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Industrial Alchemy, Part 4: Organic Chemical Feedstocks and Product Timeline

Written by Iver P. Cooper

Here, I expand upon the introduction to natural feedstocks which appeared in part 3, and then discuss some products which might be made, and when they might be available.

Coal Feedstocks

Coal Pyrolysis and Coal Tar Distillation

In 1856, Perkins reacted aniline from coal tar with potassium dichromate, serendipitously obtaining the new silk dye mauveine. In the half-century that followed, the organic chemical industry primarily derived its products from coal tar.

Coal tar is a byproduct of the production of coke from coal. Coke is the solid residue (mostly carbon) resulting from destructive distillation (heating in absence of air; "pyrolysis," "carbonization") of a coal or petroleum.

Coke. Coke is already produced down-time for use as a fuel. Early on, the up-timers will point out that coke can be used, in place of charcoal, as the fuel and reducing agent for a blast furnace. (As EA points out, coke is mechanically stronger than charcoal, and thus can support a larger charge.) This can be expected to lead to an increased demand for coke.

The up-timers know of the relationship among coke production, steelmaking, and the organic chemical industry. Josh and Colette Modi are visited by the metal magnate Louis de Geer (Colette's uncle) in April 1632, and they suggest to him that "given the chemicals that can be distilled from coal tar gases when making coke, a chemical company might be very profitable." Mackey, "The Essen Steel Chronicles, Part 2: Louis de Geer," Grantville Gazette 8.

The down-timers produce coke in crude beehive ovens, which wastefully allow the liquid and gaseous byproducts to escape. EA/Coke has a surprisingly detailed description of both the old-fashioned beehive ovens, and "byproduct ovens" designed to capture all of the byproducts. In the old timeline, the first such oven was built in 1881.

The carbonization temperature has a large influence on the nature of the products. If the temperature is less than 200^oC, they are mainly methane, water and carbon dioxide. In the range 200-400^oC, the methane is replaced by carbon monoxide. Passing beyond 400^oC, hydrogen begins to appear and once you exceed 800^oC, it is the main gaseous product. Only the coke produced by high temperature carbonization (over 800^oC) is used for metallurgical purposes (EA/"Coke"). EB15 says 900-1200^oC, with the low end for making town gas and the high end for metallurgical coke.

Coal Tar. All of the coal products, save for the coke, are initially part of the coke oven gas. As the coke oven gas is cooled, the components which are solid ("crude tar") or liquid ("ammoniacal liquor") at room temperature are separated from the light gas. Then the ammoniacal liquor is decanted from the tar, and the latter is distilled.

EB11 warns that the tar must be dehydrated before distillation. It's then pumped into a tar still. In OTL, 3-6 distillation fractions were taken. The "Grantville literature" refers to four such fractions—light ("benzoil"), middle ("carbolic") , heavy ("creosote") and anthracene ("green")—leaving a residue of pitch. The distilleries varied with respect to the precise distillation temperatures and specific gravities by which these fractions were defined, and this naturally also affects their relative proportions and composition. See Fig. 4-1 (EA; Shreve 84) for one example; others in Appendix.

 

 

Figure 4-1 Coal Pyrolysis Products

 

The fractions (which are complex mixtures) may be used as is (e.g., as solvents), or subjected to further work up as described in EB11/Coal Tar:

Light Oil: (1) extract tar acids (phenol, cresols) with caustic soda, (2) extract tar bases (pyridine) with dilute sulfuric acid, (3) remove some aliphatic hydrocarbons with concentrated sulfuric acid, and (4) steam distill to obtain benzene, toluene, xylenes, and cumenes.

Middle and Heavy Oils: (1) crystallize out naphthalene, and (2) recover the tar acids and bases.

Green Oil: (1) crystallize out anthracene, redistilling if need be; (2) extract phenanthrene with naphtha, (3) extract carbazole with pyridine.

There are hundreds of chemicals in coal tar, and the amount of each depends on the coal and how it's processed. There is quantitative data, sometimes contradictory, in Grantville Literature (McGHEST, EA, EB15, M&B373, EB11/Coal Tar; see Appendix). While not part of that literature, reasonable production estimates would be:

benzene, toluene, xylene: 1-2.5% (in proportions 6.67:2:1 per EB11)

naphthalene 4-10%

anthracene 0.25-2%

phenol 0.4-0.5%

cresols 2-3%

pyridine and quinoline 0.2-0.3%

creosote oil 25-30%

pitch 50-60%

(Chamberlain 500)

A coal gas plant opened in Magdeburg in November 1633 (Flint, 1634: The Baltic War, Chapter 2). Its gas was used for lighting and heating. From chapter 3, we know that the furnace was hot enough to generate hydrogen gas. The Magdeburg plant separated the coal tar into different products, including pitch and "light benzoils" (benzene and related compounds). Production was such that it generated a barrel or two of the light benzoils every day. It also produced ammonium nitrate for use as fertilizer. (Ammonium sulfate can be recovered from the ammoniacal liquor; figure 10 kg/metric ton coal; McGHEST.)

Coal Gasification. Since World War II, there have been efforts to convert coal into a fuel gas (EA/"Coal Gasification"). Depending on the precise process used, the gas can have a high or a low heating value, the latter having the advantage of a low sulfur content. The low BTU gas, curiously, has been made at a plant in Morgantown, West Virginia, and it is possible that some of the Grantville residents have read about its operations or even worked there.

From our perspective, a more interesting form of coal gasification is the older (Twenties) use of coal to make "synthesis gas" (syngas), a mixture of carbon monoxide and hydrogen. I discussed this in part 3.

Coal Liquefaction. The purpose of coal liquefaction is to convert the solid hydrocarbons into ones liquid at room temperature, especially those in the gasoline size range. The usual use of the liquefaction product is as fuel, but in theory the compounds could instead be used as starting materials in organic synthesis.

Coal gasification and liquefaction are advantageous if coal is cheap and petroleum is expensive.

 

Natural Gas Feedstocks

 

Natural gas is potentially an important industrial source of the lower molecular weight alkanes, notably methane, ethane, n-propane, isopropane, n-butane and isobutane. These can be separated by fractional distillation.

We know that the residents of Grantville have made an effort to switch from gasoline to natural gas (and alcohol) as fuel for their vehicles.

Many natural gas wells can be found in Grantville. The town is heated with local natural gas, and Willie Hudson runs his farm off gas from his own land (Flint, 1632, Chapter 8). There are also wells on the properties of "Birdie" Newhouse. (Huff and Goodlett, "Birdie's Farm," (1634: The Ram Rebellion), George Blanton (Jones, "Anna's Story," (Grantville Gazette 1), and John and Millie. (Huston, "Seasons," Grantville Gazette 7), and unnamed others.

Under West Virginia law, a "gas well" is a well which has an initial production such that the gas-oil ratio (GOR) is at least 6,000 cubic feet of gas for each barrel of oil. (The two then have the same energy value.) Since these gas wells in Grantville were not in commercial production at the time of the Ring of Fire, they probably fall into the category of stripper wells. A stripper well is defined by Interstate Oil and Gas Compact Commission as one producing not more than 60,000 cf gas or 10 barrels oil/day. But the average production for marginal wells in West Virginia was 0.6 barrels oil or 11,000 cf gas/day. (IPAA2004).

Natural gas is often trapped near petroleum. It may be produced ("dry gas") from a pure gas well (which in turn is tapping a gas cap above the oil horizon), from a gas-condensate well (so-called because some of the gas condenses when brought to the surface), or from an oil well, dissolved ("wet gas") in petroleum. Generally speaking, in "dry gas", methane is 70-98%, ethane 1-10%, propane 0-5%, butane 0-2%, and in wet or condensate gas, methane 50-92%, ethane 5-15%, propane 2-14%, butane 1-10%. (Rojey 80). The propane and butane are called "petroleum gas."

A 1904 analysis of natural gas from Fairmont, West Virginia reported 81.6% methane, 14.09% ethane, 3.21% nitrogen, and 0.2% heavier hydrocarbons, and Morgantown gas was similar. (UGSK 242). Hence, I think we must assume production of propane is under 0.1%.

German natural gas may not be much better as a source of propane. The natural gas produced in Neuengamme, Germany in 1910 was 91.6% methane, 0.8% heavy hydrocarbons. (Molinari, 36).

 

Petroleum Feedstocks

 

Petroleum contains a greater variety of organic compounds than does natural gas.

Fractional distillation separates the petrochemicals more or less by carbon number (Table 4-1A). To separate one class of hydrocarbon from another (e.g., aromatics vs. aliphatics), you need to use a selective solvent. The solvents used include liquid sulfur dioxide, liquid propane, furfural, and phenol (EA/Petroleum, Furfural).

 

Table 4-1A: Petroleum Distillation Fractions
Distillation Temp oC	Name	Carbon Number	Boiling Points oC, Selected Compounds
<20	Gas	C1-C4	propane -42 butane 0
20-60	Petroleum Ether (overlaps gasoline)	C5-C6	pentane 36
40-205	Gasoline	C5-C11	hexane 69 benzene 80 cyclohexane 81 toluene 111 octane 126 xylenes 138-144 undecane 196
60-100	Light Naphtha (ligroin) (Gasoline Subrange)	C6-C7	heptane 98
175-325	Kerosene (Jet Fuel)	C12-C18	naphthalene 218
275-400	Gas Oil (Diesel, Furnace)	C12-C20	anthracene 354
non-volatile liquid	Lubricating Oil	C20+
non-volatile solid	Asphalt, Petroleum Coke	C20+
(M&B 109; Solomons 112 almost identical. EB15 has light naphtha 20-95, heavy naphtha 90-165, kerosene 150-245, light gas oil 215-315, heavy gas oil, 285-370. )

 

Our initial sources of petroleum are the natural gas wells in Grantville. 1633 chapter 34 says that they were "upgraded" to produce what Mike calls a "fair amount," and Quentin, a "trickle," of oil. The implication is that the gas wells are what are sometimes called "condensate wells." Condensates are hydrocarbons, heavier than butane, which occur naturally in gaseous form in the reservoir, but which condense (liquefy) in the reservoir (after drilling), at the wellhead, or in a field separator, and can thus be separated from the natural gas. A typical composition is 40-90% C7-C8, 10-20% C9, 1-15% C6, 3-10.5% C5, and 0-4% hydrogen sulfide. (Marathon).

As for oil wells, oil composition varies from field to field, from well to well, and from formation to formation. Oils are classified as light, medium or heavy, based on their density. As you might expect, the light oils are rich in the volatile, low carbon number compounds, whereas the opposite is true of the heavy oils. The oils are mostly hydrocarbons, but include small amounts of compounds containing oxygen, nitrogen and sulfur. Oils with a low sulfur content are said to be "sweet", and those with a high content are labeled "sour." Heavy oils tend to be sour, too.

Pennsylvania oils are of the simple paraffin type (primarily linear alkanes), whereas Caucasian petroleums are more complex. (EB11 and EA "Petroleum"). At least some of the oils of Oelheim and Wietze are naphthene/asphalt type. (Bacon 888). These have a lower alkane content, but compensate by being richer in cycloalkanes (naphthenes), alkenes (olefins) and aromatic compounds (e.g., benzene, naphthalene, anthracene). They are more chemically reactive, hence more versatile, than alkanes.

By 1633, the up-timers are collecting oil at Wietze. Wietze is actually one of a dozen or so small oil fields near Hanover, and it is only a matter of time before others are discovered.

For the composition of Wietze heavy (shallow) and light (ca. 1000') oil, see Table 4-1B. In general, it's good for the organic chemical industry, not so good for automobiles.

 

Table 4-1B: Wietze and Nienhagen Oil
	Wietze Analysis 1		Wietze Analysis 2		Nienhagen
	Heavy Crude	Light Crude	Upper Triassic (Rhaet)	Lower Cretaceous (Wealden)	Middle Jurassic (Dogger)	Lower Cretaceous (Neokom)
Distillation Commenced			245oC	118oC	220oC	130oC
Cumulative %Distilled by
150oC	—	2-2.5%	2.0			0.5
250	0-2	16.5-17.5	17.5		5.0	9.5
275	2.8-5.5	22.5-23.5	23.5	1.5	10.5	13.8
300	8.5-12	30.0-31.5	31.5	6.0	15.0	19.5
325	14.5-19.5	37.5-28.5	38.5	12.5		25.2
350	31.5-34	49.5-51.0	51.0	26	35.5	30.2
.	(Holde 82)		(Kauenhowen 482)
By comparison, ~20-30% of Pennsylvanian and Galician petroleum distills at under 150oC, and 35-50% at 150-200oC. (Lucas 369).

 

Petrochemical Conversion. Initially, oil wells were drilled to obtain kerosene for use as in illumination and heating. When the automobile became popular, the emphasis switched to gasoline, especially the lighter "straight run" component (distilling at 20-150 ^oC). With the advent of high compression ratio engines, the heavier naphthas (150-200 ^oC) became more popular.

Up-time, the demand for gasoline had been great for many years, and hence processes were developed, and integrated into refinery operations, for converting heavier or lighter fractions into the hydrocarbons most suitable for auto engines. (Wittcoff).

There are three methods of down-converting. Thermal cracking uses high pressures and temperatures (exceeding the boiling points of the target hydrocarbons at the process pressure) to break carbon-carbon and carbon-hydrogen bonds, converting the heavier fractions into C5-C12 aliphatics, and in the process also converting some alkanes into alkenes M&B 138 says the main product is ethylene. There is some discussion of thermal cracking methods in EB11/Petroleum. EA/Cracking recommends 482-538 ^oC and 206-735 psi.

Steam cracking features mixing the hydrocarbons with steam, flash heating to 700-900 ^oC, and then quenching. This produces additional alkenes (ethylene, propylene, butadiene, isoprene, cyclopentadiene).

Catalytic cracking requires less vigorous conditions. EA/Cracking says "catalysts originally used were bentonite clays, but now pellets or granules of alumina, silica, zirconia, or magnesia, or artificial mixtures of these materials are more commonly used." The catalytic cracking is conducted at 427-482 ^oC and 10.3-29.4 psi (14.7 psi is normal atmospheric pressure). Catalytic cracking yields heavily branched alkanes and alkenes.

The heaviness of Wietze oil, and many other German oils, provides an incentive to develop these cracking processes, especially catalytic cracking, to provide more gasoline.

We can also up-convert the lighter hydrocarbons. The classic approach was to polymerize olefins using acid catalysts, and it was "neither easy nor inexpensive." Nowadays, it is more common to "alkylate", which in this context means to react an olefin with a paraffin to obtain a larger, branched hydrocarbon. It, too, uses an acid catalyst, usually concentrated sulfuric acid or hydrofluoric acid (EA/Petroleum).

These methods beg the question of how we obtain the olefins. It is likely to be a two step process, converting the alkanes into alkyl chlorides or alcohols, and then those intermediates into alkenes.

Up-conversion hurts the organic chemical industry by converting hydrocarbons which it might otherwise use as feedstock into gasoline for fuel use.

Catalytic reforming (1940s) cyclizes (makes open chains into rings), isomerizes (straight chains to branched), and dehydrogenates. The dehydrogenation generates alkenes and aromatics. While they are good for cars, they are great for the organic chemical industry. Indeed, catalytic reforming is what made it possible for the petroleum industry to overtake the coal industry as a source of benzene, toluene and xylene ("BTX"). Morrison & Boyd (373) say that catalytic reforming requires high temperature and pressure, and a platinum catalyst, but that's it. There are basic organic chem texts which provide more information; Bordwell (381) refers to use of 0.75% platinum on alumina, 450 ^oC, and 500 psi hydrogen.

A lot of experimentation will be needed to make any of these conversion methods commercially viable.

Botanical Feedstocks

 

Plants are a source of carbohydrates (simple sugars, starch, cellulose, carbohydrate gums), protein, fats, resins, and exotic secondary metabolites. The secondary metabolites are usually present in just small quantities but there are exceptions. Quinine is up to 8% of quinine bark; morphine, 16% opium; theobromine, 1.2% cacao bean; diosgenin, 5%, Mexican yam. (SzmantIURR 142, 166ff). Fifteen tons of dried Madagascar periwinkle leaves are needed to produce one ounce of vinblastine, and it takes the bark of more than one Pacific yew tree to yield one gram of anti-cancer taxol. (National Botanic Garden)

The chemical makeup of plants varies from species to species, and is also affected by growing conditions (climate, soil or water, pest activity) and developmental stage. Both land plants and marine plants can be of interest.

The distribution of the chemicals isn't uniform within the plant; a chemical of interest may occur preferentially in the seeds, fruit, roots, leaves, flowers, stem, buds or branches of the plant. It can be in solid tissue, or in a liquid (saps, resins, latex, etc). In the stems of woody plants, the chemistry of bark, heartwood, and sapwood can vary.

Agar. Agar is a galactose polymer derived from certain red algae and seaweed; "Grantville literature" calls attention to the Gelidium and, to a lesser extent, Gracilaria, Pterocladia, Acanthopeltis, and Ahnfeltia (EB11/Jams and Jellies; CCD; MI; EA, EB15).

I am not sure how much is known about the geographic distribution of these algae, but specialist literature shows that the closest source of Gelidium to the USE is in the coastal waters of northern Spain and Morocco; of Pterocladia, near the Azores; and Gracilaria, western South Africa. (FAO).

Cellulose and Derivatives. Cellulose is a glucose polymer and constitutes about 30% of all plant matter. The best sources are wood (~50% cellulose) and vegetable fibers. Cotton is about 91% cellulose. (Sadtler 275). Several fibers, of course, are used down-time to make textiles, rope and paper.

EB11/Cellulose says that cellulose can be obtained by treating cotton fiber with "boiling dilute alkalis, followed by chlorine gas or bromine water, or simply by alkaline oxidants. The cellulose thus purified is further treated with dilute acids, and then exhaustively with alcohol and ether." If you are making chemical filter paper, you also use hydrofluoric acid to remove silica.

Cellulose can be used to make methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, cellulose nitrate, cellulose acetate, cellulose proprionate, cellulose xanthate and other cellulose derivatives. EA "Cellulose" is a good source of information on how to make them.

Cellulose nitrate was an early explosive and also an early photographic film base. It is made by treating cellulose with a mixture of nitric and sulfuric acids, and then adding camphor as a plasticizer. Cellulose acetate is used to make rayon. The cellulose is treated with acetic anhydride. Similarly, cellulose propionate is made by treating the fibers with propionic anhydride. Cellulose xanthate is used to make viscose rayon, cellophane film, and cellulose sponges. Making the xanthate requires sodium hydroxide and carbon disulfide.

Oxidative degradation of cellulose yields , depending on conditions, acetic, butyric, oxalic and levulinic acids. (EB11; SzmantIURR 90).

In wood, the cellulose is accompanied by lignin (25%) and hemicellulose (25%). In papermaking, the lignin is disintegrated by the Kraft process (sodium hydroxide and sodium sulfide), or with sulfites or bisulfites.

Lignins. Lignins, which are complex polymers, produce different products, depending not only on their source but how they are isolated. Lignosulfonates and "alkali lignins" are byproducts of acidic and basic wood pulping, respectively. Either can be used to make dimethyl sulfide, which is oxidized to yield the special solvent dimethyl sulfoxide. Lignins can be converted to phenols (Wittcoff 161), such as vanillin (via nitrobenzene). (SzmantIURR 154ff).

Hemicelluloses. These are polymers composed of several sugars, particularly xylose.

The sugars are released by hydrolysis, and xylose can be hydrogenated into the sweetener xylitol (SzmantIURR 99). Under more stringent hydrolysis conditions, the xylose is converted to furfuraldehyde or furfural (100). Furfural is used to make furfural-phenol plastics.

Pentosans. Pentosans are polymers of arabinose and other five-carbon sugars. They can be isolated from oat hulls, corn cobs, sugar cane stalks, wood, and other sources. Acid treatment produces furfural, which as previously mentioned, is used in the petrochemical industry. (Wittcoff 144; EA/Furfural). And from corn cobs, you get acetic and formic acid as byproducts.

Starch. Starch, a composite of amylose and amylopectin, is obtained from corn, rice, potato, wheat, tapioca, arrowroot, and sago. It can be used as is, derivatized, or acid-hydrolyzed to generate glucose. Glucose, in turn, can be converted to gluconic acid, sorbitol or alpha-methyl glucoside.

Resins. Since antiquity, tree resins (e.g., the Biblical frankincense and myrrh) have been distilled to separate them into turpentine (the distillate) and rosin (the solid residue). A pine tree might yield 10 pounds gum, which in turn yields 81% rosin and 19% turpentine (EA/Turpentine).

Turpentine can be used as a solvent, or as a source of starting materials for the synthesis of various flavors and fragrances. The rosin can be cooked to yield pitch. (Dunwody 127).

Chemically, resins are mostly terpenes, which are related to isoprene (the alkene of natural rubber). However, the Jeffrey Pine and Gray Pine are sources of almost pure n-heptane, an alkane. Resins may also contain resin acids.

Essential oils are volatile, fragrant liquids isolated from various parts of plants, usually by distillation or solvent extraction. Almond oil is from a seed, sassafras from a bark, camphor from a wood, ginger from a rhizome, peppermint from a leaf, frankincense from a resin, clove from a flower, lemon from a fruit peel, and valerian from a root. The crude liquids were used in folk medicine and cosmetics.

These oils are mixtures of organic chemicals, including terpenes, camphors, alcohols, phenols, ethers, aldehydes, ketones, esters, and organic acids, and separation is possible. Sometimes one constituent predominates, menthol is about 30-50% of peppermint oil (Gildemeister 643). But the chemicals which give the essential oil its characteristic fragrance aren't necessarily present in large proportions; the "rose ketones" are less than 1% of attar of roses, but provide about 90% of its "odor content" (Wikipedia/"Rose Oil").

Oleochemicals. Vegetable fats (solids) and oils (liquids) are rich in triglycerides (triacylglycerols). A bit of chemical nomenclature is appropriate here. Glycerol is an alcohol. Alcohols are compounds comprising at least a hydroxyl (-OH) group connected to a carbon atom. In glycerol, there is a three carbon chain (like that of propane), and there is a hydroxyl attached to each carbon atom.

In a triglyceride, each of the hydroxyl groups is esterified, which means that the hydroxyl group is replaced with a "fatty acid" group. A fatty acid is a kind of "carboxylic acid"; the latter have the form HO-C(=O)-R. In a fatty acid, the R group is a long unbranched aliphatic hydrocarbon.

In soap making, the fats (triglycerides) are saponified, that is, hydrolyzed (reacted with water) in the presence of a strong base (usually sodium hydroxide, potassium hydroxide or sodium carbonate). The water cleaves the ester (-O-C(=O)-) bonds, producing a mixture of the free fatty acids, together with glycerol. Common salt is added to precipitate the mixture as soap.

The soapmakers don't separate these mixtures. However, the organic chemical industry can isolate the individual fatty acids by distillation or other means. It's possible to obtain, in purity exceeding 90%, straight chain fatty acids of carbon numbers 6, 8, 10, 12, 14, 16 and 18 (M&B 584). These fatty acids, in turn, can be converted to fatty alcohols, or reduced to the corresponding simple alcohol by treatment with lithium aluminum hydride (M&B 604). Or they can be esterified and the ester reduced to a simple alcohol (M&B 683).

Fatty acid composition varies from plant to plant. That is because they contain different triglycerides. Moreover the triglycerides aren't necessarily simple glycerides in which the three fatty acid groups are identical; they may be "mixed" glycerides. The fatty acid compositions of coconut, corn, cottonseed, olive, palm, palm kernel, peanut, soybean, linseed and tung oil are given in M&B 684. EB11/Oils sets forth plant or animal sources for each of 32 different fatty acids.

You can obtain about 5 gallons of castor oil from 100 pounds of castor oil (Ricinus communis) seeds. (EB11/Castor Oil). The fatty acids of castor oil are about 85% ricinoleic acid, a triol which can be reacted with isocyanate to make polyurethane. (SzmantIURR 60).

The glycerol byproduct is also of some interest, as it can be used in the manufacture of nitroglycerine.

Plant Juices are liquids found as such in fruit or vegetable tissue. From 1860 to 1919, lemon juice was used as a source of citric acid. (Wikipedia/"Citric Acid"). Likewise, malic acid can be produced from apple juice.

Other botanochemicals include alkaloids (e.g., atropine), tannins, terpenoids (e.g., artemisinin, an antimalarial), glycosides, and proteins. Typically, the exotic botanochemicals are obtained from a particular part of a particular plant, and separated from other chemicals by a combination of distillation, solvent extraction, and recrystallization.

Conversion by Destructive Distillation (Pyrolysis). Like coal and petroleum, plant matter can be pyrolyzed (heated in absence of air) so as to decompose the botanochemicals into simpler forms. Wood was pyrolyzed by the ancient Egyptians and their embalming fluid included methanol.

In this time line, methanol was so isolated by Boyle (1661), and acetic (pyroligneous) acid by Glauber (1648). The acetic acid is readily converted to acetone.

The destructive distillation of wood at 400^oC yields methanol (1.5-2.5%), acetic acid (3-7%), charcoal (31-41%), wood tar (11-19%), and gases (hydrogen, carbon monoxide, carbon dioxide, methane) (15-17%). (Kirk-Othmer 25:651; cp. Mills 27; Abraham 184-190; Bordwell 58; Sadtler 350).

The result depends on the species of wood and the temperature employed. Hardwoods produce more acetic acid and methanol than soft woods, but the softwoods produce more wood tar. (Sjostrom 235). EB11/Tar says that pine (a softwood) was favored.

The wood tar (turpentine) can be used for waterproofing, or in theory it can be further fractionated to recover fatty acids, phenol, cresols, guaiacol, and other aromatic compounds. However, such fractionation was not often done commercially in this time line.

Conversion by Fermentation. Plant material rich in carbohydrates, e.g., molasses, can be used as nutrients in fermentation processes. You need a microorganism which will produce the chemical of interest. The advantage of fermentation processes is that they don't require massive amounts of energy. However, isolating the product can be laborious.

Down-timers ferment grapes to make wine, and barley to make beer. Both are dilute solutions of ethyl alcohol. However, the alchemists know how to distill it to high purity (~95%), calling it aqua ardens("burning water").

Wine is perhaps 12% ethyl alcohol, 85% water, and 3% everything else. In red wines, the "everything else" is primarily glycerol, organic acids (tartaric, malic, citric, succinic), and phenols.

"Fusel oil" refers to the dregs left when the liquor of fermented grain, potatoes, molasses, etc. are distilled. It contains longer alcohols, notably amyl (C5) alcohols, and in some cases also propyl (C3) and butyl (C4) alcohol. (EB11/Fusel Oil). They arise by decomposition of amino acids (SzmantIURR 37).

While the wine yeast convert sugar into ethyl alcohol, other organisms make other chemicals. For example, Clostridium acetobutylicum ferments starch to yield 60% n-butyl alcohol, 30% acetone and just 10% ethyl alcohol. This was the World War I Weizmann process, and the acetone was needed to make smokeless powder. The butyl alcohol, originally a worthless byproduct, later became useful in the manufacture of butyl acetate(EA/Alcohols) and consequently more valuable than the acetone. (M&B 506).

For antibiotic production, the most important OTL organisms were Streptomyces (bacteria found in soil and decaying vegetation), Cephalosporium (fungus), and Penicillium (mold). It's perhaps worth noting that molds are used in folk medicine, and it would be prudent to identify them and culture them out.

It is difficult to predict in advance which fermentation organisms and processes we will discover when, but if we don't screen (culture soil and water organisms on culture media and see what they produce), we won't find new antibiotics.

 

Zoochemical Feedstocks

 

Rendering separates the animal carcass into fat, protein and bone. Down-time, animal fats were used for soap and candle making. Like vegetable fats and oils, animal fats and oils can be used as a source of triglycerides and their derivatives. As you would expect, they have their own characteristic complement of fatty acids. The fatty acid compositions of beef tallow, butter, lard, and cod liver are given in M&B 684.

In late-nineteenth century practice, fatty matter was extracted from bones with benzene or carbon disulfide for use as soap stock. The remaining material was distilled, and separated into ammonia, "bone oil," and "bone black." For the organic chemist, the bone oil is of greatest interest; it contains pyrrole, pyridine, picoline, lutidine, collidine, and quinoline. These are heterocyclic aromatic compounds. (Thorp, 281).

Mills (174) says that horn, hair and leather, when destructively distilled, yield a liquid distillate similar to that from bones.

Animal protein can be hydrolyzed to obtain the twenty genetically encoded amino acids. (That's still the industrial source of L-cysteine, leucine, asparagine and tyrosine.) (Bhat 328).

Cow's milk is composed primarily of water (87%), protein (casein and albumin, 4.75%), fat (3.5%), carbohydrate (lactose, 4%), and lactic acid, and the milk of other mammals has the same basic ingredients in somewhat different proportions. (EB11/Milk).

The wool of sheep is a source of both wool fiber (keratin) and wool grease (lanolin) (5-25% wool). Keratin is a protein and thus can be hydrolyzed to yield the individual amino acids. Lanolin, a wax, is a mixture of fatty acids, alcohols, and their esters. Cholesterol (a steroid alcohol) is obtained commercially from lanolin (SzmantIURR 139).

The exoskeletons of crustacea and insects are a source of chitin, a polysaccharide. Chitin can be deacetylated to yield chitosan or hydrolyzed to yield glucosamine.

 

Miscellaneous Inorganic Feedstocks.

 

It is also possible to make use of inorganic carbon sources other than coal, such as the carbonates, and the gases carbon monoxide or carbon dioxide. Phosgene (COCl₂), a useful albeit toxic reagent, is made by combining carbon monoxide with chlorine at 200^oC (M&B 923). Cyanides can be obtained from certain plants (bitter almonds, cassava, appleseeds) or made from other inorganics.

 

Dude, Where's My Carbon Skeleton?

 

Ideally, we keep our syntheses simple. That generally means using, if available at a reasonable price, a starting material which has the same carbon skeleton as our intended product.

Even better, the starting material should be one of the chemicals readily obtainable by processing a "natural feedstock" available in USE territory.

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In general, I don't see the lower alkanes (methane, ethane, propane, butane) as preferred C1-C4 building blocks. First, since they're gases, there's a handling problem. For storage and transport, gases must be compressed, and then pumped into either a pipeline or a tank. So you need a pump, and you need pipes and tanks which can withstand the pressures involved. For cars, natural gas is usually compressed to about 200 times atmospheric pressure. The alternative to simply compressing a gas is to liquefy it, by putting it under moderate pressure and then cooling it below its melting point. You can liquefy crude natural gas (mostly methane; LNG) or petroleum gas (propane and/or butane; LPG).

In fall 1631, when Vicky Emerson told the gas oven investors how "difficult it was to compress natural gas and store it" (Goodlett and Huff, "Poor Little Rich Girls," Grantville GazetteIV), she wasn't lying. What she didn't tell them was that she expected the compression problem to be solved within two or three years. The tanks could be made of copper or steel. (Ashby 143).

Until the compression problem was solved, the organic chemical industry could fractionate natural gas, but it would have to do so near the wellhead, and, on the spot, process the alkanes into something which would be liquid at room temperature, such as methyl alcohol, or ethyl, propyl or butyl bromide.

The second problem is that because alkanes aren't very reactive, there isn't much that can be done with them directly. We have the option of converting methane into "synthesis gas" (carbon dioxide and hydrogen). Otherwise, the derivatives most likely to be produced, for conversion into other products, are alkyl chlorides and bromides. Without ultraviolet radiation, you need 250-400^oC. With the assistance of UV, we can chlorinate methane, ethane or propane at room temperature, but in the last case, we obtain a nearly equal mixture of n-propane and isopropane. Bromination of propane requires UV treatment at 127^oC, but is highly specific for isopropane. (MB 38-40, 116-122) I would expect similar patterns of isomer production as a result of chlorination or bromination of butane.

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I see the preference as being in general for alkenes (from cracking of petroleum), alcohols and organic acids (from fermentation or destructive distillation of biological feedstocks), and simple aromatics (from pyrolysis of coal). But the exploitation of petrochemicals is dependent on both the development of oil supplies beyond that needed to satisfy fuel demands and on the realization of the necessary processing technology.

So, here're my best guesses as to what the organic chemical industry will use as its basic building blocks, and when they will be available. In general, these building blocks are primary chemicals; they are isolated from processed natural feedstocks, rather than synthesized by reaction of pure chemicals. But of course it's possible to make the larger building blocks by combining smaller ones.

C1 aliphatic: Perhaps by late 1631, but certainly by 1632, we will producing methanol by destructive distillation of wood. Methanol can be converted into methyl halides, formaldehyde, formic acid, methylamine. Formic acid can instead be obtained by distillation from the bodies of dead ants. (Gmelin VII-271). There are also the inorganic C1s, carbon monoxide and dioxide, but those are mostly used when you want to keep the C=O bond, as in aldehydes and ketones. And there is coke, the progenitor for the carbides, cyanides and related salts, cyanamide, urea, and thiourea.

C2 aliphatic. In 1631—within days after the grocery store runs out of whiskey—we will be distilling ethyl alcohol. Ethanol can be converted into ethylene, ethyl halides, ethylamine, acetaldehyde, and acetic acid. Acetic acid is an alternative C2; it is distilled from vinegar. And there is the possibility of making acetylene, too. Some years later, these will be supplanted by ethylene from steam cracking of petroleum.

C3 aliphatic. There are actually two C3 skeletons, the linear (n-propyl) and branched (isopropyl). The likeliest linear C3 building blocks are acetone (from destructive distillation of wood or, eventually, a Weizmann process fermentation), n-propyl alcohol (from the fusel oil of, e.g., the marc brandy from southern France; EB11/Fusel Oil) These could be available in 1631-32, but 1632-33 is more likely. Other possible building blocks include lactic acid and glycerol (Dimian 439), and propionic acid (by fermentation of molasses, yielding about 10%, or destructive distillation of wood, yielding 2-4%; Molinari 348) . In the longer term, we will probably use propylene.

Isopropyl alcohol is not readily available by fermentation. (Meldola 64). However, it can be made by reduction of acetone (M&B 636), and, eventually, hydration of propylene.

C4 aliphatic. There are two different isomers of C4, linear and branched, and two different ways of connecting a single functional group (R) to the carbon skeleton, so we have four different butyl functionalities: n-, iso- , sec- and tert-butyl. We ignore the latter two.

The most likely C4 building blocks are butyl alcohol and butyric acid. Isobutyl alcohol is found in fusel oil, such as that from fermented potato (EB11/Butyl Alcohols) or beet-root molasses(EB11/Fusel Oil) . N-butyl alcohol is perhaps obtainable by a "peculiar" fermentation of glycerin (Id.) Figure 1631-33. Some years later, the Weizmann process of making it will come into play.

N-butyl and isobutyl alcohol (and the corresponding aldehydes) are made in modern practice by hydroformylation of propylene (in effect, adding a carbon to a C3 building block). This will be impractical for generations in the 1632verse, because the reaction requires a fancy cobalt or iron carbonyl catalyst. (Szmant 350, M&B 507).

Butyric acid likewise comes in two isomers, with the n-isomer being available from the triglycerides of butter. EB11/Butyric acid says that the iso-form "is found in the free state in carobs (Ceratonia siliqua) and in the root of Arnica dulcis, and as an ethyl ester in croton oil."

Also in contention, we have several dicarboxylic acids—succinic acid ("spirit of amber"), fumaric acid, malic acid, and levulinic acid. (Dimian 439). Succinic acid can be distilled from amber and various resins, or synthesized by fermentation or oxidation of fats and fatty acids. (EB11/Succinic Acid). "Fumaric acid is found in fumitory (Fumaria officinalis), in various fungi (Agaricus piperatus, &c.), and in Iceland moss." (EB11/Fumaric and Maleic Acids). It can also be obtained by Rhizopus fermentation of carbohydrates (Szmant 362). And it occurs in many plants (EA). Malic acid was first isolated from apple juice in OTL 1778. It's "found abundantly in the juices of many plants, particularly in mountain-ash berries, in unripe apples and in grapes. The acid potassium salt is also found in the leaves and stalks of rhubarb." (EB11/Malic Acid). Levulinic acid is not found in natural feedstocks, but it is obtainable by hot acidification of sucrose. (EB11/Laevulinic Acid).

C5 aliphatic. A mixture of C5 (amyl) alcohols is obtainable from fusel oil, probably 1631-33. Valeric acid and valeric aldehyde are found in certain plant sources (EB11/Valeric Acid, Valerian).

C6 aliphatic. One possible source is caproic acid, in butter fat and coconut oil (EB11/Oils). Another is adipic acid (from fat), used as a nylon precursor. Still others are sorbitol (from Sorbus trees) and lysine (from animal protein) (Dimian), but they have multiple functional groups and hence might need to undergo several conversions in order to arrive at the desired product.

Higher aliphatics. In general, the alkanes can be obtained from petroleum, if the gas guzzlers let us. Straight chain, even carbon number aliphatics are available from selected fats and oils. The gaps might need to be filled in synthetically.

Cyclic Aliphatics. In modern practice these are mainly obtained from petroleum. Some crude oils are naturally rich in cyclic aliphatics, and others can be processed to produce them. Coal tar benzene could be hydrogenated to produce cyclohexane.

Carbocyclic Aromatics. Benzene, naphthalene (two fused rings) and anthracene (three fused rings) will almost certainly be obtained by coal pyrolysis, just as in the nineteenth century.

We know that "light benzoils" (probably benzene, toluene and xylene, "BTX") are being produced in Magdeburg at the end of 1633, and aniline (aminobenzene) is being produced at Essen in winter 1633-34. Since DDT was made in mid-1633, that implies that there was some coal tar production earlier, perhaps in or near Grantville. Nothing was said specifically about the polyaromatics (those with multiple rings), but they're in coal tar, too. In modern practice, "BTX" are obtained mainly by catalytic reforming of petroleum, rather than from coal tar.

Biological feedstocks are not especially good sources of the simple aromatics that are the most versatile building blocks. The simplest are benzyl alcohol, found in Peru balsam and storax; benzaldehyde, obtainable by decomposing amygdalin, itself extracted from almonds or apricot kernels; and benzoic acid (from gum benzoin). (EB11) However, we can isolate biologically active compounds from biofeedstocks and then use them outright, or "tweak" the structures a bit ("semisynthesis").

Heterocyclics. Heterocyclic chemistry is simply too complex to be more than touched upon in this article. In general, the simple heterocyclic rings are synthesized by simple addition or by condensation (a combination of addition and elimination; there is loss of water, alcohol or hydrogen halide) of linear building blocks.

A few heterocylic aromatics warrant special note. Thiophene (4C, 1S) occurs in coal and oil, and can be synthesized from acetylene and sulfur. Furfural comprises the furan (4C, 1O) ring, and is produced from agricultural waste (EA/Furfural). Pyrrole (4C, 1N), pyridine (5C, 1N), quinoline (2 fused rings, 1N), and acridine (3 fused rings, 1N) can be obtained from coal tar or bone oil.

There are numerous biomolecules that comprises heterocycles—notably nicotine (pyridine and pyrrolidine), the amino acids histidine (imidazole), tryptophan (indole) and proline (pyrrole), the purine nucleic acid bases guanine and adenine, and the pyrimidine nucleobases thymine, cytosine and uracil—but the additional substituents on these molecules limit their use as building blocks.

 

Organic Chemical Timeline

 

So, what additional organic chemicals will we want, early on? The "wish list" for the chemists will be compiled from encyclopedias, textbooks, and even product labels.

Wanting a chemical, of course, isn't the same as knowing how to make it. We know from the review of organic chemicals in canon (Part 3) that the chemists have succeeded in synthesizing DDT, chloramphenicol and sulfanilamide (Figure 4-2). So the chemists are clearly capable of synthesizing compounds with a mono- or disubstituted benzene ring. And I don't think it's too big a jump to trisubstituted benzenes, although figuring out the correct order of substitution is more involved.

It's less clear that they will be able to do much with heterocyclic compounds. From M&B, they will learn a bit about the synthesis and derivatization of pyrrole, thiophene, furan, pyridine, quinoline and isoquinoline. CCD reveals that purine (fused imidazole-pyrimidine) can be prepared from uric acid (in turn derived from guano!), and carbazole from the anthracene cake of coal tar.

EB11 has essays on at least the following heterocyclics: xanthone, pyrazoles, pyrimidines, purin(e), pyrrol(e), acridine, thiazoles, triazoles, quinazolines, tetrazoles, quinoxalines, phthalazines, adenine, phenazine, piperazin(e), piperine, indulines, azoximes, imidazoles, indole, oxazoles, pyrazines, pyridine, quinoline, safranine, thiophen(e), tropine and triazines, and the precursor pyrogallol (catechol). These may give information on how they are synthesized and used. McGHEST similarly covers furan, purine, indole, pyridine, pyramidine, and pyrrole. Some of the heterocyclic compound entries (e.g., imidazole) in Merck Index provide synthesis guidance. The richest source of heterocyclic chemistry tips is the Named Organic Reactions section of Merck Index (MI), which includes the Biginelli pyrimidine synthesis, the Bischler indole and triazine syntheses, and much more.

Synthesizing a heterocyclic ring from the basic building blocks will usually involve a minimum of three steps, one for the ring forming itself and the others to make the reactants. In the Debus synthesis of imidazole, the ring is formed by the reaction of a diketone (R-C(=O)-C(=O)-R) with an aldehyde (R'C(=O)-H) and ammonia. But you would need at least one step to make the aldehyde from our building block alcohols or carboxylic acids, and several to make the diketone (e.g., alcohol to ketone to isonitrosoketone to diketone; EB/Ketones).

If the heterocyclic ring is itself substituted then you need to figure out whether to introduce the substituent before, during or after ring formation. Because of all of the complications, I have only listed a few heterocyclic compounds.

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There are three bases for listing an organic chemical in the timeline (Table 4-4):

—it is explicitly referred to as isolated or synthesized in a story, i.e., a canonized chemical;

—it is an "essential precursor" in the manufacture of a canonized chemical by the inferred synthetic route; or

—it is a chemical which this author predicts would have been made at that stage, because it ...