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.

GHOKE PRAVEEN..

Happy Independence Day.

Today people from around the world celebrating the 68th Indian Independence Day. This is from side...

Carried with care, coated with pride,

Dipped in love, fly in glory,

Moments of freedom in shade of joy.

Proud to be an Indian, Happy Independence.

Biomass charaterisation

Biomass is very much different from biomass produce from different places. Charaterisation of biomass very important to get best possible processing strategy for production of range of fuels, also to understand how easy is it to produce, collect, store, transport, and process (crop yield, economics, equipment availability, grinding performance, etc.). 

To charaterise the biomass, we need study the combustion properties of biomass which includes that all properties of biomass.

Combustion properties of biomass:

Biomass to Bio-fuels

Biomass is abundantly available bio-fuel which is considered as carbon neutral i.e,. carbon absorbed from the atmosphere by biomass(plants) and release to the atmosphere when they burned. Hence there is no net addition of carbon added to the atmosphere. 

What is Biomass?

There are different meaning of biomass; Biologically, Biomass can be defined as Carbon based mixture of organic molecules also contains hydrogen and oxygen. Element Nitrogen based on the type of biomass and small quantities of metals and alkali, alkaline earth atoms.

Biomass is wood products, dried vegetation, crop residue, aquatic plants and even garbage. These are all natural materials; uses sun's energy to make food and store in form of chemical energy. This trapped energy is released when we process through specific conversion method. The released energy is called as BioEnergy..

Biomass is renewable source of fuel to produce BioEnergy.

Biomass Conversion process:

The defense of your thesis

Here is how the concluding part of your research effort should be handled. 

SUCCESSFUL COMPLETION: In the final analysis, your thesis should be complete in all essential respects.  

 "The best thesis is a done thesis!"

 

The all-important stage is the one where you make your `defense' of the thesis. This is no war where a group of experts are ranged against the solitary researcher. Never take it as a defense, but just a presentation of your ideas over which you have given your deepest thought during the past few years. You are sure of all the diverse aspects of the topic, perhaps far better than the members of the jury before you. Your objective is to convince your audience that you have done your job well, your methodology is sound and the findings are useful. In experimental topics, all your important findings should be based on repeated experiments which should be repeatable by anyone else.

Art of writing a thesis

On the approach that is required in writing a research thesis. 

GET IT RIGHT: Get a grounding of the writing basics before you start putting together your thesis.  

Write to be understood, speak to be heard, read to grow. Lawrence Clark Powell, American Writer

WHILE ENJOYING highly readable text, we are not aware of the pains the writer underwent in preparing it. The right choice of words is not an easy task. The richer one's vocabulary, the tougher the task is. None would appreciate you, if you delude yourself into believing that long words or complex construction would impress the readers. Never attempt grandiloquence in a thesis.

Clarity

Whether it is a simple note, a dissertation or a thesis, or any other writing for that matter, it fails in its function if the target readers do not get the message with clarity and ease. Confused thinking will lead to woolly writing. If you have not understood your point well and state it ambiguously, another person who reads it will never get the point. Your expression has to be precise. None would admire or even relish a bundle of vagueness, when looking for accurate information in a new area of knowledge. Clear and effective presentation of ideas is more important than anything else.

Since a thesis is a document to be checked and assessed by experts in the line, avoid expressions such as "In other words" and "To put it in a simpler way." Experts may not take kindly to such phrases, as they feel that they are competent to grasp even complex ideas couched in difficult idiom.

Adhering to journal styles in presentation

Insight and tips on the mechanics of writing a thesis. 

WRITE RIGHT: Writing for scholarly journals requires a different approach.  

"If there is one trait that best defines a scientist,
it is the ability to concentrate on one subject
to the complete exclusion of
everything else in the environment."

 

If at any time you feel that any part of your thesis should appear in a journal for the learned, you cannot just send a copy to its editor and expect it to be published. You will have to prune down the extra fat and edit it so that it is in tune with the style of the journal in the matter of presentation, length, and depth of treatment.

Most often you will have to re-write the piece and take off the footnotes and other obstructions to easy reading. Even the prose style may have to be different from the erudite one you have adopted in your thesis. You must bear in mind that a general editing of your thesis is not adequate to meet the demand of any journal. You have to edit it to suit the journal you have in mind. A wise approach would be to send an abstract to the editor and get the confirmation of his interest in the topic and his approval for your submission. Perhaps that is the stage at which you can start your specific editing.

Being original is the best policy

Be very careful during research to avoid anything that might give rise to the impression that one is plagiarising or being dishonest in any other way. 

Nicholas Murray Butler (1862-1947, Nobel Peace Prize 1931) and Brander Matthews (1852-1929, Literary critic) were discussing stories. Matthews: "In the case of the first man to use an anecdote there is originality, in the case of the second there is plagiarism; with the third, it is lack of originality; and with the fourth it is drawing from a common stock."

"Yes," broke in Butler, "and in the case of the fifth it is research."

Transcribe faithfully

During research, when you quote a sentence or passage for strengthening an argument, transcribe the text faithfully, including punctuation marks. Do not change even a word. Do not forget to use quotation marks to indicate clearly the quoted part.

Do not quote anything in such a way that it would send a message different from that intended by the author. You should never give an impression that that the quotation was taken out of context.

You should not make the inadvertent mistake of including a quote as your own statement. You should follow a rigour while taking notes. No excuse can save you if are caught for plagiarism, even if it is unintentional.

While taking notes, mark your personal summary, paraphrase or interpretation, and quotations separately.

Later on, you can add your views, opinions, analysis, and findings.

Chug along with search engines

Here are ways of using Internet search engines to aid the information gathering process during research.

LINKS TO INFORMATION: Google is one of the most-commonly used search engines.  

"TO AVOID sifting through irrelevant information, a user needs to be sure of the kind of information he/she wants. He/She will also, in the process, have to learn how to rate information based on its relevance." It would be relevant to give brief indications about searching the Internet. When you have to retrieve a lot of information in the shortest possible time without missing any vital element, you should make use of strategies for effective search.

Most of us usually go to search engines such as the Google or Yahoo! and type a few keywords and open the sites that are displayed on the screen. This is not the most effective way for this exercise. Let us look into this in some detail.

Search engines

There are several search engines with their own special attributes. Each one may have its own focus. Some of the search devices other than the Google and the Yahoo! are alltheweb.com, ask.com, altavista.com, answers.com, books.google.com (very useful for finding books), factbites.com, infonetware.com, lycos.com, scholar.google.com (very useful for finding research papers), search.aol.com, searchedu.com, and wisenut.com. You may see their features by visiting them.

Remember that searching for a particular piece of information is like looking for a specific tree in a dense forest. If you take a wrong turn, you may never reach your target.

Carefully select the search terms, so as to narrow down the search in your desired area. Defining the topic as succinctly as possible also narrows down the search.