Sources of Feed Stock

The original source of feed stock for the production of aviation gasoline was the butylene-isobutane portion of products from thermal cracking. Later, the thermal cracking units were replaced by catalytic cracking units, and most of the feed stocks are now derived from this source. To a 

As can be seen from Table I, only the Airlift catalytic cracking unit has sufficient isobutane to react with all of the butylenes. The isobutane requirement for alkylation is about 1.15 vol. for every volume of butylene, as indicated in Table II. Besides this quantity required for the reaction, there is also an additional quantity of isobutane which is lost from the alkylation fractionation section. The latter can be from 2 to 25% of the normal butane leaving the unit, depending upon the separation efficiency in the deisobutanizer. 

Those stocks that are deficient in isobutane require either some removal of olefins or the addition of an outside isobutane stream to give an isobutane-butylene balance. Olefin removal can be accomplished either by 

Airlift Thermofor catalytic cracking, liq. vol. % Fluid catalytic cracking, liq. vol. % Delayed coking, liq. vol. % 

Typical Commercial Yields and Product Qualities When Charging Various Feedstocks to Some of the Different Types of Alkylation 

---

Vegetable oils fijom crops, with a total lipid content of at least 20% by weight, such as soy bean, rape seed and sunflower, have been studied and cultivated in plantations as sources of feed stock for biodiesel production in the USA and in European countries such as France, Austria and Italy. For Kenya and Afiica at large, where there is a dire need for food, the use of such edible oil crops for fuel would be ridiculous. Jatropha curcas (family Euphorbiaceae), which constitutes 53-57% non-edible oils, has therefore been evaluated as a source of oil for biodiesel production. 

If feed rate and composition are invariant, there seems to be no purpose for a forward loop. Although feed rate to a column may be on flow control, this does not mean that it is invariant-it means that the stream is only subject to intentional disturbances. Supply of feed stock must come from somewhere, and its source cannot, have infinite capacity. The smaller the supply capacity, the more often feed rate will have to be adjusted. And whether feed rate is subject to random variations or intentional set-point adjustments, it can change rapidly-far more rapidly than a feedback loop on product quality can respond. 

History of disease at facility or in region, facility design, source of seed stock (e.g., wild or domestic specific pathogen-free, SPF, or resistant, SPR), type of feed used, environmental conditions, etc. 

In determining the size of storage systems the possibility of strikes or major disasters, such as fires, earthquakes, or riots, that may cut off feed stocks for along period of time is not considered. The probability of such events occurring is not great enough to warrant the added expense that would be involved. If the disaster strikes only one plant, the raw material can usually be obtained from another source. 

The fluid catalyst pilot plant has also been operated for the production of high aromatics yields to produce aromatic blending components for 115/145 grade aviation gasoline. A 200° to 300° F. (true boiling point) fraction from a mixed crude source was used as the feed stock. Inspections of this fraction are tabulated below ... 

Butenes can also be alkylated in the form of various polymers, such as the by-product diisobutene polymers from butadiene plants. In this operation, each octene molecule appears to react as two individual butene molecules, and the high alkylate quality and low catalyst consumption characteristic of butene alkylation are obtained. For the most part, polymers have been alkylated only as supplemental feed stocks from external sources in periods of high aviation gasoline demand. 

Despite the fact that formaldehyde is the minor ingredient in the production of these resins and that only part of the formaldehyde is presently derived from petroleum sources, the production of formaldehyde from petroleum feed stocks is already an industrial process of considerable volume and one that promises to be of increasing future interest to the petroleum industry. 

Another group of potentially large volume plastics that is under development are the polysulfone resins, made by the copolymerization of olefins such as 1-butene with sulfur dioxide 24). Both these feed stocks could be derived in abundant quantities and at relatively low costs from petroleum sources. The polysulfone resins are moldable thermoplastic polymers having physical properties that vary widely depending on the olefin from which they are prepared. They are considered to have excellent prospects for development to a large volume, low cost commercial plastic and may permit the entrance of plastic products into other fields in which they are now limited by the high cost and inadequate supply of present thermoplastic materials. 

On the bright side, technology is being developed for making fermentable sugars out of low-cost woody feed stocks. Ethanol produced from such inexpensive sources would be greatly cheaper than gasoline. 

Feed stock for the first sulfuric acid alkylation units consisted mainly of butylenes and isobutane obtained originally from thermal cracking and later from catalytic cracking processes. Isobutane was derived from refinery sources and from natural gasoline processing. Isomerization of normal butane to make isobutane was also quite prevalent. Later the olefinic part of the feed stock was expanded to include propylene and amylenes in some cases. When ethylene was required in large quantities for the production of ethylbenzene, propane and butanes were cracked, and later naphtha and gas oils were cracked. This was especially practiced in European countries where the cracking of propane has not been economic. 

A third trend is towards the search for cheap feed stock sources. This development started quite a while ago. Methanol used as a carbon source for microbial growth is of real interest at present. Cellulose and hemicellulose as components of wood are not yet an economic alternative, but recent progress is very impressing. It can easily be foreseen that wood will be utilized as a new resource for biotechnology within the next 10 years. 

This chapter concentrates on the possibility of producing SCP from petrochemical feed stocks, such as n-paraffin, methane, or methanol. Between 1960 and 1980, the idea to produce SCP from crude oil sources found a lot of attention and several large-scale plants with capacities of several 100,00 tons/year were built, for instance in southern Italy. Hopes were high at the time, but the development made only slow progress. One of the reasons could be the choice of the location, which is far away from both, the source of the feedstock and the consumers of the product. Another is that oil and natural gas are expensive feed stocks, because they also have other uses. Anyway, the technology for protein production from chemicals exists and may be applied with more success in other areas of the world, where more favorable starting conditions exist. 

---