Techniques of Air Pollution Control

India has done remarkably well in its transition to low-carbon energy. In the last eight years, the country has managed to increase its non-fossil fuel capacity by 396%, including large hydro. The country has already achieved its target of securing 40 percent of installed electric capacity from renewable and non-fossil fuels and ranks 4th globally for total renewable power capacity additions. The Government’s commitment at COP26 of reaching 500 GW of non-fossil fuel-based energy by 2030 is another step in the right direction. However, while the Government focuses on renewable energy, it will need to ensure a stable grid to truly reap the benefits of this investment. This calls for the adaptation of hybrid energy systems, which combine two or more renewable energy sources with storage solutions to improve the balance and reliability of energy supply. 

In India, solar output is highest from around noon to afternoon, while wind output tends to be high early in the morning and late in the evening. The nationwide demand for power, on the other hand, peaks from evening till midnight and cannot be met by either wind or solar alone. However, if some of the energy from renewable generation hours can be stored and subsequently released into the grid during peak demand time, the varying levels of demand throughout the day can be easily met. Hybrid renewable energy systems do exactly that. They can be of different types: solar-wind; hydro-wind; biomass-wind-fuel call; solar-induced hybrid fuel cell from biomass; a combination of solar, wind, biomass, and hydrogen; or any other. Storage, on the other hand, could be batteries, pumped hydro, or mechanical storage. 

According to the Central Electricity Authority (CEA), the installed capacity of solar energy in India, as of May 2023, stood at 67.82 GW while that of wind energy was 43.19 GW. India is aiming to achieve renewable energy capacity of 500 GW by 2030, most of it through solar and wind energy. Against this backdrop, wind-solar hybrid projects are gaining interest from all stakeholders in the power sector. This is because, one, wind-solar hybrid projects entail lower effective costs as compared to standalone solar or wind projects. Two, they achieve better transmission efficiency than either of the two. Three, they use land and transmission infrastructure more efficiently, which reduces capital costs and translates into a decrease in tariff for consumers. Four, the Distribution Companies can better plan their demand since the hybrid project would offer power almost round the clock.

Energy generation and transmission is one half of the picture. The other half is storage. 

The costs of energy storage systems, in general, have been steadily declining in recent years, and Lithium-ion batteries have reached a point where they can be commercially viable for grid applications. They have the added advantage of being light in weight and having high energy density, which makes them ideally suited for use in electric vehicles and electronic devices. India’s push for electric mobility thus augurs well, in a way, for the renewable energy sector because the Lithium-ion batteries in electric vehicles can be used as storage systems for renewable energy. There are, however, certain prerequisites for such a scenario – the “smartening” of the power grid with intelligent technologies; the availability of a nationwide charging network for electric vehicles; the seamless integration of this charging network with the power grid to allow bidirectional flow of power; and the implementation of stringent regulations and controls.

Undoubtedly, as battery storage gets cheaper, solar-wind hybrid projects will become increasingly feasible. Once the economics of such hybrid systems to provide schedulable and firm power become competitive with those of coal-fired power plants, they will become a viable, environment-friendly, inflation-proof means of meeting future baseload power requirements.

While solar and wind energy are poised to account for a major share of the emerging renewable energy mix, biomass and hydrogen will play important supporting roles, as will technologies like gasification and waste-to-energy. As India works towards its medium-to-long-term renewable energy goals, alternative energy sources and renewable hybrids will constitute a significant part of the energy mix. 

India’s ambitious developmental goals for the coming decades hinge significantly on how it addresses its growing energy demand. During the recently concluded G20 summit, India’s Prime Minister announced the Global Biofuel Alliance and highlighted the role of biofuels in securing the energy future of developing nations. Biofuels that are derived from biomass to produce energy have the potential to accelerate India’s energy transition by providing clean energy and reducing the nation’s reliance on fossil fuels. The rapidly growing demand for power in India underlines the need for robust power grids and flexible energy sources. The integration of biofuels or bioenergy into the energy mix will help in meeting this need, besides offering the added benefits of reducing carbon footprint and catalysing socioeconomic development in many parts of the country. 

Bioenergy unlocking the potential of decentralised energy

Bioenergy can help India transition to decentralised energy systems. It can be used to supplement renewable sources in making three-tier cities as well as rural villages self-reliant. India’s predominantly centralised power grid grapples with challenges related to power availability and reliability in many regions. High transmission and distribution losses, coupled with aged infrastructure and adverse weather conditions, can disrupt power quality and supply in rural areas. While grid connectivity and rural electrification have improved, enhancing power quality, availability, reliability, and affordability for rural communities and businesses remains crucial. With nearly two-thirds of India’s population residing in rural areas, reliable decentralised energy solutions are essential to unlocking their growth potential.

In line with this, Decentralised Renewable Energy (DRE) systems have great potential to alleviate poverty; promote good health and wellbeing; enable access to education and healthcare; and catalyse sustainable economic growth. The establishment of decentralised power stations, and the provision, installation, and maintenance of related equipment and appliances can create entrepreneurship and employment opportunities on several fronts. 

The DRE system could be of any type – solar, wind (or, even better, a wind-solar hybrid), or biomass or biofuel-based. Biofuel is a low-hanging fruit. India’s agriculture sector generates huge amounts of biomass every year, which can be used directly as biofuel or processed to produce other biofuels such as ethanol, bio-CNG, and biogas. Solar energy is the most logical and viable option in a country like ours where sunshine is plentifully available for most of the year in most parts of the country. Power producers and power distributors should also consider investing in wind-solar hybrid projects, which offer several benefits over standalone solar and wind projects in terms of cost, efficiency, and resource utilisation. 

DRE projects, by and large, are cost-effective. A World Bank report last year stated that off-grid solutions were among the most economical solutions for providing energy to unelectrified rural regions across the world. Moreover, the installation of DRE systems and mini grids is much easier and quicker as compared to that of conventional power plants. And although DRE projects tend to be relatively more labour-intensive, it is more of a positive than a drawback because it boosts rural employment. From an environmental standpoint, the use of DRE systems and electrical appliances for cooking and lighting can greatly improve indoor air quality and reduce greenhouse emissions. 

Making DRE central to achieving 500 GW of renewable energy

Despite their obvious benefits, DRE projects haven’t quite gained the kind of traction one would have liked. This is because most decentralised projects are small-sised while investors and policymakers tend to focus more on large, scalable projects. The reluctance of investors is understandable; investments in several small projects can lead to an increase in administrative and monitoring costs. Aggregating projects and using digital technologies to monitor them could be one of the ways to make DRE projects attractive for investors. 

DRE projects may be standalone at the time of establishment, but they need to be assimilated into the existing state-and-national-level distribution infrastructure at some point. The integration of DRE mini grids with the national grid entails some technical challenges. However, these can be addressed by developing standards to define how the grids will interact with each other and to ensure interoperability between them. 

DRE projects can accelerate India’s progress towards its target of installing 500 GW of renewable-energy capacity by 2030. The small size and easy installation of DRE projects, combined with the fact that they enable power generation close to the point of consumption, improve reach and affordability and reduce losses. DRE systems also strengthen the resilience of communities in the face of natural disasters as mini grids can be restored very quickly even if they get disrupted. 

DRE thus ticks several important boxes from a developmental perspective – making energy accessible and inclusive for all; spurring rural employment and enterprise; enabling the delivery of education and healthcare services; and strengthening the foundations of the clean energy grid that India is aiming for. DRE is a worthy goal for a country like ours, which has both the resources and the demand for it.

A global energy transition is underway, and India is making steady progress towards a greener, more sustainable future. While the discourse on renewable energy centers around solar and wind power, it has become apparent that we also need to find clean and efficient fuel alternatives for industrial processes, transportation, and households. India needs to adopt a multi-fuel strategy to drive socioeconomic growth and sustainable development, and Thermax is well-positioned to help commercial and industrial establishments do exactly that. 

Thermax, with its integrated energy and environment solutions, is helping India unlock the energy potential of Bio-CNG, Green Hydrogen, coal gasification, waste-to-energy, and waste heat recovery. Enabling the energy transition calls for the collective efforts of stakeholders across multiple sectors. Cognizant of the importance of policy alignment and industry participation, Thermax collaborates with farmers, municipal bodies, businesses, and other concerned stakeholders to commercialise the production of clean fuels. The company offers technologies, solutions, and services to support the multi-fuel strategy it champions. 

Biofuels, such as Bio-CNG: India’s agriculture sector generates hundreds of tonnes of crop residue and biomass every year, which can be used to produce biofuels. Compressed biogas, or bio-CNG, is one of them. Its calorific value and other qualities are similar to those of compressed natural gas (CNG). Both agricultural waste and municipal waste can serve as raw material for bio-CNG production. CNG-powered vehicles can run on bio-CNG without any change in design. In rural areas, bio-CNG can power tractors and other agricultural equipment. Thermax’s offerings in the bioenergy space include Bioenergen, an advanced and highly efficient organic biodegradable waste processing plant that produces high-yield biogas. The residue can be used as nutrient-rich fertilizer. Meanwhile, Thermax Onsite Energy Solutions Limited – our wholly owned subsidiary – manages the supply chain of various biofuels across India.

Green Hydrogen: With applications spanning energy storage, emission control, and transportation, Green Hydrogen is a versatile and clean energy solution. Thermax recently ventured to explore green hydrogen projects, including new manufacturing facilities, in India. Thermax is also aligned to the Indian government’s National Green Hydrogen Mission and ammonia/hydrogen policies. 

Coal Gasification: Thermax believes that coal gasification has great potential to strengthen India’s energy security and reduce foreign exchange outflow. India has the fourth-highest coal reserves in the world, albeit with higher ash content. To address this challenge, Thermax collaborated with IIT Delhi to develop a gasification technique suitable for Indian coal. Their efforts yielded a state-of-the-art gasifier conceptualised, designed, and installed in Pune. With it, the syngas or flue gas produced from coal gasification can be utilised to produce ethanol, methanol, and various downstream chemicals. Thermax aims to bring this technology up to commercial scale. 

Waste to Energy: Thermax’s waste-to-energy initiatives transform waste materials into valuable energy resources, thus promoting a circular economy and contributing to energy security. One such project, in collaboration with a German customer, has received the prestigious ‘German Renewables Award’. It involves converting 320,000 tonnes of waste into energy through controlled incineration. The initiative saves over 100,000 tonnes of CO2 and supplies almost 10 percent of Hamburg’s district heating needs. 

Waste Heat Recovery: Thermax provides equipment and steam generation solutions encompassing the combustion of different solid, liquid, and gaseous fuels, and the recovery of heat from turbine/engine exhaust and industrial processes. With its steam boilers, thermal oil heaters, hot water generators, thermosyphons, waste heat recovery units, Thermax optimizes energy consumption and improves overall industrial efficiency. All these outcomes are in line with India’s national goals of minimizing energy waste and promoting sustainable industrial practices.

With its strong commitment to pioneering clean technologies and responsible practices, Thermax’s business goals are aligned to India’s energy transition goals. The company continues to work closely with its customers and technology partners to help industries minimize their environmental impact. A multi-fuel approach will accelerate progress in this direction and go a long way towards powering sustainable growth for our businesses, people, and country.

The ongoing global efforts to limit global warming call for minimizing the use of energy sources whose production or consumption produces greenhouse gases. A report published in 2021 by UNOPS, UNEP and the University of Oxford stated that infrastructure was responsible for 79 percent of total greenhouse gas emissions and was therefore a priority sector for climate action. McKinsey estimates that infrastructure assets in emission-heavy industries such as power, transportation, and buildings, account for almost half the capex required to meet net-zero targets. A variety of solutions are being evaluated or developed for achieving carbon neutrality by 2050. One of these is hydrogen, especially green hydrogen. Depending on how it is produced, hydrogen is termed as being grey, blue, or green. Of these, green hydrogen can be produced in an environment-friendly manner, by splitting water into hydrogen and oxygen using renewable electricity or by utilizing biomass to generate hydrogen through a microbial decomposition or gasification-based process.

Hydrogen is very versatile – it can be used as a means of energy storage; as a fuel; or as a raw material in industrial processes. One of the key applications of green hydrogen is decarbonization of “hard to abate” industrial sectors where direct electrification is not easily possible. Sectors such as refineries, fertilizers, etc. where hydrogen is used as a feedstock for the process will need green hydrogen to decarbonize their operations. . Hydrogen can also be used to power fuel cells, where it converts the chemical energy of the fuel cell into electricity, without combustion. Fuel cells can be used greening of heavy duty transportation vehicles where batteries are not suitable. These vehicles can be supported by network of hydrogen refueling stations which are based on decentralized hydrogen generation, which in remote locations can be through locally available biomass by utilizing biomass to hydrogen technologies. Replacement of natural gas with green hydrogen in sectors such as steel, city gas distribution, glass, ceramics etc. will not only help in reducing the carbon footprint, but also help is making India energy independent as we import 46% of our total natural gas consumption.

Both government and industry acknowledge green hydrogen as an important enabler of a net-zero economy. In January 2023, the Union Cabinet approved initial outlay if INR 19744 Cr for the National Green Hydrogen Mission with the objective of making India a global hub for the production, usage, and export of green hydrogen and its derivatives. Of the total outlay INR 17490 Cr is dedicated for incentives towards electrolyser manufacturing and green hydrogen production which should help in enabling adequate supply. There is equal push from states to promote adoption of green hydrogen with various states announcing incentives on capex, electricity charges, banking and land related charges through respective green hydrogen policies over and above the incentives available under central government schemes.

The National Green Hydrogen Mission needs to be complemented with a time-bound, stepwise roadmap for its implementation. The government can help in developing the market through mandates of green hydrogen purchase for sectors that are already using hydrogen.. Any hesitancy on the part of the private sector to invest in an early-stage technology like hydrogen can be addressed, to a large extent, by offering near-term demand certainty. Such demand visibility will help India achieve scale in electrolyser manufacturing to cater to its own demand as well as to serve export markets. Current international estimates peg India’s electrolyser manufacturing capacity to reach 9-10 GW by 2030. This will help green hydrogen confidently and quickly traverse the cost reduction curve.Wide-scale adoption will almost be a certainty once economies of scale are achieved. With cost parity with grey hydrogen expected to be achieved by 2030, green hydrogen can then be used to decarbonize other sectors such as mobility, chemicals, aviation and new applications such as production of green fuels (ethanol/methanol).

Green hydrogen has potential to greatly reduce carbon dioxide emission and yield huge savings on energy imports in the coming decades. Moreover, it will bolster India’s energy security, which, in turn, will reduce the volatility of price inputs for Indian industries and strengthen India’s foreign exchange health. India has announced ambitions infrastructure projects that will be rolled out over the coming years and decades. This implies an increase in the output of heavy industries. There is also a very strong focus on expanding the country’s renewable energy capacity manifold. These goals, coupled with the policy direction we are seeing, augur well for the hydrogen ecosystem in India. Green hydrogen, on its part, will make our industries more sustainable than before and improve the feasibility of future expansion. It will be a virtuous cycle once it gets going, which we should hope will be soon.

Thermax marked a significant achievement with the commissioning of its first wind-solar hybrid captive power plant (CPP) in Gujarat, India, which has a generation capacity of 45.80 MW.

Along with the noteworthy advantages in terms of generation and distribution efficiencies, as well as optimal land utilisation, the wind-solar hybrid model stands out for its assurance of uninterrupted power supply.

This project combines 24.3 MW of wind energy with 21.50 MW of solar energy, resulting in an annual reduction of around 1,11,700 tonnes of carbon equivalent emissions. Notably, the entire project was executed within stipulated timelines with zero accidents.

Equipped with over 50,000 solar modules and nine wind turbine generator units, each with a capacity of 2.7 MW, the plant ensures seamless integration of clean energy into the grid. The plant ensures efficient transmission and seamless integration of clean energy into the power grid.

Beyond the numerical achievements, this initiative underscores Thermax’s commitment to fostering a decarbonised energy landscape, setting a precedent for sustainable power generation in the region.

In a move towards sustainability and operational cost reduction, an aluminium major in Karnataka decided to phase out fossil fuel consumption for its process heat and power requirements. The industry is traditionally known to opt for coal and other fossil fuels only.

Thermax executed a 100% biomass fired cogeneration plant, deploying a 33 TPH hybrid water tube superheated bi-drum boiler with a reciprocating grate, designed at 67 kg/cm2 pressure and 450°C temperature, for the client. The boiler has been designed to run on a mix of biomass briquettes and loose biomass fuels to generate 4 MW power as well as provide steam for processes, replacing the client’s existing oil fired boiler.

To address the ~200 tonnes/day of biomass fuel requirement, the company has developed dedicated fuel manufacturing facilities to ensure optimum fuel quality and quantity across the year.

Operated under the build-own-operate model, with this project, the client is relieved of the responsibility of operating and managing part of their steam and power requirements while also achieving nearly 48,000 tonnes/year of equivalent CO2 reduction against furnace oil.

Tackling the impending problem of non-recyclable solid waste management, Thermax has introduced an advanced solution for paper mills. The non-recyclable solid waste (NRSW) from pulping plants is an ongoing concern for most paper manufacturers, which leads to additional cost for disposal of NRSW to cement kilns and other incinerators.

One of the clients approached Thermax to provide a solution of firing it into a waste to energy boiler. Samples were collected to study its physical nature, composition, variation, ash characteristics, etc. The NRSW is a mixture of non-recyclable waste materials rejected from different process points. The mix contains very high moisture and varying sizes, making it challenging to handle and combust in any conventional boiler.

The Thermax team worked on a special design to combust this NRSW in an environment- friendly manner without any support fuel, generating free steam to the paper mill for utility or power. Leveraging its experience of working with diverse fuels, the team conceptualised a workable solution with a special combustion system to handle variations in the size, moisture, and calorific values of the fuel. Based on the previous positive experience of Thermax boilers, a leading paper mill agreed to go ahead with the implementation of a full-scale project at their plant in Gujarat that involves a 100 TPD NRSW fired boiler at a steam pressure of 45 kg/ cm2 (g) and temperature of 400ºC.

The solution is capable of utilising and disposing of 33,000 tonnes of non-recyclable solid waste in a year without harming the environment. This not only saves transportation costs to kilns but also frees up the land being utilised for waste storage due to a 90% reduction in waste volume. The steam produced can be directly utilised for paper manufacturing process or to generate captive power.

With this, Thermax has not only addressed the persistent challenge of non-recyclable solid waste but has also provided a sustainable model that enhances environmental stewardship, reduces costs, and optimises resources for our customers.

In a stride towards sustainable district heating solutions, Thermax has achieved a significant breakthrough in Germany. This milestone unfolded with the successful installation of three THP S1 H2 single-effect steam-fired heat pumps at a district heating plant in Borsigstraße, as part of its waste to energy project.

These heat pumps form the core of the nationwide unique project, which has already been awarded the ‘German Renewables Award 2021’. This innovative project notably increases the efficiency of heat generation from waste for the waste recycling plant and thus makes a further major contribution to heat transition in Hamburg.

Michael Pollmann, State Councillor of the Authority for the Environment, Climate Protection, Energy and Agriculture (BUKEA) and Prof. Dr. Rüdiger Siechau, Managing Director of Stadtreinigung Hamburg (SRH) were present when the three absorption heat pumps from Thermax were installed. They appreciated the project and emphasised MVB’s optimised waste heat usage for Hamburg’s climate goals.

A pioneering move in the heat transition in Hamburg, this will save 1,04,000 tonnes of CO2 annuaIly. This development positions the project as one of the major providers of eco-friendly energy for the city, without resorting to additional waste as fuel. With this expansion, an extra 350,000 MWh/a of heat will be incorporated into the performance network of Hamburger Energiewerke. This significant increase will allow for the provision of climate-neutral and secure heat to approximately 35,000 more households in Hamburg, derived from the waste recycling process.

The project is a significant milestone, especially crucial in times of volatile market prices for fossil fuels.

Leveraging our technical know-how, we optimise energy consumption, deploy cutting-edge technology to decarbonise processes, and foster key partnerships to advocate for green solutions across industries. Together, we are building an ecosystem that propels us towards a more sustainable energy future. With our comprehensive portfolio offering modern energy solutions, we are working towards bridging the gap between energy availability, energy affordability and energy sustainability.