h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Was watching a rebroadcast BBC4 proggy the other night called All Our Working Lives about the chemical engineering industry, followed by another proggy updating it to more modern times.

The update proggy is here for them as can:
http://www.bbc.co.uk/iplayer/episode/b00v3wwt/All_Our_Working_Lives_Revisited_Chemicals/
(can't find the original on iPlayer, but was an old proggy, I guess from the 80s?)

Fascinating program (and I'm aware we have people on here involved in the industry, or working alongside it).
But what I wondered about was the seeming progression of bases used for the engineering process, for plastics anyway.
It seemed (and i may have this wrong!) that the progression went:
Molasses
Coal
Oil

And although apparently there are still some places in the world using the first two, everything else is oil based.
I presume, with my limited knowledge, that this is because those three are sources of hydrocarbons which can then be turned into the various product materials?

The issue seemed to be cost. And cost based on ease of getting from base product to final product, not just the cost of the base material.
I.e. that it was somehow easier to produce plastics from oil than from coal (and thus from molasses).

Is this right?
And if so, why is it cheaper to use oil than coal than molasses?

Oh, and as sub question - why molasses? Seems not to sit with the other two or is that just cos I classify it as 'foodstuff' whereas the other two are 'natural fuel'?

Well I'm not an engineer but the real problem is purification.

Purification is *really* expensive and you want to minimise it - big style - for large scale processes particularly.

Making any chemical product, whether plastic, pharmaceutical or whatever requires pure starting materials (the building blocks of what you want to make). It is relatively easy to crack, boil and distill oil to get the simple precursors you need pure. From coal - being a solid it takes more energy to get the material broken down in constiutent parts. From molasses, cane sugar, lignin or whatever biomass raw material you have to extract and process those same starting materials from an incredibly complex mixture which will also likely have lots of horrid physical properties that make it hard to work with - e.g. stickiness.

Things are gradually changing though and there are now lots of companies beginning to work on getting good feedstocks like methanol and ethanol from biomass such as general human waste using engineered bugs. It's still *vastly* cheaper to do this from oil though.

Molasses by the way is basically a complex sugar. It can be acid treated (and enzyme treated) to break it down in glucose units and then the glucose can be fermented into ethanol.

So it's a good raw material for things like ethanol and sugar derivatives.

I haven't really got time to watch the programme on the link above but you can probably say that for feedstock purposes, molasses = cane sugar = beet sugar = corn syrup = same difference. They are all used as feedstocks and although they are different, they are all similar too and for the purposes of the programme it's easiest to stick to a typical one I guess.

cheers Orcus.
TBH the programme is more about the social and industrial changes aspect of the chemical engineering industry; rather than how and what they do. So the subject of source material is referenced in light of changes in the industry, their impact and how the British part of the industry struggled to keep up with the likes of Saudi (I think it was) and USA.
More a social documentary than a chemical one (but very interesting!).

I keep seeing things about bacterial production of various products, has anyone actually got things up and running in a proper prodcution environment yet? As an actual viable business or is it still early days?
E.g. have seen the research using bacteria to produce diesel, for example. Which sounds like it should be able to take off (sorry) commercially.

It's a tiny wee industry but yes it's up and running.

The stuff I've seen though is mostly pilot plant stuff run by the big boys. It *is* definitely coming though - if they are into it then it will happen.

Far and away the biggest microbial production of a product though is high frutose corn syrup production and that only succeeds I think because the USA has large trade tariffs preventing US import of cane sugar. That's what's in your sweeties and soft drinks - not the world saving bioproduction that we want.

There are many biological steps in pharmaceuticals production these days. That's where it's sneaking in at the moment.

There's also an element of progression of knowing how to do the sums. Deriving the relationships between energy input and reaction speed, understanding distillation, that kind of thing.

Another HUGE factor is straightforward economy of scale.

Here's a simple fact that still boggles my mind: petrol is cheaper than milk.

You can go out into the middle of the north sea or some other horrible, inhospitable place (somewhere with Arabs or Texans, say), spend millions building a drilling rig, more millions building a pipeline, more millions building a refinery, more millions building and buying tankers, and more millions staffing and running all of these incredibly energy intensive processes... and you can sell the product of all that incredible effort for less than the cost of a bottle of something you just squirt out of a cow, and STILL make profits that most people think of as obscene.

Think of the labour per unit of energy in molasses (lots), coal (less), and oil (negligible, once the infrastructure is in place).

Well, my degree is in chemical engineering and (except for an college internship) I don't work with large-scale organic chemistry raw materials such as the big three mentioned (molasses, coal, oil). Interestingly, natural gas was left off too, but I suppose that's because not much is made from natural gas except methane, propane, and a few other flammable gases for fuel (as an aside, I did a major design project on how methanol can be made from methane, but it's expensive and there's not much market for methanol as a fuel to be anything other than a semi-academic exercise)

My only point was that lots of chemical engineers (and the chemical engineering industry in general) working in inorganic chemistry processes, from those that may be associated with nuclear fuels processing (as I am) to those who work in semiconductors and chip manufacturing (as several colleagues from my university currently do). The big shift away from petroleum engineering side of chemical engineering seemed to really peak in the 90s.

But I would tend to agree with other posts, that since oil is a witch's brew of organic chemicals (mostly saturated hydrocarbons) to begin with, the problems of large scale separation technologies become more cost-effective when considering starting with coal (essentially elemental carbon) and having to build up to more ordered hydrocarbons that could then be polymerized. In comparison, coal is too cost-prohibitive. Molasses is a strange thing to see crop up on that list (a hydrocarbon blend, or more accurately a blend of sugars - mostly sucrose - that is not nearly as diverse as oil). In the context of making most modern plastic and/or hydrocarbon products for fuel, sugars would require even more energy to first separate them (I think molasses is only part sucrose), break them down or pyrolyze them into some sort of useful building block organic chemicals. Probably very cost-prohibitive. In fact, I think that molasses has a use for actually performing remediation of chlorinated hydrocarbons (i.e. the class of monomers that become the basis for most plastic polymers).

- Jon

thanks again for the replies.
Was having a bit of a further think on this.
There are, of course, other sources of other oils.

I'm kinda assuming that 'oil' has a specific chemical meaning as well as the lay meaning covering everything from crude through to pretty film seen on puddles.

I'm just wondering why natural oil is preferred over other oils. Would it be because of a) abundance (relative) and b) the aforementioned 'witches brew' makeup? I.e. that crude oil has lots and lots of different hydrocarbons (does that make sense?) than other oils (eg plant oils)?
And therefore can be used as a source for more products?

Crude oil is a mixture of hydrocarbons

Natural lipids are not the same thing at all really.

Do you know what an ester is?

If not, it's a compound formed when an alcohol and a carboxylic acid condense with the release of water.

http://en.wikipedia.org/wiki/Ester
http://en.wikipedia.org/wiki/Carboxylic_acid


Natural fats, membranes, lipds, oils, whatever you want to call them, whilst, yes, being a witches brew of many different things are fundamentally esters of glycerol (an alcohol with three alcohol (OH) groups) and long chain fatty acids (hydrocarbons with a carboxylic acid at one end).

So although physically they have similar properties to crude oil and some of its distillates, chemically they are very different and therein lies a major problem in doing anything with them.

Once you've broken natural oils down into their components you have glycerol and acids to deal with and they can do all sorts of nasty things to the catalysts used to crack the friendlier hydrocarbons down. Glycerol is also a blogger to get rid of from mixtures as it's thick and syrupy and soluble in all sorts of different solvents.

"So although physically they have similar properties to crude oil and some of its distillates, chemically they are very different and therein lies a major problem in doing anything with them."

Ah, I see, Thanks Orcus.

This question also may not make sense, but I'll try anyway!
Is it possible, then, to conceive of a 'better' source than crude oil? Better considered from the chemical pov, that is. Or is crude oil pretty much as good as it gets from a non (active) bio perspective?

Fundamentally, the problem is one of energy. Given an unlimited energy source, you could polymerise longer chains from shorter ones, rather than cracking long ones to get shorter ones.

It's been a bit of a zeitgeist thing this last decade to ask "where's my jetpack?", a lazy satirists' shorthand for the disappointment many people feel that the 21st century isn't the future we were promised in the sixties and seventies.

However, we were, I think, never actually promised jetpacks. We WERE promised working fusion reactors "within the next twenty to thirty years". We're still being promised the same thing, and on the same timescale. THAT's really frustrating, the more so after the chimera of cold fusion in 1989. If and when we crack fusion, the entire game will change, not overnight, but pretty quickly. And it won't be pretty, because when it happens, all the oil that currently gives Islam its global clout and keeps countries like Israel from nuking the hajj will be about as valuable a commodity as seawater. Speaking as a non-Muslim resident of a small island surrounded by seawater, I'm quite looking forward to it.

Suspected as much

As for fusion, there's problems with ITER funding at the moment as well. Not exactly unexpected, but a shame as so much is being learnt through merely the construction of the thing, never mind its operation.

Speaking as a non-Muslim resident of a small island surrounded by seawater, I'm quite looking forward to it.

And the bottom will drop out of the fancy rug market because that's what they're gonna have to start making again.

And the bottom will drop out of the fancy rug market because that's what they're gonna have to start making again.

that should be a QOTD!!!!!

Heheh, wow. These tangents people go off on. (I did laugh at that one, tho).

Just to point out one more thing regarding what Orcus and Tiggy were pointing out, while "oil" is indeed a rather poorly-defined term in that it can include several classes of organic compounds let alone several hundred examples of compounds in each class, it might help to remember that the "oil" we get from the ground to run our cars about and do clever things with plastics eventually got there by the slow application of pressure and heat on animal and plant matter (mostly plants I think, but I'm no geochemist). So there is a relation between vegetable oil and oil dug up outta the ground. The most obvious one perhaps being the plant oils that can give us chemically identical things (e.g. diesel "fuel oil" can be derived from plants directly as well as separating it from crude oil).

But yeah, there still are all those esters to get rid of first. In fact, the title of the process for turning waste vegetable oil into useable diesel fuel is "transeterfication" - bit of a give-away, innit?

- JD

An
: spontaneous combustion of oily cloths drying out.

I know that mineral oils can be subject to this and have always assumed (for safety) that vegetable oils are too - is this right?

Sure can. Linseed oil, a plant-derived oil, is traditionally used to make oilcloth. Linseed oil is very reactive in air, that is it oxidizes rapidly in air. As the linseed oil oxidizes, the rags holding it can build up heat from the exothermic reaction. If enough is piled up in one place, the oilcloth can spontaneously ignite.

I suppose there might be other oils that are as reactive in air, but most would require some external ignition source as opposed to its own heat of combustion leading to self-ignition. I'm not too familiar with any mineral oils that self-oxidize like linseed oil that could lead to the oils rags self-ignition, but as linseed oil is just a blend of unsaturated esters and fatty acids, I don't see why any mineral oil that happens to contain lots of unsaturated esters wouldn't follow the same behavior. It's just that most mineral oils don't contain them, which is what we were talking about earlier.

- JD

I am fairly confident ITER will get its funding. Too much spent already and Governments hate spending enough for half a project. Plus to EU funding bodies there is the prestige of having the worlds two largest science experiments.

Interesting what you say, Jon, thanks. My 'knowledge' came from early services training, is pretty well automatic now & my use of oils is almost all veggie now, many containing Linseed.