Adipic Acid

1. Material Overview

Adipic acid, is a carboxylic acid organic compound used as a chemical reagent and in plastics and organic synthesis. It is a white crystalline powder, slightly soluble in water, and acidic when dissolved in water. As a fundamental building block of many chemical products, adipic acid is the most important aliphatic dicarboxylic acid produced in industrial production to date. Globally, approximately 3 million tons of adipic acid are used annually to synthesize the monomer for Nylon-66. Adipic acid is also used in the synthesis of polyesters, polyurethanes, lubricants, plasticizers, adiponitrile, and as a gelling agent for flavoring in food.

2. Process Introduction

The refined adipic acid plant supplied by Tianli uses nitric acid and cyclohexanol as raw materials. Copper and vanadium are used as catalysts to oxidize and produce adipic acid. The entire process route includes the following steps: acid preparation, oxidation reaction, crude adipic acid crystallization and separation, dissolution and decolorization, refined adipic acid crystallization and separation, nitric acid recovery, mother liquor acid concentration, dicarboxylic acid removal and catalyst recovery, ultra-refined adipic acid crystallization and separation and drying, and dicarboxylic acid slicing.

3. Technological Advantages

1) Tianli's adipic acid production process adopts the cyclohexanol-nitric acid oxidation route. This advanced process boasts low raw material consumption and excellent economic benefits, making it the dominant adipic acid production process both domestically and internationally. Several mature production units already exist in China, and through years of development and improvement by domestic enterprises, significant technological breakthroughs have been made in improving the quality indicators of adipic acid products, including ash content, purity, nitrate content, oxidizable substances, and iron content. Analysis and improvements have been made to the four key processes: oxidation reaction, crystallization, centrifugal separation, and drying. These improvements have significantly enhanced the quality of refined adipic acid products. Through continuous optimization, the quality of the produced refined adipic acid has reached food-grade levels, with all technical indicators reaching international first-class standards. While the overall industry operating rate has consistently been below 40%, its refined adipic acid unit has maintained full-load production. The production equipment is mature, the product quality is high, and the technology is advanced.

4. Technical Benefit

1) From the perspective of process technology selection: Tianli's adipic acid technology boasts advanced technology, low raw material consumption, and good economic benefits. It is currently the dominant adipic acid production process both domestically and internationally, and several mature production units already exist in China.

2) From the perspective of clean production: Due to its advanced production technology, Tianli's adipic acid technology achieves high raw material utilization and low consumption, resulting in minimal waste emissions. All waste generated during production is comprehensively treated to meet national and local emission standards, complying with clean production requirements.

3) From the perspective of safety and occupational health: Tianli's adipic acid technology employs a series of preventative measures for occupational safety and health, from site layout and equipment arrangement to DCS control and SIS safety instrumented systems, and from raw material transportation to product delivery. The safety of the equipment and the operating environment are reliable.

4) From the perspective of energy conservation and consumption reduction: Tianli's adipic acid technology achieves significant energy savings and reduces raw material and energy consumption through the comprehensive and cyclical utilization of production resources and the adoption of energy-saving processes and equipment.