Technological intervention boosts Biogas plant profitability

India is poised to be a 5-trillion-dollar economy by 2025, and the mobility sector will have a huge role to play in driving this growth. To address the growing energy demands of this sector while at the same time also achieving a reduction in imports and tackling decarbonization in the future energy basket for the transportation sector. Waste-to-biomethanation projects have witnessed renewed interest across the globe – Biogas generated through anaerobic digestion of biodegradable organic feedstocks, i.e. municipal and industrial wastes, animal and agricultural residues, etc., have drawn interests across the developing and developed economies. Biogas contains a high methane content (40–70%) that can further be upgraded (90–99% methane content), which can be injected into the National gas grid to be used as low-carbon transport fuel amongst other forms of end-usages.

Anaerobic digestion of biodegradable organic wastes provides numerous social and environmental benefits, in addition to energy and manure. Biogas helps to reduce the negative externalities associated with organic wastes, such as pollution of groundwater and soil, emissions of local air pollutants including dioxins and furans, and methane, a strong greenhouse gas. When compared to untreated animal dung, the mineral nitrogen concentration of the slurry following anaerobic digestion increases, allowing it to be utilised as organic fertiliser.

This assist in partial or complete replacement of the requirement for chemical fertilisers, which have a significant energy demand during manufacturing. Even though the environmental, health, and social benefits of biogas generation are well acknowledged, the CBG sector development still has some grounds to cover in India, when compared to the developments on a global scale.

If one considers developments in countries where biomethane production is being embraced on a large scale, two factors have played a major role in its development: strong policy support, and technological innovation. While the Indian Government has given a positive thrust to this market to gain significant interest from investors and entrepreneurs, it is technology innovation that will be crucial for the next phase of growth.

Biogas generation is a well-established technique, but its commercial use is limited due to the necessity for on-site purification prior to shipment or usage. A thorough purification and upgrading procedure that eliminates pollutants is required before biogas can be supplied into the National Gas Grid system or utilised as biofuel. While conventional techniques for biogas purification and upgrading remain in use, worldwide technological developers have also created cutting-edge purification and upgrading innovations, resulting in technology that not only gives high-grade purity of methane but also is sustainable for the environment.

Investing in dependable, high-quality technology will allow us to make the most of the biogas generated by converting it to Bio-CNG. This will allow investors and Entrepreneurs to get the most out of their CBG plant while lowering the total cost of ownership, considering the chosen biogas production or upgrading method will certainly have an impact on project expenses.

Extensive upgradation and purification treatment that removes contaminants is necessary before biogas can be injected into the national gas grid or employed as a biofuel for the transportation sector. Biogas cleaning is the process of eliminating pollutants from the raw biogas, and biogas purification is the process of enriching methane content to increase the calorific value.

The membrane separation technique is very appealing for biogas purification because of its low energy consumption, excellent selectivity, readily designed modules, and hence lower operational costs. High methane recovery efficiency (>95%) can be achieved, while pure CO2 can be produced as a by-product for various industrial purposes, therefore enhancing the business.

The biogas can be upgraded to the chosen methane concentration depending on grid or user needs. Evonik's Membrane technology, marketed as "SEPURAN® Green," employs highly selective polymer membranes to convert raw biogas into extremely pure

CBG in a simple and economical manner (biomethane). With more than 800 references worldwide, SEPURAN® Green membrane technology has the highest CO2/CH4 selectivity and is, therefore, a superior technology for upgrading biogas. SEPURAN® Green, with its patented 3-step membrane-based gas separation process, significantly increases the recovery of biomethane (>99%), which has a corresponding effect on the profitability of biogas processing plants, hence making the upgrading process as efficient and economical as possible.

Deploying membrane technology also has advantages for CBG project investors in terms of profitability and sustainability. Traditional technologies require comparatively large amounts of energy as well as auxiliary materials and chemicals, resulting in waste and wastewater generation that must be treated and disposed of. Also, methane loss during extraction and upgradation process via Membrane technology is much lower than the methane loss value of several other biogas purification methods. Hence, membrane technology is the ground-breaking method of biogas separation and purification for deploying the benefits of waste-to-biomethanation projects.

The nation has huge promise in the area of biomethana- tion projects, considering the country has huge biomass and organic wastes – potential waiting to be unlocked. According to research published in Science Direct, it is envisaged that Biogas will emerge as a promising fuel in the next two decades in India - 310 to 655 billion m³/year in the year 2040, owing to rising waste generation and adequate disposition of relevant infrastructure for waste collection efficiency.

Since 1982, India, among other countries, has promoted ‘Waste-to-Energy' projects. CBG has lately emerged as an important component of India's future green mix, as described in the Government of India's 2018 Sustainable Alternative towards Affordable Transportation (SATAT) programme. The Indian government, under the SATAT scheme, envisages setting up 5,000 CBG plants by 2023-24 with a production target of 15 MMT.

Biogas produced from different waste and biomass sources in the country has several benefits, including reduced natural gas imports, reduced GHG emissions, reduced burning of agricultural residues, remunerative income to farmers, job creation, better waste management, and so on. The SATAT focused on the objectives of the ‘Aatma Nirbhar Bharat', ‘Swachh Bharat Mission,' and the national precedence to boost the MSME sector.

In short, While cost plays a key role in shortlisting technology for biogas purification, it is important to remain cognisant of the long-term implications of using technologies that are not friendly to the environment.

After all, CBG is intended to be a green and sustainable fuel source, which will only be so if the processing that goes into its production remains eco-friendly as well. The newer technologies can be the drivers of change in the patterns of biogas production in India. If India has to succeed in the biomethane journey, the awareness, deployment, and hence investment in newer technologies have to increase. These technologies are advantageous to the CBG Plant owners and work towards achieving the Sustainable Development Goals.

Aashish Maheshwari Associate Business Director Evonik India