Project: PT Algatek Karbon Nusantara - Pertamina CO₂ Biofixation System

Prepared by: Engineering Team

Date: December 25, 2025

Revision: Rev 1.0 - Corrected Mass Balance & Complete Design

EXECUTIVE SUMMARY

This report presents the corrected and complete engineering design for a 10,000 L microalgae photobioreactor (PBR) system integrated with Pertamina’s industrial gas waste stream. The system captures CO₂ from a gas source containing ~98% CO₂ (up to 1 MMSCFD capacity) and ~60 ppm H₂S, with a validated target to capture >20% of the processed CO₂ into algal biomass.

Key corrections from initial design:

• Fixed CO₂ mass balance (480 kg/h to PBR, not 2,270 kg/h)
• Corrected biomass production estimate (18-20 kg/week achievable)
• Added missing instrumentation and control loops
• Defined complete operating procedures including night/day cycles
• Specified safety instrumentation system (SIS) to SIL-2 standard
• Completed material specifications and pressure drop analysis

1. CORRECTED MASS BALANCE

1.1 Gas Phase Mass Balance

Available Gas Source:

• Total flow: 1 MMSCFD = 28,317 m³/day = 1,180 m³/h at STP
• Composition: 98% CO₂, 2% inerts, 60 ppm H₂S
• Density of CO₂ at STP: 1.98 kg/m³

Gas Distribution (Corrected):

Total Available:     1.0 MMSCFD (1,180 m³/h)
                           ↓
                    ┌──────┴──────┐
                    ↓             ↓
        To PBR: 300 m³/h    Bypass: 880 m³/h
        (25.4%)              (74.6%)