Effect of Heterogeneous Catalyst on Esterification of Pyrolysis Oil

Abstract
The bio-oil from fast pyrolysis of biomass cannot be used effectively as engine fuel because of its high corrosiveness and instability mainly due to substantial amounts of organic acids and reactive aldehydes. In this paper treatment of acids in the bio-oil was focused and esterification with different catalyst to convert the acids. Synergistic interactions among reactants and products were determined. Acid-catalyst removed water and drove the esterification reaction formation equilibria toward ester products. Effect of Amberlyst-15 on different acids present in the bio-oil was carried out and characteristics properties of bio-oil shown after treatment were improved. Catalyst characterization was carried and observed that carbon deposition on the surface of catalyst reduces the activity of the Amberlyst-15. The catalysts with high surface area, large pore size distribution, and strong acid sites may be beneficial for the esterification reaction.

https://link.springer.com/chapter/10.1007/978-3-319-63085-4_30

Utilization of Waste Biomass into Useful Forms of Energy

Abstract

The rising cost of fossil fuel and environmental concern has motivated the scientific committee to research on alternative sustainable solution for energy and economic development. One of such sustainable energy resource is biomass, which is abundant, clean and carbon neutral. Agricultural residue which is abundant and causing problems of storage being wasted without using in any form energy source. The present study highlights utilization of residue biomass to useful form of energy using different thermochemical conversion technologies. This study is presented as a technical review cum analysis study which has been done on various common agricultural wastes for their Thermochemical conversion technologies which includes combustion, gasification, pyrolysis, torrefaction and liquefaction. The common agricultural wastes that are being taken for study are coconut shell, rice husk, corn cobs, cotton stalk, groundnut shell, cotton, sugarcane (bagasse). In Combustion process, the yield of gaseous product is around 50%, which can be utilized for combined heat and power production. In the combustion process, drawbacks are discussed and specified. It was observed that suitable combustor can be implemented for improving its oxidative characteristics so that the product gas yield can be increased for high quality steam production. In Gasification process, the biomass is partially oxidized to give a raw product gas or syngas which can be used in IC engines and for running gas turbines to produce electricity. It was observed that product gas or syngas obtained is around 85–90% pure compared to the gases obtained from coal gasification. Suggestions are made to improve the yield of syngas by suitable designs for specially downdraft gasifiers. Finally, Pyrolysis process of biomass is discussed, and focuses on improving the yield of liquid content by varying the operating conditions. Bio-oil production from pyrolysis can be varied from 65 to 75% by varying operating temperatures (500–650 °C) and heating rate. Finally, in this study we suggest the design of pyrolyser with different operating conditions for maximum yield of liquid, an attempt was made to increase the liquid product and reduce the char/gas content.

https://link.springer.com/chapter/10.1007/978-3-319-47257-7_12

A comparative assessment of single cylinder diesel engine characteristics with plasto-oils derived from municipal mixed plastic waste

Abstract
Recycling of municipal mixed plastic waste (MPW) is an emerging technology for conversion of waste to wealth. In the current study, MPW was processed to produce plasto-oils (PO1 and PO2) by thermochemical depoly- merization in a batch production of 0.5 ton/batch. These oils were used in a 3.7kW rated power single cylinder direct injection compression ignition (CI) engine to assess performance, combustion and emission behavior of the engine. The experimental results with plasto-oils were compared with base diesel fuel operation at different brake mean effective pressures (BMEPs) of 1.8, 3.8, 5.8, 7.8 and 10.8 bar. It is explored that brake thermal efficiency of the test engine with plasto-oils was almost comparable with the diesel fuel at all engine loads. Carbon based emissions such as unburnt hydrocarbon (HC), carbon monoxide (CO), and smoke emissions from the engine at 3.8–10.8 bar BMEPs were slightly higher with plasto-oils than diesel fuel. Nitrogen oxides emission decreased faintly with the use of plasto-oils at medium and high BMEPs (5.8–10.8 bar). However, at lower BMEPs (1.8–3.8 bar), emission behavior of the engine (HC, CO, smoke and NOx emissions) was same with all kinds of fuels (diesel, PO1 and PO2). Overall, it is ascertained from the study that the plasto-oils exhibited a comparable performance with the conventional diesel fuel, which further promises its viability to use as a fuel candidate for CI engines.

https://doi.org/10.1016/j.enconman.2018.04.068

Stabilization of Fast Pyrolysis Oil Derived from Wood through Esterification

Abstract:
In the present work, crude bio-oil obtained from vacuum pyrolysis of babul wood was stabilized by esterification with 1-butanol using the cation exchange resin, Amberlyst-15, as a solid acid catalyst.Ester formation reduces the pH, thereby increasing the shelf-life of the bio-oil. Since esterification is a reversible reaction, simultaneous separation of water during the course of the reaction helps to obtain high conversion. Azeotropic removal of water by reactive distillation was found to be effective in this work. Apart from reducing pH and improving shelf-life, this process also enabled water removal from crude bio-oil, and viscosity was reduced when the bio-oil was blended with alcohol. Amberlyst-15 was found to get deactivated after repeated use. Characterization of fresh and used catalyst by Brunauer–Emmett–Teller (BET) surface area measurement and thermal analysis showed that the deposition of carbonaceous material on the catalyst is responsible for its deactivation. The condensation and oligomerization reactions of unstable compounds (e.g. furfural and its derivatives) are suspected to be the main reasons underlying catalyst deactivation.

https://www.degruyter.com/view/j/ijcre.2015.13.issue-3/ijcre-2014-0102/ijcre-2014-0102.xml

10.1515/ijcre-2014-0102

Kinetic Modeling of Indian Rice Husk Pyrolysis

Abstract:
To efficiently utilize agricultural biomass waste, kinetic modeling of the pyrolysis of rice husk, including both physical (mainly heat transfer) and chemical (reactions) terms,was conducted at different heating rates from (10 to 20 Kmin−1) to develop a transport model. For chemical kinetics, the parameters were estimated using different kinetic models, namely the single- or parallel-reaction kinetic model with higher orders and the two-step consecutive reaction model. The two-step model could adequately explain the pyrolysis reaction of multiple reactions with different reaction orders i. e., first step is of the first order (m = 1) with respect to the mass of biomass, and the second step is of the second order (n = 2) with respect to the mass of the intermediate to char. The intrinsic kinetics at different heating rates in the absence of oxygen was derived through thermogravimetric analysis. The kinetics of the evolution of non-condensable gases was studied in a self-designed reactor, and an appropriate kinetic model of rice husk biomass pyrolysis that showed excellent agreement with experimental data was established.

10.1515/ijcre-2017-0048

http://www.degruyter.com/view/j/ijcre.2018.16.issue-2/ijcre-2017-0048/ijcre-2017-0048.xml

Managing and Identifying the Risks Related to Biochemical Conversion of Waste-to-Energy

The ever-increasing release of greenhouse gas emissions leading to global warming has ignited development of a number of newer technologies for reducing the effect of energy production. One of the technologies emerging for utilization of wastes to generate energy, i.e., produces syngas by gasification to generation heat and power. Energy industries have safety issues relating to steam pressure, combustion, turbines, generators, heat and power distribution are well defined as per standards. The ascent in the quantity of biofuel process plants has brought about various occasions bringing about death toll and property. We have deduced that roughly six to seven fire blast occurrences are accounted for consistently from biodiesel and ethanol enterprises in the India and other countries. The procedure business is very much aware of the money-related dangers and natural risks related with creation and utilizing biofuel as an eco-accommodating option fuel. Be that as it may, restricted data is accessible on the procedure dangers because of the dangers required in the creation of the biofuels. New advancements particularly for refinement, negligible operational involvement with untalented/semi-talented administrators, building and operation of biofuel process plants in hypothetically wrong areas (close to defenseless populaces), require a need to distinguish the procedure perils which bring down the dangers. Overall population organization administrators are not completely mindful of the dangers related with the creation of biofuel. This paper will include the vital perils and necessity of over- seeing procedure hazards in the biofuel business. The discoveries are from hazard examining thinks about led for various sorts of biofuel tasks and biofuel prepare plants.

https://www.springer.com/in/book/9789811071218

http://link.springer.com/10.1007/978-981-10-7122-5

Kinetic parameter evaluation of groundnut shell pyrolysis through use of thermogravimetric analysis

ABSTRAC T

With growing interest in environmentally-friendly sources of energy, biofuel and pyrolysis are increasingly seen as potential solutions. In this study, the pyrolysis of groundnut shell is being investigated, with the intention of determining key kinetic parameters to provide a deeper understanding of the chemical process. A small sample of groundnut shell was pyrolyzed at different heating rates of 10, 20 and 30 K min−1. The thermogravimetric data was used to compare various kinetic models: including a single reaction, consecutive reaction, and dis- tributed activation energy model. The results showed that the consecutive reaction model best described the process when both reactions were set to the second order.

https://doi.org/10.1016/j.jece.2018.07.012

Characterization and Pyrolysis of various Biomass residues

Introduction

Sustainable heat and power generation from biomass are at the center of scientific and industrial interest owing to the increasing awareness of limiting the availability of fossil fuels [1]. Biomass is environmental friendly as well as abundant in nature. 

Combustion of a biomass particle is quite complex as it undergoes various physical and chemical processes including drying, devolatilization/pyrolysis and char burnout [2]. Thus, pyrolysis process is one of unavoidable step during the biomass utilization for heat and power generation and need to investigate carefully at combustion conditions [3].

In the present work, pyrolysis of different biomass is carried out in non-isothermal conditions. Biomass as fuel is currently under research because it has certain major drawbacks. The large varieties of heterogeneous biomass feedstock are available in nature whose properties are required to characterize. The de-polymerization of biomass feedstock results in varieties of different chemical depending upon its composition, can corrode equipment, introducing further reactor design and configuration issues. Nevertheless, depleting fossil fuels are expected to wider use of biomass and the implementation of new technologies and processes.

Characterization of biomass

Physical characterization

Biomass is low in carbon (roughly between 30 wt% to 40 wt% on dry, ash-free basis) and high in volatile matter and oxygen, which result in low calorific values. But significant advantage of biomass with respect to coal is that the contents of nitrogen and especially sulfur are low. Proximate and ultimate analyses of biomass are carried using TGA and CHNOS analyzer respectively. Table 1 proximate analysis and Table 2 shows ultimate analysis.

Table 1. Proximate analysis of different biomass

Biomass	Proximate analysis (dry basis, wt %)
	Volatile matter	Fixed carbon	Ash
Corn cob	71.41	25.75	2.84
Cotton stalk	66.16	27.15	6.68
Ground nut shell	64.63	29.45	5.91
Rice husk	61.23	14.96	17.08

Table 2. Ultimate analysis of different biomass

Biomass	Ultimate analysis (wt %)
	Carbon	Hydrogen	Nitrogen	Oxygen
Corn cob	43.8	6.41	0.64	49.13
Cotton stalk	44.19	6.3	0.74	48.74
Ground nut shell	42.02	5.8	1.88	50.28
Rice husk	34.87	5.3	0.8	59.01

*Oxygen is calculated by difference.

From the Table 2 we can correlate between hydrogen/oxygen (H/O) and carbon/oxygen (C/O) ratios which is used to predict the energy content. The materials with a relatively low O/C ratio have more energy density and higher HHV.

Chemical characterization of biomass is carried out using Fourier transform infrared spectroscopy (FTIR), to know the presence of functional groups in the biomass. Figure 1 shows that different kinds of functional groups that are present in the biomass. 

Figure 1. Characterization of Biomass using FT-IR.

Wave number (cm-1) 3392 represents the O–H stretch and H–bonded, presence of this functional group has much higher concentration in cotton stalk when compare to other biomass, 2922 represents H–C=O: and C–H stretch in the cotton stalk and rice husk has same concentration, 1639 represents –C=C– stretch in cotton stalk and groundnut shell has same concentration, 1051 represents C–N stretch and =C–H bend in the cotton stalk and rice husk has same concentration, 609 represents –C(triple bond)C–H: C–H bend in the cotton stalk and rice husk has same concentration.

The determination of chemical composition biomass is used to predict the release of compounds during the pyrolysis. In species evolution of pyrolysis, end products are predicted using FTIR technique applied to char at different temperatures.

Experimental set-up and procedure

The thermal decomposition behavior of wood was studied in a thermo-gravimetric analyzer (TGA, Perkin-Elmer Diamond) with horizontal TG/DTA holder having a least count of 0.1 µg. To achieve pyrolysis condition, nitrogen gas was used as oxygen free environment. The constant volume flow of nitrogen was set to 200 mL/min.

Experimental procedure is described below:

Pyrolysis was carried out at non-isothermal conditions. TGA data was taken at different heating rates as 10 20, 30, and 40 K/min in the temperature range of 383–1123 K at the end of the heating process, isothermal mode was set for 10 min to ensure that the process is completed. Typical thermo-gravimetric behavior of biomass decomposition is shown in Figure 2. From the figure 2, it is observed that, the thermal decomposition starts at approximately 500 K, following a major loss of weight at 630 K. 

Figure 2 TGA profiles of different biomass at 20 K/min.

Figure 2 shows the pyrolysis profiles of different biomass with temperature. It is observed from figure that pyrolysis rates for different biomass is different, this can be explained using the mineral content in ash of biomass and specifically potassium in form oxide acts as catalyst for biomass pyrolysis. The K2O of corncob, cotton stalk, groundnut shell and rice husk is 44.81%, 15.84%, 10.70% and 1.75% respectively. These results are in-line with Raveendran et al. (1995) [4].

Figure 3. Pyrolysis profiles of different biomass. 

Profiles in Figure 3 indicate that the pyrolysis of biomass depends on the heating rate. As heating rate increases pyrolysis rate decreases, due thermal conductivity of the biomass particle.

Conclusions 

Thermo-gravimetric studies show that each kind of biomass has unique pyrolysis characteristics, by virtue of the specific proportions of the components present in it. The influence of ash, specifically K2O on pyrolysis rate has studied. 

References 

[1] C. Di Blasi, “Modeling chemical and physical processes of wood and biomass pyrolysis,” Prog. energy Combust. Sci., vol. 34, pp. 47–90, 2008. 

[2] Y. Haseli, J. A. Van Oijen, and L. P. H. De Goey, “Modeling biomass particle pyrolysis with temperature-dependent heat of reactions,” J. Anal. Appl. Pyrolysis, vol. 90, no. 2, pp. 140–154, 2011. 

[3] X. Zhang, M. Xu, R. Sun, and L. Sun, “Study on Biomass Pyrolysis Kinetics,” J. Eng. Gas Turbines Power, vol. 128, no. 3, p. 493, 2006. 

[4] K. Raveendran, A. Ganesh, and K. C. Khilar, “Influence of mineral matter pyrolysis characteristics on biomass,” fuel, vol. 74, no. 12, pp. 1812–1822, 1995.

Stabilization of pyrolysis oil derived from wood through Reactive Chromatography

Charaterisation of wood Pyrolysis oil

This part describes an analytical approach to determine the physico-chemical composition of bio-oil.

With declining petroleum resource and more concerns on environment and climate, the development for renewable energy is getting more necessary. Substantial research is being carried out within the field of energy in order to find alternative fuels to replace fossil fuels. The optimal solution would be renewable energy resource which is equivalent to the fuel which is sustainable and will decrease the CO₂ emission.

Biomass derived fuels could be the prospective fuels of tomorrow as these can be produced within a relatively short cycle and are considered benign for the environment. Biomass derived fuel is pyrolysis oil which is renewable liquid fuel which can be directly used for burning in boilers, readily stored, transported, retrofitting, and flexibility in production and marketing of chemicals.

It is important to characterize the bio-oil as every bio-oil has different composition, depending on its source and pyrolysis conditions. We have used various characterization techniques to characterize the bio-oil. Physical characterization was done by the measurement of viscosity, density, higher heating value, moisture content and pH. GC-MS was used to identify the different chemical composition. Fourier Transform Infra-Red Spectroscopy was used to identify the functional groups. 

Bio-oil obtained from vacuum pyrolysis of wood at 773 K at heating rate of 30 K/min is usually dark brown free-flowing liquid having a distinctive smoky odor. The physical properties of the bio-oil are resultant of chemical composition of the liquid which is significantly different from petroleum-derived oil. Bio-oil is a complex mixture of more than 300 compounds resulting from the depolymerization of biomass building blocks cellulose, hemi-cellulose and lignin. Bio-oil is differ from petroleum based fuels both is physical and chemical composition. Bio-oil is highly polar containing about 40-50 wt% oxygen resulting in low calorific value. This liquid is acidic in nature and unstable when heated, especially in air tends to polymerize i.e increases viscosity. Bio-oil typically contains high moisture and micron size char particles which insoluble with petroleum based fuels.

The chemical composition of bio-oils is very complex, mainly composed of water, organics and a small amount of ash. It is globally represented as: around 20 % water, around 40 % GC-detectable compounds, around 15 % non-volatile HPLC detectable compounds and around 15 % high molar mass non-detectable compounds. A complete analysis of bio-oils requires the combined use of more than one analytical technique. A precise description of bio-oil composition has not yet been achieved. The accuracy of some of these analytical techniques has been highlighted in Round Robin tests conducted by different laboratories.

Table 1. Describes the physical properties of crude bio-oil obtained from waste wood.

Physical Properties	Values
Moisture content (wt %)	26.36
pH	2.80
Density (kg m-3)	1.08
Ash (wt %)	0.03
HHV (MJ kg-1)	22.20
Viscosity (cP) at T=313K	73.62
Elemental composition (wt %)
Carbon	50.92
Hydrogen	8.27
Oxygen (by difference)	38.57
Nitrogen	2.23

The chemical characterization of crude bio-oil includes GC/MS procedure followed to obtained bio-oil fractions using column chromatography eluted using different polarities of solvents.

n-Hexane Fractionation

Phenol, 4-methyl

2-Pyridinemethanol

Phenol, 2,4-dimethyl

Phenol,2-methoxy-4-methyl

Phenol- 4-ethyl-2-methoxy-

Phenol, 2,6-dimethoxy

1,2,4-trimethoxybenzene

Phenol, 2-methoxy-4-(1-propenyl)-

5-tert-butylpyrogallol or 5-tert-Butyl-1,2,3-trihydroxybenzene

Phenol,2,6-dimthoxy-4-(2-propenyl)-

DCM Fractionation compounds

2-cyclopenten-1-one, 2-hydroxy-3-methyl

phenol, 2-methoxy-

phenol, 2-methoxy-4-methyl-

phenol, 4-ethyl-2-methoxy

phenol, 2,6-dimethoxy-

1,2,4-trimethoxybenzene

5-tert-butylpyrogallol or 5-tert-Butyl-1,2,3-trihydroxybenzene

phenol,2,6-dimethoxy-4-(2-propenyl)-

Desaspidinol or 1-(2,6-Dihydroxy-4-methoxyphenyl)-1-butanone

1,3-Benzodioxol-5-yl-1-oxo-2,4-pentadienyl-piperidine

Benzene Fractionation

2-cyclopenten-1-one, 2-hydroxy-3-methyl

Phenol, 4-methyl

Phenol, 2-methoxy-

Phenol, 2-methoxy-4-methyl

Phenol, 4-ethyl-2-methoxy-

Phenol, 2,6-dimethoxy

1,2,4-trimethoxybenzene

5-tert-butylpyrogallol or 5-tert-Butyl-1,2,3-trihydroxybenzene

Phenol,2,6-dimthoxy-4-(2-propenyl)-

1,3-Benzodioxol-5-yl-1-oxo-2,4-pentadienyl-piperidine

Ethyl Acetate Fractionation

Phenol, 2-methoxy-4-methyl

1,2-Benzenediol, 3-methoxy-

Phenol, 4-ethyl-2-methoxy-

Phenol, 2,6-dimethoxy

Dehydroacetic acid

5-tert-Butylpyrogallol

Phenol, 2,6-dimethoxy-4-(2-propenyl)-

Ethanone, 1-(4-hydroxy-3,5-dimethoxyphenyl)-

Desaspidinol or 1-(2,6-Dihydroxy-4-methoxyphenyl)-1-butanone

Methanol Fractionation

Benzoic acid

1,2-Benzenediol

Phenol 2,6-dimethoxy

2-propenooic acid, 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl ester,exo

1,2,3-Trimethoxybenzene

1,6-anhydro-beta-d-glucopyranose

5-tert-Butylpyrogallol

Phenol 2,6-dimethoxy-4-(2-propenyl)-

Ethanone 1-(4-hydroxy-3,5-dimethoxyphenyl)-

Desapodinol

4H-1-Benzopyran-4-one,2-(3,4-dimethoxyphenyl)-7-hydroxy-3-methoxy-

Benzaldehye, 4-hydroxy-3,5-dimethoxy-

10,11-dihydro-10-hydroxy-2,3,6-trimethoxydibenz(b,f)oxepin

Benzene,1,1',1'',1'''-(1,6-hexanediylidene)tetrakis- (9CI)

Determination of functional groups of pyrolysis oil

The pyrolysis oil of wood obtained was analysed for its functional group composition using Fourier Transform Infra-Red Spectroscopy (FTIR). The system used was a Bunker`s Tensor 27 series with an on-line pen plotter to produce the IR-spectra of the derived liquid. It provides the absorbance spectra units along the wave number 4000 to 500 cm^-1. 

Figure 1 below shows the absorbance unit vs. IR frequency of crude bio-oil.

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