Process Synthesis for Fuel Ethanol Production
Book file PDF easily for everyone and every device.
You can download and read online Process Synthesis for Fuel Ethanol Production file PDF Book only if you are registered here.
And also you can download or read online all Book PDF file that related with Process Synthesis for Fuel Ethanol Production book.
Happy reading Process Synthesis for Fuel Ethanol Production Bookeveryone.
Download file Free Book PDF Process Synthesis for Fuel Ethanol Production at Complete PDF Library.
This Book have some digital formats such us :paperbook, ebook, kindle, epub, fb2 and another formats.
Here is The CompletePDF Book Library.
It's free to register here to get Book file PDF Process Synthesis for Fuel Ethanol Production Pocket Guide.
Wet-mill plants primarily produce corn sweeteners, along with ethanol and several other co-products such as corn oil and starch. Wet mills separate starch, protein, and fiber in corn prior to processing these components into products, such as ethanol. Making ethanol from cellulosic feedstocks—such as grass, wood, and crop residues—is a more involved process than using starch-based crops. There are two primary pathways to produce cellulosic ethanol: biochemical and thermochemical.
The biochemical process involves a pretreatment to release hemicellulose sugars followed by hydrolysis to break cellulose into sugars. Sugars are fermented into ethanol and lignin is recovered and used to produce energy to power the process. The thermochemical conversion process involves adding heat and chemicals to a biomass feedstock to produce syngas, which is a mixture of carbon monoxide and hydrogen. Syngas is mixed with a catalyst and reformed into ethanol and other liquid co-products. Most U. According to the U. To put this into perspective, a tanker truck can carry 8, to 10, gallons of ethanol, and one rail car can carry approximately 30, gallons of ethanol.
Ethanol, gasoline blendstock, and additives are delivered separately to fuel terminals where they are blended into fuel trucks for delivery to stations. Delivering ethanol by pipeline is the most desirable option, but ethanol's affinity for water and solvent properties require the use of a dedicated pipeline or significant cleanup of existing pipelines to convert them into dedicated pipelines. Kinder Morgan ships batches of ethanol through its Central Florida Pipeline.
More Ethanol Publications All Publications. The mesopores are important for easy flow of fluids to the micropores. Ethanol, with only two carbons per HO group, remains a very polar compound, but of course is less so than water. Thus, separations are still possible, but adsorption of organics is less favourable from ethanol than from water. The adsorbability of compounds will change in ethanol solutions generally decreasing , but trends are expected to hold.
Hexanol and higher alcohols are hardly soluble in water.
Long hydrocarbon chains increase molecular mass, which contributes to an increase in the adsorbability through hydrophobic effects and increased London dispersion forces with the AC. Compared with their alcohol analogues, aldehydes are adsorbed slightly less efficiently from water, but the trend with carbon chain length remains the same. Although acetaldehyde is difficult to remove with AC, it is possible to remove it by prior oxidation to acetic acid.
Aromatic compounds show low polarity and low solubility. Therefore, their adsorbabilities are relatively high. Activated alumina Al 2 O 3 is another type of adsorbent that is made from aluminium hydroxide. The main applications of activated alumina are water removal from a gas stream or liquid samples 44 - 46 , refining of petroleum 47 and fluoride ion removal from water 48 - Silica gel SiO 2 is an adsorbent made from the neutralization of sodium silicate with mineral acid Although it is commonly used as a desiccant 53 - 55 and an adsorbent to separate organic compounds from one another, it is not commonly used in water or wastewater treatment.
A molecular sieve is a class of porous material with crystalline structure, in contrast to AC, activated alumina and silica gel, which have amorphous structures. They can be made from various materials such as carbon 56 - 58 , titanium silicate 59 - 61 and aluminophosphate 62 - The most common molecular sieve is based on anhydrous aluminosilicate zeolite 65 , For ethanol treatment, dehydration after distillation is completed with molecular sieves selected for their high selectivity for water derived from uniform appropriate pore diameters 67 - A membrane can separate a mixture of two or more liquids by applying a vacuum on one side.
This causes a gradient of chemical potential, resulting in the penetration of the mixture into the membrane and evaporation from the other side. The separation by PV is governed by the difference in solvents sorption affinity and diffusion coefficients in the membrane Sun et al. Additionally, Chovau et al. Ozonation is not a purification method, per se, but rather it is a very inexpensive and clean way to oxidize many organic compounds whose products can be more easily removed by one of the other purely physical methods.
It is commonly used in the treatment of water. Ozone, O 3 , is an allotrope of oxygen — made in situ from O 2 — that is much less stable than O 2 , the diatomic species. The gas has a pale blue colour and a unique sharp odour. It is also a powerful oxidant.
Ethanol from Biomass - eXtension
Ozone can be used to oxidize various organic and inorganic compounds contained in ethanol, regardless of their boiling points. The oxidation has dramatic impact on the boiling points, and thus separability, of these components. Carbon—carbon double bond scission is the net result of the most common ozonolysis reaction, resulting in compounds that are more volatile and may be efficiently removed by gas stripping. Other reactions result in compounds with higher boiling points than previously, allowing for more efficient separation by distillation.
Initial oxidation can also increase biodegradability and reduce toxicity of certain impurities, making subsequent biological purification steps more effective or directly removing a hazard. For example, Brooke et al. Also, it is reported that the efficiency of membrane bioreactors can be improved by ozonation Sludge can be ozonated, and the reduction in its production was observed in wastewater treatment. There was no adverse effect on the biological performance of mineralization and nitrification by sludge ozonation.
Ozone has also been used within activated sludge for selective disinfection to enhance the settleability of the biomass 79 , 80 and for selective oxidation to reduce toxicity and increase biodegradability It was pointed out under adsorbability that oxidation of many organic compounds leads to substances that adsorb more readily. Ozone is particularly suitable to achieve such oxidation. Selective oxidation of impurities is used in the purification of vodka 27 , Moreover, ozonation has cost advantages relative to other oxidative methods.
Ozone treatment operates under atmospheric pressure and does not oxidize the alcohol under controlled reaction rates. Thus, ozonation does not leave harmful residuals in a treated sample and readily decomposes in the headspace. It is archetypal for ozone to undergo cycloaddition reactions with unsaturated hydrocarbons, resulting in carbon—carbon scission after several spontaneous subsequent steps and this is the dominant mechanism by which ozone is effective for ethanol purification.
Another potential reaction mechanism is where hydroxyl radicals are produced during reactions between aqueous hydroxide ion and O 3. Only one hydroxyl radical per ozone molecule is produced, thus halving the electron acceptor number. However, the hydroxyl radical is significantly more reactive with a wider range of electron donors, and thus considerably less selective in its reactivity. In fact, hydroxyl radical would be expected to react with ethanol itself and introduce new impurities. Thus, indirectly, ozone can oxidize both saturated and unsaturated compounds.
However, under proper conditions, direct oxidation of alcohols, aldehydes, ethers, and other saturated compounds is slow and indirect oxidation can be minimized. This represents a selectivity for oxidizing certain of the ethanol impurities selectively. For a more extensive discussion, see Bailey A subsequent purification treatment such as UV radiation and physical adsorption or stripping is required to remove these compounds. Onuki et al.
The research had the aim to remove impurities after distillation. A combination of three approaches effectively removes eight organic impurities. A summary of the main analytical techniques for ethanol analysis is illustrated in Fig. Gas chromatography is a useful analytical technique for volatile and semivolatile compounds, typically requiring submicrolitre liquid samples or gas samples.
It is a physical method in which the solvent and analytes are separated on the basis of volatility and affinity to a particular column coating. Samples are directly injected or thermalized on a solid absorbent. Recent developments in GC instrumentation provides a substantial decrease in analytical time and improvements of analytical sensitivity and selectivity. Some compounds were found to occur commonly in all kinds of alcoholic beverages. It does not provide any structural information, but like all GC methods, retention times are characteristic for a given compound under fixed conditions.
Gas chromatography with olfactometry is a technically developed sensory evaluation system to enable the evaluation of odour qualitatively and quantitatively can be used for the odour evaluation of alcoholic beverages Newer extraction techniques have been developed for analysis of ethanol.
Campo et al. Pino et al. Different detection methods can be used, such as UV absorption, fluorometry, and mass spectrometry. Among the advantages of HPLC are no limitation by volatility or heat sensitivity of sample compounds. HPLC is a suitable analytical technique for a liquid sample such as ethanol, in which the impurities are the analytes.
Loukou and Zotou 99 determined biogenic amines in alcoholic beverages by HPLC with fluorometric detection. HPLC in general is the most common determination technique of biogenic amines in wine and beers - Still, derivatization with reagents is in many cases required when the unmodified analyte is not amenable to the chosen or available detection method , Yarita et al. Nascimento et al. You et al. Aldehydes were derivatized for accurate quantification - similarly to Zhu et al. Infrared spectroscopy IR vibrational spectroscopy is one of the most common classic spectroscopic analysis techniques for organic compounds.
Originally thought of as a method to identify key functional groups in compounds, it became possible to use the vibrational spectrum as a fingerprint for identifying compounds against libraries in the advent of the computer age. Thus IR is suitable for routine quality assurance analysis of alcoholic beverages when screening for particular identifiable impurities , Lachenmeier used Fourier Transform infrared spectroscopy in combination with multivariate data analysis to determine the quality of alcoholic beverages.
Recent ethanol production methods, purification techniques adapted from water and wastewater treatment to ethanol, and ethanol analysis techniques were reviewed.
Process Synthesis for Fuel Ethanol Production
Volatile byproducts are generated during any kind of ethanol production process. Many purification techniques for water and wastewater treatments are applicable as new purification techniques of ethanol. The purification techniques that do not rely on volatilities of impurities for separation, such as ozonation and physical adsorption, have the potential to overcome disadvantages of distillation or exist as complementary additional purification steps.
The recent development of separation techniques, such as GC and HPLC, has improved the detection capabilities of impurities in ethanol and enabled the development of pure vodka.
This allows for the determination of low concentration impurities responsible for flavour or toxicity. The use of IR could make the quality assurance of ethanol more economical and faster. Whether ethanol is targeted for fuel, beverage, or other applications, relevant purification and analysis techniques are crucial for quality enhancement and value addition.
Taking ethanol quality beyond fuel grade: A review
Volume , Issue 4. The full text of this article hosted at iucr. If you do not receive an email within 10 minutes, your email address may not be registered, and you may need to create a new Wiley Online Library account.