Chloroacetic acid is the organochlorine compound with the formula ClCH2CO2H. This carboxylic acid is a useful building block in organic synthesis.
Chloroacetic acid is prepared industrially via two routes. The predominant method involves chlorination of acetic acid:
CH3CO2H + Cl2 → ClCH2CO2H + HCl
Acetic anhydride serves as a catalyst for this reaction. The other main industrial route to chloroacetic acid is hydrolysis of trichloroethylene using sulfuric acid as a catalyst.
CCl2CHCl + 2 H2O → ClCH2CO2H + 2HCl
The hydrolysis method produces a highly pure product, which can be important since mono-, di-, and trichloroacetic acids are difficult to separate by distillation.
Industrially, chloroacetic acid is used in the production of a wide variety of useful compounds, e.g. drugs, dyes, pesticides. Most reactions take the advantage of the high reactivity of the C-Cl bond. It is the precursor to the herbicide glyphosate. The herbicides MCPA (2-methyl-4-chlorophenoxyacetic acid) and dimethoate are prepared by alkylation with chloroacetic acid. Chloroacetic acid is converted to chloroacetyl chloride, a precursor to adrenaline (epinephrine). Displacement of chloride by sulfide gives thioglycolic acid, which is used as a stabilizer in PVC and a component in some cosmetics.
In its large scale application, chloroacetic acid is used to prepare the thickening agent carboxymethyl cellulose and carboxymethyl starch.
In India 4 units in the organized sector and a dozen units in the small scale sector are engaged in making MCA. The total capacity for MCA is estimated at 121,000-tons. Nearly 50% of the capacity is in the organized sector with 3 companies and the rest 50% is in the small scale sector. Since most of the capacity is in the small-scale sector, the unit-wise production details are not available. The total MCA production is estimated to have grown from 60,000-tons in the year 2009-2010 to around 80,000-tons in 2016-17.
Around 80% of the total production of MCA is in the western region. Production of MCCA has been growing at around 6 to 8 % per annum.
CABB Karnavati Chemicals, IOCL Chemicals & Pharmaceuticals Ltd., Rayalseema Hi-Strength and Meghmani Fine-chem are the four major producers in the organised sector.
Besides the four units in the organised sector mentioned above a new unit, namely Gujarat based Atul Ltd has announced plans to enter into manufacturing of MCA. Dutch specialty company AkzoNobel and Atul Ltd, a part of Lalbhai Group, have formally agreed the joint venture partnership announced last year for the production of MCA in India. The companies will establish a new plant at Atul's facility in Gujarat by first quarter 2019, with each partner holding a 50-percent stake in the joint venture, to be registered as Anaven.
Building on AkzoNobel's leading position in the MCA market - with plants in the Netherlands, China, Japan and the US - the partnership will also enhance Atul's status as a key global supplier of the herbicide 2,4-D, which uses MCA as a key raw material.
The partnership will use chlorine and hydrogen manufactured by Atul to produce monochloroacetic acid, taking advantage of both Atul's existing infrastructure and the leading eco-friendly hydrogenation technology of AkzoNobel. From an initial annual capacity of 32,000 tonnes per annum (TPA) at start-up, the plant has been designed for future expansion to 60,000 TPA. The facility will produce enough MCA to meet Atul’s growing demand for MCA and supply the expanding Indian market.
Consumption and demand
The domestic consumption of MCA in 2016-17 is estimated to be around 62,000-tons and exports around 13,000-tons. Agrochemical intermediates and pharmaceutical sector followed by CMC are the major end-use segments consuming MCA.
The domestic demand has been growing at around 8 percent per annum. Assuming 8 percent growth the domestic demand by the year 2022-2023 is expected to reach at 88,000-tons. Adding an export demand of around 30,000-tons, a total demand of around 118,000-tons can be projected by 2022-2023.
The current total capacity in the industry is estimated at 120,000-tons and other 32,000-tons would be added by Atul Ltd. in the next couple of years making total capacity at 152,000-tons. The current capacity utilisation is only around 60 percent within the industry. With improvement in the capacity utilisation by 2022-23 the capacity seems to be sufficient to meet the projected demand by increasing the capacity utilisation. However, if export demand increases, there might be scope for expansion of capacities.
According to consulting company Persistence Market Research the global consumption of monochloroacetic acid is estimated to be 823.1 Kilotons in 2016 and is anticipated to increase to 1,127.9 Kilotons by the end of 2024, registering a volume CAGR of 4.0% over the forecast period (2016 - 2024).
Production of glycine is the major end use, globally, for MCA. The most significant production of glycine is now in China, where it is an intermediate in the production of glyphosate herbicide. Glyphosate is probably the largest-volume herbicide produced worlwide. However, there are three common synthetic routes used to manufacture glyphosate and it is only in China that the MCA route is dominant, accounting for 60% of the glyphosate produced in the country.
The MCA market will continue to be driven by the Chinese market. China is the largest consumer of MCA, accounting for about 61% of the global total in 2016, and the country continues to increase capacity and demand for the product. About 74% of the global capacity increase in the next five years will take place in China. Overall MCA consumption in China is expected to grow at 3.6% per year through the forecast period.
In the United States, MCA consumption has experienced some recovery since the economic downturn, increasing steadily with the increased use of CMC in oil field applications since 2010. US consumption of MCA currently represents about 6% of the global market.
Western Europe accounts for about 12.5% of total global consumption of MCA, and 36% of total global MCA demand for CMC production. Western European MCA consumption is expected to grow at 1.2% annually. Nearly half of the MCA consumed in Western Europe is used for CMC production. Other MCA uses in this region include surfactants and herbicides (2,4-D and MPCA); consumption for these markets is expected to show sustained growth over the next five years.
The following pie chart shows world consumption of MCA in different regions:
Global Market by Enduse
MCA use for glycine production makes up the largest market, with about 41% of total global MCA demand in 2016. Glycine is used to produce glyphosate, an herbicide used worldwide. China is the largest global producer and exporter of glyphosate and over 60% of its glyphosate capacity is glycine- and MCA-based. MCA consumption for glycine is expected to grow at 3.6% per year through the forecast period.
The second-largest market for MCA is for production of carboxymethylcellulose (CMC), which accounts for about 25% of total MCA consumption in 2016. MCA consumption is expected to grow at 2.9% annually in this market.
MCA consumption for downstream products 2,4-dichlorophenoxyacetic acid (2,4-D)/MCPA (herbicides) has increased in recent years. Total MCA demand for this use accounts for 10% of total MCA consumption. India will be the fastest-growing market for this end use.
The MCA market in India has experienced significant growth in recent years; both domestic capacity and exports have increased in the region. Demand is driven by use in agrochemicals (herbicides) and for the production of ibuprofen. Because lower-quality MCA can be used for ibuprofen manufacture, Indian ibuprofen is very competitive in the global market. MCA consumption is expected to grow at 5.6% annually in India from 2016 to 2021.
MCA demand in 2,4-D/MCPA herbicides will continue to be driven by markets in India, China, Western Europe, South America, and the United States. India will continue to be the largest and fastest-growing market in this sector.
Note: The profile on MCA was first published in Chemical Weekly