Fuel Additive

The fuel additive contains a metal, in the form of a soluble organo-metallic compound.

From: Studies in Surface Science and Catalysis, 1998

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28th European Symposium on Computer Aided Process Engineering

Ali Attiq Al-Yaeeshi, ... Rajesh Govindan, in Computer Aided Chemical Engineering, 2018

2.3.2 Methanol production

Qatar Fuel Additives Company (QAFAC) operates a methanol plant based on natural gas feed (mainly methane C1) with a capacity around 3,000 tonne/day. The average market price was around $220/t of methanol in 2016 (Argus Media, 2016). In this study, it is proposed that an external CO2 source can be utilised to meet methanol production targets by integrating CO2 source to the methanol synthesis unit with 500 t/day (AlHitmi, 2012). Additionally, an opportunity exists for QAFAC to increase the production of methanol by using hydrogen, which is available in Messaid, together with the captured CO2 as raw materials with ratio H2/CO2 3:1 (Pérez-Fortes, et al., 2016). This option can potentially contribute to a relatively higher net reduction in CO2 emissions for the same methanol production target. The capital cost of methanol plant corresponding to this target was estimated to be approximately $1,200 million, with the average price of $4,000/t of hydrogen (Pérez-Fortes, et al., 2016).

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22nd European Symposium on Computer Aided Process Engineering

Sebastian Recker, Wolfgang Marquardt, in Computer Aided Chemical Engineering, 2012

3 Illustrating Example

The fuel additive ethyl tertiary buthyl ether (ETBE) is commercially produced by a liquid-phase reaction of isobutene (IB) and ethanol (EtOH) with a strong acidic macroporous ion exchange resign[11]. The potential side reactions, the dimerization and isomerization of IB, can only take place in the absence of EtOH. They are neglected in this work. The feed to the process also contains the inert n-butane (nBA), which is part of the C4-stream from a cracker.

Fig. 2 shows a few possible candidates for ETBE synthesis. Alternatives 1 and 2 are simple single-stage variants without and with recycle. Due to the binary ETBE-EtOH azeotrope, the mixture has a distillation boundary. Thus, separating the outlet of the reactor system into the product and unconverted raw materials by simple distillation is not possible. Therefore, two additional variants 3 and 4 are considered, where a second stage is introduced to transform the unconverted raw materials and which avoid the accumulation of the inert nBA in the first reactor system.

Fig. 2. ETBE process alternatives (R: reaction system, S: separation system)

By using the proposed NLP model for the reactor system and simple split models for the separators, the optimal operating point of the process variants can be found by maximizing the economic objective function θ = KRevKRawKCatKSep. This objective function consists of the revenue of the process KRev, the costs of raw materials KRaw, the costs of catalyst KCat, and the costs of separation KSep. The costs of separation are approximated by the FAM[3], whereby the split factors are constrained by the distillation boundary and the product specifications.

Tab. 1 shows the results of the optimization for a given capacity of 124.2 kmol/h ETBE. Alternative 1 shows the lowest economic potential θ, as the reaction equilibrium limits conversion. The recycle of unconverted raw materials increases the economic potential of alternative 2. However, some raw material has to be purged to avoid accumulation of the inert. In the two-stage alternatives 3 and 4 this unconverted raw material is transformed in a second reactor system to further improve the economic potential. As both variants show no significant difference in their economic potential, both two-stage processes should be further investigated with more detailed models for reaction and separation units. It should be noticed that the industrially used Oxeno process[5] is covered by alternative 4, which has been identified as one of the promising variants.

Tab. 1. Optimization results

alternative 1 alternative 2 alternative 3 alternative 4
KRaw [
/h]
7712 7125 6957 6960
KCat [
/h]
140 153 101 111
KSep [
/h]
35 114 54 56
θ [
/h]
769 1253 1532 1518
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Hot corrosion of alloys and coatings

S. Prakash, in Developments in High Temperature Corrosion and Protection of Materials, 2008

7.7.2 Use of inhibitors

Inhibitors and fuel additives have been used with varying success to prevent oil ash corrosion. There are a number of inhibitors commercially available that are intended to reduce the severity of oil ash corrosion. Because of its effectiveness and relatively low cost the most common fuel additives are based upon MgO (Paul and Seeley, 1991). The inhibition of hot corrosion by MgSO4 has also been reported by Barbooti et al. (1988) for stainless steel 304. Further the MgO, CaO, ZnSO4, PbO and SnO2 based inhibitors are reported to be effective to decrease the extent of hot corrosion pertaining to molten salt environment (Na2SO4–60%V2O5) for iron-, nickel- and cobalt-based superalloys by Gitanjaly and Prakash (1999), Gitanjaly et al. (2002) and Gitanjaly (2003).

For adequate corrosion protection of a metal in an aggressive environment, it is important to select materials and techniques that are compatible. For example, addition of an organic inhibitor (e.g. pyridines, pyrimidines, quinolines) is sufficient to mitigate corrosion of metals in many corrosive media. However, these inhibitors have shown only limited success due to solubility and/or thermal stability problems in high-temperature, concentrated salt solutions such as in chemical heat pumps (Priyantha et al., 2003).

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Ethanol

S.C. Bhatia, in Advanced Renewable Energy Systems, 2014

21.15.8 Bioethanol from waste potatoes

Ethanol fermented from renewable sources for fuel or fuel additives are known as bioethanol. Additionally, the ethanol from biomass-based waste materials is considered as bioethanol. Currently, there is a growing interest for ecologically sustainable biofuels. The target in the European Union is to increase bioenergy contributions in total energy consumption from 3 to 12 per cent by the year 2010. In Finland bioethanol is already used as additive in some gasoline products instead of toxic MTBE and TAME.

Bioethanol production from potatoes is based on the utilisation of waste potatoes. Waste potatoes are produced from 5–20 per cent of crops as by-products in potato cultivation. At present, waste potatoes are used as feedstock only in one plant in Finland. Oy Shaman Spirits Ltd. in Tyrnävä (near Oulu) uses 1.5 million kilograms of waste potatoes per year. Because this potato-based bioethanol production is just in embryo in Finland, there is a strong need for its research and development. Therefore, the aim of this study was to develop different analytical methods for bioethanol production from waste potatoes and to study the effect of potato cultivar on bioethanol production. As well, the waste solution from the distillation process was analysed.

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Catalysis and Automotive Pollution Control IV

S.J. Jelles, ... J.A. Moulijn, in Studies in Surface Science and Catalysis, 1998

2.2 The application of catalytic fuel additives

The high soot oxidation activity that can be obtained with fuel additives can be explained as follows. The fuel additive contains a metal, in the form of a soluble organo-metallic compound. This compound decomposes in the engine combustion chamber and the metallic part is integrated in the soot, from the moment of nucleation, while the organic part is combusted. The metal is finely dispersed in the soot. Transmission electron microscopy proved that copper particles in soot collected from an engine running with 100 ppm copper in the fuel were smaller than 1 nm, while the soot particles were 30 - 40 nm in diameter [3]. Obviously, the almost atomic distribution of the metal through the soot creates a large interaction surface between carbon matter and catalyst and the result is a very high oxidation rate compared to catalytic coatings of the same metal.

Besides copper fuel additives in combination with wall flow monoliths, the influence of a copper coating on the performance of the system has been extensively studied. It was found that the catalytic activity of the copper coating is negligible compared to the activity of the copper additive. Nevertheless a copper coating might be useful. It was found that the thermal conductivity of the trap material can be of great influence on the stability of the system. High thermal conductivity of the trap, for example of silicon carbide, contributes to stable operation. Regenerations of the trap, during which all the soot collected on the trap is burnt, occur without extreme temperature excursions, whereas with cordierite traps temperatures up to 1200 K can be observed. Continuous operation of a system with a copper fuel additive and a wall flow monolith is feasible at temperatures above 625 K.

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Natural Gas Conversion VI

T.H. Fleisch, ... JonesG.R. Jr., in Studies in Surface Science and Catalysis, 2001

2 Natural Gas Refinery

Studies of future market demands for clean liquid fuels, fuel additives, and economical chemical feedstocks show the need for oxygenates primarily in power generation (the largest energy sector), diesel engines and hybrids, fuel cell applications and in the olefin industry. These demands can be met by multiple products that are produced from natural gas as the only hydrocarbon feedstock. This concept is also called the “Natural Gas Refinery”. Oxygenates, particularly methanol and DME, are key intermediate/end-products. As shown in Figure 1, starting from stranded natural gas, liquid hydrocarbons (condensates and LPG) are separated and sold separately. From the remaining main component, methane, all key products, can be produced via intermediate syngas production. Areas in the world that are gas-rich, such as Trinidad, can benefit from an integrated natural gas refinery.

Figure 1. – Natural Gas Derived Products.

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ELEMENTAL SPECIATION | Practicalities and Instrumentation

D.J. Butcher, in Encyclopedia of Analytical Science (Second Edition), 2005

Example of Application of Environmental Speciation

An example of environmental speciation involves the determination of the manganese containing fuel additive, methylcyclopentadienyl manganese tricarbonyl (MMT), and its derivative, cyclopentadienyl manganese tricarbonyl (CMT). As discussed above, the toxicity of this compound and concerns about human exposure to inhaled manganese have raised concerns about the widespread use of this compound in gasoline. Instrumentation for this work (Figure 1) involved the combination of LC coupled with DL-FAAS. The speciation instrumentation included a reversed phase C18 column for the determination of MMT, CMT, and inorganic manganese. The mobile phase was 65:35 methanol/aqueous pH 4 buffer (0.05 mol l−1 ammonium acetate).

An example of a chromatogram is shown in Figure 2, illustrating good separation between the various manganese-containing species. It should be pointed out that this analysis was performed in less than 3 min, providing rapid analysis. The manganese detection limit for LC–DL-FAAS was 2 ng per ml, with a linear dynamic range of 3 orders of magnitude.

Figure 2. Chromatogram of inorganic manganese, CMT, and MMT by LC–DL-FAAS.

The suitability of DL-FAAS to perform practical analysis was evaluated by the addition of MMT to samples of tap water, gasoline, and human urine (Table 4). Saturated solutions of MMT were prepared to simulate its determination in ground water. MMT was added to gasoline at the maximum allowable level in the United States. Urine was selected because of its significance in toxicological studies. For all samples, good agreement was obtained between the measured and spiked values.

Table 4. Analysis of environmental samples spiked with MMT

Sample Added concentration (μg ml−1) Reported solubility in water (μg ml−1) Determined value by HPLC–DL-FAAS, (μg ml−1)
Tap water 10–70 36±2
Gasoline 8.3 8.0±0.8
Human urine 4.0 4.2±0.3
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Polylactic acid and polyhydroxybutyrate chemistry

Nayyereh Sadat Soheili Bidgoli, ... Zahra Nezafat, in Biopolymer-Based Metal Nanoparticle Chemistry for Sustainable Applications, 2021

6.3.4 Application of PHB

PHB polymers can be used to replace petrochemical plastics in numerous applications as additives, fuels, and molded goods. The main applications of the PHA family, include substitutes for petrochemical-based plastics currently in use for coating and packaging, disposable items such as feminine hygiene products, razors, diapers, utensils, as well as disposable containers, including cups and shampoo bottles. In addition to their potential uses as plastic materials, the PHA family is also useful as stereoregular compounds, which can be used as chiral precursors for synthesizing optically active compounds, including compounds particularly utilized as biodegradable transporters for the long-term dosage of medications, drugs, hormones, herbicides, and insecticides (Fig. 6.9). They are also broadly employed as osteosynthetic materials, vascular grafts, bone plates, surgical sutures, and heart valves [93].

Fig. 6.9. PHA applications in different fields.

In the past decades, the potential applications of bacterial PHB and related PHAs as biodegradable and biocompatible materials in medicine have attracted much attention. A challenging combination of biomedical and biodegradable properties of PHB is a perspective tool in designing novel medical devices and tissue engineering. Over the past years, PHAs, particularly PHB, have been used to develop devices, including sutures, repair devices, repair patches, slings, cardiovascular patches, orthopedic pins, adhesion barriers, stents, guided tissue repair/regeneration devices, articular cartilage repair devices, nerve guides, tendon repair devices, bone marrow scaffolds, and wound dressings [93]. Moreover, the capability of PHB for encapsulation and controlled release of different drugs allow their application for the development of therapeutic systems of sustained drug delivery [94]. High biocompatibility of PHB was demonstrated both in vitro and in vivo [93].

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12th International Symposium on Process Systems Engineering and 25th European Symposium on Computer Aided Process Engineering

Lik Yin Ng, ... Denny K.S. Ng, in Computer Aided Chemical Engineering, 2015

3 Case study: Production of biofuel additives from palm-based biomass

In this case study, a mixture design problem of bio-based fuel additives with a specified set of properties is produced from palm-based biomass. The optimal mixture is designed such that it possesses target properties which fall within the specified target property ranges. These target properties include higher heating value (HHV) which is estimated by group contribution (GC) model developed by Yunus (2014), lethal concentration (logLC50) estimated by connectivity index from Koch (1982), viscosity (η) estimated by GC model from Conte et al. (2008), heat of vaporisation (Hv) estimated by GC model from Marrero and Gani (2001) and oxygen content (OC). The target property range for HHV is within 3500 and 5500 kJ/mol, OC within 2.00 and 6.70 wt %, logLC50 within 2.40 and 3.60, Hv within 30 and 50 kJ/mol and η within 0.30 and 0.90 cP. The main component (MC) of the fuel is predetermined by using a pseudo-component consists of different types of hydrocarbons. The objective of the mixture design is to improve HHV and OC of the main component by designing additive component made from alkane and alcohol for the fuel. In this work, linear mixing rule is applied to estimate HHV, logLC50, OC and Hv of the mixture. For η, a mixing rule developed based on property integration as proposed by Qin et al. (2004) is utilised. In order to target the multiple objectives, fuzzy optimisation approach has been applied along with CAMD techniques. Following the proposed approach, the best five solutions for the design of additives made from both alkane (Alk) and alcohol (Alc) are obtained and summarised in Table 1.

Table 1. Possible designs of additives made from alkane and alcohol

Sol. Properties
HHV (kJ/mol) OC (wt %) log LC50 Hv (kJ/mol) η(cP)
Alk. A 6767 0.00 1.08 44.32 0.89
Alk. B 6765 0.00 0.86 46.24 0.69
Alk. C 6751 0.00 0.90 44.60 0.60
Alk. D 6126 0.00 1.16 42.97 0.64
Alk. E 6112 0.00 1.25 41.33 0.56
Alc. A 2683 21.62 3.05 50.90 2.50
Alc. B 2669 21.62 3.11 49.25 2.18
Alc. C 3335 18.18 2.60 55.80 3.09
Alc. D 3321 18.18 2.63 54.16 2.70
Alc. E 3307 18.18 2.78 52.52 2.36

By mixing the MC with the identified additive components, the best five mixtures identified together with the mixing ratio of main and additive components are shown in Table 2. Mixture A possesses HHV of 4626 kJ/mol, OC of 4.34 wt %, logLC50 of 2.97, Hv of 40.22 kJ/mol and η of 0.83 cP.

The numbers in Figure 1 represent different conversion pathways and technologies that process the biomass into the intermediates, and convert the intermediates into the final product. In this case study, the optimisation objective of the integrated biorefinery is to identify the conversion pathways with maximum product yield (Scenario 1) and maximum economic potential (Scenario 2). From the optimal mixture generated in the first stage of the methodology, it is identified the mixing ratio of additives alkane (Alk. A) and alcohol (Alc. C) for mixture A is 1:1. Thus, the production ratio of alkane and alcohol in the integrated biorefinery is fixed as 1:1. With a feed of 50,000 tonnes per year of palm-based biomass, superstructural optimisation model is formulated and solved. The results are shown in Table 3.

Figure 1. Superstructure of conversion pathways to produce additive components

Table 2. Possible designs of mixture

Mixture MC (wt %) Alk (wt %) Alc (wt %)
A. 52.30 Alk. A (23.85) Alc. C (23.85)
B. 53.30 Alk. D (23.44) Alc. D (23.26)
C. 53.74 Alk. A (26.90) Alc. A (19.36)
D. 53.71 Alk. C (26.99) Alc. B (19.30)
E. 52.30 Alk. B (23.85) Alc. C (23.85)

Once the optimal mixture is identified in stage one, the optimal conversion pathways that convert palm-based biomass into the identified additive components is determined in stage two. The superstructure model of this case study is shown in Figure 1.

Table 3. Comparison of results for Scenario 1 and 2.

Scenario 1 2
Conversion pathways 1,3,4,6,9,11,12,16, 23,26,27,28,29 1,3,4,6,9,10,12,17, 23,26,27,28,29
GPTotal (U.S $/y) 5.43 × 106 19.71 × 106
Alkane production rate (t/y) 1169.38 406.33
Alcohol production rate (t/y) 1169.38 406.33
Alkane by-product production rate (t/y) 10303.30 10831.65
Alcohol by-product production rate (t/y) 2710.84 9650.45

In scenario 1, Alc.C is produced from biomass in the sequence of ammonia explosion, Organosolv separation, dehydration of sugars, hydrogenation of furfural, hydrogenation of THFA 2 and fractional of distillation of alcohols. Meanwhile, Alk. A is produced from fractional distillation of alkanes, which are produced from pyrolysis of biomass followed by Fischer-Tropsch process 1 together with dehydration of alcohols 2. In scenario 2, most of the conversion pathways of scenario 2 are similar to those of scenario 1. However, hydrogenation of THFA 1 is chosen instead of hydrogenation of THFA 2 and Fischer-Tropsch process 2 is selected over Fischer-Tropsch process 1 in order to produce the additives while generating maximum profit.

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Catalysis and Automotive Pollution Control IV

J.P.A. Neeft, ... J.A. Moulijn, in Studies in Surface Science and Catalysis, 1998

An exploratory study was carried out with respect to the performance of a copper fuel additive in combination with monolithic wall flow filters for the removal of soot from diesel exhaust gas. Cordierite filters, copper coated cordierite filters, and silicon carbide filters were studied. Model experiments have been performed to investigate the influence of contact between soot and catalyst on the oxidation rate.

The observation that the effect of a copper coating on the filter performance is marginal compared to the influence of the copper additive is supported by the model experiments. The contact between soot and catalyst is a crucial parameter for the performance of a catalyst. The contact between a copper coating applied to a filter and soot collected on this filter is not sufficient to achieve continuous, complete soot oxidation under realistic diesel engine exhaust conditions.

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