How you design and operate the plant has a major effect on performance and cost.
The scale and pace of producing RNG has increased significantly over the last 10 years, driven by demand for green energy, carbon credits, and government incentives.
Unfortunately, few RNG projects have achieved financial or performance expectations. Did you know that over 52 RNG projects or operating facilities were canceled or shut down across the US in 2020?
RNG projects are not without challenges.
RNG project challenges are best addressed in the front-end planning phase and throughout operations.
Many of the facilities produce less gas than forecast. Frequently a high initial production yield tapers off as solids accumulate in the digester degrading its performance. This challenge can be solved through optimized designs that focus on conversion of feedstock to gas yield and ensuring that inert solids do not accumulate.
Gas production may be highly variable over the seasons, creating problems meeting offtaker expectations. This challenge can be solved through feedstock inventory management and improved feedstock pre-processing such as briquetting.
Operating and maintenance costs are higher than expected. This is due to problems managing solids accumulation. This challenge can be solved through maximizing feedstock conversion, high-performance solids removal, and dewatering.
Odor problems create stakeholder relation issues and can even lead to shutdowns. This challenge can be solved by paying close attention to leaks and other fugitive emissions in design and throughout operations. We understand common conflicts and issues. Our experience shows this is a particularly important consideration and we advise on stakeholder concerns relating to the environment, odor, noise, traffic, and more.
Lagoon-style digesters pose safety challenges due to risks of explosion, odor, suffocation, or drowning. This challenge can be solved through use of robust, high performance, facilities and systems that are designed to similar standards to the rest of the energy industry.