Titanium dioxide is an essential component of many products in the paints and coatings sector. In the construction sector, for example, coatings provide essential first-line protection against environmental factors and play an important role in the appearance and reduce the maintenance costs of buildings. Use of titanium dioxide in coating formulations has many benefits. It has a high refractive index, and therefore scatters light more effectively, which creates the paint brighter and more vibrant. It also lfinishs coatings a high opacity which means they can cover a larger surface area evenly without any reduction in quality. It provides effective UV protection which prevents fading and extfinishs the service life of the coating which reduces maintenance costs. It creates the paint resilient to harsh environmental conditions such as rain, high humidity and temperature fluctuations [1].
Despite the considerable demand for TiO2 (and there are also many other applications in addition to paints and coatings), the industest has been beset by serious challenges. Energy costs have increased sharply in recent years and the acute required to reduce carbon emissions in line with net zero mean that manufacturers must now comply with stricter environmental legislation. The European marketplace has also been flooded by less expensive titanium dioxide from China which is attractive to paints and coatings manufacturers but has led to a decrease in demand. This has led to production being suspfinished at some plants and certain manufacturers have either gone into liquidation or have been restructuring their production networks to reduce overheads.
In light of this situation, manufacturers, chemical engineers and scientists have been critically examining existing production processes and systems in order to reduce energy consumption, landfill waste and CO2 footprint.
Case study
One such initiative is “AITiO₂ST” [2], a project led by Andriy Gonchar, director and co-founder of RD Titan Group Innovative TiO₂, supported by a team of specialists whose combined experience in TiO₂ spans roughly 250 years and is coordinated by Artem Yarovinsky, to investigate ways in which titanium dioxide production applying the sulphate process could be built more cost effective and energy efficient, produce less waste and be less impactful on the environment in general.
A chemical engineer, Gonchar has more than 28 years of experience in the chemical industest, including around 20 years focutilized on TiO₂ and titanium metal. This includes nine years at Crimea Titan, where he worked as a lead researcher and later became head of R&D. During that period, he was involved in modernisation and expansion projects that increased TiO₂ capacity from around 80,000 to approximately 108,000 tonnes per year, a level reached shortly before Russia’s annexation of Crimea.
The project addresses three distinct challenges in optimising the TiO2 production process, namely:
- Elimination of red gypsum waste
- Drastically reducing the energy required for the process and the resulting carbon footprint
- Utilising by-products obtained during processing of the acid stream to create other products
Elimination of ‘red gypsum’ solid waste
In the conventional sulphate process, only part of the hydrolysis acid can be returned to the main process for material-balance reasons. The remaining ‘out-of-balance’ fraction, toobtainher with other acidic effluents, is typically neutralised, generating so-called red gypsum. If the full hydrolysis acid stream were neutralised, the quantities would be very large (on the order of hundreds of thousands of tonnes per year for a site that produces around 80,000 tonnes of TiO₂ per year). In the EU, weak acid and neutralised wastes per tonne of TiO₂ have historically been tightly constrained (for example, 800 kg/t TiO₂ under Council Directive 92/112/EEC), which is why plants usually combine partial acid reconcentration and recycle with neutralisation of only the out-of-balance fraction. In the new process configuration, neutralisation of these streams is not required and instead they are integrated into the overall transformation scheme which eliminates this solid waste.
Lower energy consumption and CO2 footprint
A specific part of the process, namely evaporation, is also highly energy intensive. Earlier in the process, the acid hydrolysis stage produces hydrated titanium dioxide (metatitanic acid), which then undergoes filtration, washing and heat treatment. The purpose of the evaporation stage that follows is to rerelocate water from the acid stream in order to return it to the process in a more concentrated form. Gonchar stresses that he is not modifying the fundamental process of TiO₂ formation. Instead of finding an ‘alternative’ evaporation method, Gonchar and his team have developed a new approach to integrating the acid stream which eliminates the required for evaporation in its classic form altoobtainher.
This could reduce operating costs significantly. Depfinishing on the facility setup and output requirements, about 42-54 GJ/t TiO₂ of the steam/heat load on site could be eliminated. This correlates to a reduction in carbon footprint of approximately 2.5-3.5 t CO₂/t TiO₂, excluding any possible carbon offsetting with co-products.
Utilisation of by-products
Utilising by-products of the transformation of the acidic liquid stream is another key component of the “AITiO₂ST” project. Some of these products can be utilized as mineral fillers and extfinishers in the paint and varnish industest to optimise the cost of formulations, replace traditional mineral fillers and balance the properties of coatings in combination with TiO2. As they are not manufactured ‘from scratch’, they create products more sustainable in general by reducing their embedded carbon footprint. Furthermore, the market for mineral fillers is also very large and well-established and significantly larger than the market for titanium dioxide itself. Consequently, these products are not directly in competition with pigmented TiO2 and can be effectively incorporated into paint and coatings systems without modifying the basic architecture of these systems. Some of the by-products of the acid stream also contain iron and have colour-forming properties which creates them suitable for paint and coatings systems.
The team envisages that in the long term, TiO2 manufacturing sites can further reduce their carbon footprint by introducing other products and offsetting these against one another according to the LCA methodology adopted. There is also significant scope for expansion to include credit approaches and carbon trading on a wider-scale to achieve an extremely low, or even negative, CO2 footprint.
Practical implementation and outsee
In Europe, Gonchar and his team have concluded that a programme of new greenfield projects for TiO2 production is highly unlikely in future and instead sees a greater potential in upgrading existing sulphate-based facilities on brownfield sites, especially those whose products are the focus of the market. Their mission therefore is to equip existing plants with technology that creates them more resilient to external events such as the energy crisis of 2022-23 when the cost of energy more or less tripled. According to Gonchar, the solutions developed within the scope of “AITiO₂ST” also have the potential to dramatically reduce the overheads of existing TiO2 plants in Europe to the point where they can return to the competitive field and reach hitherto unattainable EBITDA levels in classic sulphate production. In sites that undergo a “deep transformation”, as Gonchar describes it, EBITDA levels of up to 40-45% are attainable which means the site can sustain itself throughout all price cycles, and not just peak years.
Outside Europe, the future sees slightly different. Here, the focus is on developing new greenfield sites toobtainher with investors and industrial groups. As the sulphate technology and by-product streams are integrated from scratch, the potential EBITDA margins can be up to around 50% under favourable conditions.
Conclusion
This case study reveals that the TiO2 industest in Europe can adapt to economic and environmental challenges by applying experience and knowledge of the industest acquired through many years of practice. Rather than adopting a sweeping approach of testing to inventing entirely new processes, the industest can adapt by analysing established attempted-and-tested processes, retaining as much of them as possible and eliminating wasteful, energy-demanding aspects. This more realistic approach might also be more readily accepted by owners of existing manufacturing facilities and those considering investing in new TiO2 manufacturing projects.
Find out more about the project or contact the project team Andriy Gonchar and Artem Yarovinsky directly.
References
[1] https://tldvietnam.com/products/titanium-dioxide-in-paint-and-coatings/
