Sustainability Engineering for Enhanced Process Design and Manufacturing Profitability

Chapter 1 develops some background and historical framework for sustainability engineering (SE). The chemical process industry is a mature and robust discipline focused on turning large quantities of raw materials into finished products, safely, in compliance with environment, safety, and occupational health (ESOH) best practices and is always economical. But a focus on short- to medium-term economics, and a limited scope boundary, has however constrained it. Newer concerns regarding the perpetuity of supply of both energy and material have brought to light a concern over its long-term sustainability. This has come about with an awakening to more external concerns over a more global sustainability of the entire world we operate in. In addition, a popular interest in all things, “Green,” has informed marketing efforts to address and request products that are minimally damaging to health and environment. In other words, we have demonstrated a popular willingness to pay a bit extra for sustainably made products—everything from cars with high miles per gallon (mpg) to electric ones with even higher mpg to more healthy foods. Finding ways to use more permanently renewable resources is the new bottom line. As you read on, consider sustainability engineering as a continuous improvement module to the existing mature and vibrant system of chemical process design.

Until relatively recent times, the overall approach to process engineering design considered what is needed, what can be spent, how much can be made, and how fast can an investment be recovered and profits begin to flow. In a world of overabundance, unlimited space, and raw materials, this was sufficient. Modern SE design however, must also consider safer alternatives to the desired product, permanent availability of raw materials, with strict, primary emphasis on renewable resources, and Environment, Safety and Occupational Health (ESOH) compliance and protection for the public as well as industrial workforce.

The basic cost estimating, technical requirements determination, and methodology of design have not changed. But CAD-aided design methods, e.g., Aspen plus, Hysys (Luyben WL, Distillation and control using aspen simulation. Wiley-AIChE, New York, 2006) and others, e.g., UNISYSM, can greatly simplify, through automation, the level of effort and often provide a greater degree of accuracy in design. Some can even provide real-time dynamic plant modeling. We look here at these classic design steps as married to SE design to improve all aspects including safety and profitability, a new look at efficiency, integrating disparate processes and energy to maximize resource utilization.

This chapter also discusses training upcoming design engineers to respond to new market forces that allow sustainability considerations to now be accounted for as a profit center.

Obtaining sustainable materials and energy sources and sinks is the holy grail of SE. This is not always possible within the restraints of classic process design, so it may require combining other, disparate processes. We will take a look at the BTU as the new “coin of the realm,” as well as examine SE elements such as quality management–based modeling, existing efficiency standards to build on, and start to examine combining production with onsite energy generation. This chapter discusses the following: new and existing methods to reformat chemicals for use elsewhere to improve overall utilization; an initial look at energy use overall; methods to use chemistry reformatting to create battery-like storage opportunities; common unused energy sources including potential onsite generation and sharing with other processes; common unused wasted materials and material and energy integration approach; an SE classification system for production resources; and SE technologies needing cost improvement. A peek at geothermal energy and its processing cognate methodologies applicable to large-scale industry is offered.

The concept of efficiency can be surprising at first, but can eventually lead to understanding and focus on how to improve things. A focus on this can lead to new ways to approach overall design. Also examines relevant US Energy Policy, existing efficiency standards, and the need for new SE ones. That a seemingly straightforward process design on paper that would cost, say $100 dollars to purchase, would in fact cost as much as $500 to install and get up and running when all was said and done was bad enough. The energy to operate pumps, motors, columns, etc., and the actual delivered power can cost anywhere from two to five times more than the theoretical estimates. The importance is on comparing theory versus practice through use of adjustable or, tunable models, e.g., Aspen, ChemCad, and others, in order to better represent a process. This chapter looks at some pertinent economic comparisons applicable to SE, onsite power generation as an SE efficiency booster, hidden issues affecting SE, various equipment efficiency considerations, an SE efficiency rating system, some DOE overviews for refining energy consumption, and initial electric grid plant interconnection challenges.

This EPA congressionally mandated program sets review requirements for the introduction of new chemical products. It establishes guidelines for evaluating new products; setting permissible exposure limits for health and human safety for workforce as well as end users and setting spill remediation requirements; outlines Federal reporting requirements for bringing new chemicals to market. Premanufacturing notice PMN, chemical identification CAS, models to examine toxicity, health, and safety prior to manufacturing to fine-tune designs. This chapter reviews the EPA new chemicals program along with examples pertinent to SE that allow EPA to characterize new chemicals prior to entering production with an eye toward protecting the environment and chemical workforce. The EPA chemical model ECOSAR (ECOlogical Structure-Activity Relationship used to evaluate toxicity is described. Congressionally established EPA review time limits protect industry as well. This process assists companies in the initial phase of design for manufacturing.

After publication of “Silent Spring” in 1961 by Rachel Carson, her congressional testimony, and several environmental and safety catastrophes, the ESOH issues moved front and center into the public eye. This chapter looks at the various ESOH regulations that govern chemical manufacturing and handling in the USA. CPI manufacturing must comply with various ESOH regulations. Permits are issued prior to operation. Designs begin with the ESOH compliance review. This chapter provides historical review leading to regulations as formalized by the act of congress, and signed by the president, and discusses the spreading of financial burden evenly across the states and the congressionally required economic burden analysis for all EPA and OSHA regulations. Some of the larger regulations are summarized, and points of contact at the websites listed. In many instances, EPA has delegated authority to the States to administer elements of their programs.

So, why is this section in this book? ESOH should always be considered prior to committing to even a preliminary design effort. Do not work on something that will be too unsafe to be permitted. The review process is surprisingly uncomplicated, generally leading to safer and more profitable manufacturing alternatives and their attendant designs.

This chapter presents an overview of practices needed in conjunction with classical design and economics methodologies to support SE design. In this chapter, we started with technology examples, e.g., equipment and, in Chap. 8, we will examine cobbling them together in complete SE systems.

SE really is an incremental improvement over existing process design and product design and development engineering. This chapter discusses the classic methodologies of economic evaluation, product development, conceptual as well as detailed design engineering, process control, maintainability, operability, and profitability, as the point of departure. The chapter also looks at the following: SE technical additions to classic design and definitions/criteria; the BTU as the SE coin of the realm; SE elements to coordinate plant-wide; gasification opportunities; heat exchanger networks (HEN); heat pumps, process energy and steam; onsite power production; the heat recovery steam generator (HRSG) in electric power generation; companies that build and service onsite power systems; system integration of process materials and energy; a few common SE design process, utility and offsite needs; and some generic SE tools for technology examples.

We start by looking at some small examples without power integration. With the advent of usable micro-turbines, it may be possible to generate electricity on a small scale. Furthermore, solar projects might also be coupled here as well. Several large-scale problems are presented that were used in teaching integrated power and process design. Also highlighted are the US DOE industrial energy programs and relevant AIChE articles.

Co-locate and interconnect disparate processes to maximize material and energy utilization, while minimizing overall SE footprint. Integrating power may not always be necessary, but it sure makes the most sense. It is also an ideal use of an excess supply of natural gas. The 40% HRSG power generation efficiency is increased considerably by SE design integration of heating and cooling of both low- and high-quality heat, realistic only in chemical production. Power transmission line losses all but disappear, and this is one big electric power topping cycle that uses the grid as a storage battery.

I have had a long-time interest in total quality management (TQM) and similar quality programs, and the following is from the last 34 years of experience. In 1994, I co-chaired, along with the American Society for Quality [1], a symposium on pollution prevention and quality management (Perl JP, Pollution prevention, quality programs and training. AIChE, Chicago, IL, 1994). The managers from Burlington Northern Santa Fe Railroad, UOP, Motorola, United States Air Force Center for Environmental Excellence, and the USEPA all presented the manner in which their respective organizations used quality management in the pursuit of pollution prevention and waste minimization. ASQ provided a generic quality management training program. When it gets right down to it, sustainability engineering design is all about optimization and therefore quality management principles must prevail.

In 1970, things in the USA came to a critical mass regarding the need for environmental regulatory intervention. So many major publicized events took place that the past environmental damage caused by unregulated practices of the industry came home to roost and the federal government was forced to act. The ESOH regulations were needed then and now, but now they are institutionalized. I was a party to discussions regarding the question of the early 1990s that asked how industry would respond to the land disposal bans. The answer, the Pollution Prevention Act of 1990, provided a combination of reporting requirements that industry actually met ahead of schedule. While doing so, this activity started to combine with the nascent green movement in consumerism and led industry to see the value in this new proactive environmental compliance approach that became advertisements, not complaints.

Most of the examples in this book have been drawn from the chemical process industry (CPI). The importance of activities in the other disciplines, however, is equally important. I have highlighted examples where great improvements in process efficiency and improvement have been made and are needed. Clearly, all the activities listed below will need to fall under strict SE criteria as well. At least ranking them would be a good start as unacceptable, good, better, or best. I included this to demonstrate to all my engineering colleagues a jump-started dialog on SE in their respective disciplines and industry segments. It also serves to remind my ChE colleagues of the importance of a close interaction with all the disciplines to assure an optimal design and finished product.

Sustainability engineering represents a way forward, above and continuous improvement beyond the existing process and product design engineering methodology. We have covered a lot of ground thus far. The basic roadmap is gleaned from the preceding chapters. There are a few nontechnical programmatic items to help complete the path forward along the way toward normalizing SE included here.