Kristal® in Chemical Industry: From Municipal Sewage to High Grade Industrial Water

Introduction

Ranked as the third largest chemical market in Asia, the Indian chemical industry currently holds up to 3 percent market share of the global industry. As the Indian market continues to experience vigorous growth across the various industrial sectors, the Indian chemical industry is expected to experience an upsurge. In May 2014, according to Nadir Godrej, the chairman of CII National Committee on Chemicals, the government’s target is to reach 6 percent of the global industry by 2020.

Challenges still arise for the chemical industry players. More focus will be placed on the production quality of products which can be attributed to factors such as the quality of raw materials (clean influent water), equipment and processes used in producing chemicals plus rising cost of raw materials and stringent regulations for wastewater discharge containing toxic chemical effluent. It will make water efficiency and energy savings critical for all chemical companies.

The Solution

Kristal® ultrafiltration (UF) hollow fibre membrane is one of the pioneer products fully designed and developed by Hyflux. By removing impurities such as suspended particles, organics and microorganisms, major pollutants found in many water sources, it is ideal for the pretreatment of RO systems. Made of specially formulated modified Polyethersulfone (PES), Kristal® is more hydrophilic than many other polymer-based membranes commonly used today. This feature reduces fouling when handling streams of very high suspended solid organic content. Its unique asymmetric structure is formed using a phase inversion approach. Ultra thin skin built above Kristal®’s porous substrate allows it to achieve both high water flux and mechanical strength. Kristal® also eliminates traditional land-intensive conventional treatment processes. With a simple, modular and compact design, Kristal® provides a larger membrane area per unit volume at a smaller footprint size, hence lowering capital and installation costs.

Compared to conventional treatment methods, Kristal® membrane systems offer advantages like:

  • Higher system recovery
  • Little or no odour – effluent is contained
  • No foaming
  • Small installation footprint
  • Higher flux rate
  • Consistent production, no regeneration interruptions • Simple operation and maintenance
  • Better permeate quality
  • Longer lifespan of RO system
  • Reduced chemical consumption

Case Study

Government-owned company RCF is one of the leading fertilizer producers in India. Its sewage recycling plant was then using a conventional multi-grade filtration pre- treatment system for the reverse osmosis (RO) process. This plant recycles municipal sewage into high-grade industrial water to be used in chemical and fertilizer production processes. However, the plant faced the issue where the feed water did not meet the required standards and thus severely shortened the life span of the RO membranes used in the plant.

RCF first selected Hyflux’s proprietary Kristal® ultrafiltration (UF) membrane technology to replace its conventional system because Kristal® UF membranes effectively remove suspended solids, colloids, organics, bacteria and other microorganisms in the sewage and is able to ensure a consistent, high-quality feed to the RO membranes.

The plant, with the capacity of 5,000 cubic metres per day, saw a marked improvement in the feed water quality which in turn, optimized the performance of the RO membranes and reduced membrane fouling. This consequently helps RCF to enjoy lower chemical and operating costs resulting from the increased lifespan of the RO membranes.