Trying Not To Use Energy While Making Energy

Hello,

This post will be on the optimization of energy within an oil refinery.  In many ways, energy optimization is a subset of economic optimization because if you save energy you save money.  However, I feel that it is important to set it aside because it is one area of refineries that has waste in some form (nor is it possible to completely prevent really).

So first things first, what do I mean by energy optimization?  In refineries, it takes energy to heat and cool the products for the distillation process.  Furthermore, there are compressors that require energy to pump the fluids and even light sources that require power amongst other parts of the refinery that require energy.  The optimization comes into play through figuring out our to best layout the refinery to use the least amount of energy as possible.

Energy optimization in refineries starts with heat.  To gain some perspective at the heat differences, some substances are heated to well over 1000 degrees fahrenheit while others are cooled to a good amount under 0 degrees.  As you would expect, the heating and cooling of these substances takes a lot of energy.  Also, for distillation to work, substances have to be heated to their boiling point, then condensed back into their liquid state.  This leads into the waste in energy.  When a heated substance is cooled, there is a waste of energy in the form of heat.  To combat this refineries use heat exchangers.

A heat exchanger allows a heated substance to heat a different substance, thereby using the thermal energy of the first substance.  It is important to note that the heat exchanger does not mix the two substances (that would be counter productive…) but rather only allows heat to be transferred between the two.  Heat exchangers are more efficient when they limit the amount of heat lost to the environment.

Another important area for refineries is that of pumping the fluids from unit to unit.  Compressors are the main energy drain here and are required when pumping a substance from low to high pressure.  This means that the best way to optimize energy in this regard is to lay out the refinery in such a way that limits the need for compressors.  To put it in simpler terms, engineers try to adjust the layout of the refinery to use gravity and pressure in their favor when moving substances from one unit to another.  

Well that’s the basics of energy optimization.  If there is anything not clear in here, I will be happy to answer questions in the comments.  On a side note, my 18th birthday is tomorrow, so I’ll be writing next week a year older (because that’s how age works, best not to question it).

Stephen

Making Something From Nothing....Kinda

Hi again,

In my last post I mentioned that I would dive into the different areas of optimization, and how they are achieved.  This week I will go into how lower end products are made into products of higher value.  To achieve this, there are a multitude of units that work towards this goal, so I will go over the general concept, and talk about one unit in particular.

The general concept of a refinery is to take crude oil and create valuable products, most notably gasoline.  To do this, the refinery takes the heavy crude, and breaks the long hydrocarbon chains into smaller ones.  However, during this process, a number of other products are created, some more valuable than others.  Generally, the lighter the product (smaller hydrocarbon chains creates a lighter product) the more valuable it is.  The least valuable product from refineries tends to be asphalt, which is a mixture of heavy byproducts.  

So now the quest is to make those heavy byproducts lighter and thus more valuable.  Enter the magical coker unit.  What does it do? Great question.  This unit will take those super heavy products, such as residual oils (heavy byproducts from units that create what eventually turns into gas), and makes them into a few different lighter products.  The main products are naphtha (mixed with other products to make gasoline), light and heavy gas oils (used as an energy source), and petroleum coke (also called pet. coke or simply coke).  As you may have guess, the last product is where the name of the unit comes from.  

The petroleum coke in many ways is why this unit is so useful.  Petroleum coke is very similar to coal in use and appearance.  This means that the coker takes what would eventually turn into asphalt, and creates a valuable energy source.  I also mentioned last week about the need to optimize energy, and some coker units do this by using some of the petroleum coke produced to provide the necessary energy to run the unit itself (I’ll continue into energy optimization next week).

Now why is the coker and units like it important to mention?  The reason is that these units are one of the main ways that refineries are currently implementing to find better economic optimization.  The reason for this is because cokers are more useful as the quality of crude oil declines (remember in the last post I mentioned that the quality is in constant decline currently), as poor quality crude creates heavier byproducts that need a unit like the coker to refine.  Thus, units that refine these heavy byproducts are becoming increasingly necessary in the world’s refineries.

Well, that’s a bit on economic optimization.  It is a pretty complicated topic and I may revist this again later, but next week will be on energy optimization.  See you then.

Stephen

Goodbye California

Hello,

Well, I have now returned to Arizona after an all around great experience in California.  I learned so much about the industry I hope to enter, insight into the possible major I will choose, and of course, how to optimize refineries.  In this post I will go over the general aspects of optimizing a refinery, and go into specifics in the upcoming weeks.

So first off I feel it would be good to clear some misconceptions about the oil industry that plays into my research.  The largest one is that oil is quickly becoming more scarce and that it has a huge effect on the market.  Any changes to scarcity are happening slowly and does not really change the market all that much.  If there are any changes in scarcity, it is that over time the quality of the crude oil being processed has decreased (I will go into this more later).  Another misconception, related to the scarcity one, is that there is going to be more money in oil sooner rather than later, because the scarcity will cause the price to increase.  In reality, the oil market is cyclical, and highly dependent on a variety of factors.  

Anyways, onto the optimization.  Refineries are optimized to reach the highest level of economic efficiency as possible.  This means that it is very common that over time refineries try to invest in units that take lower end products and make higher end products.  An example of this would be using products that would normally go into asphalt, and making gasoline products from them.  There are little to no waste products from refineries, it’s just the value of the product and which product is being produced that is optimized here.

Another area of optimization for refineries is that of energy usage.  They are designed to avoid wasting energy throughout the process, and to try to use heat from the process that is needed elsewhere in the process to try not to waste that energy.  In many ways, heat is often the highest area of waste and could be where future changes are made.

Environmental concerns are also playing into the industry.  As legislation is passed to decrease emissions, refineries are forced to implement units that will help them meet the specifications.  The most common form of this is decreasing sulfur levels in fuels.  There have been huge advancements here in the past few decades, and as more legislation is being passed throughout the United States and the world as a whole.

Anyways, that’s the brief overview.  I will go into more detail in the upcoming blog posts.

Stephen