^ Pellets of caustic soda. Attribution: Walkerma, Public domain, via Wikimedia Commons
Article by John Butterfield
The total cost of the project will be about Rs. 230 Crores. This additional caustic plant is expected to be operational by March 2022 and will potentially generate additional revenue of Rs. 250 Cr.
After this expansion, the installed capacity of chlorine will be increased to 352000 TPA and hydrogen to 116 million NM3 per annum. Chlorine and hydrogen produced from this plant will cater to the growing demand from various segments, such as agrochemicals, pharmaceuticals, etc.
This plant will also cater to various application segments like alumina, soap & detergent, paper and pulp, agrochemicals, pharmaceuticals, textile, petroleum refining, dyes & pigments. This expansion project will be the basic building block for future additions of downstream products, epichlorohydrin and CPVC resin ensuring continuous supplies to existing customers.
Epichlorohydrin and CPVC resin plants are expected to be commissioned in FY 2022 and FY 2023 respectively. These major steps would, it is understood, reduce the country’s imports dependency and also save valuable FOREX.
During the past five years, MFL has brought its business to a significantly higher level and consolidated its position as one of the largest chloroalkali and derivatives complex in India. The company’s stated aim is to reach total revenues of Rs.2000 Cr in FY 2024, with key contributions from existing caustic chlorine, potash and derivatives such as chloromethane, hydrogen peroxide, epichlorohydrin (ECH) and chlorinated polyvinyl chloride (CPVC Resin).
This expansion further demonstrates the company’s strong leadership in providing continuous supply to customers during difficult and uncertain situations relating to production continuity and competitiveness in the region, the announcement concluded.
Looking for information about suitable materials, Valve World India & Middle East found a wealth of detail on a ‘Chemical resistance guide for valves’ issued by Val-Matic. This document indicates that a wide range of metals can be considered when selecting valves for use with caustic soda (given a concentration of 15% and normal conditions). These include: carbon steel, nickel (used for valve seats because of its good welding ability and lack of brittleness), cast iron, bronze, aluminium bronze (widely accepted as a disc material and used in many valves for liquid service), 304 stainless steel (commonly used for valve trim), 14-4PH stainless steel (primarily used as a stem material for high pressure butterfly and ball valves), 316 stainless steel (common uses in valves are stem, body and ball materials), Nitronic 60 (used for valve trim when extreme wear resistance or strength is required), Monel (very resistant to strong caustic solutions) and Inconel
Further, the Val-Matic guide highlights a number of elastomers and plastics that can be used with caustic soda, provided that recommended maximum temperatures are kept in mind. These include Buna-N, Neoprene, EPDM, Hypalon, natural rubber, Teflon and nylon.
Finally, careful storage is needed when handling caustic soda for use, especially bulk volumes, according to Wikipedia. They recommend following caustic soda storage guidelines and maintaining worker/environment safety given the chemical's burn hazard.
As regards materials for storing caustic soda, Wikipedia state that it is often stored in bottles for small-scale laboratory use, within intermediate bulk containers (medium volume containers) for cargo handling and transport, or within large stationary storage tanks with volumes up to 100,000 gallons for manufacturing or waste water plants with extensive caustic soda use. Common materials that are compatible with caustic soda and often utilized for storage include: polyethylene (HDPE, usual, XLPE, less common), carbon steel, polyvinyl chloride (PVC), stainless steel, and fiberglass reinforced plastic (FRP, with a resistant liner).
As a final note, caustic soda must be stored in airtight containers as it will absorb water from the atmosphere.