Chemical Batch Process Quality Management - Communications

by: Pierce Burns, PE

 

Introduction

Over a period of years being involved with the operation and supervision of batch process operations, it became obvious to the author that a major cause of accidents, lost product and lost processing time in batch operations was due poor communications between the various plant functions involved in the operation. The process of insuring that the communications occur seems perfectly obvious in hindsight but is almost always missed if a systematic approach is not followed. The rewards are great: on specification product, no reportable accidents, optimum equipment utilization and improved relations between departments. The procedure described here should be used with a statistical process control - statistical quality control (SPCSQC) program.

This article outlines the principles involved in the procedure. It should be  modified to meet the needs of a specific plant and the organization within that plant. It should be noted that the procedure described here is based on successful use over several years.  It was the experience of the author that a dramatic improvement was achieved in plant operation when this procedure and SQCSPC were both initiated. SPCSQC is not covered in this article.

 

Functions Involved

In a normal batch process in a chemical plant, the following sections (or divisions) of a plant are involved:

• Operations - the chemical operators, shift supervisors, and the engineers or supervisors in charge of operating the equipment,

• Process Engineering - Plant process engineers, these may be called plant tech service in some plants,

• Maintenance - maintenance craftsmen and supervision,

• Analytical - Technicians and supervisors,

• Safety - Plant safety personnel,

• Sales or Marketing - A person who represents these functions for the plant involved,

• Shipping - Warehousemen and supervision.

The names of the sections or divisions will vary from plant to plant, so the individual plant nomenclature should be substituted for the names used by the author. In some small plants, some of these functions may be combined.

Preparation Work

Before any batch can be made in a plant, preparation work needs to be done. This should include:

• Written Process Description - a complete step-by-step description of the process with operating conditions and a process flow diagram. The chemistry and safety concerns should be addressed. Analytical and control tests should be described.,

• Run Sheet - This sheet should be used for recording charges, operating conditions, control test results and observations. This may be computer based.,

• SPCSQC Data Sheet For recording statistical data,

• Product Specifications - formal and written with methods of test,

• MSDS’s - Material safety data sheets should be in hand for all chemicals involved.,

• Equipment - The equipment should be clean, tested and suitable for the job.,

• Materials - All chemicals and operating materials on hand and on-specification.

 

Pre-Run Meeting

The pre-run meeting is the key to bring together all plant functions and create common goals and objectives. The general rules for the pre-run meeting are:

1. All functions must have a representative authorized to agree to common decisions.,

2. Chemical operators and laboratory technicians actually doing the work must attend along with their supervisors and must be full participants. Overall success is doubtful if only supervision is present. A team approach depends on this.,

3. There must be a written agenda and meeting notes. These can be combined on the same document if desired. The notes must be kept on the unit and available to all participants.,

4. The meeting coordinator is responsible for maintaining a positive meeting atmosphere and he or she must insure that the group comes to common goals.,

5. The meeting should be focused and to the point. It was the experience of the author that the first meeting required an hour or two and later meetings might only last ten or fifteen minutes. There are too many busy people attending to waste their time by getting off the subject.

The agenda for the meeting may be similar to the following one:

• Purpose of the batch production and size of the batch - Operations

• Customer requirements - Sales Representative

• Product and raw material specification - Analytical Section

• Review of the Process Description and the Run Sheet. At this point the group will go over the process description and the run sheet step by step. This is the time that questions from chemical operators, analytical technicians, safety personnel and maintenance should be brought up and answered or a commitment made to provide answers before the run is started. The chemistry should be explained in detail if this is a new product. - Operations Engineers and/or Process Engineers.

• Data requirements; what data needs to be taken, what statistical treatment will be used on the data, who is responsible for taking the data and who is responsible for reviewing the data - Operations Engineers

• Control testing, product testing - Analytical Section

• Special safety concerns - Safety

• Maintenance support requirements, off-hours scheduling or call-out plan, maintenance supplies needed  - Maintenance

• Shipping requirements, truck or drum specs, drum fill weights - Shipping

The first reaction to a procedure such as this is normally that it is just another meeting and surely a waste of time. On the other hand what weighs on the other side is the cost of producing off-specification batches that must be disposed of or reworked. Also, when there are bad batches produced, there is frequently blame and finger pointing resulting in hard feelings and friction between sections in the plant. If the effort is not coordinated, there are unexpected calls in the middle of the night for analytical and maintenance help. Does any of this sound familiar?

The experience of using a procedure such as this has been a reduction of off-specification batches by as much as 90% when combined with a quality SPCSQC program. The program is difficult to initiate, but when it is done, the preventable problems seem to just go away over a period of time.

One pre-rum meeting can be used for a series of identical batches in a series. In that case, the pre-run meeting is tailored for the series. The amount of product is the sum of all batches, but the process description is for a single batch. Raw material and shipping addresses the total. Going from a single batch to a series should pose only minor adjustments.

One problem with the program described here is insuring that it does not get dropped. The very success of the program works against it being continued. For example, say that a common product, Detergent X, is made frequently in the batch kettle. The procedure here can be used for a series of identical batches. That is one Pre-run meeting for a series of batches. If another product is made for a series of batches following this and then a second series of Detergent X is planned, is it necessary to have a pre-rum meeting for the new series of Detergent X runs since they are the same as the previous ones? The answer is only if you can afford to discard off-spec product and rework product. Each series is a whole new world. Are maintenance, analytical and shipping ready? Probably not. Are customer requirements the same? You may never know unless these questions are addressed in a structured manner.

The rewards for using this structured approach are many. Overall it may be summarized by saying: every batch on-specification every time, with a minimum of cost and a work force that works closely together for common goals and objectives.

Pierce Burns, PE

Biography:

Pierce Burns, PE, retired from Texaco Chemical after 34 years of service. During his career with Texaco, he worked first in process development and later was in charge of the Process Demonstration Section at the Austin Labs. The section manufactured products during the transition from research to large-scale plants.