RHE AMERICA - Synthetic Resins and Polymer Emulsion Manufacturing Process

CASE HISTORY

CHEMICAL COMPANY BUILDS STATE OF THE ART RESIN PLANT

Eternal Chemical Co. LTD, headquartered in Kaohsiung, Taiwan is the second largest resin manufacturer in Asia, producing over 180,000 metric tons per year (mty) of resin. Eternal successfully exports a large portion of the produced resins to other Asian countries despite operating in a very competitive market. In 1994 Eternal needed to increase its capacity and upgrade its operations and profit situation.

Eternal - Resin Manufacturing Plant

Eternal placed an order with RHE Händel Engineering GmbH, specialists in the design and supply of a wide range of resin manufacturing plants. Eternal learned of RHE through a joint venture project in Thailand and was impressed by the efficient operations, innovative design, and the high profitability of the Thailand project. In comparison the existing resin manufacturing plants operated by Eternal in Taiwan, all supplied by local engineering houses, experienced operational and profitability problems. These problems included long batch times and high raw material consumption rates. The order placed by Eternal with RHE included two resin manufacturing trains, one for the manufacture of alkyd resins and one for the manufacture of both alkyd and polyesters resins.

RHE developed a turnkey operation including the complete basic and detail engineering and the key equipment such as reactors and pressure vessels, agitators, etc. The alkyd resin train included a 12,000 gallon reactor. The alkyd and polyester resin train included a 6,750 gallon reactor. Eternal purchased some pieces of equipment locally based on RHE workshop drawings and specifications.

For the execution of this project, RHE drew on 40 plus years of experience in both the design of resin manufacturing plants and the specialized knowledge of reaction processes. In order to provide all the engineering and design work, RHE only required a minimum amount of information about the raw materials from Eternal

RHE designed the production trains with the following technical features:

Charging Of Liquid Raw Materials - Reactors and dilution tanks are installed on load cells so that liquids from storage tanks are charged by weight through special charge valves.
Charging Of Solid Raw Materials - Solids from bags (or big bags) are charged through dust-free systems into hoppers installed on load cells. Screw pumps with variable speed drives, pump the solids into the reactors.
Heating and Cooling Of Reactors - The reactors are heated and cooled by thermal oil, which is circulating through half-pipe coils on the exterior of the reactors. These secondary circuits include pumps, heat exchangers and automatic control valves.
Reaction Equipment - The reactors are equipped with free-flying disk type pitched blade turbine agitators, custom designed by RHE to provide the most efficient mixing for every application. The reactors are also equipped with efficient distillation systems, which include a packed column, an automatic decanter and a reflux pump.
Plant Control - Both trains are designed for an almost fully automatic operation through PC/DCS systems with recipe management.
Online Viscosity and Acid Number Measurement - The reaction product viscosity and acid number are continuously monitored by the unique, patented, RHE developed online circuit included with each reactor. This allows the resin manufacturer to preset target values for the final product.

The highly efficient design and execution of the plant equipment resulted in considerable batch time reductions in comparison to the existing plants. For the manufacture of alkyd resins, a two-step process starting from vegetable oils, batch times of between 16 and 18 hours are standard using the RHE supplied equipment.

Use of the computerized process control system and the online measurement system for determining product viscosity and acid number have largely eliminated the manufacture of off-spec batches and greatly reduced the manpower needed. Additionally, the product quality has improved since it is possible to manufacture resins with very narrow specification ranges.

The profitability of the alkyd and polyester resin manufactured on the RHE trains exceeded the expectations of the customer. During the economic downturn starting in 1997 which resulted in the loss of Eternal's main export market, Japan, only the RHE resin plants remained in operation while the less productive trains were, at least temporarily, shut down.