Why carbon capture for biogas and RNG?
Innovative carbon capture solutions that connect directly to biogas upgrading systems and combustion equipment offer RNG and biodigester operators an entirely new revenue stream from a waste product they currently waste. This integrated approach combines the reliability of CarbonQuest’s modular DCCS™ platform with the high-concentration CO2 streams that biogas facilities produce as a byproduct — delivering a cost-effective, drop-in solution that pays back on its own economics.
Technology Overview
Distributed Carbon CaptureCarbonQuest DCCS™ systems are specifically designed to integrate with biogas upgrading equipment, anaerobic digesters, and combustion systems to minimize the environmental impact of those assets while delivering a new, contracted revenue stream. Modular, containerized systems can be retrofitted to existing RNG upgrading installations or integrated into new facilities for comprehensive carbon management — with no changes required to existing equipment and minimal disruption to ongoing RNG operations.
Key Features:
- Direct CO2 capture from RNG upgrading reject streams (85–99% concentration), biogas engines and CHP (10–14%), and biogas-fired boilers (12–15%)
- Modular, containerized system design — skids laid out to site-specific requirements; familiar to operators already running PSA upgrading systems
- No chemicals, steam, or water — solid adsorbent VPSA technology with zero towers, thermal swings, or toxic byproducts
- Optional methane recycle — up to 99% CH₄ recovery from reject streams, increasing pipeline RNG output while eliminating contamination risk
- Retrofit compatibility — drop-in installation downstream of existing upgrading systems; from contract to CO2 production in 12–15 months
- Comprehensive carbon management — end-to-end CO2 handling including CMS monitoring, ESG reporting, and offtake logistics
CarbonQuest Carbon Capture + RNG Upgrading
RNG upgrading systems — whether membrane, PSA, or water scrubbing — strip CO2 from raw biogas to produce pipeline-quality renewable natural gas. The resulting CO2 reject stream runs continuously at 85–99% purity, making it the lowest-cost-of-capture source in the distributed carbon capture landscape. CarbonQuest’s DCCS™ system connects directly downstream of the upgrading system, requiring no modification to the existing RNG equipment or production process.
Captured CO2 is liquefied onsite and transferred under a take-or-pay offtake agreement — a fixed, predictable revenue stream regardless of spot market fluctuations. For facilities with PSA upgrading systems, the DCCS™ technology will be familiar: it is a natural downstream extension of the same adsorption technology already in operation on site.
An optional methane recycle module recovers methane slip from the CO2 reject stream, recycling it back into RNG production and increasing pipeline gas output — improving the facility’s overall economics and reducing its carbon intensity score for LCFS purposes.
10+ RNG and biogas combustion projects currently in active development at CarbonQuest
Many biodigester facilities combust biogas directly in reciprocating engines, turbines, or CHP units for heat and power rather than upgrading it to pipeline gas. These combustion systems produce flue gas at 10–14% CO2 — similar in concentration to natural gas combustion — and CarbonQuest’s DCCS™ systems are already proven in this application. Whether fueled by natural gas, biogas, or a blend, engines and fuel cells are a well-understood integration point for CarbonQuest’s post-combustion capture systems.
For facilities with biogas-fired boilers — common at food processing plants, wastewater treatment facilities, and industrial sites — post-combustion flue gas runs at 12–15% CO2. CarbonQuest has multiple commercial boiler installations and offers the same drop-in, containerized system design for boiler applications. These sites often have onsite CO2 demand for food production or refrigeration, creating the opportunity to reuse captured CO2 directly rather than selling it to a third-party offtaker — maximizing project economics.
Across all combustion pathways, the CarbonQuest system is modular, containerized, stackable, and can be installed indoors or outdoors. The modularity offers a flexible building block that allows customers to expand capacity as facility throughput grows.
End-to-End CO2 Lifecycle Management
CarbonQuest offers a turnkey solution from design through installation, ensuring seamless integration of the DCCS™ system with existing biogas upgrading or combustion infrastructure. Once emissions are captured, CarbonQuest handles the entire CO2 lifecycle — managing offtake logistics and working with a pre-built network of utilization and sequestration partners to secure the highest-value available buyer for each project.
Key Benefits of Biogas Carbon Capture
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- New Revenue Stream
- Zero Upfront Capital
- Methane Recovery & RNG Uplift
- BECCS & CDR Credits
- Regulatory Upside
- Scalable & Modular
New Revenue Stream
Convert a waste CO2 stream — currently vented at no value — into a contracted, recurring revenue source. CarbonQuest secures take-or-pay offtake agreements at fixed prices, providing a predictable income stream independent of CO2 spot market fluctuations.
Zero Upfront Capital
CarbonQuest’s Carbon Capture-as-a-Service model is financed entirely by CarbonQuest and its financing partners. Site operators receive a fully operational DCCS™ system, monitoring software, and offtake management with no capital outlay — earning from the day the system comes online.
Methane Recovery & RNG Uplift
CarbonQuest’s optional methane recycle module recovers methane slip from the CO2 reject stream, recycling it back into RNG production. This increases pipeline-quality gas output, improves LCFS carbon intensity scores, and eliminates contamination risk — adding a second economic benefit alongside CO2 revenue.
BECCS & CDR Credits
CO2 from anaerobic digestion is biogenic — carbon drawn from the atmosphere through photosynthesis. Capturing and permanently sequestering this CO2 constitutes genuine carbon dioxide removal (BECCS), qualifying for voluntary CDR markets at $100–$400/MT. This is the highest-value credit tier available in carbon markets today.
Regulatory Upside
Additional revenue economic benefit comes from potential for federal 45Q tax incentive for capture projects above 12,500 metric tons per annum, and potential for carbon credits for biogenic CO2 capture.
Scalable & Modular
Standardized DCCS™ product line scales from approximately 2,600 MTPA (DCCS-0800) to over 30,000 MTPA (DCCS-9600). Units can be combined at larger facilities, and additional trains can be added as biogas throughput grows — no full system replacement required.
Target Applications
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- Dairy/Agriculture & Food Waste
- Landfill Gas Collection Sites
- Wastewater Treatment

Dairy/Agriculture & Food Waste
Agricultural manure digesters, food-waste processing facilities, and municipal wastewater treatment plants with biogas combustion or direct gas streams
Specific Applications:
- Dairy and agricultural digesters upgrading to RNG
- Food-waste digesters at food processing plants with onsite CO2
- Anaerobic digestion that is combined with CHP and power applications
Benefits:
- Premium RIN pricing for dairy and food-waste digesters with negative carbon intensity scores
- Onsite CO2 reuse option for food & beverage sites eliminates CO2 procurement costs and supply chain exposure
- Containerized DCCS™ units designed for site constraints at farm and municipal facilities
- CaaS model removes capital barrier at sites with limited capex allocation
- BECCS qualification: biogenic CO2

Landfill Gas Collection Sites
Active landfills with gas collection systems generating continuous LFG streams for power generation, direct use, or RNG upgrading
Specific Applications:
- Landfills with LFG-to-energy infrastructure combusting gas in reciprocating engines or turbines
- Landfills with LFG-to-RNG upgrading systems generating high-purity CO2
- Waste-to-energy facilities processing landfill gas with additional pretreatment capability for complex gas compositions
- Municipal and private landfill operators seeking additional revenue from existing gas collection infrastructure
Benefits:
- Additional revenue from landfill gas infrastructure already in place — no new wells or collection infrastructure required
- CarbonQuest incorporates pretreatment systems designed to handle variable LFG compositions including H₂S and siloxanes
- 45Q and voluntary CDR credit potential from biogenic fraction of LF CO2
- Supports ESG reporting for waste management operators and municipal facility owners
- CaaS model removes capital barrier at municipally operated sites

Wastewater Treatment
Membrane, PSA, and water scrubbing upgrading systems at dairy farms, landfills, food-waste processors, and wastewater treatment plants
Specific Applications:
- Municipal wastewater treatment facilities upgrading t0 RNG
- PSA-based upgrading sites — familiar technology that extends naturally to downstream CO2 capture
- Municipal wastewater facilities with biogas-fired boilers or engines generating continuous post-combustion CO2
- Operators seeking a repeatable, scalable carbon capture model across facilities
Benefits:
- Immediate new revenue from a previously vented, zero-value waste stream
- Take-or-pay offtake agreement at fixed price — predictable revenue regardless of CO2 market fluctuations
- 45Q federal tax credit eligibility for qualifying volumes (12,500+ MTPA)
- Environmental footprint reduction for an emissions-heavy sector
- Drop-in installation with no changes to existing upgrading equipment
- From contract to CO2 production in 12–15 months
Technical Specifications
CO2 Capture Range
1,000–30,000+ MTPA
- Scalable from single-unit to multi-train configurations
- DCCS-0800 to DCCS-9600 standard product line
- Units combinable for larger facilities
System Availability
99.9%+ uptime
- Fully automated, unattended operation
- Remote monitoring via CarbonCore™ CMS
- 24/7 operations center support
Source CO2 Concentration
10–99% CO2
- RNG reject streams: 85–99%
- Engine/CHP flue gas: 10–14%
- Boiler post-combustion: 12–15%
- Raw biogas: 30–50%
Deployment Timeline
12–15 months
- From contract execution to CO2 productio
- 18–34 months for larger or more complex sites
- Turnkey EPC managed by CarbonQuest
Getting Started
Initial Assessment
- Facility Evaluation: Identify your CO2 source — upgrading reject, post-combustion flue gas, or direct biogas stream — and provide 12 months of operational data
- Technical Review: Share tail gas or exhaust volume and characteristics (CO2%, CH₄%, flow rate) for system sizing
- Financial Analysis: Calculate IRR and payback period including 45Q, LCFS credit impact, methane recycle uplift, and merchant CO2 revenue
- System Design: Select the appropriate DCCS™ configuration and optional methane recycle for your facility
Next Steps
- Consultation: Schedule a no-obligation facility scoping — results delivered in under two weeks
- Proposal: Receive detailed system specifications, site layout, and project economics
- Engineering: Custom design and integration planning with CarbonQuest’s engineering team
- Implementation: Turnkey installation and commissioning — from contract to CO2 production in 12–15 months