Fıxed bed slow pyrolysıs of bıomass solıd waste for bıo-char

The waste to renewable energy source has become a priority in the wastes treatment field. The research goal is not only the wastes destruction but also a better thermal energy recovery from the processes. The municipal solid waste presents a high heterogeneity degree from the dimensional point of view, form and its components specific weight of as well as thermal-chemical characteristics. That’s why there are many treatment methods, each one with its own particularities. For a better understanding of the phenomenon during thermal degradation processes both under pyrolysis or atmospheric pressure gasification stages we first accomplished a laboratory scale series of experiments in a tubular reactor, on small quantities (5 – 10 grams) of reconstituted urban wastes. For the validation of the obtained data on more representative samples we extended the experiment to an original industrial scale pilot installation that enables the continuous thermal treatment of 10 – 50 waste kilograms per hour under oxidant or non-oxidant atmosphere (on choice) and at variable temperature between 400 °C – 1100 ºC. The residential time of the treated sample in the installation and the flow conditions can be set independently. The installation reproduces the incinerators or the pyrolysis / gasification reactor process conditions and provides complete information on the wastes thermal degradation kinetics and on the pollutant emissions. The particularity of the device consists in the product advancing piston – like flow system based on the bed vibration. The product particles in the bed have a translation movement without any layer shift. Therefore the particles distribution in a given product bed section is the same all along the installation from the feeding inlet to the extraction. That characteristic enables us to extrapolate and compare the laboratory results of the fixed bed treatment to the industrial pilot continuously treatment applied on the same product: reconstituted municipal solid waste, one of the most heterogynous solid wastes in mixture. The main targets were the sample mass reduction rate, the resulting gases composition, the samples mechanical behavior for different temperature levels, residential time, treatment atmosphere conditions and different steam flow rates (in the gasification process). The results were compared to an established reference – the incineration. The paper presents the research and results on the degradation mechanisms of MSW treated samples in those two equipments from the Science Division CNRS, Department of Industrial Methods, University of Technology Compiègne, France.

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IMPROVE THE PYROLYTIC GAS PRODUCTION BY USING THE CO-PYROLYSIS TECHNIQUE : AN EXPERIMENTAL STUDY

PLANT ARCHIVES ◽

10.51470/plantarchives.2021.v21.no2.032 ◽

2021 ◽

Vol 21 (2) ◽

Author(s):

Abo . Zahra A.I ◽

M.K. Abd El- Wahab ◽

M.A. Tawfik

Keyword(s):

Energy Conversion ◽

Fluidized Bed ◽

Conversion Efficiency ◽

Fixed Bed ◽

Energy Conversion Efficiency ◽

Gas Production ◽

Operating Conditions ◽

Energy Unit ◽

Heating Value ◽

Slow Pyrolysis

The target of the biomass co-pyrolysis is improvingthe heating value of the produced bio-products of a certain type of feedstock, besides disposal of more than one residue in the same time. Thus, this work aims to operate a local fabricated fixed-bed pyrolyzer to improve the pyrolytic gas yield produced by the ground pieces of three biomass residues namely Mango trees Pruning Logs (MPL), Sugarcane bagasse (SB) and Rice straw (RS) using an affordable slow pyrolysis technique. This work was carried out under slow pyrolysis conditions represented in final pyrolysis temperature of 400 °C, vapor residence time of 4 min, heating rate of 0.01-1 °C/s in full absence of oxygen. The pyrolytic gas production was assessed under different feedstock mixing ratios of (1:2:1), (1:1:2) and (2:1:1) as ratio of (RS: SB: MPL), particle lengths of 1-5, 10-15 and 20-25 mm, with and without sandy bed at the bottom of pyrolysis chamber as a fluidized bed. The obtained results showed that, using the fluidized fixed-bed pyrolyzer under slow co-pyrolysis conditions gave the optimum results where in, the pyrolytic gas concentration, gas yield, higher heating value of pyrolytic gasand energy conversion efficiency were 55%, 1.09 Nm3 /kg, 14.97 MJ/Nm3 and 85.43%, respectively, and 53.7%, 1.08 Nm3 /kg, 13.75 MJ/Nm3 ,77.71% in case of using the pyrolyzer without fluidized bed under the same operating conditions. So, the pyrolyzer with fluidized bed achieves an increment in the higher heating value and energy conversion efficiency by about 8.15% and 9.03%, respectivly over the pyrolyzer without fluidized bed.Furthermore, the cost per energy unit of pyrolytic gas produced by the fluidized bed pyrolyzer is lower than the common two fossil gaseous fuels of natural gas and LPG costs by about 28.57% and 80%, respectively.

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Modeling and simulation of a fixed bed gasification process for thermal treatment of municipal solid waste and agricultural residues

Energy Reports ◽

10.1016/j.egyr.2021.07.124 ◽

2021 ◽

Vol 7 ◽

pp. 256-269

Author(s):

Matheus Oliveira ◽

Ana Ramos ◽

Eliseu Monteiro ◽

Abel Rouboa

Keyword(s):

Thermal Treatment ◽

Municipal Solid Waste ◽

Modeling And Simulation ◽

Solid Waste ◽

Fixed Bed ◽

Agricultural Residues ◽

Gasification Process

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Substrates for slow pyrolysis

MATEC Web of Conferences ◽

10.1051/matecconf/201816808004 ◽

2018 ◽

Vol 168 ◽

pp. 08004

Author(s):

Václav Peer ◽

Jaroslav Frantík ◽

Jan Kielar ◽

Drahomír Mašek

Keyword(s):

Sewage Sludge ◽

Chemical Industry ◽

Raw Materials ◽

Ash Content ◽

Wood Chips ◽

Simple Construction ◽

New Materials ◽

Solid Materials ◽

Slow Pyrolysis ◽

Pyrolysis Of Biomass

Slow pyrolysis of solid materials can produce new materials usable for energy or chemical industry. The advantage of pyrolysis devices is the simple construction and process control and the ability to utilize materials with different properties (composition, ash content). Produced gaseous, liquid and solid materials could be used as a sources of energy, raw materials in chemical industry or substances for improving of soil properties. At article are described products of slow pyrolysis of biomass (wood chips), agrifuels (hay, wheat straw) and sewage sludge.

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Effect of Steam on the Homogeneous Conversion of Tar Contained from the Co-Pyrolysis of Biomass and Plastics

10.21203/rs.3.rs-454069/v1 ◽

2021 ◽

Author(s):

Feng Tang ◽

Yuqi Jin ◽

Yong Chi ◽

Zhongxu Zhu ◽

Jie Cai ◽

...

Keyword(s):

Fixed Bed ◽

Apparent Effect ◽

Subsequent Reaction ◽

Furnace Temperature ◽

Atom Ratio ◽

Pyrolysis Tar ◽

Tar Cracking ◽

Two Stages ◽

Hydrogen Radicals ◽

Pyrolysis Of Biomass

Abstract The co-pyrolysis tar formed from microcrystalline cellulose (MCC) and polyethylene (PE) was used to study their further conversion path under the effect of steam. This paper addressed the yield and transformation of tar with different steam/feedstock mass ratios (S/F= 0.8, 1.6) in a two-stage fixed-bed when the two stages furnace temperature was set at 600℃ and 800℃, separately. Compared with pyrolysis, steam promoted tar cracking effectively, the tar yield decreased at least 1/3. However, with the addition of steam, the cracking effect of tar is not further improved. The tar yield depended more on the PE content in the mixture, which was enhanced with PE increment. Besides, the H/C atom ratio was related to the conversion path of tar. Steam was beneficial to the cracking of compounds, but the generated hydrogen radicals affected the direction of the subsequent reaction. The steam mainly promotes the cracking of long-chain hydrocarbons, accompanied by cyclization and aromatization when the steam was limited. Nevertheless, these reactions were hindered when the steam was excessive due to the apparent effect of hydrogenation. In this process, the short-chain hydrocarbons come to recombine instead of cyclization and aromatization.

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