The NMP market is huge and showing an upward trend

In the past 5-10 years, due to the rapid development of the lithium battery industry, the consumption scale of NMP has grown rapidly. The consumption of NMP in China in 2022 is approximately 1.52 million tons, of which the consumption in the lithium battery field is approximately 1.428 million tons, accounting for 94.0% of the total consumption in China. With the continuous expansion of the new energy vehicle market, the demand for lithium batteries has also increased. It is expected that by 2025, China's NMP consumption will reach 3.44 million tons. Between 2022 and 2025, the compound annual growth rate of consumption was around 31.3%.

In addition to being used in the field of lithium-ion batteries, NMP can be used as a photoresist remover and semiconductor display panel cleaning agent in the field of electronic chemicals. In polymer synthesis, it can be used as a reaction solvent for special polymers such as para aramid, Polyphenylene sulfide (PPS) and polyimide (PI).

1. NMP synthesis technology

In the synthesis of NMP, the vast majority of production enterprises adopt the process route of dehydrogenation of 1,4-butanediol (BDO) to produce GBL, followed by amination and condensation to prepare NMP. Mitsubishi Chemical uses hydrogenation of maleic anhydride to produce GBL, followed by amination and condensation to obtain NMP.

The industrial production of NMP is realized earlier and the production process is mature. At present, the industrial Technology roadmap of NMP production worldwide is mainly the condensation of GBL and monomethylamine to produce NMP. According to different reaction conditions, it can be divided into non catalytic reaction and catalytic reaction, with the former being the production process adopted by most production enterprises.

The catalytic condensation of GBL and monomethylamine to produce NMP was developed by E. Spath et al. in 1936, and was later industrialized by BASF in Germany and GAF in the United States. It is currently the most commonly used NMP production technology. Due to the high temperature and pressure required for non catalytic NMP production processes, high equipment requirements, high energy consumption, and the use of catalysts to reduce reaction conditions and save energy. Therefore, in recent years, many researchers both domestically and internationally have begun to pay attention to the role of catalysts in this process. In 2008, Korean pear tree chemistry adopted ZSM molecular sieve catalytic synthesis technology, which can reduce reaction conditions to a certain extent.

In China, Sinopec adopts the Cu Zn Cr Zr catalyst BDO dehydrogenation ammoniation process technology to produce NMP. Although catalytic processes have obvious advantages, due to some engineering and technical issues (such as catalyst lifespan), there are currently few industrial applications.

Mickey Chemical's NMP production adopts a catalytic process, and its self-developed new molecular sieve ZSM composite rare earth cerium catalyst can effectively accelerate the speed of intermediate NMH closed-loop.

2. NMP recycling and purification market has broad prospects

The NMP industry does not have a high entry threshold, and due to the continued prosperity of the downstream lithium battery industry, more and more enterprises are starting to produce NMP, resulting in an increasingly large industry scale. As a solvent, the vast majority of NMP can be recycled and reused, which can save costs and reduce its impact on the environment. According to industry data, producing 1GWh power batteries requires 1500 tons of NMP. With the rapid growth of domestic power battery production, the market for NMP recycling and purification is developing rapidly. Since 2021, the NMP recycling and purification market has shown explosive growth. In the same year, China launched a large number of NMP recycling and purification devices, with a total annual recycling capacity of over 400000 tons. According to the trend of power battery production in 2022, 825000 tons of NMP will need to be recycled and purified throughout the year, with a recovery and purification capacity expected to exceed one million tons.

At present, new energy vehicles have become the mainstream development trend, and China is the largest production and consumption market for new energy vehicles and power batteries. It is expected that in the coming years, the annual growth rate will be 20% to 30%, and NMP recycling and purification still have good market development potential.

There are two main modes of recycling NMP: one is for NMP users to self recycle and form internal circulation, and the other is to entrust manufacturers to refine or purchase NMP products refined by manufacturers. Among NMP production enterprises, there are both those specializing in synthetic or recycled products, as well as those with both synthetic and recycling capabilities.

3. NMP recycling technology

The NMP recovery and purification technology includes two parts: recovery and purification. Currently, the main treatment processes for NMP tail gas recovery include condensation+honeycomb wheel adsorption process, condensation+water spray process, and multi-stage water spray process.

1) Condensation+adsorption process:

Firstly, cool the coating exhaust gas, collect most of the NMP, and then treat the exhaust gas to meet the standard through an adsorption wheel. At the same time, the desorbed exhaust gas returns to the front end.

2) Water spray process:

Utilizing the excellent water solubility of NMP, water is used to absorb NMP, thereby achieving standard exhaust emissions.

Each process has its own scope of application, advantages and disadvantages, and needs to be selected based on actual production conditions and engineering experience. When NMP is transferred from exhaust gas to aqueous solution or condensed into liquid, it forms NMP waste liquid, and its purity often does not meet the requirements of battery production, requiring further purification before reuse.

4. NMP purification technology

NMP waste liquid generally contains other organic impurities such as NMP, water, amines, etc. Due to the direct use of battery grade NMP in electrode production, high purity requirements are required to maintain battery consistency. Therefore, strict purity requirements are required for recycling.

At present, the mainstream recycling electronic grade NMP adopts distillation technology, but the difference lies in the differences in process and core equipment design, resulting in significant differences in product quality and recovery rate that can be achieved. Against the backdrop of high NMP prices and a surge in usage, choosing high-quality, high yield, and low consumption purification processes is the trend.

In China, the Tianjin Zhongfu Environmental Protection NMP waste liquid purification system uses core technologies such as pre-treatment technology, precision distillation technology, high-precision filtration and adsorption, heat exchange network optimization, and other process enhancement technologies to purify NMP solvents to battery level. It is reported that Zhongfu Environmental Protection is an early enterprise in the development of NMP purification technology. As early as 2014, it cooperated with BYD to carry out the research and development of NMP solvent purification and resource utilization technology, as well as the transformation of achievements. It was the first to build an NMP solvent purification device in China, achieving in plant purification and reuse of NMP. Afterwards, multiple sets of NMP solvent purification projects were put into operation, with over 30 related cases. We have collaborated with multiple leading companies in the lithium battery industry, including BYD, Yiwei Lithium Energy, Haichen New Energy, and Bangpu Recycling, and have a good market reputation in the NMP purification field.