Problem Solving

I’ll be blogging a lot about the chemical and energy industries, but it’s a fact that chemical engineers have interesting jobs in a number of other industries. I learned this quite early when taking my master’s degree in Chemical Engineering Practice and spent an
entire term solving manufacturing problems in three different plants making, respectively, paper, steel and explosives. MIT had practice stations at Eastern Paper Company in Maine, Bethlehem Steel in Lakawanna, NY and at Hercules in New Jersey. At these stations, eight or students under the guidance of a professor were given real industrial problems or at these plants which required chemical engineering solutions. At the paper mill, the assignment was to design and use special equipment to measure the amount of fines issuing from a stack and to figure our ways to reduce these emissions. We also did some work on the paper machine—a fascinating piece of equipment called a Fourdrinier machine invented over a hundred years ago that converts bleached wood pulp into paper at speeds of 5000 feet per minute.

At Lackawanna, we worked on improving the performance of a distillation column that separated phenol from coke over gases. Today, phenol (now a petrochemical) is made almost exclusively from propylene-based cumene, but up to several decades ago, steel companies operated coke ovens that made metallurgical coke under reducing conditions by heating coal to high temperature, with various chemicals issued from the oven. These included ammonia, phenol, naphthalene, benzene, toluene and higher aromatics. Most coke ovens have been shutdown by now as steelmaking technology changed.

The Hercules plant primarily made explosives, principally trinitrotoluene (TNT), but also chlorinated plastics. Nitration can be dangerous so that students were generally kept away from that part of the plant. I believe that our work problems involved the manufacture of nitric acid from ammonia and chlorination of different thermosetting resins.

Having students help in solving plant problems worked well for both the companies and the students. We left these practice stations with a much better knowledge of how chemical engineers can solve practical problems and had mixed feeling about getting back to courses in thermodynamics, physical chemistry and fluid flow.

Over the years, substantial change has occurred in all three of these industries. I already mentioned the shift from coke oven-based chemicals to petrochemicals, a momentous change that I will write about another time. In the paper industry, the use of chlorine gas for bleaching pulp has been entirely eliminated for environmental reasons, with bleaching now carried out with chorine compounds or hydrogen peroxide. Also, much of the pulp is now based on recycled newsprint and other paper products. The separation of the cellulosic pulp from the lignin which binds it in the wood is now far less polluting and the lignin id used as an energy source. Many additives have been developed to strengthen the paper, and to limit the amount of pulp fines dropping from the screens of the papermaking machine into the waste water. Chemical engineers and chemists continue to improve the papermaking process. Much more information can be obtained from The Pulp and Paper Institute (TAPPI), an industry association.

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1 Response to Problem Solving

  1. you should post more often great read, also like the look of the page.

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