scholarly journals Production of clean synthetic gas from palm shell in a fixed bed gasifier with recycle system of producer gas

2018 ◽  
Vol 197 ◽  
pp. 09004 ◽  
Author(s):  
Sunu Herwi Pranolo ◽  
Muhammad Tasmiul Khoir ◽  
Muhammad Fahreza Pradhana

Tar as side product of biomass gasification could potentially degrade internal combustion engine performance if syngas is used for the fuel. Tar reduction may be achievable with recycling of outlet producer gas back into the gasifier. This research studied the effects of recycle system to tar content in syngas as product of palm shell gasification in a fixed bed gasifier. The effects of recycling system were examined using gasification of palm shell with primary air at 3.30 Nm3/h, mixture of primary air at 1.80 Nm3/h and secondary air at 1.50 Nm3/h, and mixture of primary air and recycled gas. Volumetric rate of recycle gas were varied at 0.90 and 1.20 Nm3/h respectively. Gasification performance evaluation was based on Specific Gasification Rate. Syngas quality was rated with tar content, CO, CH4, H2, CO2, and N2 composition. The highest Specific Gasification Rate of 111.71 kg/m2h and tar reduction up to 61.95% were achieved using recycle system at volumetric rate of 0.90 Nm3/h with temperature of operation is 750°C. The highest heating value of 6.34 MJ/Nm3 was attained using recycled gas volumetric rate at 1.20 Nm3/h.

2019 ◽  
Vol 14 (2) ◽  
pp. 120-129
Author(s):  
Sunu Herwi Pranolo ◽  
Joko Waluyo ◽  
Jenni Prasetiyo ◽  
Muhammad Ibrahim Hanif

Biomass gasification is potentially generating not only producer gas but also tarry components. Practically, the gas may substitute traditional fuel in an internal combustion engine after reducing the tar. This research examined a producer gas recycle system to reduce tar component of producer gas generated with cocoa pod husks gasification using air as gasifying agent in a fixed-bed downdraft gasifier. Cocoa pod husks feed sizes were +1” sieve, -1”+ 0.5” sieve, and -0.5” sieve. The gasification process was operated at the temperature range of 491 – 940oC and at various gasifying agent volumetric rates of 62.84; 125,68; and 188.53 NL/min or at equivalent ratio range of 0.014 – 0.042. A recycle system of outlet producer gas to gasifier was set at volumetric rates of 0.139; 0.196; and 0.240 L/min. The performance of the system was evaluated with analyzing the tar component using gravimetric method of ASTM D5068-13, and the gas component of CO, H2, CO2 and CH4 compositions in producer gas were analyzed using Gas Chromatography GC-2014 Shimadzu sensor TCD-14. This recycle system succeeded in reducing tar content as much as 97.19% at 0.139 L/min of recycle volumetric rate and at biomass feed size of -1”+0.5” sieve. The producer gas contained CO, H2, CO2 and CH4 of 23.29%, 2.66%, 13.30%, and 14.18% respectively. The recycle system cold gas efficiency was observed 65.24% at gasifying agent volumetric rate of 188.53 L/min and at biomass feed size of +1” sieve.


2018 ◽  
Vol 67 ◽  
pp. 02041 ◽  
Author(s):  
Hafif Dafiqurrohman ◽  
Adi Surjosatyo ◽  
Muhammad Barryl Anggriawan

Indonesia has a huge potential rice husk waste of 150 GJ/year, a third more than the overall potential of biomass in Indonesia of 470 GJ/year. Gasification of small-scale biomass fixed bed downdraft becomes one of the best solutions to become energy for power and heat generation. From studies that have been conducted abroad and from previous studies, the use of double stage air intake on the reactor proved effective in reducing tar because tar formed from the pyrolysis zone must pass through two zones below before then out with the gas producer. Implementation of secondary air intake at position Z = 38 cm right on the pyrolysis zone, obtained results at ER 0.25. With the same size, as much as 80.82% with tar content on the producer gas of 11.62 grams/Nm3. While at ER 0.23 figures found the highest gasification efficiencvby 33.41%.


2021 ◽  
Vol 13 (4) ◽  
pp. 2027
Author(s):  
Md. Emdadul Hoque ◽  
Fazlur Rashid ◽  
Muhammad Aziz

Synthetic gas generated from the gasification of biomass feedstocks is one of the clean and sustainable energy sources. In this work, a fixed-bed downdraft gasifier was used to perform the gasification on a lab-scale of rice husk, sawdust, and coconut shell. The aim of this work is to find and compare the synthetic gas generation characteristics and prospects of sawdust and coconut shell with rice husk. A temperature range of 650–900 °C was used to conduct gasification of these three biomass feedstocks. The feed rate of rice husk, sawdust, and coconut shell was 3–5 kg/h, while the airflow rate was 2–3 m3/h. Experimental results show that the highest generated quantity of methane (vol.%) in synthetic gas was achieved by using coconut shell than sawdust and rice husk. It also shows that hydrogen production was higher in the gasification of coconut shell than sawdust and rice husk. In addition, emission generations in coconut shell gasification are lower than rice husk although emissions of rice husk gasification are even lower than fossil fuel. Rice husk, sawdust, and coconut shell are cost-effective biomass sources in Bangladesh. Therefore, the outcomes of this paper can be used to provide clean and economic energy sources for the near future.


Fuel ◽  
2014 ◽  
Vol 120 ◽  
pp. 91-97 ◽  
Author(s):  
Rakhi N. Mehta ◽  
Mousumi Chakraborty ◽  
Parimal A. Parikh

Author(s):  
Jakub Lasocki

The World-wide harmonised Light-duty Test Cycle (WLTC) was developed internationally for the determination of pollutant emission and fuel consumption from combustion engines of light-duty vehicles. It replaced the New European Driving Cycle (NEDC) used in the European Union (EU) for type-approval testing purposes. This paper presents an extensive comparison of the WLTC and NEDC. The main specifications of both driving cycles are provided, and their advantages and limitations are analysed. The WLTC, compared to the NEDC, is more dynamic, covers a broader spectrum of engine working states and is more realistic in simulating typical real-world driving conditions. The expected impact of the WLTC on vehicle engine performance characteristics is discussed. It is further illustrated by a case study on two light-duty vehicles tested in the WLTC and NEDC. Findings from the investigation demonstrated that the driving cycle has a strong impact on the performance characteristics of the vehicle combustion engine. For the vehicles tested, the average engine speed, engine torque and fuel flow rate measured over the WLTC are higher than those measured over the NEDC. The opposite trend is observed in terms of fuel economy (expressed in l/100 km); the first vehicle achieved a 9% reduction, while the second – a 3% increase when switching from NEDC to WLTC. Several factors potentially contributing to this discrepancy have been pointed out. The implementation of the WLTC in the EU will force vehicle manufacturers to optimise engine control strategy according to the operating range of the new driving cycle.


2021 ◽  
pp. 146808742110464
Author(s):  
Yang Hua

Ether and ester fuels can work in the existing internal combustion (IC) engine with some important advantages. This work comprehensively reviews and summarizes the literatures on ether fuels represented by DME, DEE, DBE, DGM, and DMM, and ester fuels represented by DMC and biodiesel from three aspects of properties, production and engine application, so as to prove their feasibility and prospects as alternative fuels for compression ignition (CI) and spark ignition (SI) engines. These studies cover the effects of ether and ester fuels applied in the form of single fuel, mixed fuel, dual-fuel, and multi-fuel on engine performance, combustion and emission characteristics. The evaluation indexes mainly include torque, power, BTE, BSFC, ignition delay, heat release rate, pressure rise rate, combustion duration, exhaust gas temperature, CO, HC, NOx, PM, and smoke. The results show that ethers and esters have varying degrees of impact on engine performance, combustion and emissions. They can basically improve the thermal efficiency of the engine and reduce particulate emissions, but their effects on power, fuel consumption, combustion process, and CO, HC, and NOx emissions are uncertain, which is due to the coupling of operating conditions, fuel molecular structure, in-cylinder environment and application methods. By changing the injection strategy, adjusting the EGR rate, adopting a new combustion mode, adding improvers or synergizing multiple fuels, adverse effects can be avoided and the benefits of oxygenated fuel can be maximized. Finally, some challenges faced by alternative fuels and future research directions are analyzed.


Author(s):  
Federico Perini ◽  
Anand Krishnasamy ◽  
Youngchul Ra ◽  
Rolf D. Reitz

The need for more efficient and environmentally sustainable internal combustion engines is driving research towards the need to consider more realistic models for both fuel physics and chemistry. As far as compression ignition engines are concerned, phenomenological or lumped fuel models are unreliable to capture spray and combustion strategies outside of their validation domains — typically, high-pressure injection and high-temperature combustion. Furthermore, the development of variable-reactivity combustion strategies also creates the need to model comprehensively different hydrocarbon families even in single fuel surrogates. From the computational point of view, challenges to achieving practical simulation times arise from the dimensions of the reaction mechanism, that can be of hundreds species even if hydrocarbon families are lumped into representative compounds, and thus modeled with non-elementary, skeletal reaction pathways. In this case, it is also impossible to pursue further mechanism reductions to lower dimensions. CPU times for integrating chemical kinetics in internal combustion engine simulations ultimately scale with the number of cells in the grid, and with the cube number of species in the reaction mechanism. In the present work, two approaches to reduce the demands of engine simulations with detailed chemistry are presented. The first one addresses the demands due to the solution of the chemistry ODE system, and features the adoption of SpeedCHEM, a newly developed chemistry package that solves chemical kinetics using sparse analytical Jacobians. The second one aims to reduce the number of chemistry calculations by binning the CFD cells of the engine grid into a subset of clusters, where chemistry is solved and then mapped back to the original domain. In particular, a high-dimensional representation of the chemical state space is adopted for keeping track of the different fuel components, and a newly developed bounding-box-constrained k-means algorithm is used to subdivide the cells into reactively homogeneous clusters. The approaches have been tested on a number of simulations featuring multi-component diesel fuel surrogates, and different engine grids. The results show that significant CPU time reductions, of about one order of magnitude, can be achieved without loss of accuracy in both engine performance and emissions predictions, prompting for their applicability to more refined or full-sized engine grids.


2015 ◽  
Author(s):  
Luz M. Ahumada ◽  
Arnaldo Verdeza ◽  
Antonio J. Bula

This paper studied, through an experiment design, the significance of particle size, air speed and reactor arrangement for palm shell micro-gasification process in order to optimize the heating value of the syngas obtained. The range of variables was 8 to 13 mm for particle size, 0.8–1.4m/s for air velocity, and updraft or downdraft for the reactor type. It was found that the particle size and air velocity factors were the most significant in the optimization of the output variable, syngas heating value. A heating value of 2.69MJ / Nm3 was obtained using a fixed bed downdraft reactor, with a particle size of 13 mm and 1.4 m/s for air speed; verification of the optimum point of operation under these conditions verified that these operating conditions favor the production of a gas with a high energy value.


1981 ◽  
Vol 103 (3) ◽  
pp. 173-180 ◽  
Author(s):  
L. M. Sweet

This paper is a review of current research on applications of control systems and theory to achieve energy conservation in automotive vehicles. The development of internal combustion engine control systems that modulate fuel flow, air flow, ignition timing and duration, and exhaust gas recirculation is discussed. The relative advantages of physical and empirical models for engine performance are reviewed. Control strategies presented include optimized open-loop schedule type systems, closed-loop feedback systems, and adaptive controllers. The development of power train and hybrid vehicle control systems is presented, including controllers for both conventional transmissions and those employing flywheel energy storage.


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