAND Gate

Herein, we discuss the synthesis and deposition of thin films amorphous zinc oxide (a: ZnO) by custom-designed spray pyrolysis unit for Thin Film Transistor (TFT) application towards NAND gate fabrication. Top gate top contact TFT was fabricated on a glass substrate, a: ZnO as the channel layer, PVA as gate dielectrics material and Al as electrodes. Electrical properties of a: ZnO TFT (W/L = 500/200μm) were probed. The individual transistor with a threshold voltage (Vth = 2.1 V), off and on current (Ioff = order of 10-8A; Ion = 10-3) and Ion / Ioff ratio (order of 105). The linear mobility is calculated and obtained as 3 cm-2/Vs. NAND gate is one of the universal and basic building blocks of a digital circuit. The fabricated NAND gate is subjected to the logic operation in the range of 0 to 10 V was tested. The result implies that it can be utilized for logical circuit operation.