From crude oil and natural gas to the C1-C4 building blocks

By the end you will be able to

• Describe what crude oil and natural gas contain and which refinery and gas-plant streams go to chemicals
• Trace a steam cracker from furnace to cold-end separation and explain each operating choice
• Compare ethane, propane, naphtha and gas oil cracking by co-product slate and net feed cost
• Explain the sources of propylene, the C4 olefins and BTX aromatics, and why their supply is regional
• Follow methane and coal through synthesis gas to methanol, ammonia, formaldehyde and acetic acid
• Use feedstock, capital, scale, integration and CO2 data to explain the regional cost curve

Contents

1. Part 1 The raw materials: crude oil, natural gas and the refinery

   Nearly every organic chemical starts as a hydrocarbon molecule pumped out of the ground. Before any chemistry happens, crude oil and natural gas are sorted by boiling point and cleaned up. This part looks at what those raw materials contain, how a refinery splits and reshapes them, and why the chemical industry gets only the leftovers of a business built to make fuel.

   • Seven building blocks carry most of the industry, and they come from two raw materials
   • Crude oil is a mixture sorted by boiling point, and naphtha is the cut that matters most
   • Refineries are built for fuel; chemicals get by-products of cracking and reforming
2. Part 2 Steam cracking: the engine of the petrochemical industry

   Steam cracking makes almost all the world's ethylene and much of its propylene and butadiene. It uses no catalyst, only heat, speed and a very cold separation train. This part follows the gas through the furnace, the quench and the cold end. It then shows how the choice of feed, ethane or naphtha, changes everything that comes out and what each tonne of ethylene really costs.

   • The hot end: a few hundredths of a second at 800 C
   • The cold end: separating a cracked gas costs more than cracking it
   • The feedstock decides the co-product slate, and the slate decides the economics
3. Part 3 Propylene, the C4 stream and the aromatics

   Ethylene comes almost entirely from steam crackers. Its sister products do not. Propylene comes from crackers, refinery catalytic crackers and purpose-built plants. Butadiene and isobutene must be pulled out of a crowded C4 mixture. Benzene, toluene and xylenes come from reformers and from cracker pyrolysis gasoline. How each is sourced explains regional shortages and gluts.

   • Propylene has four sources, and on-purpose routes fill the gap ethane crackers leave
   • The C4 stream is a crowded mixture that must be taken apart in a fixed order
   • Aromatics come from reformers and pyrolysis gasoline, and nature's mix never matches demand
4. Part 4 C1 chemistry: synthesis gas, methanol, ammonia and coal

   Methane cannot be cracked into olefins the way ethane can. Its value comes instead from synthesis gas, a mixture of carbon monoxide and hydrogen, from which ammonia and methanol are made. The same gas can be made from coal, which is how China built a coal-based chemical industry. This part traces those routes and what they cost in energy and carbon.

   • Steam reforming turns methane into synthesis gas, and the mix is tuned to the product
   • Methanol: a low-pressure copper catalyst, a big recycle loop and giant plants
   • Ammonia, formaldehyde and acetic acid: what syngas and methanol become
   • Coal can replace gas through gasification, and China does so at scale
5. Part 5 The economics: feedstock, scale, integration and carbon

   The same molecule of ethylene can cost very different amounts depending on where and how it is made. Feedstock price matters most, then co-product credits, then capital and scale, and finally whether the cracker shares a site with a refinery. This part pulls those threads together. It looks at the regional cost curve and at the energy and carbon tied to each tonne.

   • Feedstock price decides who sits at the bottom of the cost curve
   • Capital, scale and integration: why crackers are huge and sit next to refineries
   • Energy and emissions: where the carbon goes for each building block
6. Wrap-up Key terms, try it in the table, final quiz, sources