Manufacturing and Energy

Energy: Why important for Process Engineers

Sat, 10 May 2008 23:15:42 -0700

Fuel for energy is generated by the nature. For example, C1 (carbon in the form of CO2) is naturally synthesizes (photosynthesis in presence of natural UV radiation) to molecule Cn (like starch, sugar or cellulose), which are used directly /or indirectly as fuel/ or feed stocks for fuel generation. Consumption of available fuels higher than generation is creating not only fuel shortage but also leaving behind bad consequences to the environment due to exhausted excess carbon dioxide.

Being desired transformations can�t be avoided in the process industries, higher energy wastages in them demands higher input energy. How energy is wasted in the process industry? To understand it, consider following cases:

Doing more, thus wasting more
Doing more, but using less
Wasting more, thus doing more

Doing more, thus wasting more
For example, pump filling overhead constant level tank at higher flow rate than required, thus subsequently overflowing excess amount of liquid to ground tank. Being pump is operating at much higher capacity than required, excess energy is wasted.

Doing more, but using less
For example, use of higher capacity conveyor for small amount of material transportation. Underutilization of material conveyor wastes more energy for unit production rate.

Wasting more, thus doing more
For example, high number of pipe fittings used in the pipe routing leads to high fluid energy wastage in terms of frictional pressure drop, thus more work is to be done by the pump.

Right amount of energy for desired transformations is the ultimate aim of energy conservation. Reduction in energy wastage to minimum reduces the energy demands in the process plants. Following steps for energy conservations are discussed here:

Good Housekeeping
Optimization of Plant Operation
Hardware Modification or Replacement
Process Modification

Good Housekeeping
This is foremost simple step, which any process industry can easily adopt. Arresting steam leakages, stopping idle operating pumps or mixing agitators, etc. are the typical examples falls under this category. Being the simple steps, it absolutely doesn�t require any financial investment and can be implemented at any time. It requires only the energy conscious culture in the process industry. This step itself can save ~5% in energy bills of the industry.

Simply organizations need culture where everyone from shop floor to top management feels himself involved in the process.

Optimization of Plant Operation
Excess capacity, provided by the plant designer as safety margin, of the plant hardware provides the scope of using it during actual plant operation. Thus, process plant hardware need to be tuned for energy efficient operation. Liquid transportation with maximum flow capacity of the pump, minimizing reflux ratio for distillation column, etc. are the well known examples for process plant optimization. The optimization exercise require either no or minor financial investment. Though some operational time may be consumed for setting rightful optimum parameters, but often results attained are very positive as far as energy saving is concerned.

Hardware Modification or Replacement
Reduced efficiency of existing hardware e.g. scaled or blocked heat exchanger tubes, entry of innovative energy efficient devices in the market like high efficiency distillation column packing, poor selection of hardware at the time of first purchase e.g. lower pipeline size, etc. demands much higher input energy than actually required for desired transformation. Necessary hardware modification or replacement conserves energy in the process plant. Unlike previous two categories, it requires low to medium level financial investment along with process plant stoppage for changeover of the troubling hardware.

Process Modification
Many times overall or part of the process is modified for the sake of overall energy savings. Process routes as well as transformation steps are altered to minimize input energy supplies. It requires extensive studies at various levels starting from paperwork to laboratory, pilot plant & semi-commercial levels. Usually such process modifications require high investments as well as higher implementation time for gaining energy benefits. But they are essential at a stage when business need improvement due to tough market competition.

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Positive Displacement Vs Centrifugal Pumps - How to Select

Sun, 23 Mar 2008 21:10:16 -0700

When to use a centrifugal or a Positive Displacement pump (PD) is not always a clear choice. To make a good choice between these pump types it is important to understand that the two types of pumps behave very differently. By looking at the performance chart below you can see just how different they are. The centrifugal has varying flow depending on pressure or head, whereas the PD pump has more or less constant flow regardless of pressure

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Ethanol: How far, How Close

Fri, 21 Mar 2008 01:23:17 -0700

In recent years, everybody is dreaming about one cheaper & cleaner fuel ethanol. Though the cleanliness over its total life cycle is still a debatable point along with energy efficiency debates. I am considering few Nos which were presented in some othe blog for my visitors. In this we will see the total requirement & growth of Ethanol as fuel & as industry demand

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100 Posts, 100 Users & More.......

Thu, 20 Mar 2008 04:46:05 -0700

This blog was conceptualized to share the information for young process engineers who need guidance at each step in the early career of their professional life. Since May2007 I started active blogging. Now we had 100 Posts in 10 Months & 75 readers which is a very good growth specially when your focus area is so specific. I am not blogging for my own thoughts, day to day happening like my personal diary but this blog is meant for purely technical & useful learnings

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P&ID - learning small things for big projects

Wed, 12 Mar 2008 03:07:12 -0700

Normally a project passes through various phases e.g. basic engineering, detail engineering, equipment fabrication, erection, commissioning etc. The conceptual idea of business from the process development cell is converted to executable documents during basic engineering.

This is the step where we need P&ID or piping and Instrumentation diagram

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New Idea for better & low cost Insulation

Sun, 09 Mar 2008 23:13:35 -0700

Common problem of carrying out calculation of optimum insulation thickness, Yet loosing lot of energy in the form of heat loss or cold loss, need re-work on insulation due to damage over a certain period of 2-3 years during annual turnaround etc. etc..............

Poor process engineers. Need survey of thickness, need good maintenance & monitoring program....lots of cost items..& still not satisifed.

After so many years of struggle, I thought about this Idea which is very cost effective & higher savings for lifetime. No need of re-work etc. No maintenance cost.

Interesting.........Ya....Very good business idea too....here is my input

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Handy Excel Tool for Orifice Calculations

Wed, 05 Mar 2008 01:09:07 -0700

Process engineers need many calculations related to orifice design e.g. for

Restriction Orifice Dia.
Maximum possible flow through Restriction Orifice for a given dia.
Flow of gases through spargers with a given hole size & pipe Dia.
calculation of new size of holes for spargers.
Pressure drop across Orifice.

And many more..........SO I am attaching a very simple excel sheet for such calculations, which is not very complicated yet useful for almost 98-99% accuracy.

To Download the file , just click ....

Water Saving :: Amazing Nos.

Sun, 02 Mar 2008 23:28:33 -0700

Recently going through some blog articles, I found the use of low flush toilets where water can be saved by more than 50%. Amazed by numbers, I thought to work out my self these numbers with ref to India & possible quantum of savings.

Therefore, my search began on this issue & found that technologies are available which can reduce the consumption to more than 80-90% and is totally developed indeginously by Indians. We do not realize the importance of any small change unless we see its impact in totality which may be very useful for the nation as a whole

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