What factors are causing the sudden 30% decrease in Divert's biogas production at the Freetown anaerobic digestion facility?

Introduction

The sudden 30% decrease in biogas production at Divert's Freetown anaerobic digestion facility is a critical issue that demands immediate attention. This analysis will systematically identify, validate, and address the root cause while considering both short-term and long-term implications for the facility's operations and overall biogas production strategy.

Step 1

Clarifying Questions (3 minutes)

• Looking at the timeline, I'm wondering about recent operational changes. Have there been any significant modifications to the facility's processes or equipment in the past month?

Why it matters: Recent changes could directly impact biogas production efficiency. Expected answer: Yes, a new pre-treatment system was installed two weeks ago. Impact on approach: If confirmed, we'd focus on the new system's integration and performance.

• Considering input quality, has there been any change in the composition or source of organic waste being processed?

Why it matters: Feedstock quality significantly affects biogas yield. Expected answer: No major changes in waste sources, but there's been a slight increase in food waste percentage. Impact on approach: We'd investigate if the increased food waste is affecting the digestion process.

• Regarding environmental factors, have there been any unusual weather patterns or temperature fluctuations recently?

Why it matters: Anaerobic digestion is sensitive to temperature changes. Expected answer: Temperatures have been stable, within normal operating ranges. Impact on approach: If confirmed, we'd rule out weather as a primary factor and focus on internal processes.

• Thinking about maintenance schedules, when was the last comprehensive system check performed?

Why it matters: Overdue maintenance could lead to decreased efficiency. Expected answer: Regular maintenance was performed last month, but a deep clean is overdue. Impact on approach: We'd prioritize investigating the impact of delayed maintenance on system performance.