Sunday, June 7, 2015

Unexpected Results From Computers

Subtitle: If A Human Can't Find It, The Result Is Unexpected

Computers are sometimes discussed as slaves to their programmers; that is, they produce only the results the programmer wanted when he (or she) wrote the software that runs in that computer.   I have discussed this before on other forums, and this article addresses some of my experience in this arena. 

My qualifications to discuss computers and software programming are as follows: software development, design, debugging, and various sorts of computer programming since 1971 (44 years at this time), from simple BASIC, Hewlett-Packard's programming on HP-35 pocket calculator, FORTRAN of various vintages (starting with FORTRAN 66 on IBM mainframes), Artificial Intelligence software in LISP and neural networks, Lotus 123 and MS Excel (tm), to html and similar programming on modern internet applications.   Computing platforms covered a variety, such as IBM mainframes, CDC machines, programmable pocket calculators, desktop PC (personal computers), and modern laptops. 

The primary purpose of my programming efforts has been related to chemical engineering tasks, where very large databases from a process plant running 24/7 provide information that must be retrieved, analyzed, processed, and results returned in a timely manner for appropriate decision-making.   Also, very complex oil refining, petrochemical, and inorganic chemical process unit simulations (including kinetics in reactor systems) were developed and enhanced - including various forms of optimizers (e.g. LP, successive LP,  and open-equation).   In short, computers and software are merely tools to the chemical engineer, not our reason for living.  We have real problems to solve in the real world, with (at times) hundreds of millions of dollars at stake (or more).  There are almost always time constraints in the problems that require a quick solution, such that a program that runs too long is totally useless even if it provides the correct answer.   The process unit conditions will have changed far too much for an answer to be useful.   Time frames for computer solution can be measured in hours, but often a few minutes is required, and on rare occasions, a few seconds.  

So, do the computers we use provide predictable, unsurprising results?  Are they truly slaves to their programmers?  No.   Chemical engineers know very well that our software provide unexpected results on many occasions.   This is a hard concept for many to grasp, perhaps because they have been conditioned to believe that a computer merely adds 1 plus 1 to obtain 2, but does it very, very quickly.  And, I agree that computers can and (sometimes) do add 1 plus 1 to obtain 2.  And, they do that very, very quickly.  

Examples of unexpected results follow.  One arena is in optimization of complex process units.  Another is recognition of patterns, such as "this event X always happens after that event Y occurs, but only after Z time passes from event Y."  

Complex process unit optimization.  

Process modeling and optimization is sufficiently important in chemical engineering that, for example, a session at an AIChE conference was held recently (see link), with the session description as:

"Modeling is the art of simplification of complex physics underlying the chemical processes to account for observed phenomena and make falsifiable predictions. A good predictive model provides the basis for optimization of objective function in a multi-parameter space. This session invites talks that elucidate the practice of model building, the challenges involved in optimizing validated models and reduction of optimized results to practice."

In addition, a major division of AIChE is devoted to computing and optimization, the CAST division (Computing And Systems Technology Division) (see link).  Their description reads:

"The CAST division provides relevant programs for AIChE members who share interests in computing and systems technology, especially in the analysis, design, and control of process and management systems. CAST also coordinates the Institute's activities with other societies active in this field."

Many other conferences, seminars, webinars, books, etc. are devoted to optimization in chemical engineering (see link). 

The unexpected results occur when the process model, or process model with an optimizer produce a solution that a human could not have produced, especially within the timeframe required.  Some may argue (and many have) that this is a matter of semantics, that the computer's results are within the realm of possible outcomes that the programmer allowed the computer to explore.   The argument appears to be that, given enough time, even a human could have found the same solution.  However, that defeats the purpose when, by definition, a solution is worthless if not produced within the required time constraints.  

One personal experience follows, of an unexpected result in a simulation of a petroleum refining process unit; a vapor-recovery process for a Fluid Catalytic Cracker (FCC) unit in a large, integrated and complex refinery in the US.  There was no chemical reaction in this process, merely five inter-connected towers with vapor-liquid equilibria, mass-transfer, heat-transfer, mass recycles, heat recycles, and absorption, all constrained by the typical issues of pumping capacity, compression capacity, heat exchanger capacity, and tower diameters.  The goal, or objective function, was to maximize unit throughput without undue loss of valuable components to a fuel gas system.   The process unit was simulated on an industry-standard process flowsheet software, then optimized with the internal optimizer.  Manipulated variables included the lean oil flow rate into the primary absorber, sponge oil flow rate into the sponge absorber, total feed rate, pressures, temperatures, and various heat inputs and removals.  

In this particular case, conventional, prior "wisdom" held that the lean oil flow rate was to be minimized - reduced to zero - because the lean oil material consumed energy due to being recycled.  However, the simulation and optimizer showed that the energy savings were very small while the value of increased feed rate due to a non-zero lean oil rate was many times greater, indeed, extremely valuable.   The solution was implemented with the predicted results being measured and then confirmed.  (note the "... falsifiable predictions" wording above; this lean oil optimization certainly qualified).   So, was this an "unexpected result?"   I maintain that it was, because the then-existing management believed the path they had followed was optimal until the new operating paradigm was presented and implemented.  They were quite impressed when the FCC unit was able to process a significant increment of feed (approximately 10 percent more per day).  

Other examples of unexpected results are very common, almost too many to mention.  Another refinery used a computerized kinetic simulation and optimizer on their FCC plant and found they could increase feed rate and conversion to a much more profitable state.  The same has been done many times on other process units.  

Pattern Recognition 

As mentioned above, process plants, including oil refineries, have databases with large amounts of data.  A process engineer routinely extracts data from the database and performs analyses to follow the progress of the unit.  There may be catalyst deactivation, heat exchanger fouling, distillation efficiency reduction, among many other parameters that change rather slowly over time.  Other changes are more rapid, sometimes requiring only minutes or even seconds to appear in the data.   Where a pattern can be recognized, a good engineer can and should determine the cause.   Indeed, it is fairly simple in these days to use a data-mining software to rapidly evaluate thousands of variables in pairs and other combinations to determine the extent of any correlation.  In engineering, especially chemical engineering, linear fits are possible, but the physics of the process dictate that many times, a log or exponential, or quadratic fit are indicated.  

An example from personal experience follows.  In a complex oil refinery that processed heavy oils in a Delayed Coker Unit (DCU), and processed the virgin and cracked gasoils in a FCC, data analysis found a pattern:  the cyclical production of heavy coker gasoil created an undesirable cyclical change in FCC operation.  Simulation and optimization on the FCC showed that a better operating strategy was to store the coker gasoil for a short time rather than pump the coker gasoil as it was produced into the FCC system (note, there was a gasoil hydrotreater upstream, as usual).  A steady flow of coker gasoil allowed the FCC controls to more easily optimize the unit; in effect, the control system was always "hunting" for the optimum as the coker gasoil rate fluctuated.   This result was contrary to the established "wisdom" that it was more profitable to minimize all storage, and run intermediate streams between process units right away rather than into storage and back.  The solution was presented, then implemented with great success.  The result was unexpected in the eyes of the then-existing refinery management.    

(Note: this is entirely consistent with my career as a process consultant; many times the conventional "wisdom" was false, based on invalid original assumptions, or the previously valid  assumptions had changed materially.  One refinery with a Hydrocracking Unit told me and my colleagues that their unit was optimized, thus there was no need for us to examine it.  I asked when the latest optimization had been performed, and the reply was "a few years ago after startup."  That refinery made a substantial increase in profit after being shown why a Hydrocracker Unit optimization should be performed on a periodic basis.)

Conclusion

It has been shown that unexpected results from computer software indeed exist, both for complex process unit optimization and for pattern matching.  Other categories also exist, which may be the subject of future articles.  

Roger E. Sowell, Esq. 
Marina del Rey, California

copyright (C) 2015 by Roger Sowell







Saturday, June 6, 2015

More Thorium Silliness

Just a few thoughts that came to mind while reading comments on WUWT, the latest puff-piece on Thorium-based nuclear power plants. 

First, very few commenters have a grasp of what a molten salt is or does, especially when that molten salt contains radioactive thorium and uranium and other fission products.  

One comment, in particular, shows a vast ignorance of economics. claiming ". . . near-free (sic) and unlimited electrical power ($0.03/kWh), which will gut the remaining industrial sectors of Western economies. . ."  This refers to thorium-powered nuclear plants built in China.   The 3 cents per kWh might be the fuel and variable operating cost, but certainly does not include amortized capital costs.  As shown previously on SLB, a molten-salt reactor using liquid fluoride salts will cost much more than the present generation of uranium-powered pressurized-water reactors, and those cost approximately $10,000 per MW or more.  The per-kWh cost just for the capital cost would be approximately 25 cents, depending on how much state subsidy is applied to the capital cost.    Note: apparently "forgetting" to include the capital costs is a favorite ploy of nuclear proponents, because it allows them to compare (barely favorably) a nuclear plant's "cost" to natural gas.  

Another clueless commenter states ". . . there isn’t really much for the CHinese (sic) to do except size up the design. . . "  This particular commenter claims to be ". . .a design engineer who worked on projects for nearly 40 years. . ."   The "size up the design" refers to scale-up of a thorium molten salt reactor.   As I wrote elsewhere on SLB, scale-up from the pilot plant size at Oak Ridge to a full-scale commercial plant of 1,000 MW electrical output is a massive, daunting task.  (see link)  In pertinent part: "Scale-up from ORNL size (7 MW thermal) by 500 times is an enormous challenge.   Note that scale-up with a factor of 7 to 1 is a stretch, yet such a factor (using 6) requires four steps (40, 250, 1500, and 3500) to use round numbers.   Each larger plant requires years to design, construct, and test before moving to the next size, and that is if the larger design actually works the first time."  

The same clueless commenter on scale-up added to his list of errors with this:  ". . .corrosion problems that some rag on about . . . were all but solved. . ."   This refers to the very real corrosion and cracking in the reactor material, in fact, any material that touched the hot molten radioactive fluoride salt.  A material was developed and tested, but not for the 40 or more years with multiple heating-up and cool-down cycles that a commercial reactor must withstand, not to mention any vibrational stresses caused by any earthquakes.   The Oak Ridge National Laboratory "developed (in 1977) an improved and very expensive alloy Hastelloy N for nuclear applications with molten Fluoride salts.   In tests, Hastelloy N with Niobium (Nb) had much better corrosion resistance to molten fluoride salts."  (source: link just above from SLB article on thorium molten salt reactors).  

There are many other, equally silly comments. 

Roger E. Sowell, Esq. 

Marina del Rey, California
copyright (C) 2015 by Roger Sowell




Saturday, May 30, 2015

Thoughts on Graduation and Starting Engineering Career

Subtitle: Go With What You Know

This article is for the new engineering graduates, but also applies to those with a year or two of industrial experience.   Some of this may seem quite obvious, but perhaps some will be useful. 

I recently was invited to speak for an hour to the AIChE student group at University of California at Irvine, or UCI.  The topic was Engineering Ethics.  During the question and answer period afterward, I was asked what was the most unexpected thing I encountered after graduation.  My reply was, I did not expect to be so unprepared for the variety and depth of topics in the industrial world.   I gave a few examples to illustrate.

My engineering degree is from The University of Texas at Austin, one of the top engineering schools in the country, if not the world.  I learned what they taught, but the fact is that the engineering curriculum cannot possibly teach everything one needs to know in only 4 years of study.    The amount of knowledge that an engineer should know increases yearly as more and more fields are created (e.g. environmental engineering, bio-engineering, nano-materials) and existing fields are expanded. 

What the new engineer should know can be viewed as 1) the fundamentals are key, 2) a vast body of topics exists and should be studied, and 3) time is your ally if used properly. 

A brief side-bar on my career start: my first job was as a process engineer in a chlor-alkali plant in a medium-sized chemical company that no longer exists.  The plant is still operating, though, after being sold to other companies.   For details, the plant was designed and built by Diamond Shamrock Corporation of Cleveland, Ohio, and was known as the Battleground Plant after the nearby San Jacinto Battleground and monument in LaPorte, Texas - just east of Houston.   This was a merchant plant, in that the products were sold on the open market and not used internally by the company.   

My first problem was understanding what a chlor-alkali plant did, and how it did it.  An engineer would do well to understand what his (or her) plant does.  Chlorine, caustic, and hydrogen are produced via electrolysis of sodium chloride dissolved in water.  I did not recall that electrolytic cells were mentioned in the undergraduate courses I took, not in chemistry, nor in reactor design.   It was all foreign to me.   At that time (1977), two technologies existed for chlor-alkali plants, diaphragm and mercury cells.  The company had both types in its fleet of plants, but the Battleground Plant had the diaphragm cells. 

The solution to curing my ignorance of chlor-alkali technology was in two steps: 1) attending the mandatory safety orientation class, and 2) reading in the Perry's Chemical Engineering Handbook.   The safety orientation class gave a good overview of the chemical plant, but was mostly concerned with the dangers and toxicity of the various processes and chemicals.  The chlor-alkali plant had plenty of dangers and toxicity: deadly DC current at 800 volts and 90,000 amps in the cell room; chlorine gas is toxic and can be deadly; caustic soda even in dilute strength (cell liquor) is hot, corrosive, and can blind the eyes; hydrogen is invisible, auto-ignites, and the flame is a pale blue that is essentially invisible in daytime.  The plant also used asbestos in creating the diaphragms.  There was also sulfuric acid in one process area, with the acid strength ranging from 70 to 98 percent.   There were also the usual dangers in a process plant, steam at various pressures, fuel gas, AC current at various voltages, and rotating machinery, to name just a few.  

After gaining an appropriate respect for the hazards I would face on a daily basis, the next task was to read the Perry's, where Electrochemistry was discussed in a few pages.  However, the Perry's treatment was mostly theoretical and I was not much wiser for having read the material.  I then turned to another favorite, Chemical and Process Technology Encyclopedia by D. M. Considine (McGraw-Hill 1974).   This excellent resource had what I needed: about half a dozen pages on chlorine production, including a process flow diagram.  (readers should note the time frame, 1978.  At the time, there was no internet with vast resources.)  Finally, the plant library had design books specific to the Battleground Plant, with process flow diagrams and material balances. 

This brings me to point 1) from above, the fundamentals.  I finally had a grasp of the fundamentals of electrochemistry and how a chlor-alkali cell operated.   In its simplest form, DC current passed through a conductive brine attracts the chlorine ions, Clˉ, to the positive electrode, and the sodium ions, Na+, to the negative electrode.   The chlorine ions combine to form a molecule of Cl2, while the sodium ions combine with OHˉ ions to form NaOH.  The left-over hydrogen ions combine to form a molecule of H2.   From there, the products Cl2, NaOH, and H2 were processed, purified, and condensed (the chlorine) into products for sale or internal use. 

The new engineer must, in my opinion, gain a good understanding of the fundamentals of his (or her) assigned process, no matter what that process is.  The above outlines the steps I took to gain an understanding.  Next, the fundamentals of engineering are key to success.  No matter what field or area one is working in, the various laws apply: material balance, heat transfer, mass transfer, equilibrium, fluid flow, etc.    

Now to point 2), a vast body of topics exists and should be studied.   The list below includes a number of topics that are common to the process industries, both batch processes and continuous processes.  Budgeting, Control and Instrumentation, Corrosion, Cost Estimation, Economics (especially incremental economics),  Environmental, Equipment, Feed Specifications, HazOps, Laboratory,  Maintenance,  Metallurgy,  Operations,  Optimization, People, Pinch Technology, PFD & PIDs, Plant's Design, Project Implementation, Product markets, Product Specifications,  RAGAGEP,  Regulations, Safety,  Technical Plan, and Trade Offs.    These are the main issues that a plant process engineer will encounter.  Those working in other areas will have different issues to learn.  Engineers also work in EPC companies, Engineering/Procurement/Construction, research, catalyst development and production, technical sales, government agencies, and others.  

Point 3) from above, time is your ally if used properly.  A new engineer could, and should in my opinion, strive to learn as much as possible as quickly as possible about the areas in which he (or she) is deficient.   Time for such learning can be found by arriving an hour early to work, at the lunch break, and staying an hour after formal work hours.   A study plan can be developed that will encompass the topics.   Another way to increase knowledge is regular attendance at AIChE monthly chapter meetings where continuing education credits are given.  Many times, these meetings include a presentation or lecture by industry experts on a particular subject.   Reading industry literature, including magazines or e-zines is especially helpful.  

UPDATE: 6/6/2015 - brief expansion on the additional topics to be studied. 

Budgeting - the engineer should know that a process plant has at least one budget, there being typically three or more.  These include a) annual operating budget, b) capital budget, c) local spending budget (under the control of the plant manager).  Learning what each budget controls, the budget size, and how the budgets are prepared are all vital to understanding the plant's operation.  

Control and Instrumentation - many times, the new engineer has had a course in the basics of process control and instrumentation; if not, he or she should study this.  The basics include (but certainly are not limited to) the four basic controlled parameters: temperature, flow, level, and pressure (and note there are several others); the measurement instruments that collect the signal; the controller that processes the measurement and sends out the correction signal; the control device (usually a control valve but not always); and the actuator that moves the control device.  In addition, the engineer should understand the basics of various control schemes, and why each controller exists at that particular point in the process.  Higher (and lower) levels of instrumentation and control exist, including safety and machinery health (bearing temperatures, shaft vibration), DCS (distributed control systems), advanced process control (computerized integration of basic controls with process models including optimization and constraints).   Other areas include inferential controls, analyzer-based controls, to name just two.  

Corrosion - the measurement and management of corrosion in a process plant is extremely important, even vital.  The engineer should read and understand the basics of corrosion - it is simply a rather slow chemical reaction that (typically) removes molecules from the corroded surface and results in thinning (usually) and weakening of the material.  The corroded material may be a process vessel, a pipe, or other equipment.  Corrosion control and management may include passivating chemicals added to slow down the corrosion rate, upstream removal of corrosive molecules (e.g. sulfur and salts), and temperature control to keep the corrosion rate manageable.  Wall thicknesses are measured during periodic shutdowns.   

Cost Estimation - the new engineer almost always has some experience in cost estimation in undergraduate studies, but the employer likely has its own cost estimation philosophy and software.  

Economics (especially incremental economics) - the new engineer also likely has some experience with economics in undergraduate studies.  The process plant likely has various criteria that the engineer is required to use for economic studies, including a list of values (or prices) for each utility, feedstock, intermediate streams, products, and process unit operating costs.  Sometimes feeds, intermediates, and products prices are confidential and guarded with great secrecy.   Incremental economics must be understood, as these are quite different from average values.   It is also crucial to understand that not all energy is equal, as a BTU (or kW) saved in one area may actually have zero value.   In addition, the cost to install equipment to save energy, or increase yield, or improve product separations may greatly exceed the benefits.   Some plants have a strict guideline that no potential project is to be advanced for consideration that has greater than two years simple payout.  

Environmental - the new engineer should learn what environmental issues exist in his or her plant, with the three standard classifications of air, water, and solids.  Typically, the plant has one or more permits from state or federal agencies that list the quantity of allowable emissions for each pollutant.   Potential modifications to the plant, e.g. adding a new fired heater, may require expensive and time-consuming revisions to the environmental permits.  

Equipment - the new engineer likely has a good understanding of the basic equipment types from undergraduate work.  The plant likely has equipment that was not included in the classwork, and almost certainly has variations on familiar equipment.  As an example, there are many types of pumps (centrifugal, positive displacement) with several variations of each.  The same is true for relief valves, control valves, block valves, compressors, heat exchangers, filters, separator vessels, fired heaters, boilers, piping, fittings, turbines, electric motors, reciprocating engines, and many more. 

Feed Specifications - each plant, and each unit within a plant, will have one or more feed specifications.  The engineer should understand what each specification is, what the allowable limits are, and how that item is measured.   Equally important, the engineer should know what the ramifications are when a feed specification is above or below the limit.  

HazOps - or hazard and operability study, is an important part of a process plant's safety plan.  This should be thoroughly understood by the engineer. 

Laboratory - the plant laboratory, the samples, and analytical tests should be understood by the engineer.  The plant may have a laboratory on-site, or may send samples to off-site labs for testing.  Many laboratory tests are described by an ASTM number (American Society for Testing and Materials), or other designation.   Reference books exist that describe each test; these should be on the engineer's bookshelf and be read and understood. 

Maintenance - the plant maintenance is one of the three major organizations in a typical plant (the others are Operations, and Technical Services).   Maintenance is a vast, complicated, and essential aspect of a process plant's success, safety, and profitability.  The engineer should learn the essentials of the plant's maintenance organization and program.  Typically, maintenance is organized by craft: millwrights, electrical, instrumentation, and piping.   Safe shutdown and isolation procedures must be understood by the engineer, as well as startup procedures once the maintenance is completed.  

Metallurgy - the engineer should understand the metallurgy and other non-metallic materials used in the plant.  Typically, various metallurgies could be used in a plant, and the choice is made based on several considerations: safety, cost, durability, corrosion, and others. 

Operations - plant operations is one of the big three organizational arms in a plant (Maintenance and Technical Services are the other two, typically).  The engineer should get to know the operations staff, from the Operations Manager to Unit Supervisors, to shift staff.  Typically, the shift staff has a Shift Supervisor, each unit has a Lead Operator (or other title such as Head Operator), and Unit Operators and helpers.   The engineer should understand the role of each.   Terminology for the various operating positions can vary by industry and by plant.  For example, there may be one or more Board Operators and Outside Operators where the Board Operator remains at a computer control console in a central control room, while Outside Operators (as the title suggests) work outside among the equipment. 

Optimization - the engineer should learn as much about optimization as possible, including what optimization systems and procedures are in place, and what they accomplish.  Optimization is a vast topic.  One thing a new engineer should know is that seasoned veterans in the Operations and Technical management are usually distrusting of new optimization schemes - especially the benefits that supposedly derive from the optimizer.  

UPDATE: 6/14/2015 -  (see link) to my March 1998 article in Hydrocarbon Processing, "WHY A SIMULATION DOES NOT MATCH THE PLANT," in which process plant simulations and optimizations are discussed.   An excerpt from the article: 

". . . there are many reasons why a process simulation doesn't match the plant. Understanding these reasons can assist in using simulations to maximum advantage.

The reasons simulations do not match the plant may be placed in three main categories: 
1) simulation effects or inherent error,
2) sampling and analysis effects or measurement error, and 
3) misapplication effects or set-up error."   
The article then discusses these three categories.   --  end update 6/14/2015

People - people skills are essential to success, not just in engineering but in almost every endeavor.  The new engineer would do well to focus on what may be called "human engineering," or practical psychology.  This is a vast topic, but crucial to success.  Stating one's views in a meeting, learning how and when to disagree without offense, learning how to network effectively, all are important aspects.   Dealing with incredibly difficult people is to be expected.   One good source for process industry engineers is the "You And Your Job" series of articles in Chemical Engineering magazine (online and archived in libraries).  

Pinch Technology - the engineer should understand Pinch Technology, (developed years ago by Bodo Linhoff) and how it applies to process heat transfer and other areas.   PT has many articles and publications that the engineer can read for an understanding. 

PFDs & PIDs - the engineer likely has a basic understanding of Process Flow Diagrams (PFD) and Piping and Instrumentation Diagrams (PIDs) from undergraduate work.  The process plant will have detailed drawings of each, which should be read and studied until the engineer is completely familiar with each figure on the drawings.   (Note that PID has a different meaning in the process control context, where it means Proportional, Integral, and Derivative).  

Plant's Design - where possible, the engineer should know the basics of the plant's design - the capacity basis, the choices among various technologies, storage and inventory quantities (i.e. number of days' storage for feedstock and for products).   Unit constraints are also important.  

Project Implementation - the engineer should learn how a project is implemented in the plant, whether a capacity expansion, or other type of project.  There may be a separate group for project work, or the engineer may be expected to develop and manage a project.  The area of project management is (or can be) complicated, with construction contracts, project schedules, disruption to the existing plant, and many other aspects to consider. 

Product Markets - the engineer should understand the market or markets for the plant's products.  This could include the historic demand, projected demands, whether his or her plant is a low-cost producer or a marginal producer, and especially: how disruptive technologies could make the plant obsolete.   This last point is rather important to chemical engineers.  

Product Specifications - similar to the above on feedstock specifications, the engineer should know and understand the specifications on each product.  At times, no variations in product specifications are tolerated.  In other plants, there may be incentives for higher purity and lower prices for selling a product with lower purity.  

RAGAGEP - the engineer should understand RAGAGEP (Recognized And Generally Accepted Good Engineering Practice) and how it applies in the plant. RAGAGEP are "engineering, operation, or maintenance activities based on established codes, standards, published technical reports or recommended practices (RP) or a similar document." They "detail generally approved ways to perform specific engineering, inspection or mechanical integrity activities such as fabricating a vessel, inspecting a storage tank, or servicing a relief valve." (source: OSHA NEP for refineries, 2007)  

Sources of RAGAGEP are many. Examples are the API Standards (American Petroleum Institute), ASME Code, CCPS (AIChE's Center for Chemical Process Safety), OSHA, NEC (National Electric Code), NFPA (National Fire Protection Association), and other engineering disciplines such as ASCE (American Society of Civil Engineers).

The intent of RAGAGEP is to ensure that process plants, manufacturing plants, structures, civil works, electrical works, and other things designed and built are as safe as possible. This extends to ongoing repairs and maintenance, alterations and changes, inspection and testing.  

Regulations - the engineer should develop at least a basic understanding of the multitude of government regulations that apply to the plant.  These likely include (but are not limited to) environmental, OSHA, FTC, labor laws, and others. 

Safety  - the engineer should understand the basics of the plant's safety program.  Safety should be first, as the slogan says (Safety First).  Whether the engineer is designing a new process, a modification to an existing process, or reviewing operating procedures, safety is critical.  

Technical Plan - the Technical Plan is (or could be) a part of the Technical Services division.  The engineer should become familiar with the tasks or projects that are underway or were recently completed, and those that are contemplated for future work.  Unless the plant is recently completed and started up, the engineer will find there is a legacy of studies, projects, and reports for each that can be read and studied.  

Trade Offs - the engineer should know what trade-off opportunities exist in the plant (this is a subset of the Economics and the Optimization areas above).  Trade-offs exist for making or purchasing utilities, feedstocks, and processing or selling intermediate streams.  

-- end update 6/6/2015


Roger E. Sowell, Esq.
Marina del Rey, California
copyright (c) 2015 by Roger Sowell







Saturday, May 16, 2015

Thorium Nuclear Reactor Not the World Savior

Subtitle: Archibald Writes Wrong on Thorium

A recent article on Watts Up With That, WUWT (see link) sings the praises of thorium-fueled nuclear power plants as the savior of the world.  The article is by David Archibald, "a visiting fellow at the Institute of World Politics in Washington, D.C."  

Mr. Archibald could not be more wrong in his assessment - with one small exception, see end of this article. 
Thorium molten salt reactor schematic
source: Idaho National Lab


As written in several articles on SLB, nuclear power in any form is hopelessly uneconomic, impractical and unsafe.  see link, and link, and link.   As a result, almost full subsidy from government is required for any nuclear plants to be constructed and operate  (see link). 

Mr. Archibald opines that fossil fuel will disappear "soon" and only thorium-based nuclear power will be available.   He states that solar and wind will be unable to provide power, especially economic power.  

He states that a 250 MWe thorium power plant would be the basis for new plants.  This suffers from the same economy of scale problem that plagues small nuclear reactors (see link).   He further makes the mistake of using overnight (estimated) cost for the fully installed cost of a plant.  He uses $3,246 per Kw for overnight cost and a plant size of 250 MWe, then states the installed cost is $800 million each.   The fact is, as written on SLB (see link), major industrial projects require far more costs than just overnight cost.  The costs associated with material and labor inflation over time, and interest on construction loans can easily double or triple the overnight costs.  Construction schedules, or time to construct, typically stretch far beyond initial estimates, with actual time from start to startup being 8 to 10 years or more.  

Now, as to what Mr. Archibald got right.  He correctly stated that coal will run out.  His timetable is off by a couple of centuries, but he is correct that it will run out.  As earlier stated on SLB, the facts that coal will soon run out, and coal presently provides almost one-half of the world's electricity present one of the biggest challenges of our times.  Perhaps, it is the single biggest challenge.  

The alternative to coal is not nuclear, as Mr. Archibald states, but the vast amounts of free, renewable, zero-pollution, reliable power provided by ocean currents, solar, and wind with appropriate energy storage.  Note carefully, though, that ocean current power needs no storage.  (see link) 

I have not read the comments on Mr. Archibald's article at WUWT, but they are sure to be entertaining.  And for the most part, very wrong.  

Roger E. Sowell, Esq.
Marina del Rey, California
copyright (c) 2015 by Roger Sowell


Sunday, May 10, 2015

Mars Colony - Bad Idea

Subtitle: A One-Way Death Voyage

The idea of sending men (and presumably, women) to Mars, and having them establish a base in which to live has long been discussed. NASA has a webpage on the subject. (see link)  This article, and subsequent articles, discusses the Mars colonization issue from the perspective of an experienced process engineer.   The conclusion is grim: A Mars colony has very little hope of success due to very difficult conditions on Mars, the frailty of humans, and inevitable decay and malfunction of processes.   Evidence is presented from a variety of sources, including Massachusetts Institute of Technology, and NASA's own studies.  
credit: NASA website

To begin with the basics: humans require several things for life.  These things include (but are not limited to) breathable air, drinkable water, palatable and nourishing food, heat or cooling to maintain the body within a narrow comfort range, medical care, sanitation, protection from intense radiation, and protection from deadly meteors that fall from the sky.  For a colony to be self-sustaining, basic biology dictates that a sufficient number of unrelated people be included to produce healthy children.  

The conditions on Mars are now fairly well-known: the atmosphere is unbreathable, even corrosive; water exists but requires great effort to make clean enough for drinking, cooking, and bathing; ambient temperatures range from a few moments of 70 degrees F in daytime down to minus 200 F at night; soil is likely poisonous to plant life; radiation at the surface is deadly, plus the radiation penetrates as much as 3 feet into the surface; and the atmosphere is too thin to effectively burn up meteors.   As if those conditions were not sufficient, the long journey from Earth to Mars requires prospective colonists to endure strong, inter-planetary radiation.    

Ideas for colonies generally attempt to overcome these obstacles.   There is typically some energy source to provide electricity that is then used for air production, heating, lighting, and powering various equipment.   The energy source typically is stated as solar photo-voltaic, or PV.  What is not stated is the very weak solar energy at Mars' distance from the sun, nor the difficulty create by tremendous dust clouds that obscure the sun.   How much the PV system will be degraded by wind-blown dust is not mentioned much, if at all.   Storing the limited PV-provided electricity for use at night and during dust storms is a major issue.   

Living quarters must be enclosed to keep out the thin Martian atmosphere, and retain the human-tolerant air inside.   The pressure inside is much greater than that outside, so any leaks or punctures will send precious air out into the atmosphere.  That air must be replaced.  Living quarters must also provide shielding from deadly radiation from space, and from meteors of any size that smash into the surface.   Some proposals call for cave-like living quarters located under the surface.  

One recent MIT study (see link) showed the plans for growing plants would result in a poisonous air composition within a short time due to an imbalance of oxygen and carbon dioxide, CO2. 

It is assumed by colony proponents that seeds will survive and be viable after the long journey from Earth, even after being exposed to deep-space radiation.  Studies on Earth show that seeds are detrimentally affected by ionizing radiation. 

One of the greatest problems, though, is the impact on mechanical systems and especially their lubricants, from fine dust found on Mars.  It is as yet unknown how long a system would operate before the grit in the dust causes the mechanical systems to fail.   It may be that filtration or cyclonic systems can be designed and implemented to reduce dust-related failures.  

The lack of spare parts, and additional food to sustain the colonists are issues to be considered.   It is likely that unmanned, resupply ships must be sent on a regular basis to the colony.  Given the long transit time, it will be difficult to obtain needed parts and supplies on a timely basis.  This is not like contacting an internet store and having the items appear at your doorstep the next day.   Crop failures, and critical equipment malfunctions, could and probably will cause early death for the colonists. 

Finally, for this article, the basics of biology dictate that Mars colonists should not have children.  A small gene pool would result in birth defects in subsequent generations.   Proponents might respond that that problem can be overcome with sperm banks and ova, however the technology to successfully perform artificial insemination may be far beyond that found in a Mars colony. 

UPDATE 1 - 5/31/2015.  

Regarding spare parts, some have mentioned the 3-D printers would solve that problem. That may actually be true, in a very limited set of circumstances.  Perhaps a plastic o-ring seal can be made to replace one that failed.  However, it is questionable (meaning I seriously doubt this one) that an item made of stainless steel, shaped in a forge with high heat and pounded with heavy hammers, then heat treated, and finally ground and polished to close tolerances will exit from a 3-D printer.  The same issues exist for other metals: copper wiring, aluminum castings, even bolts with their strength requirements and threads cut into their end.  

The biology issue was mentioned to me, and the proposed solution is simply to send more colonists until the gene pool is sufficiently great.   One can only wonder what the new colonists will eat, and what air will they have to breathe, and water to drink.   Plus, who will be spared from the ongoing work to devote time to caring for infants, then toddlers, then see to their education until they can be productive members of the colony.  Children are great (I have two), however in a Mars colony environment that is likely on the verge of starvation or suffocation each and every day, children may be a significant contributor to extinction. 

For more on the negative side, NASA recently noted unexpected corrosion on the rover's wheels.  This is attributed to acidic vapor rising from the surface as the sunlight warms the Martian soil.  -- end update. 

Roger E. Sowell, Esq. 
Marina del Rey, California

Copyright (c) 2015 by Roger Sowell






Saturday, April 25, 2015

Arctic Sea Ice Not Melting in 2015

Subtitle:  Where Is All The Heat That Melts The Ice?

Arctic sea-ice extent, 4/22/2015, Red line is 2015
source: NORSEX SSM/I
One of the interesting aspects of being a global warming skeptic is observing the data that cannot be easily falsified, fabricated, adjusted, or plain made-up.   As readers of SLB will know, my view of the entire Anthropogenic Global Warming (AGW) issue is that there is zero cause for alarm from warming.  There is, however, genuine reason for concern over global cooling.   

The graph at the right shows a close-up of sea-ice extent data from NORSEX for the past few years, with the red line indicating extent for 2015  (see link).  What caught my attention is the relative flat-ness of the red line, compared to most of the earlier years.  The graph shows ice extent in millions of square kilometers on the vertical axis.  The horizontal axis shows time in approximately 10 day increments (three increments for each month), with January 1 at the far left. 

Is this normal, or unprecedented?   Careful inspection of the graph shows that the light green line, representing the data for 2011, also had a similar flat trend over the same period.  Therefore, the flat trend for this year has a precedent.  

One can also speculate on the reasons for the ice not melting at the "normal" rate, where "normal" is provided by the blue dotted line.  The blue dots represent the monthly average of the period 1979 - 2006.   The slope of the blue dotted line from the maximum (roughly March 10th) to April 22 is (very roughly estimated) 15 million to 14 million, or a decrease of 1 million square kilometers.  Yet this year, only (roughly) one-third that amount of ice melted.    Could the reason be that CO2 in the atmosphere is not getting the job done?   Are there clouds over the Arctic this year, preventing solar heat from hitting the ice?   Are the ocean currents that enter the Arctic colder than usual this year?   Is the black carbon soot that normally falls on the ice absent this year?    Perhaps the Arctic winds are not blowing the ice floes to the south, where they meet warmer waters and melt.  

I don't know the answer or answers.  What I do know is that the ice is not melting this year, at least not at the historic rate.  

Roger E. Sowell, Esq. 
Marina del Rey, California
Copyright (c) 2015 by Roger Sowell




Sunday, April 19, 2015

Nuclear Plant May Have Unsafe Steel

Subtitle:  France May Have Installed Unsafe Steel In Flamanville Reactor

Several recent articles, including this one from BBC (see link), and this from RT (see link) state that the new nuclear power plant under construction in France's Flamanville complex has reactor vessel components with high carbon content; making the steel weaker than it should be.  
EPR Reactor Vessel for Flamanville, France


From the BBC article:

"In a joint statement, Areva and EDF said new tests were under way on the "reactor vessel head and bottom".

"It said this followed initial tests which had shown "greater than average carbon content" - something French regulators said caused "lower than expected mechanical toughness" in the steel."

This nuclear plant is the new, 1600 MWe EPR design, or European Pressurized Reactor.  Another EPR is under construction at Olkiluoto, Finland.   The planned new reactor at UK's Hinkley Point is to also have the same EPR design.   

Not having access to the laboratory test reports for the reactor components at Flamanville, it is not possible to assess the problem.  However, a few comments are in order. 

First, what quality control measures are in place that would allow such steel to be fabricated and installed?   It would appear that French regulators are remiss in their duty to ensure only acceptable materials of construction are used. 

Next, what impacts will occur if (and when) the reactor is rejected as unsafe?  How long will a new reactor require for fabrication and installation?    What will be the cost impacts?  Will the plant be finished, or abandoned as hopelessly costly?   Alternatively, can the reactor be modified at this time and made safe?  What will be the cost and schedule impacts of such modifications?

Next, what impact will there be on future plants?  Is the reactor at Olkiluoto made of the same steel?  The Hinkley Point EPR reactors are also stated as made from the same steel.  

Roger E. Sowell, Esq. 
Marina del Rey, California USA

copyright (c) 2015 by Roger Sowell