The Man Who Stays

When the commissioning crew flies home and the digester clock begins its twenty year run, one kind of professional steps forward. Dr. Srinivas Kasulla has spent a career being that person.

Dr. Srinivas Kasulla learned this early. He has spent the better part of his career occupying the space between what a project document promises and what the morning shift actually finds. In that gap, between the controlled optimism of a bankable feasibility report and the stubborn reality of biological systems under continuous industrial load, he has built an expertise that is genuinely rare in India’s rapidly expanding Compressed Biogas sector. He does not speak from conference podiums about theoretical best practices.

He is the kind of professional found inside a pre processing hall at six in the morning, watching a sand separator choke on feedstock the agricultural supplier had certified as clean paddy straw, working backwards to understand why. The kind who has watched a two stage thermophilic digestion system find its biological equilibrium at 4 a.m. not because of a software override, but because a team he had trained understood what the temperature curve was telling them. That is a different kind of knowledge. It cannot be downloaded or replicated in a simulation. It is built slowly, and sometimes painfully, by staying.

Feedstock First, Always

Kasulla’s philosophy begins before the first tonne of feedstock enters the system. India’s bioenergy projects draw on feedstocks that are fundamentally seasonal and regionally diverse: paddy straw, sugarcane press mud, cattle dung, food waste, segregated municipal solid waste. Each carries its own biochemical methane potential, its own total solids profile, and each changes, subtly or dramatically, depending on the season, the geography, and the supply chain reliability of the aggregator.

He has seen projects that modelled their energy yields on a single representative cattle dung sample taken during a productive monsoon, then extrapolated it across a twenty year financial model. Two years into operations, when the dung quality shifted to lower volatile solids and higher sand content from changing cattle management practices nearby, the gas yield assumptions simply did not hold. The plant underperformed. Investors were confused. The O&M team absorbed the blame for a problem baked in at the feasibility stage.

“You cannot operate your way out of a feedstock problem that was never honestly characterised in the first place. But you can build an operations protocol that detects the drift, quantifies it accurately, and gives you the tools to adapt before the biology pays the price.”

His response to this reality is what he calls a living feedstock management system: structured laboratory analysis of incoming feedstock, a seasonal variance matrix, and defined operational responses for each deviation scenario. When volatile solids drop below threshold, the organic loading rate adjusts. When sand contamination crosses a trigger point, the pre-processing configuration changes. Simple in concept. Demanding in execution. It requires institutional commitment and a team that understands why it matters. Both are harder to sustain than any piece of equipment.

The Digester is not a Tank

There is a line Kasulla uses in training programmes that unsettles people who come from mechanical or civil engineering backgrounds. He says: “The digester is not a tank. It is an ecosystem. Your job is not to run the tank. Your job is to keep the ecosystem alive.”

Anaerobic digestion is a four stage biological cascade carried out by distinct microbial communities that must coexist in a carefully balanced chemical environment. The methanogenic archaea at the end of this chain, the organisms that actually produce the biogas, are among the most metabolically sensitive microorganisms in industrial biotechnology. They are slow growing, which means they recover slowly from disruption. They are acutely sensitive to pH, which means even moderate acidification events caused by overloading or temperature shock can suppress their activity for weeks, sometimes months.

His framework for managing this is built on what he calls early signal literacy: the ability to read warning signs of digester stress before they escalate into performance losses. Daily monitoring of the methane to carbon dioxide ratio. Weekly volatile fatty acid analysis, because VFA accumulation is the precursor to pH drop and the biological cascade that follows. Maintaining alkalinity within a defined operating band. And, critically, building a team that reads these not as abstract numbers but as a story the biology is telling about its own condition.

“A SCADA system shows you the data. It does not tell you what the data means. Biological literacy is the difference between a team that monitors a plant and a team that understands one.”

Mechanical Honesty

The mechanical layer, Kasulla says, is the most honest of the three layers of plant operations. “When a mechanical component fails, it fails. There is no negotiation. If your main agitator shaft seizes at eleven on a Sunday night with 2,000 cubic metres of actively fermenting slurry in the digester, you are not having a theoretical discussion. You are solving a problem that is happening right now, and the quality of your preparation for that moment determines whether it is a manageable incident or a catastrophic one.”

His approach to mechanical reliability rests on three principles: prevention, prediction, and preparation. Prevention is the non negotiable maintenance calendar, budgeted before the plant ever turns on, calibrated not just to manufacturer specifications but to the actual operating conditions of that specific plant. Prediction is the monitoring layer above the calendar: vibration analysis on rotating equipment, thermal imaging on gearboxes, oil analysis on critical machinery, and the pattern recognition that accumulates from watching equipment behave over months and years. Preparation is the spare parts philosophy informed by failure history, lead times, and one blunt question: what happens to gas output if this component fails on a Friday afternoon and the supplier’s warehouse is in another state?

“If the answer to every parts question is ‘the supplier will support us,’ that tells me the developer has never had a critical failure at the wrong time. Once you have, you build buffer stock. Preparation is not pessimism. It is the operational discipline that separates plants running at year twenty from those that stopped at year four.”

The Hardest Infrastructure

In Kasulla’s assessment of why biogas and CBG plants underperform, the most common root cause is neither technology nor feedstock. It is the human system around the plant. Staffing models for most Indian biogas projects are designed for the capital expenditure phase. They are not designed for the sustained, skilled, twenty year commitment that real long-term performance requires.

A plant processing 100 tonnes per day of mixed feedstock requires, at minimum, three rotating shift crews covering 24 hours, 365 days a year. Each shift needs a trained process operator, a mechanical technician, and an electrical technician capable of responding to control system alerts. The plant needs a dedicated laboratory analyst, a maintenance engineer with the authority to halt operations for scheduled work without seeking management approval each time, and a plant manager with genuine operational competence, not someone rotated into the role because the plant is running.

Training for this team is not a one time induction. It is continuous: structured refreshers on process chemistry, scenario based emergency drills, and a knowledge transfer protocol that captures institutional learning in documented form before it walks out the door.

“The plant pays back in gas, in digestate, in avoided gate fee revenue, in carbon credits,” he says. “But what the plant actually runs on, day after day, for twenty years, is the competence and commitment of the people inside the fence. That is not a soft consideration. That is the hardest infrastructure in the project. It needs to be invested in accordingly.”

What the Sector Must Decide

India’s CBG and biogas sector stands at a genuine inflection point. The policy foundations are in place under SATAT. The feedstock base is vast. The technology has matured and the economics, supported by tipping fees, offtake agreements, and carbon market mechanisms, are increasingly bankable. The question is not whether the sector will grow. It will.

The question is whether the plants being commissioned today will still be performing in 2040. That answer will be determined, to a very large degree, by how seriously operations and maintenance are treated from day one. Not from year three when performance begins to slip. Not from year seven when the first major equipment overhaul creates a liquidity crisis nobody planned for. From day one. From the moment the digester foundations are poured. The digester clock starts running at commissioning. It does not stop for twenty years. What happens inside those 7,300 days is the whole story.